Breeding Dendrobium Orchids in Hawaii 9780824845452

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Breeding Dendrobium Orchids in Hawaii

Breeding d robium OrcJi¡ d s "^HawSn HARUYUKI KAMEMOTO, TERESITA D. AMORE, AND ADELHEID R. KUEHNLE

UNIVERSITY

OF

H A W A I 'I

PRESS,

HONOLULU

Library of Congress Cataloging-in-Publication Data

© 1 9 9 9 U n i v e r s i t y of H a w a i ' i Press A l l r i g h t s reserved

Kamemoto, Haruyuki.

P r i n t e d in C a n a d a 04

03

02

01

00

99

5

4

3

2

1

B r e e d i n g d e n d r o b i u m o r c h i d s in H a w a i i / H a r u y u k i K a m e m o t o , Teresita D. A m o r e , and Adelheid p.

P r e v i o u s l y p u b l i s h e d f i g u r e s a n d t a b u l a r m a t e r i a l in t h i s b o o k

I n c l u d e s b i b l i o g r a p h i c a l references (p.

a p p e a r w i t h t h e p e r m i s s i o n of t h e o r i g i n a l p u b l i s h e r s .

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1. D e n d r o b i u m — B r e e d i n g — H a w a i i . D., 1 9 6 1 -

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cm.

I. A m o r e , Teresita

II. K u e h n l e , A d e l h e i d R.

III. T i t l e .

1999 99-10176 CIP

This book is dedicated to Ethel H. Kamemoto, wife of the senior author, for her patience, inspiration, encouragement, and support for nearly five decades

Contents

PREFACE

ix

CHAPTER 1

Introduction

CHAPTER

Section Section Section Section Section Section Section

2. Dendrobium

C o m b i n a t i o n s Involving the P and C Genomes 56 O r i g i n of A m p h i d i p l o i d s 57 Multigenome Hybrids 57

1 Species

3

6. Inbreeding Effects 62 Inbreeding Dendrobium Species 62 Inbreeding and Selection in A m p h i d i p l o i d Dendrobium J a q u e l y n Thomas 63

CHAPTER

Phalaenantbe 3 Spat u lata (Ceratobium) 5 Eleutheroglossum (Spatalata) 8 hat our ta 8 Dendrobium (Untenant he) 9 Callista 13 Formosae (Nigrohirsutae) 14

7. Reciprocal Crosses 67 Breeding Behavior of Dendrobium phalaenopsis 'Lyon's Light No. 1' 67 Reciprocal Crosses Involving Dendrobium May Neal 'Sunset' 69 Dendrobium canaliculatum D 1 7 3 - 2 and D129 69 Dendrobium canalicidatum D173-2 x Dendrobium streb loceras D 3 8 - 3 70 Dendrobium J a q u e l y n Thomas ' U n i w a i Supreme' ( U H 2 3 2 ) 70

CHAPTER

Dendrobium Species Relationships Chromosome N u m b e r s 18 Karyotype 36 Genome Size 37 Cross C o m p a t i b i l i t y 38 Meiotic Behavior 43

C H A P T E R 3-

18

4. Polyploidy B r e e d i n g Significance of Polyploidy 48 O r i g i n of Polyploids 49 Chromosome Transmission of Polyploids 49

CHAPTER

Genome Breeding Genome Designations in Dendrobium Early A l l o p o l y p l o i d Cultivars 52 Meiotic Behavior in Intersectional Hybrids 53 Meiotic Behavior and Fertility of Amphidiploids 54

48 CHAPTER 8.

71

9. C y m b i d i u m Mosaic V i r u s 75 Incidence and Expression 75 Breeding for Resistance to Floral Necrosis 79 Nontransmission of C y M V by Seed or Pollen 81 Chemotherapy for Virus Eradication 84 Eradication of C y M V in A m p h i d i p l o i d Breeding Plants through Androgenesis 85

CHAPTER

CHAPTER 5.

Androgenesis

52

52

vii

viii

/

CONTENTS

Genetics of S o m e Characters Inheritance of Semi-Alba and Alba in

CHAPTER 10.

Dendrobium

87

88

Breeding for Albas 90 Pansy-Lip in Dendrobium

APPENDIXES

91

B r e e d i n g Cut-Flower Cultivars 93 Pollination to Flower 93 Evaluation of Progenies 93 Amphidiploid Parents 95 Amphidiploid Seed-Propagated Cut-Flower Cultivars Developed at the University ofHawai'i 96 Seed-Propagated Cultivars Other Than

CHAPTER 11.

Amphidiploids 103 Clonally Propagated Cut-Flower Cultivars 105 Breeding Potted Plant Cultivars Seed-Propagated Hybrids Utilizing Amphidiploids 107 Other Seed-Propagated Hybrids 11 5 Clonally Propagated Cultivars 116 Seasonality 118 Preservation of Breeding Plants 119 Breeding Yellows and Novel Characters Polyploidy in Yellow Cultivars 123 Yellow Pigments 125 Yellow Cultivar and Selections 126 Pansy-Lip Cultivar 127

107

CHAPTER 13.

123

14. Breeding by Genetic Engineering 129 Overview of Methodology 129 Gene Transfer by Microparticle Bombardment 131 Gene Transfer by Electroinjection 133 Protoplast Isolation and Culture for Gene Transfer by Electroporation 133

CHAPTER

Dendrobium-Agrobacterium Interactions Agrobacterium-ÌAeàidXed

Transformation

135

A. Technique for Counting Chromosomes (from Tanaka and Kamemoto 1984) 141 B. Germination of Dendrobium Seeds and Transflasking Seedlings 143 C. Micropropagation and Chromosome Doubling of Dendrobium 146 D. Glossary 147

REFERENCES

151

I N D E X O F DENDROBIUM

SPECIES, HYBRIDS,

AND CULTIVARS GENERAL INDEX

CHAPTER 12.

and

Target Trait: Pigment Biosynthesis 137 Target Trait: Virus Resistance 138

159 163

Preface

THI-: CULTIVATION of orchids in Hawaii became popular after World War II. Hybridization of orchids, particularly dendrobiums and vandas, was practiced by numerous orchid breeders in Hawaii, and by the time the Second World Orchid Conference was staged in Hawaii in 1 9 5 7 , Hawaii had already emerged as a prominent center for orchid hybridization and culture.

dation. The basic knowledge accumulated enabled rapid improvement of cultivars for commercial crop production. In particular, the utilization of amphidiploids has resulted in the unique breeding method of producing seed-propagated instead of traditionally clonally propagated dendrobium cultivars. T h e main purpose of this book is to assemble and summarize into one source for ready reference research on cytogenetics and breeding of dendrobiums conducted during the past five decades, mainly at the University of Hawai'i. The format follows that of the recently published companion book entitled Breeding Anthuriums in Hawaii (University of Hawai'i Press, 1 9 9 6 ) . Scientific data have been condensed for ease of comprehension. Numerous color photographs illustrate species, species hybrids, and cultivars. Thus, this book should be of interest to growers, hobbyists, and horticultural scientists associated with dendrobium orchids.

T h e research program on orchid cytogenetics and breeding at the University of Hawai'i was ini tiated in 1 9 5 0 by the senior author, Haruyuki Kamemoto, immediately upon his return from Cornell University, where he earned his Ph.D. degree in floriculture and plant breeding under Kenneth Post and L. F. Randolph. Professor K a m e m o t o has continued his research involvement for nearly five decades. In 1 9 8 8 Adelheid R. Kuehnle joined the University of Hawai'i after receiving her Ph.D. degree in plant breeding, also from Cornell University. She has brought into the program her expertise in tissue culture and genetic engineering. In 1 9 8 5 , Teresita D. Amore arrived from the Philippines and served as graduate research assistant to Professor K a m e m o t o while earning her M.S. degree in 1 9 8 6 and Ph.D. degree in 1991- She has since served as a research associate involved in studies of dendrobium cytogenetics and breeding.

General readers may want to focus on chapters I I to 13, which describe the cultivars and selections developed at the University of Hawai'i, amply illustrated in color. Breeders and scientifically minded readers will find chapters 2 to 10 and chapter 14 of particular interest. W e express our appreciation to the many colleagues, research associates, and graduate students who have contributed over the years to expanding our knowledge of dendrobium orchids as well as in developing new cultivars. Special thanks go to Nellie Sugii for providing valuable laboratory assistance in genetic engineering research as well

Early research emphasis was to develop and expand knowledge o f orchids through basic or fundamental research. Studies on chromosome numbers, karyotypes, meiotic behavior, and relationships of paleotropical orchids were aided by research grants from the National Science Foun-

IX

x

/

PREFACE

as in micropropagating selections for naming and release and inducing amphidiploids in tissue culture. W e acknowledge the Administration of the University of Hawai'i College of Tropical Agriculture and H u m a n Resources, the State of Hawaii Governor's Agricultural Coordinating Committee, the D e n d r o b i u m Growers Association of H a w a i i , the B i g Island Dendrobium Growers Association, the West Hawaii Orchid Growers Association, the Honolulu Orchid Society, the Wilhelmina Tenney

F u n d , and many other contributors for support of our program. Federal support came through the National Science Foundation, the National Defense Education A c t , and the United States Department of Agriculture. W e are indebted to Richard W. H a r t m a n n and J o s e p h A . Arditti for reviewing the manuscript. We convey our thanks to Susan Takahashi for assistance in typing the manuscript.

CHAPTER 1

introduction

orchids introduced into Hawaii as early as 1896 was Dendrobium anosmum (D. superbum) from the Philippines (Beaumont 1951). This orchid with its hanging pseudobulbs and delightfully fragrant flowers is still a favorite among gardeners in Hawaii. The cultivation and hybridization of the Phalaenanthe—Spat!/lata (Ceratobium) group of dendrobiums, commonly referred to as cane-type dendrobiums, became popular in Hawaii during and immediately following World War II. Ellen W i l l i a m s , in 1938, was the first to register a Dendrobium hybrid from Hawaii. From 1941 to 1944 seven Hawaiian hybrids were registered, and after 1945 the number of registrations increased steadily to a peak of 109 in 1955 (Fig. 1.1). The intensity in Dendrobium hybridization coincided with the anticipated staging of the Second World Orchid Conference in Honolulu in 1957. About that time Hawaii had already emerged as the center for hybridization of Dendrobium orchids. ONE

OF

THE

have figured heavily in the development of commercial cut-flower cultivars in Hawaii. The research program on Dendrobium cytogenetics was initiated at the University of Hawai i in 1950. In 1987 Kamemoto presented a special lecture at the 12th World Orchid Conference in Tokyo entitled "Four Decades of Research on Orchid Cytogenetics and Breeding" in which research activities at the University of Hawai'i were summarized (Kamemoto 1987). The first decade was characterized as the period of initiation and conduct of research on chromosome numbers and polyploidy. Research revealed the significance of polyploidy in breeding superior hybrids (chapter 4). During the second decade emphasis was placed on basic research on cytogenetics and cytotaxonomy. Meiotic behavior of species hybrids, karyotype analyses, and cross compatibility studies elucidated species relationships in the genus Dendrobium (chapter 3).

FIRST

The Dendrobium breeding program was activated during the third decade (chapter 11) because of the potential of dendrobiums as a commercial cut-flower crop. The Hawaiian dendrobium industry was in its infancy at that time. Research on cytogenetics in the previous decade had laid a solid foundation for the rapid development of improved cultivars for commercial cropping. Five seed-propagated amphidiploid cultivars involving species from the Pbalaenanthe and Ceratobium sections were released from 1972 to 1978. The major advantages of these seedpropagated cultivars over clones propagated by

Immediately following the orchid congress in 1957, the number of Dendrobium registrations began to decline. However, registrations increased in the early 1980s and have been maintained up to the current time (Fig. 1.1). Among the early interspecific hybrids, two were outstanding. Dendrobium Neo-Hawaii was registered by Walter Carter in 1945 as a hybrid between D. phalaenopsis and D. grantii and D. Jaquelyn Thomas by Rolla K. Thomas in 1949 as a hybrid between D. phalaenopsis and D. gouldii. Both D. J a q u e l y n Thomas and D. Neo-Hawaii

1

2

/

I n t r o d u c t i o n

120

100

A > M

II •Q E

COCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCQCO

CO tD CO (D CD CO 00 00 CO CD CP CO ro

Figure 1.1 Annual registrations of Dendrobtum

a

CD

od

o

ro

hybrids produced in Hawaii from 1941 to 1995.

tissue culture are that it is an easier, faster, and cheaper method of propagation and the seedlings are free of c y m b i d i u m mosaic virus because the virus is not transmitted from seeds (chapter 9)Thus, our program has continued to concentrate on seed-propagated cultivars. These five cultivars laid the foundation for Hawaii's dendrobiurn industry. Genome breeding was emphasized during the fourth decade, utilizing new amphidiploids induced by treating protocorms with colchicine in tissue culture (chapter 11). In addition to new cut-flower cultivars, we also produced new seed-propagated potted plant cultivars, utilizing

amphidiploids but with objectives suited for potted plants (chapter 12). Also research was conducted on androgenesis (chapter 8) and cymbidium mosaic virus (chapter 9)In 1989 Kuehnle initiated orchid genetic engineering research at the University of Hawai'i. Thus, the fifth decade might be considered the decade of genetic engineering (chapter 14). However, the development of both cut-flower and potted plant cultivars (chapters 11, 12, 13) for the dendrobiurn industry of Hawaii has remained the ultimate objective of all our research activities.

CHAPTER 2

Dendroblum species

DENDROBIUM IS ONE of the largest genera in the family Orchidaceae. It comprises over 1,000 species distributed from the foothills of the Himalayas through Southeast Asia to Japan, Australia, Tasmania, and the Pacific Islands. Schlecter (1927) subdivided the genus into 41 sections. Important sections from the standpoint of breeding commercial Dendrobium cut flowers and potted plants for the Tropics are Phalaenanthe, Spatulata (Ceratobium), Eleutheroglossum (Spatulata), and Latouria. Section Dendrobium (Eugenanthe) includes perhaps the best-known species, D. nobile, which has been in cultivation for over a century in temperate countries. More recently, tetraploid hybrids of D. nobile have been popularized by Yamamoto Orchids of Japan. Section Callista comprises several handsome species particularly from Thailand, and section Formosae (Nigrohirsutae) has several species with large white flowers.

Stewart (1992).

(1990),

and Seidenfaden

SECTION

and

Wood

PHALAENANTHE

The Phalaenanthe section comprises only a few species. However, one species, D. phalaenopsis, a native of Queensland, Australia, has played a prominent role in the improvement of cane-type dendrobiums. The advanced-generation polyploid Phalaenanthe hybrids are a considerable improvement over species collected from the wild. Dendrobium phalaenopsis has also been used in crosses with species of the Ceratobium section to produce intersectional hybrids that are widely cultivated in Hawaii.

Dendrobium phalaenopsis Fitzg. (Fig. 2.1 A) Dockrill (1969, 1992) relegated D. phalaenopsis to a botanical variety of D. bigibbum, but not all

Brief descriptions of species of horticultural significance mainly in the Tropics are provided. There have been several changes over the years in sectional names and classification as well as species names. W e have retained the old classification when there are previously assigned genome symbols for sections (e.g., genome C for Ceratobium, which is now Spatulata [see Table 5.1}). For taxonomic treatments or for more detailed descriptions of species the reader is referred to the following references: Schlecter (1927), H o l t t u m (1953), Seidenfaden and Smitinand ( 1 9 5 9 - 1 9 6 5 ) , Dockrill (1969, 1992), Kamemoto and Sagarik (1975), Cribb (1983, 1986), Valmayor (1987), Clements (1989), Upton (1989), Schelpe and

Figure 2.1 A. Dendrobium

3

phalaenopsis.

4

/

DENDROBIUM

SPECIES

popular for producing

miniature

or

compact

potted plants. Dendrobium bigibbum Lindl. (Fig. 2 . 2 ) Flowers of this species are similar to those of D. phalaenopsis, but are somewhat smaller and usually slightly darker mauve. Sepals and petals are often reflexed. Like D. phalaenopsis var. compactum, D. bigibbum var. compactum has become popular for breeding miniature potted plants. Dendrobium

orchidists are in accord with this treatment. W e have retained the species ranking of D. phalaenopsis because of the long-standing use of this nomenclature, cspccially in hybrid registrations. Un doubtedly there have been more hybrids produced with D. phalaenopsis in their background than with any other Dendrobium species.

affine

(Decne.) Steud.

(Fig. 2.3/4) This species from New Guinea produces inflorescences up to 6 0 cm long with many small white flowers about 3 cm across. The Australian orchid previously known as D. dicuphum (Fig.

T h e erect pseudobulbs on D. phalaenopsis are 6 0 cm or more long with flowers about 6 to 8 cm across. T h e broad, flat flowers vary from white to different shades of purple. This is probably the finest Dendrobium species in cultivation. It occurs in Cooktown, on the east coast of northern Queensland, and Indonesia. Recently, the compact or dwarf form, D. phalaenopsis var. compactum (Fig. 2 . I B ) , has become

Figure 23A.

Figure 2.2. Dendrobium bigibbum.

Figure 2.3B. Dendrobium dicuphum.

Dendrobium

affine.

DENDROBIUM

SPECIES

/

5

2.3B) produces attractive flowers with white sepals and petals and contrasting deep maroon lip. This orchid has produced hybrids that are white w i t h a colored lip. According to Upton (1989), Cribb and Lavarack determined that D. dicuphum of Australia is a synonym of D. a f f i n e from New Guinea.

SECTION SPATULATA

(CERATOBIUM)

Cribb ( 1 9 8 6 ) revised the section Spatulata Lindl., known for many years as section Ceratobium, and recognized 4 6 species distributed from Java to the Philippines and the Pacific Islands. The greatest concentration of species is in New Guinea. This section consists of evergreen cane-type species that are easy to grow in the Tropics and bear numerous racemes with relatively small flowers. Many species can be grown outdoors in full sun. They hybridize readily with Dendrnbmm phalaenopsis of section Pbalaenanthe and have played a major role in the development of commercial cultivars.

Figure 2AA, Dendrobium

gouldii.

Because Ceratobium was in general acceptance until recently, and also because we continue to use the genome symbol C in our breeding program for members of this group, Ceratobium has been retained to eliminate confusion. It might be noted that there have been several name changes in this group: D. discolor for D. undulatum, D. antennatum for D. d'albertisii, and D. lasianthera for D. ostrinoglossum.

Dendrobium gouldii ~Kc\\b. f. (Fig. 2.AA-D) Native to Bougainville, Malaita, and Guadalcanal in the Solomon Islands, D. gouldii is highly variable, with white, pale yellow, gold, bronze, and violet flowers. Inflorescences are 30 to 70 cm long, carrying numerous small flowers. This is the parental species of several commercial cutflower cultivars of Hawaii. According to Cribb (1986), there has been some confusion whether to include D. lineale (syn. D. veratrifolium) from New Guinea in D. gouldii. Also, D. grantii, a registered parent of D. NeoHawaii, described by W h i t e from a specimen collected in New Guinea, could not be distinguished from D. lineale and, therefore, Cribb reduced it to

Figure 2AB. Dendrobium gouldii.

Figure 2 AC. Dendrobium

gouldii.

6

/

DENDROBIUM

SPECIES

Figure 2.5B. Dendrobium discolor var. broomfieldti. Figure 2 AD.

Dendrobium gouldii.

synonymy. O u r plant, received from the Foster Botanical Garden, Honolulu, as D. grantii, strongly resembled D. gouldii. Thus, the hybrid registered as D. Neo-Hawaii, with parents D. phalaenopsis and D. grantii, m i g h t be a variation of D. Jaquelyn Thomas, which is D, phalaenopsis x D. gouldii. Dendrobium discolor Lindl. (Fig. 2 . 5 A ) For many years this species was known as D. undulatum. It is a highly variable species distributed from northeastern Australia to New Guinea. The pseudobulbs are upright, canelike, and reach up to 5 m. The erect inflorescences bear numerous flowers that are variable in color from yellow to brown to bronze. The sepals are recurved and twisted, with undulate margins. Several vari-

eties have been recognized; the best known is D. discolor var. broomfieldii Fitzg. (Fig. 2 . 5 B ) , which is distinguished by its pure canary yellow flowers. Dendrobium x superbiens Rchb. f. is a natural hybrid between D. bigibbum and D. discolor. An excellent cultivar of D. superbiens is Superba'. Dendrobium superbiens crossed with D. phalaenopsis produced D. Louis Bleriot, and D. Louis Bleriot crossed with D. phalaenopsis produced D. P o m p a dour, the famous cut-flower cultivar of Thailand. Dendrobium helix C r i b b (Fig. 2.6) This endemic orchid species of N e w Britain was identified by Cribb (1986) as D. helix. It has been known horticulturally under such names as Talasea Lime Yellow', 'Pomio Brown', and 'Talasea Mushroom Pink'. The petals are twisted several times.

¡ • ^ f j l • P ^ ^ ^ H b ri H9 (Awj' ^^k/o Mlcv /&®§fJi

||j flH^HraSB^fl' --MB. S ^ ^ n B Jp- a, If •

E *Jm' •

L

,

fcdÈÈÉKjflr

Jm

W m J i |

£ j

[

i

rSEmÈWkMy*.

Figure 2.5A. Dendrobium discolor.

U | F M ' fw ' -.muMmH Figure 2.6. Dendrobium helix.

- -Mflr '

.„figga

DENDROBIUM

SPECIES

/

Dendrobium lasianthera J . J . S m . (Fig. 2 . 7 ) A spectacular species with large rose purple to maroon flowers, D. lasianthera is a native of N e w Guinea and found in swampy forest and on small trees over rivers and streams at sea level. The long sepals are upright and twisted two to three times. Pseudobulbs attain a height of over 2 m. It was known earlier as D. ostrinoglossum. Uendrobium tangerinum C r i b b (Fig. 2 . 8 ) A native of New Guinea, D. tangerinum was misidentified in the past as D. strepsiceros and D. strebloceras, and also was known as the "tangerine" orchid. Our plant, originally obtained from New Guinea, was identified by an orchid taxonomist as D. strebloceras. However, Cribb has named it D. tangerinum. As the name indicates, the flowers are orange yellow to orange red. The dorsal sepals are upright and twisted two to three times.

Figure 2.7. Dendrobium lasianthera

Dendrobium taurinum Lindl. (Fig. 2 . 9 ) Dendrobium taurinum. a native of the Philippines, has been hybridized extensively and has contributed to the development of bluish lavender flowers with a conspicuously broad lip. Inflorescences are erect, bearing 20 to 30 flowers. Sepals are white and the lavender to purple petals are upright and slightly twisted. The lip is broad, white, and flushed with purple. Dendrobium antennatum Lindl. (Fig. 2 . 1 0 ) Long known as D. d'albertisii, D. antennatum has been utilized in producing short-statured flowering potted plants. Flowers are small, measuring under 2.5 cm across, with upright, twisted, green to yeilow green petals and white recurved sepals. The long-lasting flowers are produced throughout most of the year. This variable species is widely distributed from New Guinea to northeastern Australia and the Solomon Islands. Dendrobium stratiotes R c h b . f. (Fig. 2 . 1 1 ) This is the most handsome species in the section, with flowers about twice the size of those of D. antennatum. Sepals are white, and the 6 - c m long, upright, twisted petals are green to yellow

Figure 2.8. Dendrobium

tangerinum.

Figure 2.9Dendrobium taurinum.

7

8

/

DENDROBIUM

SPECIES

retain the sectional classification of Eleutheroglossum for both D. canaliculatum and D. carronii because of their distinct miniature stature, and we continue to use the genome symbol E for these two species in our Dendrobium breeding program.

Figure 2.10. Dendrobium

antennatum.

green at the apical end and white at the base. The lip is white, veined with purple. It is a native of Indonesia and New Guinea.

SECTION

ELEUTHEROGLOSSUM (SPATULATA)

A relative newcomer to the Dendrobium hybridizing scene has been the diminutive D. canaliculatum and more recently the closely related miniature species, D. carronii. W h e n we started hybridizing D. canaliculatum in the 1960s, it was classified by Dockrill ( 1 9 6 9 ) in section Eleutheroglossum. Cribb ( 1 9 8 6 ) placed D. canaliculatum and D. carronii in the section Spatulata (Ceratobium), and Dockrill, in his revised edition of Australian Indigenous Orchids (1992), accepted that classification. W e prefer to

Figure 2.11. Dendrobium

stratiotes.

Dendrobium canaliculatum R. Br. (Fig. 2 . 1 2 ) This highly variable species distributed in Australia and New Guinea is commonly found growing on Melaleuca sp. from swampland to savanna. The short pseudobulbs are 5 to 12 cm long, usually swollen around the middle and clumped. Flowers are small, about 2 - 3 cm across. Sepals and petals are white with yellow to brown apical halves. The leaves are semiterete and channeled on the upper surface. Uetidrobiutn carronii Lavarack & C r i b b (Fig. 2 . 1 3 A , B ) Distributed in Australia and New Guinea, Dendrobium carronii is similar to D. canaliculatum, but appears to be slightly smaller. The clustered pseudobulbs attain a height of only about 5 cm. This species can be distinguished from D. canaliculatum by the petals that are twice as long as the sepals. Petals are pink to purplish red. It grows in moist areas such as watercourses or eastern sides of mountains with reliable year-round rainfall.

SECTION

La\TOURIA

The section Latouria comprises 4 8 species distributed in New Guinea, Java, and neighboring

Figure 2.12. Dendrobium

canaliculatum.

SPECIES

DENDROBIUM

/

9

spectabile (Bl.) Miq. (Fig. 2.15)

Dendrobium

A widespread species native to N e w G u i n e a and the Solomon Islands, D. spectabile

has spec-

tacular large flowers that are somewhat grotesque. Sepals and petals are yellow, c o m m o n l y heavily m o t t l e d with maroon. T h e midlobe o f the threelobed lip is much longer than the side lobes.

SECTION

DENDROBIUM

(EUGENANTHE) This Figure 2.13A. Dendrobium

section

Eugenantbe.

carroña.

It

was

for

many

comprises

years

a widely

known

as

distributed

group o f diverse species characterized by fleshy pseudobulbs, sheath-bearing deciduous or semideciduous leaves, and m e d i u m to large showy flowers.

Figure 2 . 1 3 B .

islands

Dendrobium

(Cribb

1983).

Most

species

make handsome

carronii.

Sheathless

leaves

are

clustered near the top of the thickened pseudobulbs. Flowers are generally

long lasting

are green with purple markings as in D.

Figure 2 . 1 4 . Dendrobium

macrophyllym.

Figure 2 . 1 5 . Dendrobium

spectabile.

and macro-

phyllum., or brownish and somewhat grotesque as in D.

spectabile.

Dendrobium

?nacrophyllum

A. Rich.

(Fig. 2 . 1 4 ) T h i s is the most widespread species in the section, distributed from Indonesia to Samoa. Flowers are highly variable in size and color. Sepals are often yellow or green with

purple

stripes on the side lobes and spots or stripes on the midlobe. W e crossed D. macropbyllum D. bigibbum,

with

and an amphidiploid clone has been

used to produce commercial cultivars.

potted

10

/

DENDROBIUM

SPECIES

plants when in full flower. Dendrobium nobile and its hybrids continue to be popular, especially in more temperate areas. Dendrobium anosmum (syn. D. superbum) has been a favorite in gardens of Hawaii. Because the g e n o m e symbol Eu is used for m e m b e r s of this section, we have retained the name Eugenanthe instead of Dendrobium. Dendrobium nobile Lindl. (Fig. 2 . 1 6 ) T h e most popular m e m b e r of the Eugenanthe section, D. nobile has been cultivated and hybridized for more than a century. It is a highly variable species distributed from the Himalayas, t h r o u g h Burma, Thailand, and Laos, to South China. The stems are erect, from 30 to 45 cm high and 2.5 t m thick. D u r i n g March and April, two to four flowers are produced at a node, usually on leafless pseudobulbs. Flowers are about 6 cm across. Sepals and petals are often white toward the base and lavender toward the tip. T h e lip is purple in the throat, with a yellow or white border and a purple edge. Several color variations exist. Flowering plants make glorious displays under suitable environmental conditions. Recently, improved polyploid hybrids involving D. nobile developed by J i r o Yamamoto of Japan have popularized this g r o u p of orchids.

to B u r m a , T h a i l a n d , Indochina, and Malaysia. Stems are 1 to 2 m high, up to 2 cm thick, and erect. Leaf sheaths are characteristically striped w i t h purple. P e n d e n t inflorescences are produced from March to April on the apical portion of m a t u r e leafless stems. They carry about 10 large, handsome flowers, measuring 10 cm across. Sepals and petals are broad, waxy, and pale yellow, often tinged w i t h lavender in the back. T h e lip is cupped, hairy, and fringed and has two conspicuous dark maroon patches. This species is in the background of an early hybrid, D. G a t t o n Sunray, that received a First Class Certificate from the Royal Horticultural Society. Dendrobium moschatum ( B u c h . - H a m . ) Sw. (Fig. 2 . 1 8 ) Stems of this orchid are erect to suberect and attain 1.5 m or more in length. T h e basal region of the young stem is purple, spotted w i t h green. Leaves are glossy, smooth, thin, and pliable. A b o u t 10 attractive flowers are carried on pend u l a n t sprays from the upper portions of the stem, usually in March and April. Flowers are about 6 cm across and of good form. Sepals and petals are light orange; the cup-shaped, fringed lip is darker orange with two maroon blotches in the throat. T h e species is native to the H i m a l a yas, Burma, Laos, and Thailand.

Dendrobium. pulchellum R o x b . ex Lindl. (Fig. 2 . 1 7 ) C o m m o n l y known as D. dalhousieanum, this orchid is widely distributed from the Himalayas

Dendrobium fimbriatum Hook. This is one of the more attractive orchids in the Eugenanthe g r o u p . Stems are u p to 1 m h i g h ,

Figure 2.16. Dendrobium nobile.

Figure 2.17. Dendrobium pulchellum.

DENDROBIUM

Figure 2.19. Dendrobium erect, and produce pendulous inflorescences from the upper portions in February and March. Inflorescences carry up to 15 flowers, each measuring about 5 cm across. Petals and sepals are orange yellow, and the large, round, fringed lip is deep orange yellow. Dendrobium fimbriatum var. oculatum (Fig. 2 . 1 9 ) has a contrasting dark maroon blotch in the throat. T h e species is native to Nepal, Burma, T h a i l a n d , and Indochina.

Dendrobium anosmum L i n d l . ( F i g . 2 . 2 0 ) Dendrobium anosmum was introduced into H a w a i i in 1 8 9 6 from the Philippines as D. superbum (Beaumont 1 9 5 1 ) and has been a popular garden plant, often attached to trees or g r o w n in h a n g i n g baskets. Its major attribute is the strong fragrance. Flowers are large, m e a s u r i n g 7—10 cm across. T h i s species is widely distributed in the Philippines, Indonesia, New Guinea, Sri Lanka, Malaysia, and T h a i l a n d .

fimbriatum

SPECIES

var.

/

11

oculatum.

Dendrobium parishii R c h b . f. ( F i g . 2 . 2 1 ) Pseudobulbs of this orchid are unevenly curved and up to 30 cm long. Often the nodal area is s l i g h t l y swollen. Flowers are h i g h l y scented, about 5 cm across, and borne in twos or

Figure 2.20. Dendrobium

anosmum.

12

/

DENDROBIUM

S P E C I E S

Dendrobium pierardii R o x b . (Fig. 2 . 2 2 ) T h e species produces small, delicate flowers in abundance on long (60 to 150 cm) p e n d e n t stems and lends itself well to the production of spectacular specimen plants. T h e flowers, which measure about 4 cm across, are produced in pairs at the nodes around April and May. Sepals and petals are light mauve. Petals are approximately twice as wide as the sepals. T h e hairy lip is pale yellow lined w i t h purple at the base. This species is widely distributed from the Himalayas, Burma, Thailand, and Indochina to Malaysia. Figure 2.21. Dendrobium parishu.

threes on short scapes from the apical April and May. Sepals and petals are ender and of good substance. T h e lip is bears two dark purple blotches. This found in northern Thailand as well as boring Burma, Laos, and Cambodia.

Figure 2.22. Dendrobium pierardii.

nodes in dark lavhairy and species is in neigh-

Dendrobium primulinum Lindl. (Fig. 2 . 2 3 ) Dendrobium primulinum is similar to D. pierardii. but the stems are slightly shorter and thicker. Petals and sepals are narrow and of equal d i m e n sions, with the large lip much wider than it is long. Flowers, about 5 cm across, are often borne singly at the nodes, around March. Sepals and

Figure 2.23. Dendrobium primulinum.

DENDROBIUM

petals are light mauve, and the hairy lip is light yellow with purple veins. Its distribution is similar to that of D. pierardii.

CALLISTA

This section includes relatively few species, which are native to Burma, Thailand, and neighboring countries. They are generally characterized by attractive, compact, arching or drooping inflorescences and sheathless nondeciduous leaves. Some are relatively easy to grow and flower in lowland Tropics and make glorious potted plant specimens in full bloom. Unfortunately, flowers are short lived, lasting only one to two weeks. Dendrobium lindleyi Steud. (Fig. 2 . 2 4 ) Long known as D. aggregation Roxb., this species can be distinguished easily from the other callistas by its one-leaved pseudobulbs. T h e clustered pseudobulbs are about 7 cm high and bear solitary dark green, heavy-textured leaves measuring 7.5 cm long and 2.5 cm wide. Pseudobulbs are plump when young, but gradually develop furrows and wrinkles with age. Pendent inflorescences arising from the sides of the pseudobulbs are about 18 cm long and carry 2 0 or more flowers. Petals and sepals are pale to bright yellow and usually deepen in color with age. T h e labellum is golden yellow. Flowers are delicate and relatively short lived.

Figure 2.24. Dendrobium

lindleyi.

/

13

Dendrobium jenkinsii

Wall, ex Lindl. (syn. D. ag-

var. jenkinsii)

is a dwarf species similar

gregatum to D.

lindleyi.

D. lindleyi

SECTION

SPECIES

It can

be distinguished

from

by its diminutive size, more laterally

compressed pseudobulbs, and inflorescences that bear fewer flowers. Dendrobium chrysotoxum Lindl. (Fig. 2 . 2 5 ) This handsome species occurs in the deciduous forests of Thailand, usually above 6 0 0 m elevation. It is also distributed in Burma, the Himalayas, and Indochina. Pseudobulbs are narrow at the base, gradually thickened toward the middle, and tapered at the tip. They may attain a height of 3 0 cm and a thickness of 4 cm. Older pseudobulbs are yellowish. Six to seven leaves are borne near the top of the pseudobulbs. T h e arching or drooping inflorescences, sometimes as long as 30 cm, may produce 2 0 or more fragrant and attractive flowers, which last about two weeks. Indi-

Figure 2.25. Dendrobium chrysotoxum.

14

/

DENDROBIUM

SPECIES

Dendrobium thyrsiflorum R c h b . f. ex Andre (Fig. 2 . 2 7 ) This has been one of the more popular Callista species of northern Thailand. Its pendent inflorescences, about 23 cm long, carry 3 0 to 50 densely arranged flowers. Individual flowers are about 3 cm across. Sepals and petals are overlapping, white, and delicate, and the rounded labellum is a highly contrasting orange yellow. Flowers are very attractive and have a delicate fragrance, but unfortunately they are short lived, often lasting only five to seven days. Unlike the four-angled pseudobulbs of D. farmeri, those of D. thyrsiflorum are long and cylindrical with vertical grooves and reach a height of 4 5 cm. T h e four to six leaves borne toward the tip of the psuedobulb are smooth, flexible, and dark green.

S E C T I O N FORMOSAE

vidual flowers are about 4 cm across, with waxy, bright yellow sepals and petals and a fringed orange yellow-centered labellum. Dendrobium farmeri Paxt. (Fig. 2 . 2 6 ) Dendrobium farmeri is widely distributed from India, Burma, Thailand, Malaysia, and Laos to Vietnam. Individual flowers of the typical species, which measure about 4 cm across, have roundish, overlapping white sepals and petals. T h e labellum is round and orange yellow with a white rim. T h e drooping inflorescence carries up to 2 0 flowers, loosely arranged. Flowers usually appear in February, ahead of those of other Callista species. Three or four smooth, thintextured leaves are clustered at the tip of the four-angled pseudobulb. Considerable variation exists within this species. A yellow-flowered variety, D. farmeri var. aureoflava, is distributed at relatively high elevations in the Khamburi Forest of western Thailand.

(NIGROH1RSUTAE)

T h e Formosae (Nigrobirsutae) section contains about 35 species native to the Himalayas and Southeast Asia. T h e black or brownish hairs present on the leaf sheaths characterize this section. T h e large, handsome, and relatively long-lasting flowers of some of the species are important horticultural attributes. Although Formosae is recognized as taxonomically correct, we have retained the earlier designation of Nigrobirsutae because of our assignment of the genome symbol N for species within this section. T h e majority of species in section Nigrobirsutae have white flowers with a blotch of yellow in the

Figure 2.27. Dendrobium

thyrsiflorum.

DENDROBIUM

throat or the lip. Recently D. cruentum with its conspicuous red lip has been utilized in breeding in Hawaii to produce remarkable hybrids (Tokunaga and Nash 1996). Dendrobium formosum Roxb. ex Lindl. (Fig. 2.28) This is the most popular and widely cultivated member of Nigrokirsutae. It is distributed from the Himalayas to Burma and Thailand. The largeflowered variety, which occurs in abundance in the Ranong region in southwestern Thailand, is D. formosum var. giganteum. Flowers of this orchid, which measure as much as 10 cm across, are borne in twos or threes on short inflorescences, usually from October to December. Sepals and petals are white and of good substance. The lip is white with a golden blotch in the throat, indented at the apex, and lacking distinct side lobes. The

Figure 2.29. Dendrobium infundibulum.

SPECIES

/

15

delicately scented flowers last about two weeks. Plants attain a height of 50 cm, although they tend to be shorter and stockier when grown in the open. An excellent hybrid in commercial production in Japan is D. Formidible (D. formosum x D. infundibulum). Dendrobium infundibulum Lindl. (Fig. 2.29) The lovely paper-white flowers of this orchid are about 9 cm across and slightly smaller than those of D. formosum var. giganteum. One or two flowers are borne on very short scapes toward the tip of the pseudobulbs, usually from January to March. The lip is blotched with cadmium orange in the throat, sharply indented at the apex, and serrated at the edges. The m e n t u m is relatively long and brown tipped. Although petals and

Figure 2.30. Dendrobium scabrilingue.

16

/

DENDROBIUM

SPECIES

sepals are t h i n t e x t u r e d , flowers o f t e n last m o r e

f o u n d in n e i g h b o r i n g B u r m a a n d I n d o c h i n a . It

t h a n a m o n t h . T h e l o n g , t h i n p s e u d o b u l b s are

p r e f e r s a cool c l i m a t e for best g r o w t h a n d flower-

a b o u t 4 5 c m tall and o f t e n less t h a n 1 c m t h i c k .

i n g . S h o r t inflorescences bear t w o to five flowers,

Leaves are g r e e n , t h i n , a n d flexible.

m e a s u r i n g 5 c m across. T h e glossy w h i t e petals Range,

a n d sepals are narrow, t a p e r e d , a n d reflexed. T h e

generally at elevations above 1 , 3 0 0 m in relatively

m i d l o b e of t h e l a b e l l u m is also t a p e r e d a n d re-

dense, m o i s t s u r r o u n d i n g s .

flexed a n d has a wavy m a r g i n . T h e t h r o a t is b r i g h t

This orchid inhabits the Tenasserim

red. T h e s p u r is l o n g , narrow, a n d t u b u l a r .

Dendrobium

scabrilingue

Lindl. (Fig. 2.30)

T h i s d e l i g h t f u l l y f r a g r a n t orchid g r o w s at h i g h elevations in n o r t h e r n , n o r t h e a s t e r n , a n d eastern T h a i l a n d . Flowers are small for t h e g r o u p , measuri n g only 3.5 c m across, b u t their d i s t i n c t a n d p l e a s i n g f r a g r a n c e m a k e s t h e m a favorite in T h a i land. P s e u d o b u l b s , m e a s u r i n g 15 by 1 c m b e a r i n g several short inflorescences of t w o to five flowers each, are generally cut at t h e base a n d w o r n in t h e hair or placed in a b o w l of" w a t e r for h o m e d e c o r a t i o n . T h e f l o w e r i n g season b e g i n s in late D e c e m b e r a n d e n d s in February. I n d i v i d u a l flowers last m o r e t h a n five weeks, a n d because b u d s c o n t i n u e to o p e n over a period of t i m e , p l a n t s may r e m a i n in excellent display a n d frag r a n c e for m o r e t h a n t w o m o n t h s . Petals a n d sepals are w h i t e , waxy, a n d of g o o d s u b s t a n c e . T h e m i d l o b e of t h e l a b e l l u m is l i g h t yellow to o r a n g e , a c u m i n a t e , and s o m e w h a t reflexed, a n d t h e i n n e r surfaces of t h e a n g u l a r side lobes are s t r i p e d w i t h g r e e n . T h e c o l u m n is l i g h t g r e e n .

Dendrobium

cariniferum

Rchb. f. (Fig. 2.32)

T h i s species is s i m i l a r to D. draconis in its d i s t r i b u t i o n , h a b i t a t , and general r e q u i r e m e n t for g r o w t h a n d f l o w e r i n g . In C h i e n g m a i Province in T h a i l a n d it can be f o u n d g r o w i n g w i t h D. draconis. It is also d i s t r i b u t e d in A s s a m a n d n o r t h e r n B u r m a . Flowers are a b o u t 5 c m across. Petals a n d sepals are creamish yellow a n d s l i g h t l y d a r k e r t o w a r d t h e tips. Sepals are keeled a l o n g t h e m i d v e i n on t h e o u t e r surface. T h e m i d l o b e is c r e a m i s h yellow, t h e reflexed side lobes are d a r k e r yellow, a n d t h e t h r o a t is r e d d i s h o r a n g e . T h e l o n g , t a p e r e d , a n d curved s p u r is b r o w n i s h p u r p l e . T h e ovary is t h r e e - a n g l e d .

Dendrobium

cruentum

Rchb. f. (Fig. 2.33)

W i d e l y d i s t r i b u t e d in T h a i l a n d , p a r t i c u l a r l y a l o n g t h e Tenasserim R a n g e , this species is also

T h i s d e l i g h t f u l species, w i t h l i g h t g r e e n petals a n d sepals a n d a h i g h l y c o n t r a s t i n g b r i g h t red lip, is e n d e m i c to p e n i n s u l a r T h a i l a n d . P l a n t s can be f o u n d on s m a l l trees in open forests at relatively low elevations. Slender p s e u d o b u l b s a t t a i n a h e i g h t of 35 c m . Leaves are only 12 c m l o n g a n d a b o u t 2 c m wide. O n e to t h r e e flowers are p r o d u c e d on s h o r t inflorescences along t h e u p p e r

Figure 2.31. Dendrobium draconis.

Figure 2.32. Dendrobium

Dendrobium

draconis Rchb. f. (Fig. 2.31)

cariniferutn.

DENDROBIUM

SPECIES

/

17

Figure 2.33- Dendrobium cruentum.

Figure 2.34. Dendrobium trigonopus.

half of the pseudobulb. Individual flowers measure about 3 cm across. Sepals and petals are light green with darker green veins. Petals are verynarrow and tapered, and the lateral sepals are broad at the base, tapering to a sharp point. T h e lip is distinctly three-lobed. T h e midlobe is fleshy and stiff, acute and reflexed, with somewhat wavy, red side margins. Five bright red keels are banded at the base of the lip.

Dendrobium trigonopus R c h b . f. (Fig. 2 . 3 4 ) Another inhabitant of northern Thailand is the rather u n c o m m o n D. trigonopus. It is also distributed in Laos and neighboring southwestern China. Pseudobulbs are about 12 cm long and 2 cm wide, purplish brown, and wrinkled. Leaves are clustered at the tip of the pseudobulbs. The sheaths are covered with brownish hairs. T h e inflorescence, arising from the upper portion of the pseudobulb, is short and carries two or three flowers in February and March. Flowers are slightly under 5 cm across. Sepals and petals are waxy, straw yellow, thick, and tapered. T h e labellum is three-lobed. T h e midlobe is yellow with a greenish center, and the side lobes are chartreuse with brown stripes. Dendrobium cruentum crossed to D. trigonopus produced D. Lemon Ice (Tokunaga and Nash 1996).

In Bangkok, this orchid flowers continuously t h r o u g h o u t the year, with individual flowers lasting slightly more than a m o n t h . Its attractive, t h o u g h small, flowers, continuous flowering habit, and apparent ease of culture make this little-known member of the Nigrohirsutae a worthy one for cultivation. Furthermore, these fine attributes are of value in a hybridization program as indicated by the recent hybrids D. Lime Frost (D. scabrtlingue x D. cruentum), D. Lemon Ice (D. cruentum x D. trigonopus), and D. Dawn Maree (D. formosum x D. cruentum) (Tokunaga and Nash 1996).

CHAPTER 3

Dendrobium species Relationships

2 we indicated that the genus Dendrobium, comprising over 1,000 species, was subdivided into numerous sections. We briefly described the important sections from the horticultural standpoint along with representative species. The degree of relationships among species is affected by chromosome numbers, karyotypes, crossability, and meiotic behavior of hybrids.

The chromosome numbers for 257 Dendrobium species accumulated to date from various researchers are listed in Table 3-1- Although this number represents only about one-fourth of the total number of species in the genus, the majority of those with horticultural value are included. There are several discrepancies in counts. As mentioned earlier, some of the earlier counts are unreliable because of the limitations of cytological techniques before the development of the squash method for counting chromosomes. Other inconsistencies may be the result of a number of reasons: difficulty of chromosome determinations because of the relatively small Dendrobium chromosomes, poor cytological technique, misidentification of species, and sampling of an atypical individual of the species. Table 3-2 shows the distribution of chromosome numbers in the genus Dendrobium. The majority of species have 2n = 38, but 38 species have 2n - 40. Several early counts of species reported before I960, especially 2n = 40, were undoubtedly in error and have been verified as 2n = 38. Also as shown in Table 3-2, 23 species are reported as 2n = 38 and 40. Whether both numbers exist for these species needs verification. Numbers such as 39, 41, and 43 are obviously aneuploid variants. Some counts are given with fragments (f). These fragments might possibly have been B chromosomes.

IN CHAPTER

CHROMOSOME N U M B E R S When we initiated our research on orchid cytogenetics in 1950, relatively little was known about the chromosomes of Dendrobium species. Hoffmann (1930) had recorded counts for three species, Miduno (1940) for one species, and Eftimiu-Heim (1941) for three species. Some of these early counts were inaccurate undoubtedly because of inadequacies of early cytological techniques. The University of Hawai'i research group determined the chromosome number of 66 Dendrobium species, most of which are of horticultural interest (Kosaki and Kamemoto 1961, Kamemoto and Sagarik 1967, Wilfret and Kamemoto 1971). Vajrabhaya and Randolph ( I 9 6 0 ) at Cornell University reported the numbers for 15 species. The Kew group utilizing the large living collection at the Royal Botanical Gardens recorded chromosome numbers for 169 species (Jones 1963, Jones et al. 1982, Lim 1985). More recently, K. Hashimoto (1987) of the Hiroshima Botanical Garden determined the numbers for 82 species used in his comprehensive research on karyomorphology.

Polyploid forms of species have been recorded. Many triploid and tetraploid forms have been developed through hybridization in D. nobile and D. phalaenopsis, two extensively hybridized species.

18

Table 3.1. Chromosome numbers o f Dendrobium Species

n

2n

D. acerosum Lindl. D. acinaciforme

Reference Hashimoto ( 1 9 8 1 ) , Lim ( 1 9 8 5 )

38

Roxb.

species

Mehra and Sehgal ( 1 9 7 5 )

19 38

Hashimoto ( 1 9 8 2 , 1 9 8 7 ) , J o n e s et al.

40

Pancho ( 1 9 6 5 a , b)

D. adae F. M . Bail.

38

Lim ( 1 9 8 5 )

D. aduncum W a l l , ex Lindl.

38

Hashimoto ( 1 9 8 2 , 1 9 8 7 )

40

Vij and Shekhar ( 1 9 8 5 ) , Shekhar and Vij

38

Hashimoto ( 1 9 8 1 , 1 9 8 7 )

38

Jones ( 1 9 6 3 )

39

Hashimoto ( 1 9 8 1 , 1 9 8 7 )

38

Hashimoto ( 1 9 8 7 )

( 1 9 8 2 ) , Cheng et al. ( 1 9 8 5 ) D. acuminatissimum

(Bl.) Lindl.

(1986) D. aemulum

R . Br.

D. affine (Decne.) Steud. (as D. dicuphum

F. Muell.)

D. agro\tophyllum var. superbum

F. Muell. Hort.

D. alaticaulinum D. albayense

van Royen

Ames

D. albosanguineum D. alpestre

Lindl.

Royle

38

Hashimoto ( 1 9 8 1 )

38

J o n e s et al. ( 1 9 8 2 ) , Lim ( 1 9 8 5 )

40

Pancho ( 1 9 6 5 a , b)

40

Lim ( 1 9 8 5 ) , Hashimoto ( 1 9 8 7 )

20

Arora ( 1 9 6 8 ) , Mehra and Kashyap ( 1 9 7 6, 1984, 1989)

D. amethystoglnssum var. superbum

Rchb. f

Hort.

40 20

D. amoenum Wall, ex Lindl.

Lim ( 1 9 8 5 ) , Hashimoto ( 1 9 8 7 )

40

Hashimoto ( 1 9 8 1 )

38

Jones 0 9 6 3 )

20

Mehra et al. ( 1 9 7 0 ) , Arora ( 1 9 7 1 )

19, 2 0 O. ampbigenyum

Ridl.

D. ameps Sw.

40, 80

Shekhar and Vij ( 1 9 8 6 )

36

Lim ( 1 9 8 5 )

+

2f

Mehra et al. ( 1 9 7 0 )

19 + ( 0 - 2 B ) 19 + ( 0 - 6 B )

D. anosmum Lindl. (= Ü. superbum R c h b . f)

38

Lim ( 1 9 8 5 ) , Vij and Shekhar ( 1 9 8 5 )

.38

Shekhar and Vij ( 1 9 8 6 )

40

E f t i m i u - H e i m ( 1 9 4 1 ) , Ito and Mutsuura (1957) Kosaki ( 1 9 5 8 ) , Vajrabhaya and Randolph

19

( I 9 6 0 ) , Kosaki and K a m e m o t o ( 1 9 6 1 ) (as D. leucorhodum

Schltr.)

38

J o n e s ( 1 9 6 3 ) , Wilfret and K a m e m o t o

38

Hashimoto ( 1 9 8 7 )

38

J o n e s et al. ( 1 9 8 2 )

( 1 9 7 1 ) , Hashimoto ( 1 9 8 1 ) , L i m ( 1 9 8 5 ) var. album (as D. superbum var. album Hort.) D. antennatum

Lindl.

(as D. d'albertsu D. aphrodite

R c h b . f.)

19

Kosaki and K a m e m o t o ( 1 9 6 1 )

38

Wilfret and K a m e m o t o ( 1 9 7 1)

R c h b . f.

var. superbum Hort. D. aphyllum

38

( R o x b . ) C. E. C. Fisch.

40

Hashimoto ( 1 9 8 1 )

38

J o n e s ( 1 9 6 3 ) , J o n e s et al. ( 1 9 8 2 ) Mehra and Kashyap ( 1 9 7 9 , 1 9 8 4 , 1 9 8 9 ) ,

19

Mehra and Sehgal ( 1 9 8 0 ) 38, 4 0 (as D. pierardii

R o x b . ex H o o k . )

Cheng et al. ( 1 9 8 5 ) Kosaki ( 1 9 5 8 ) , Kosaki and K a m e m o t o

19

(1961) (continued)

19

(continued) Species

2n 38

Reference Vajrabhaya and R a n d o l p h ( I 9 6 0 ) , K a m e m o t o and Sagarik (1967), Sarkar et al. (1978), H a s h i m o t o (1987) Chardard (1963)

19, 20 19

38, 57

19

38

Sharma and C h a t t e r j i ( 1 9 6 6 ) H a s h i m o t o (1981), Sau and Sharma (1983), Z a m a n and Sultana (1984), Shekhar and Vij (1986)

D. aqueum Lindl.

38

J o n e s (1963), H e d g e and Boraiah (197 3),

D. arachnites Rchb. f.

38

Pancho (1965a, b)

D. atroviolaceum Rolfe

38

Wilfret and K a m e m o t o (197 1),

D. aurantiacum Rchb. f.

38

Banerji and C h a u d h u r i (1972),

D. aurantiroseum van Royen

76

Lim (1985)

D. baileyt F. Muell.

38

H a s h i m o t o (1982)

D. bairdianum F. M. Bail.

36

Lim (1985)

D hambuiifolium

38

H a s h i m o t o ( 1 9 8 2 , 1987)

38

Singh (1981), J o r a p u r and Krishna

Singh (1981)

Lim (1985) Jones et al. ( 1 9 8 2 )

D. barbatulum

Par. & Rchb. f.

Wight

Mohan ( 1 9 8 6 ) Vij et al. ( 1 9 8 6 )

20 D. balanense Ames & Q u i s u m b .

19

D. beckler, F. Muell. var. superhum ( H o r t . )

19

38

H a s h i m o t o (1981)

38

J o n e s ec al. ( 1 9 8 2 )

38

J o n e s et al. (1982), H a s h i m o t o (1987)

38

H a s h i m o t o (1981)

D. bellatulum Rolfe

38

H a s h i m o t o (1982)

D. bensonae Rchb. f.

38

Vij and Shekhar (1985), Shekhar and

D. bicallosum Ridl.

40

Pancho (1965a, b)

D. bicameratum Lindl.

38

Jones (1963), Mehra and Kashyap (1978),

40

H a s h i m o t o (1982) Arora (1968)

19 + ( 0 - 4 B )

38

Mehra and Kashyap ( 1 9 8 4 , 1989)

19

40

Shekhar and Vij ( 1 9 8 6 )

D. bifalce Lindl.

38

J o n e s et al. ( 1 9 8 2 )

D. biflorum (Forst.) Sw.

38

J o n e s et al. ( 1 9 8 2 )

D. bigibbum Lindl,

38

var. bigibbum

2x", 38, 57

Vij (1986)

var. compactum C. T. W h i t e (= D. litho-

W i l f r e t and K a m e m o t o (1971) Jones (1963)

38

Hashimoto (1987)

D. bilobum Lindl.

38

J o n e s et al. ( 1 9 8 2 )

D. bracteosum Rchb. f.

38

H a s h i m o t o (1982), Jones et al. (1982)

D. bronckartii W i l d e m a n

40

E f t i m i u - H e i m (1941), Ito and

D. brymerianum R c h b . f.

40

Ito and M u t s u u r a (1957), Lim (1985)

38

J o n e s (1963), H a s h i m o t o (1987)

38

Lim (1985)

cola Jones & Clements)

Mutsuura (1957)

D. bulbophylloides Schltr.

(continued)

20

(continued) Species

n

2n 38

Wilfret and K a m e m o t o (197 1)

19

38

H a s h i m o t o (1987)

D. bullenianum Rchb. f. (as D. topaziacum Arnes)

Reference

38

Pancho (1965a, b), H a s h i m o t o (1981)

38

Jones et al. (1982)

D. camaridiorum Rchb. f.

38

Jones et al. (1982)

D. canaliculatum

2x»

Jones ( 1 9 6 3 )

38

Wilfret and K a m e m o t o (1971),

38

H a s h i m o t o (1981)

38

Jones (1963), H a s h i m o t o (1981, 1987)

D. cakaratum

Lindl. R. Br.

H a s h i m o t o (1987) 19 D. candidum Wall, ex Lindl.

Malla et al. (1977)

19 38, 57

Cheng et al. (1985)

D. capillipes Rchb. f.

38

Jones ( 1 9 6 3 )

D. capituliflorum

38

Jones (1963), H a s h i m o t o ( 1 9 8 2 , 1987),

Rolfe

Jones et al. (1982) D. capra J . J . Sm.

19

D. cathcartii H o o k . f.

19

H a s h i m o t o (1981) Mehra et al. (1970)

D. cbameleon Arnes (as D. lonpcalcaratum

Hayata)

D. chrysantbum Lindl, ex Wall.

19

38

Pancho ( 1 9 6 5 a , b), H a s h i m o t o (1982)

38

Hsu ( 1 9 7 2 )

38

Vajrabhaya and Randolph (1960),

38

Kosaki and K a m e m o t o (1961), Jones

40

Mehra and Kashyap ( 1 9 7 8 , 1984, 1989)

Shekhar and Vij (1986) (1963), K a m e m o t o and Sagarik (1967) 20

38, 4 0

Sau and Sharma (1983)

76

Cheng et al. (1985)

38

Jones et al. (1982), Cheng et al. (1985)

38

Hsu (1972)

ca. 7 6

Jones ( 1 9 6 3 )

D. chryseum Rolfe (as D. clavatum Wall, ex Lindl.)

Mehra and Vi) (1970)

19

(as D. flaviflorum Hayata) D. chrysocrepis Par. ex R c h b . f. D. chrysotoxum Lindl.

20

H o f f m a n n (1929, 1930) 40

Ito and M u t s u u r a (1957), Chardard

38

Kosaki and K a m e m o t o (1961), Jones

(1963) (1963), Tanaka (1964), K a m e m o t o and Sagarik (1967), W i l f r e t and K a m e m o t o (1971), H a s h i m o t o (1981, 1987), C h e n g et al. ( 1 9 8 5 ) Shekhar and Vij (1986)

19 var. suavissimum H o o k . f. D. clavator Ridi. D. compactum Rolfe ex H a c k e t t

20

38

Jones ( 1 9 6 3 )

38

H a s h i m o t o (1987)

40

H a s h i m o t o (1981)

40

H a s h i m o t o (1987)

38

Jones et al. (1982), Lim ( 1 9 8 5 )

D. confusum Schltr.

38

Lim (1985)

D. crasstfolium Schltr.

38

Lim (1985)

D. Conanthum Schltr.

(continued)

21

(continued) Species

2n

n

D. crepidatum Griff.

38

Reference Jones (1963), K a m e m o t o and Sagarik (1967), H e d g e and Boraiah (1973), C h e n g et al. (1985), Lim (1985)

19 D. criipilingum

Cribb

D. cruentum Rchb. f.

38

Shekhar and Vij (1986)

38

Jones et al. (1982)

40

D. crumenatum Sw.

38, 38 + If

K a m e m o t o and Sagarik (1967) Jones (1963)

40

Pancho (1965a, b)

38

K a m e m o t o and Sagarik (1967), Wilfret and K a m e m o t o (197 1), H a s h i m o t o ( 1 9 8 1 , 1987), Jones et al. (1982)

38 + ( 0 - 2 B ) (as D. kwashoteme Hayata)

Shekhar and Vij (1986)

38

Tanaka (1965), H s u (1972)

D. cruttwellii Reeve

38

Jones et al. (1982)

D. crystallinum Rchb. f.

38

Jones (1963), K a m e m o t o and Sagarik

D. cucumerinum MacCleay ex Lindl.

38

H a s h i m o t o (1981, 1987)

D. cumulatum Lindl.

40

H a s h i m o t o (1982)

D. cunninghama

38

Jones et al. (1982)

(1967), Lim (1985)

Lindl.

D. cutbbertsonii F. Muell. (as D. iophroniies Schltr.)

76

Lim (1985)

ca. SO

Jones (1963)

38

H a s h i m o t o (1981, 1987)

D. cyanocentrum Schltr.

38

Lim (1985)

D. delaiourii Guill.

38

K a m e m o t o and Sagarik (1967), Wilfret

40

H a s h i m o t o (1981)

40

Lim (1985)

and K a m e m o t o (1971) 20 (as D. cillatum Par. ex Hook, f.) D. denneanum Kerr

40

H a s h i m o t o (1987)

38

Cheng et al. (1985), Vi] and Shekhar

38

Shekhar and Vij (1986)

(1985) 19 D. densiflorum Lindl.

4 0 + 2f 42 20 + ( 1 - 2 B )

Kosaki (1958), H a s h i m o t o (1987) Chatterji (1968) Mehra et al. (1970)

4 0 + If 40, 4 0 + 3f

H a s h i m o t o (1981) H a s h i m o t o (1982)

38

Sau and Sharma (1983), Cheng et al.

40

Shekhar and Vij (1986)

40

Jones (1963), H a s h i m o t o (1981, 1987)

40

Shekhar and Vij (1986)

(1985) 20 + ( 0 - 2 B ) D. denudans D. D o n 20 D. devonianum Paxr.

Chardard (1963)

19 38

Banerji and C h a u d h u r i (1972),

D. dichaeoides Schltr.

38

Lim (1985)

D. dillonianum

38

Lim (1985)

C h e n g et al. (1985) H a w k e s & Heller

(continued)

22

Ccontinued) 2n

Species D. discolor

Reference

Lindl.

(as D. undulatum

R. Br.)

19

38

Kosaki and Kamemoto (1961)

38

Jones (1963), and Wilfret and Kamemoto (1971)

var. broomfieldii

Fitzg. (as D.

var. broomfieldii

undulatum

Kosaki and Kamemoto (1961)

19

Fitzg.)

'Shimonishi 1 AM/AOS HOS b D. distichum

(Presl.) Rchb. f.

57

Kamemoto et al. (1987)

57

Vajrabhaya and Randolph ( I 9 6 0 )

38

Pancho (1965a, b), Wilfret and Kamemoto (1971), Hashimoto (1987)

38,57

19 D. dixantbum

Rchb. f.

Hashimoto (1981)

41

Jones (1963)

40

Kamemoto and Sagarik (1967), Wilfret and Kamemoto (197 1)

40 + 2f 40, 40 + 4f D. draconis

Rchb. f.

38

Hashimoto (1981, 1987) Hashimoto (1982) Shindo and Kamemoto (1963), Kamemoto and Sagarik (1967), Wilfret and Kamemoto (197 1), Jones et al. (1982)

D. engne Reeve

38

Jones et al. (1982)

36

Lim (1985), Hashimoto (1987)

D. equitans

Kranzl.

38

Hashimoto (1981, 1987)

D. falconeri

Hook

2x J

Jones (1963)

38

Hashimoto (1981, 1987), Vij and Shekhar (1985), Shekhar and Vij (1986)

D. jiirmeri

Paxt.

40

Kamemoto and Sagarik (1967), Banerji and Chaudhuri (1972), Hashimoto (1981)

var. albiflorum var.

Hort,

40

aureoflava

D. fimbriatum

Hook.

Jones et al. (1982)

40

Kamemoto and Sagarik (1967)

38

Ito and Mutsuura (1957), Jones (1963), Kamemoto and Sagarik ( 1 9 6 7 )

20

Arora (197 1) 40

Sau and Sharma (1983), Cheng et al. (1985) Mehra and Kashyap (1984, 1989)

19 18, 19 var. oculatum

Hook.

38

Shekhar and Vij (1986)

38

Ito and Mutsuura (1957), Kosaki and Kamemoto (1961), Mehra and Sehgal (1980), Hashimoto (1981)

D. findlayanum

Par. & Rchb. f.

43

Lim (1985)

38

Jones (1963), Kamemoto and Sagarik

40

Ishida et al. (1992)

(1967), Hashimoto (1981, 1987) D. fmetianum D. finisterrae

Schltr. Schltr.

40 38 + 2B

Hashimoto (1981, 1987) Jones et al. (1982) (continued)

23

(continued) Species

w

D. flammula

2n

Schltr.

Reference

38

Jones (1963)

D. flecken

Rupp. & C. T. W h i t e

38

Lim ( 1 9 8 5 )

D. forhesu

Ridl.

40

Hashimoto (1981)

3 8 + 2B

J o n e s e t al. ( 1 9 8 2 )

D. formosum

Roxb. ex Lindl.

.38

Ito and M u t s u u r a ( 1 9 5 7 ) , Shindo and

.38

Shekhar and Vij ( 1 9 8 6 )

38

Kosaki and K a m e m o t o ( 1 9 6 1 ) ,

Kamemoto (1963) 19 var. giganteum

Rchb. f.

K a m e m o t o and Sagarik ( 1 9 6 7 ) , W i l f r e t and K a m e m o t o ( 1 9 7 1), Hashimoto ( 1 9 8 1 , 1 9 8 7 ) D. friedericksianum

R c h b . f.

38

Chardard ( 1 9 6 3 ) , J o n e s ( 1 9 6 3 ) , K a m e m o t o and Sagarik ( 1 9 6 7 ) , Hashimoto ( 1 9 8 1 , 1987), Jones et al. (1982)

D. fuscescem

Griff.

40

Vi) and Shekhar ( 1 9 8 5 ) , Shekhar and Vij (1986)

D. gamblei

King & Pantl.

2x"

Jones (1963)

D. gtbsonü

Faxt.

38

Vajrabhaya and Randolph ( I 9 6 0 ) , Cheng

40

H a s h i m o t o ( 1 9 8 2 ) , Sau and Sharma

38

Shekhar and Vij ( 1 9 8 6 )

38

J o n e s et al. ( 1 9 8 2 )

38

Kosaki and K a m e m o t o ( 1 9 6 1 )

38

Kosaki ( 1 9 5 8 ) , Kosaki and Kamemoto

et al. ( 1 9 8 5 ) , I.im ( 1 9 8 5 ) (1983) 19 D. goldfinchit

F. M u e l l .

D. gurdtmii D. gou/dii

S. Moore Rchb. f.

( 1 9 6 1 ) , W i l f r e t and Kamemoto ( 1 9 7 1 ) , Hashimoto ( 1 9 8 2 , 1987), Jones et al. (1982) D. gracilicaule

F. M u e l l .

38

Jones ( 1 9 6 3 ) , J o n e s et al. ( 1 9 8 2 )

Maiden

38

J o n e s ( 1 9 6 3 ) , J o n e s et al. ( 1 9 8 2 )

Rchb. f.

38

Jones (1963), Hashimoto (1982)

40

J o n e s et al. ( 1 9 8 2 )

var. bowcanum D. gratiosisiimum D. griffithianum D. gmrrerot

Lindl.

Arnes & Q u i s n m b .

40

Hashimoto ( 1 9 8 1 )

40

Cheng et al. ( 1 9 8 5 )

38

Hsu ( 1 9 7 2 )

'Lime Yellow'

.38

J o n e s et al. ( 1 9 8 2 )

'Pomio Brown'

38

J o n e s et al. ( 1 9 8 2 )

38

J o n e s et al. ( 1 9 8 2 )

38

Jones ( 1 9 6 3 )

38

Singh ( 1 9 8 1 ) , J o r a p u r and Krishna

38

J o n e s et al. ( 1 9 8 2 )

D. hancockii

Rolfe

D. heishanaense

Hayata

D. hehx Cribb

D. hellwtgianum

Kranzl.

D. hendersonii D. herbaceum

H a w k e s & Heller Lindl.

20

Abraham and Vatsala ( 1 9 8 1 ) Mohan ( 1 9 8 6 )

D. hercoglossum (as D. wangü

Rchb. f. Tso)

38, 57

Cheng et al. ( 1 9 8 5 ) (continued)

24

(continued) Species

n

2n

D. heterocarpum Wall, ex Lindl.

38

(= D. aureum Lindl.)

Reference Kosaki (1958), K a m e m o t o et al. (1961), Kosaki and K a m e m o t o (1961), Jones (1963), Pancho (1965a, b), K a m e m o t o and Sagarik (1967), W i l f r e t and K a m e m o t o (1971), Banerji and C h a u d h u r i (1972), H a s h i m o t o (1981, 1987), J o n e s et al. (1982)

D. hookerianum Lindl. 20

40

J o n e s (1963), Mehra and Sehgal (1980)

40

Sau and Sharma (1983), Shekhar and Vij (1986)

D. infundibulum

Lindl.

20

H o f f m a n n (1929) 40

H o f f m a n n (1930)

38

Tanaka (1964), K a m e m o t o and Sagarik (1967), H a s h i m o t o ( 1 9 8 1 , 1987), Lim (1985)

19 var. jamesianum (Lindl.) Veitch D. insigne (Bl.) Rchb. f. ex Miq.

38

Shekhar and Vij (1986)

38

Jones (1963), Tanaka (1964)

36 + 2f

D. jenkinsii Wall, ex Lindl.

H a s h i m o t o ( 1 9 8 1 , 1987), L i m ( 1 9 8 5 )

38

Jones (1963)

38

Lim (1985)

(as D. jusifarme F. M. Bail.)

38

Kosaki ( 1 9 5 8 )

(as D. ruppianum Hawkes)

38

H a s h i m o t o ( 1 9 8 1 , 1987), Jones et al.

D Johannis Rchb. f.

Kosaki and K a m e m o t o (1961)

19

D. johnsomae F. Muell. D. jonesii Rendle

(1982) D. kauldorumit D. kingianum

Reeve

ca. 36

Bidwill ex Lindl.

76

Jones et al. (1982), Lim (1985) Vajrabhaya and Randolph ( I 9 6 0 ) , Tanaka (1964), H a s h i m o t o (1981)

38, 1 1 2 - 1 1 4 var. album Will. var. silcockii F. M. Bail.

Jones (1963)

.38, 57, 7 6

Maxwell ( 1 9 6 7 , 1971)

ca. 57, 7 6

J o n e s (1963), Maxwell (1967)

76 ca. 76

J o n e s (1963) Maxwell ( 1 9 6 7 )

D. lamellatum (Bl.) Lindl. (as D. platycaulon Rolfe)

38

Pancho ( 1 9 6 5 a , b)

D. lasianthera J . J . Sm.

38

H a s h i m o t o ( 1 9 8 1 , 1987), Jones et al.

D. lauanum

38

H e d g e and Boraiah (1973)

D. lawesii F. Muell.

38

H a s h i m o t o (1982), Jones et al. (1982)

D. leonis (Lindl.) Rchb. f.

40

Wilfret and K a m e m o t o (197 1)

(1982) Lindl.

38

H a s h i m o t o ( 1 9 8 1 , 1987)

38

Lim (1985)

D. leucohybos Schltr.

38

Lim (1985)

D. hcbenastrum (F. Muell.) Kranzl.

40

H a s h i m o t o (1981)

38

J o n e s et al. ( 1 9 8 2 )

38

J o n e s et al. ( 1 9 8 2 )

D. leucocyanum Reeve

var. lichenastrum var. prenticei (F. Muell.) Dockr. D. linawianum

Rchb. f.

38, 4 0 , 7 6

C h e n g et al. (1985) (continued)

25

(continued) Species D. lindleyi

2n

Reference

38

Vajrabhaya and Randolph (I960), Kosaki

Steud.

(as D. aggregation

Roxb.)

19

and Kamemoto (1961) 32-35 38

Chardard (1963) Jones (1963), Kamemoto and Sagarik (1967), Wilfret and Kamemoto (1971), Jones et al. (1982), Vij and Shekhar (1985), Shekhar and Vij (1986)

var. jenkinsii

(as D. aggregatum

var. jenkinsii

Roxb.

38

Hashimoto (1982)

38

Kosaki (1958), Hashimoto (1981, 1987)

38

Jones et al. (1982)

38

Kosaki (1958), Kosaki and Kamemoto

38

Kosaki (1958), Vajrabhaya and Randolph

Wall, ex Lindl.)

var. majus (as D. aggregatum

Roxb. var.

majus Rolfe) D. lineale Rolfe (as D. grantii

C. T. White)

(1961), Wilfret and Kamemoto (197 1) (as D. veratrifolium

Lindl.)

(1960), Kosaki and Kamemoto (1961), Jones (1963) D. Itnguella

Rchb. f

(= D. hercogloautn

38

Kamemoto and Sagarik (1967), Wilfret and Kamemoto (1971), Hashimoto

Rchb. 0

(1982), Jones et al. (1982) 38

Jones (1963), Hashimoto (1981, 1987),

38

Jones (1963), Kamemoto and Sagarik

40

Ito and Mutsuura (1957)

38

Chardard (1963), Jones (1963),

D. lohohense Tang & Wang

38

Cheng et al. (1985)

D. /imgiiornu Wall, ex Lindl.

38

Jones (1963), Hashimoto (1982)

D. hnguiforme

Sw.

D. lituiflorum O. loääigesti

Jones et al. (1982)

Lindl.

(1967), Shekhar and Vij (1986)

Rolfe

Jones et al. (1982), Cheng et al. (1985)

Malla et al. (1977), Mehra and Sehgal

19

(1980) 38

19 var. java

Shekhar and Vij (1986)

43

Hashimoto (1981)

D. inabelae Gammie

38

Jorapur and Kulkarni (1980)

D. macranthum

38

Jones et al. (1982)

38

Kosaki (1958), Kosaki and Kamemoto

A. Rieh.

D. macrophyllum

A. Rieh.

(1961), Hashimoto (1981, 1987), Jones et al. (1982) 38

19

38 + 2f D. macrostachyum

Lindl.

A r o r a ( l 971)

20 38

D. mannii

Ridl.

D. mayandyi D. microbulbon

Abraham and Vatsala (1981) Lim (1985)

Reeve & Renz A. Rieh.

Hedge and Boraiah (1973), Singh ( 1 9 8 1 )

38

Hashimoto (1987)

38

Jones et al. ( 1 9 8 2 )

38

Jorapur and Hedge (1980) Jorapur and Krishna Mohan (1986)

19

(continued)

26

(continued) Species

n

D. mirbellianum

2n

Gaud.

Wilfret and Kamemoto ( 1 9 7 1 )

38

D. miyakei Schltr. (as D. victoriae-reginae

Reference

Hsu ( 1 9 7 2 ) , Hashimoto ( 1 9 8 1 , 1 9 8 7 )

38 var. miyakei

Peng et al. ( 1 9 8 6 )

19

(Schltr.) Liu & S u ) D. mohlianum

Kranzl.

Jones et al. ( 1 9 8 2 )

38

D. monile Kranzl.

38

Hashimoto ( 1 9 8 1 , 1 9 8 7 )

D. moniliforme (L.) Sw.

38

Miduno ( 1 9 4 0 ) , Ito and Mutsuura ( 1 9 5 7 ) , Mutsuura and Nakahira ( 1 9 5 8 ) , Kosaki and Kamemoto ( 1 9 6 1 ) , Tanaka ( 1 9 6 5 , 1 9 7 1 ) , Wilfret and Kamemoto ( 1 9 7 1 ) , Hsu ( 1 9 7 2 ) , Karasawa and Hashimoto ( 1 9 8 1 ) , Jones et al. ( 1 9 8 2 ) , Yang and Zhu ( 1 9 8 4 )

38 + (0-3f) ca. 38 'Ginryu' Pink Flower' D. monophyllum F. Muell.

Jones ( 1 9 6 3 ) Nakasone and Moromizato ( 1 9 6 4 )

38

Tanaka(1962)

48

Mutsuura and Nakahira ( I 9 6 0 )

38

Hashimoto ( 1 9 8 2 , 1987), Jones et al. (1982)

D. ttwHticola Hunt & Summerhayes D. mwreanum

Vij et al. ( 1 9 7 6 )

19, 2 0

Lindl.

36

Lim ( 1 9 8 5 )

D. mortii F. Muell.

38

Lim ( 1 9 8 5 )

D. moschatum (Buch - H a m . ) Sw.

38

Chardard ( 1 9 6 3 ) , Wilfret and Kamemoto

40

Jones ( 1 9 6 3 ) , Sau and Sharma ( 1 9 8 3 )

( 1 9 7 1 ) , Hashimoto ( 1 9 8 1 , 1987) 38, 39 var. cupreum Herbert

38

+

38

Kamemoto and Sagarik ( 1 9 6 7 ) Shekhar and Vi) ( 1 9 8 6 )

38

19

3f

Kosaki ( 1 9 5 8 ) Kosaki and Kamemoto ( 1 9 6 1 )

D. muKiferum Schltr.

40

Hashimoto ( 1 9 8 2 )

D. mutabile (Bl.) Lindl.

2x a

Jones ( 1 9 6 3 )

40

Jones et al. ( 1 9 8 2 )

38

Karasawa and Hashimoto ( 1 9 8 1 )

30

Hsu(1972)

D.

nagasaki

D. nakabaraei

Schltr.

D. nebularum Schltr. D. nobile Lindl.

40

Hashimoto ( 1 9 8 2 , 1 9 8 7 )

38

Lim ( 1 9 8 5 ) Chardard ( 1 9 6 3 )

19 ca. 2 0

Hoffmann ( 1 9 2 9 , 1 9 3 0 ) 38

19

Miduno ( 1 9 4 0 ) , Ito and Mutsuura ( 1 9 5 7 ) , Vajrabhaya and Randolph ( I 9 6 0 ) , Shekhar and Vij ( 1 9 8 6 )

40

Eftimiu-Heim ( 1 9 4 1 ) , Sau and Sharma

38

Kamemoto and Sagarik ( 1 9 6 7 ) , Tanaka

(1983) ( 1 9 7 1 ) , Hashimoto ( 1 9 8 1 , 1987), Karasawa and Hashimoto ( 1 9 8 1 ) , Jones et al. ( 1 9 8 2 ) , Cheng et al. ( 1 9 8 5 ) (continued)

27

(continued) Species

n

2n 38

Banerji and C h a u d h u r i (1972)

38

76

Ito and M u t s u u r a (1957)

(as D. formosanum (Rchb. f.) Masam.) ' K i n g George' 'Sir F. Moore' var. cooksonianum R c h b . f.

19

(as 'Cooksoniae')

Reference

76

Tanaka(1962)

76

Jones et al. (1982)

38

Ito and M u t s u u r a (1957)

38

Jones ( 1 9 6 3 )

38

J o n e s et al. (1982)

var. nobile

38, 57

Jones (1963)

var. nobilius R c h b . f.

ca. 57

Jones (1963)

(as ' N o b i l u s ' )

38

var. pendulum

38

var. sanderianum

38-40

J o n e s et al. (1982) Banerji and C h a u d h u r i (1972) Chardard (1963)

var. virginale H o r t .

57

Jones (1963)

var. wallichianuvi

38

Jones ( 1 9 6 3 )

Hort.

D. normale Falc.

38

Shekhar and Vij (1986)

D. ochreatum Lindl.

2x"

Jones (1963)

40

Sau and Sharma (1983)

38

Vi, and Shekhar (1985), Shekhar and

38

H a s h i m o t o (1981)

D. oreodoxa Schltr.

38

J o n e s et al. (1981)

D. ovalum (L ) Kranzl.

40

J o n e s (1963), Singh (1981)

38

J o r a p u r and Krishna Mohan ( 1 9 8 6 )

D. palpebrae Lindl.

40

J o n e s (1963), H a s h i m o t o (1987)

D. papdin Loher

40

Vij (1986) D. opbioglossum Rchb. i.

D. parcoides G u i l l .

H a s h i m o t o (1982) Chardard (1963)

20

D. parishii Rchb. f.

40

Ito and M u t s u u r a (1957)

.38

J o n e s (1963), K a m e m o t o and Sagarik (1967), H a s h i m o t o (1981, 1987), Lim (1985)

38, 7 6

Shekhar and Vij (1986)

D. patentilobum Ames & Schweinf.

38

Lim ( 1 9 8 5 )

D. pauciflorum K i n g & Pantl.

38

Vij and Shekhar (1985), Shekhar and

D. pendulum Roxb.

2x a

Jones (1963)

Vij (1986) 38

J o n e s et al. (1982)

(as D, crassinode Benson & Rchb. f.)

38

K a m e m o t o and Sagarik (1967),

(as D. wardianum

W a r n . var.

2x a

Jones ( 1 9 6 3 )

Warn.)

38

H a s h i m o t o ( 1 9 8 1 , 1987), Shekhar and

40

Sau and Sharma (1983)

H a s h i m o t o (1981, 1987) wardtanum) (as D. wardianum

Vij (1986) 20 var. album (as D. wardianum var. album Will.)

ca. 57

Jones (1963)

var. gtganteum (as D. wardianum

var. giganteum)

40

H o f f m a n n ( 1 9 2 9 , 1930) (continued)

28

(continued) n

Species D. petiolatum

2n

Schltr.

D. pbalaenopsis

Fitzg.

Reference

38

Lim ( 1 9 8 5 )

38

Kosaki ( 1 9 5 8 ) , Tanaka ( 1 9 7 1 ) , W i l f r e t and K a m e m o t o ( 1 9 7 1 ) , Hashimoto (1981, 1987)

19 (as D. bigibbum

var. superbum

Hort.)

19

'Extra'

38

Kosaki and Kamemoto ( 1 9 6 1 )

38

Hashimoto (1981)

76

K a m e m o t o et al. ( 1 9 6 i )

'Giganteum'

ca. 7 6

'Hololeucum'

38

Vajrabhaya and R a n d o l p h ( I 9 6 0 )

'Lyon's Light No. 1'

38

K a m e m o t o et al. ( 1 9 6 1 ) , Kamemoto and

38

Kosaki and Kamemoto ( 1 9 6 1 )

Kosaki ( 1 9 5 8 ) , Kosaki and K a m e m o t o (1961)

Tara ( 1 9 6 8 ) 19, 38

38

Dorn and Kamemoto ( 1 9 6 2 )

'Lvon's Light No. 1' (selfed)

56-59

K a m e m o t o and Tara ( 1 9 6 8 )

('Lyon's Light No. 1' X 'Lyon's Light

38, 39

K a m e m o t o and Tara ( 1 9 6 8 )

No. 2') ('Lyon's Light No. 2' X 'Lyon's Light

57

K a m e m o t o and Tara ( 1 9 6 8 )

Variable

No. 1') Ruby'

ca. 7 6

Kosaki ( 1 9 5 8 ) , Kosaki and Kamemoto (1961)

'Shibata'

76

K a m e m o t o et al. ( 1 9 6 1 )

38

K a m e m o t o et al. ( 1 9 6 1 )

38

Vajrabhaya and R a n d o l p h ( I 9 6 0 )

var. r c h r o e d e r i a n u m (as 'Schroederianum') D. philippinense

19

Ames

D. phlox Schltr var. flavii D. pinifolium

Rull

D. platygastrium

Rclib. f.

38

Kosaki and Kamemoto ( 1 9 6 1 )

38

Hashimoto ( 1 9 8 2 , 1987), Lim ( 1 9 8 5 )

38

Hashimoto (1981)

40

Lim ( 1 9 8 5 )

40

H a s h i m o t o ( 1 9 8 1 , 1987), Jones et al. (1982)

D. polyanthum

Lindl.

(as D. cretaceum D. polyschistum D. polysema

Jones ( 1 9 6 3 )

Lindl.)

Schltr.

38

Schltr.

D. porphyrochtlum

38 + 2B>

Lindl.

D. porphyrophyllum D. primuhnum

38, 38 + If

Guill.

Lim ( 1 9 8 5 ) J o n e s et al. ( 1 9 8 2 ) Mehra and S e h g a l ( 1 9 7 5 )

19

Chardard ( 1 9 6 3 )

19

Lindl.

38

Ito and M u t s u u r a ( 1 9 5 7 ) , Jones ( 1 9 6 3 ) , Kamemoto and Sagarik ( 1 9 6 7 ) , M e h r a and Kashyap ( 1 9 7 6 ) , Cheng et al. ( 1 9 8 5 ) , Lim ( 1 9 8 5 ) Mehra et al. ( 1 9 7 0 )

19

D. prostratum

38

19

3 8 , 57

Ridl.

D. pseudoglomeratmn D. pugioniforme

19

J . J . W o o d & Reeve

A. C u n n .

Mehra and Kashyap ( 1 9 8 4 , 1989) Shekhar and Vij ( 1 9 8 6 )

2x a

Jones ( 1 9 6 3 )

38

Lim ( 1 9 8 5 )

38

Hashimoto ( 1 9 8 1 , 1987), Jones et al. (1982) (continued)

29

(continued) Species

n

D. pulchellum

2«

R o x b . ex L i n d l .

(= D. dalbousieanum

D. punamense

D. regium

Jones (1963) K a m e m o t o and S a g a r i k ( 1 9 6 7 ) J o n e s et al. ( 1 9 8 2 )

C h e n g & Tang

38

C h e n g et al. ( 1 9 8 5 )

Schltr.

38

Hashimoto (1981, 1987)

Lindl, ex W a l l . Prain

D. revolutum

2x" 38

Ames

D. ramosum

Kosaki a n d K a m e m o t o ( 1 9 6 1 )

40

D. quinquecostatum D. ramosii

38

Wall.)

Schltr.

D. quangxiensis

Reference

Lindl.

40

Hashimoto (1981, 1987)

40

Jones ( 1 9 6 3 )

38

Jones ( 1 9 6 3 )

40

K a m e m o t o and S a g a r i k ( 1 9 6 7 ) ,

38

Hashimoto (1981)

Hashimoto (1981) D. rhodopterygium

R c h b . f.

D. rhodostictum

F. M u e l l . & Kranzl.

38

J o n e s et al. ( 1 9 8 2 )

D. rhylidothece

Schltr.

38

Lim ( 1 9 8 5 )

D. rigidum

Lindl.

D. rotundalum

38

Bench.

20 20

D. rugmosum D. salaccense D. sanderae

Ames ( B l . ) Lindl. Rolfe

D. scabrihngue

H a s h i m o t o ( 1 9 8 2 , 1987), L i m ( 1 9 8 5 ) Mehra et al. ( 1 9 7 0 )

20

Lindl.

40

Vij and S h e k h a r ( 1 9 8 5 )

40

S h e k h a r and Vij ( 1 9 8 6 )

38

J o n e s et al. ( 1 9 8 2 )

38

J o n e s et al. ( 1 9 8 2 )

40

S h i n d o and K a m e m o t o (196.3)

40

Hashimoto (1987)

38

K a m e m o t o and S a g a r i k ( 1 9 6 7 ) ,

38

H a s h i m o t o ( 1 9 8 1 , 1987), L i m ( 1 9 8 5 )

40

S h i n d o and K a m e m o t o (196.3)

38

V a j r a b h a y a and R a n d o l p h ( I 9 6 0 )

40

Jones (1963), Kamemoto and Sagarik

40

Hashimoto (1981)

38

J o n e s et al. ( 1 9 8 2 )

38

K a m e m o t o and S a g a r i k ( 1 9 6 7 ) , W i l f r e t

40

Hashimoto (1981)

2x"

Jones (1963)

Hashimoto (1981, 1987) D. schneiderae

F. M . B a i l .

D. schuetzei

Rolfe

D. schulleri

J. J. Sm.

D. secundum

20

( B l . ) Lindl.

Chardard ( 1 9 6 3 )

20

(1967), Hashimoto (1987) 20 D. seemanii D. senile

L. O. W i l l i a m s Par. & R c h b . f.

and K a m e m o t o ( 1 9 7 1 ) , L i m ( 1 9 8 5 ) D. signatum

R c h b . f.

(as D. hildebrandii

Rolfe)

3 8 , 3 8 + If

Kosaki ( 1 9 5 8 ) , Kosaki and K a m e m o t o (1961)

38

Jones (1963), Kamemoto and Sagarik

D. simplex J . J . S m .

36

J o n e s et al. ( 1 9 8 2 ) , L i m ( 1 9 8 5 )

D. smilieae

38

Jones (1963), Hashimoto (1981, 1987),

38

B l u m e n s c h e i n ( I 9 6 0 ) , J o n e s et al. ( 1 9 8 2 )

(1967), Lim (1985) F. M u e l l .

Lim ( 1 9 8 5 ) D. speciosum

J . E. S m .

var. fusiforme var. hilii

F. M . B a i l .

Masters

38

Kosaki and K a m e m o t o ( 1 9 6 1 )

38

Jones ( 1 9 6 3 ) (continued)

30

(continued) Species

n

2n

D. spectabile (Bl.) Miq.

38

Reference Kosaki (1958), Kosaki and Kamemoco (1961), W i l f r e t and Kamemoco (1971), J o n e s et al. (1982)

D. spurium (Bl.) J . J . Sm.

40

Pancho (1965a, b)

D. stratiotes Rchb. f.

38

Kosaki (1958), Vajrabhaya and R a n d o l p h (1960), Kosaki and K a m e m o t o (1961), Jones ( 1 9 6 3 )

var. giganteum D. stricklandianum

38

W i l f r e t and K a m e m o t o (1971)

40

M u t s u u r a and N a k a h i r a (1959)

38

Tanaka ( 1 9 6 5 , 1971)

Rchb. f.

(as D. tosaense Makino) ¡9 D. striolatum Rchb. t. D. stuposum Lindl.

38

H a s h i m o t o (1981)

38

Jones et al. ( 1 9 8 2 )

38

H a s h i m o t o (1981, 1987)

40

Sau and Sharma (1983), Vij and Shekhar

38

Lim ( 1 9 8 5 )

D. subulatum (Bl.) Lindl.

38

H a s h i m o t o (1987)

D. sulcatum Lindl.

40

H a s h i m o t o (1981, 1987)

D. sulpbureum Schirr.

76

Jones et al. (1982)

D. sutepense Rolfe ex D o w n i e

2x"

Jones (1963)

38

Wilfret and K a m e m o t o (197 1),

38

Jones et al. ( 1 9 8 2 )

38

Jones (1963), Wilfret and K a m e m o t o

D. taurinum Lindl.

38

Kosaki (1958), Kosaki and K a m e m o t o

D. tenmssimum R u p p .

38

Lim ( 1 9 8 5 )

D. teretifolium R. Br.

2x"

Jones (1963)

var. fasaculatujn

40

H a s h i m o t o (1981)

76

Jones et al. (1982)

(1985), Shekhar and Vij (1986) D. subclausum Rolfe

H a s h i m o t o (1981, 1987) D. tangerinum C r i b b (as D. strebloceras Rchb. f.)

(1971), H a s h i m o t o (1981) (1961), H a s h i m o t o (1981)

Rupp.

D terminale Par. & Rchb. f. D. terrestre J . J . Sm.

38

H a s h i m o t o (1981)

40

Lim (1985)

38

Jones et al. ( 1 9 8 2 )

38

H a s h i m o t o (1981), Lim (1985)

D. tetragonum A. C u n n . var. giganteum Gilbert D. thyrsiflorum Rchb. f. ex A n d r e

20

H o f f m a n n (1929, 1930), Skekhar and Vij ( 1 9 8 6 ) 40

Vajrabhaya and R a n d o l p h ( I 9 6 0 ) , Kosaki and K a m e m o t o (1961), K a m e m o t o and Sagarik (1967), H a s h i m o t o (1981), J o n e s et al. (1982), C h e n g et al. ( 1 9 8 5 )

D. toftii F. M. Bail.

38

Vajrabhaya and R a n d o l p h ( I 9 6 0 ) , Kosaki

D. tokai Rchb. f.

38

Vajrabhaya and R a n d o l p h ( I 9 6 0 ) , J o n e s

and K a m e m o t o (1961) (1963) (continued)

31

(continued) Species

n

2n

Reference Kosaki and K a m e m o t o (1961)

19 D. toressae(E M. Bail.) Dockr.

38 ca. 36

D. tortile Lindl.

38

Jones et al. (1982) Lim (1985) Kosaki and K a m e m o t o (1961), J o n e s (1963), K a m e m o t o and Sagarik (1967), Wilfret and K a m e m o t o (197 1), H a s h i m o t o (1981, 1987), Jones et al. (1982)

D, transparens Wall, ex Lindl. 20

38

Jones (1963)

40

Sharma and Chatterji ( 1 9 6 6 ) Mehra et al. (1970)

20

Mehra and Sehgal (1980)

19 19

38

Sau and Sharma (1983)

20

40

Shekhar and Vij (1986)

D. tngonopus Rchb. f.

38

Wilfret and K a m e m o t o (197 1),

D. unicum Seid.

38

H a s h i m o t o (1982), Lim (1985)

D. uniflorum Griff.

40

H a s h i m o t o (1987)

D. vannouhuysu J . J . Sm.

38

J o n e s et al. (1982)

38

Pancho (1965a, b)

D. verruitferum Rchb. f.

41

Ishida et al. (1992)

D. vexillartusJ.J.

Lim (1985)

D. ventricosum Kranzl. 20

Hsu (1972) 38

Jones et al. (1982)

D. victoriae-reginae Loher

Sm.

38

Jones (1963), Wilfret and K a m e m o t o

D. violdceum Kranzl.

38

Jones et al. (1982)

D. wangi Tso

38

Cheng et al. (1985)

D. wassellii S T. Blake

.38

H a s h i m o t o (1981, 1987), Jones et al.

(1971), H a s h i m o t o ( 1 9 8 2 )

(1982) D. wilhamsianum D. u'illiumsonii

Rchb. f. Day & Rchb. f.

38

Lim (1985), H a s h i m o t o (1987)

38

H a s h i m o t o (1982, 1987), Jones et al.

57

Shekhar and Vij (1986)

38

Kosaki and K a m e m o t o (1961),

36

J o n e s et al. (1982)

(1982) (as D. cariniferum Rchb. f.)

K a m e m o t o and Sagarik ( 1 9 6 7 ) D. woodsn Cribb

"Plant is known to be diploid, b u t uncertainty exists as to w h e t h e r it has 2n = 38 or 2n = 4 0 (Jones 1963). b

Award of Merit: American O r c h i d Society, H o n o l u l u Orchid Society.

32

DENDROBIUM

Table 3.2. Distribution of chromosome numbers of species in the genus Dendrobium (tabulated from Table 3.1) Chromosome numbers

(2n)

N o . of s p e c i e s

3 6 , 36 + 2 f

7

36, 38

2

38

161

38, 39

1

38, 40

23

38, 39, 4 0 , 38 + 3 f

1

3 8 , 4 0 , 4 0 + 1 - 3 f, 4 2

1

pr,

CO

1

38, 40, 57

2

38, 40, 57, 76

1

38, 40, 7 6

2

38, 40, 8 0

1

3 8 , 57

7

38, 57, 7 6

1

3 8 , 5 7 , 7 6 , 114

1

38, 76, 80

1

40

38

- I 11

\

1 I

4 0 , 4 0 + 2—1 f, 4 1

1

40, 76

1

76

3 257

Total species

Wf mt J

SPECIES

/ M

> ê

33

A new basic n u m b e r , x = 18 (2» = 36), was discovered by J o n e s et al ( 1 9 8 2 ) a n d Lim ( 1 9 8 5 ) in seven species of section Latouria f r o m P a p u a N e w G u i n e a and the S o l o m o n Islands. O t h e r species of section Latouria have 2n = 38 or 2n = 38 + Bs. To s u m m a r i z e , the most c o m m o n basic n u m b e r is .v = 19 ( 1 6 1 species), followed by x = 2 0 ( 3 8 species), and the new n u m b e r .v = 18 (seven species). It m i g h t be assumed t h a t .v - 19 is t h e m o s t c o m m o n n u m b e r in Dendrobium. It is d i f f i c u l t to conclude the direction of e v o l u t i o n b e t w e e n x = 19 and 20.

*

, «* rV A

R

%

»

«

/

Dendrobium kingianum of A u s t r a l i a is r e p r e s e n t e d by 2n = 38, 57, 7 6 , and 114. A c c o r d i n g to M a x well ( 1 9 7 1 ) the ploidy of D. kingianum increased w i t h elevation, and triploids occur w h e r e d i p l o i d and tetraploid p o p u l a t i o n s overlap. T h r e e species, D. aurantiroseum, D. chrysocrepis, and D. sulphureum, have been reported only as t e t r a p l o i d s w i t h 2n = 16. Dendrobium cutbbertsonii (syn. D. sophronites) was reported by J o n e s ( 1 9 6 3 ) as t e t r a p l o i d , and c o n f i r m e d by L i m ( 1 9 8 5 ) , b u t H a s h i m o t o ( 1 9 8 7 ) has recorded a d i p l o i d form w i t h 2n = 3 8 for the same species.

*

À

RELATIONSHIPS

ft

^

B Figure 3 -1. Somatic metaphase chromosomes of Dendrobium species in section Nigrohirsutae (1,91 IX). A, D. sanderae; B, D. formosum; C, D. draconis (from Shindo and K a m e m o t o 1963).

è tu o 1 N -/ V & tu V

\r\ T

I-c\ o o

E .j rvj

q rs «¡ m v rsri

Oo Öó H • O q o Ö

O Ö O

o Oo OOO OÖ o OO

O Ò

M r r-i rsi H • H - H • \T\rr T I S I T s C Ñ fN

T IS

O o •—< Ö H • ö H • Ö H • 00 i — i —

O Ö •H rr C N

rr N ÍH H • ÍH • • N rT O rT r i\ ir\ rT

\rsN OrO rC\f N rsi

C Nrsj rr, O r i\•^r

T

H •s r« r-

r i \N OrT

rr. M •H

Ö H •

rT,

—. r\i n — rsi •T rsi rsi + H < H • ^ H - H • O rsi co — rT rr O \ó rv s i ~ /\ ir\ »rs T IS

rr •H

ó

r i\ Ó

o < N

o + H v-r

a

s Q

S Op c

o

-C u

"3 c M < U a b o « m u 3 £

E o t/i o E o U i x; U

1 -S / V N 00 O O -H o o O Ö Ö Ò O o Ò H • + 1rH -sj u + 4H O C N rT, N 00 G O rsj — < — < — « — < —!
. years after pollination. Flowers are relatively small with a natural spread of about 2.5 cm (1 inch) across. Although peak flower production occurred between July and December, flowers were obtained throughout the year. Plant height averaged only 38 cm (15 inches) at maturity (Kamemoto and Kobayashi 1988). Dendrobiurn Caesar ( U H 9 2 I ) . Dendrobiurn Caesar was registered decades ago by Nagrok as a cross between D. phalaenupsis and D. stratiotes. Most offspring from various crosses involving these two species are tall and show a high incidence of bud drop. To reduce the height ot D. Caesar, we crossed D. stratiotes D200-1 with

Figure 12.20. Dendrobiurn Mari Marutani U H 1 4 2 0 .

UH785.

116

/

BREEDING

POTTED

PLANT

CULTIVARS

pseudobulbs 81 cm (32 inches) tall and D. pbalaenopsis var. compactum D 2 9 1 with pseudobulbs only 7.6 cm (3 inches) tall. The cross was made in October 1983. Offspring began to flower in J a n u a r y 1986, only two years after germination. Petals and sepals are purple violet ( R H S C C 8 0 B ) edged w i t h white, and the lip is darker purple violet ( R H S C C 80A). Although petals and sepals are narrow, the flowers are fairly large, measuring about 7.6 cm (3 inches) in height (Fig. 12.22). W i t h i n the first year of flowering, all plants produced at least two sprays within the same month. Flower yield increased during the second year of production. Flowers were obtained throughout the year; however, production was greater during J u l y to December than from J a n u ary to J u n e . Plant height averaged 4 0 . 6 cm (16 inches) in December 1986 and 76 cm (30 inches) in December 1987. It is surprising that the bud drop percentage was only 6.8% compared with 4 0 . 2 % for another D. Caesar cross, D. stratiotes D 2 0 0 - 1 X D. pbalaenopsis 'Mauna Loa' (Kamem o t o e t a l . 1989).

Dendrobium S a m a r a i ( U H 9 8 8 ) . The cross between D. stratiotes and D. antetinatum was registered as D. Samarai by Limberlost in 1967. W e remade the cross ( U H 9 8 8 ) using D. stratiotes D 2 0 0 - 1 and D. antennatum K 7 4 1 - 1 3 . The shape and color of flowers of U H 9 8 8 and both parental

Figure 12.22. Dendrobium

Caesar UH921.

species are similar. The petals are upright, twisted, and yellow green ( R H S C C 154B) toward the tip and white to-.vard the base. The sepals are white; the lip is white with purpie violet ( R H S C C 8 0 B ) stripes. The height of plants and other characteristics are more or less intermediate between the two parents. The hybrid U H 9 8 8 (Fig. 12.23) is floriferous and produces flowers throughout the year like D. antennatum, and flowers are long-lasting (Kamemoto et al. 1989)-

CLONALLY PROPAGATED CULTIVARS

Dendrobium A u t u m n Lace ' F l o r i d a T w i s t ' . The cross between D. strebloceras (D. tangerinum) of section Ceratobium and D. canaliculatum of section Eleutberoglossuvi was made at the University of Hawai'i in 1969 by Gary Wilfret while he was a graduate research assistant. He flowered some seedlings at the University of Florida at Bradenton and selected a plant that was later micropropagated by Yoneo Sagawa at the University of Hawai'i. It was registered as D. A u t u m n Lace, given the clonal designation 'Florida Twist' (Fig. 12.24), and jointly released in 1979 by the University of Florida and the University of Hawai'i (Wilfret and Kamemoto 1979a,b). Pseudobulbs of'Florida Twist' are up to 50 cm (19-5 inches) tall. Graceful arching racemes up to 6 8 cm (27 inches) long carry as many as 53 gray orange flowers between August through May, usually peaking in autumn in Florida. A plant

Figure 12.23. Dendrobium

Samarai UH988.

BREEDING

with 28 racemes and over 700 flowers received a Certificate of Cultural Merit in 1972 from the American Orchid Society. Dendrobium A u t u m n Lace 'Uniwai Sunset'. Dendrobium A u t u m n Lace was remade in August 1975, with the same D. strebloceras, but a different D. canaliculatum (D173-2) that produced upright sprays instead of the arching sprays of the clone used in the earlier cross. A selection from this cross, K 4 3 2 - 2 (Fig. 12.25), was floriferous like 'Florida Twist' but produced shorter and more upright sprays. Flower color, size, and shape were similar in both clones. The length of pseudobulbs was about 25 cm (10 inches). This new selection was named 'Uniwai Sunset' to distinguish it from 'Florida Twist'. 'Uniwai Sunset' produced flowers from September through J u n e with peak production during the months of May and June, rather than during a u t u m n in Florida for 'Florida Twist'. A few plants o f ' U n i w a i Sunset' were distributed to growers in Hawaii ( K a m e m o t o and McConnell 1986).

POTTED

PLANT

CULTIVARS

/

117

one seedling of this cross was selected, labeled as K 5 8 0 - 3 , transplanted into a 13-cm (5-inch) clay pot, and put in the greenhouse at the Mauka Manoa Campus for evaluation as a flowering potted plant cultivar. K 5 8 0 - 3 produced 14 sprays in February 1982 and an additional 14 sprays in April 1982 (Fig. 12.26). The sprays remained attractive for a month in the air-conditioned, artificially lighted office. We named this clone 'Elaine Fuchigami' and proceeded to mericlone it for release to growers as a potted plant cultivar. Although mericlones grew well in the glasshouse, they performed poorly in the saranhouse because of the excessive rainfall d u r i n g the winter of 1 9 8 4 - 1 9 8 5 . It seems that, like both parental species, D. btgibbum and D. canaliculatum, D. Mini Pearl cannot tolerate excessive moisture. However, if excess moisture can be avoided, 'Elaine Fuchigami' should make an excellent miniflowered potted dendrobium (Kamemoto and Kobayashi 1985).

Dendrobium Mini Pearl 'Elaine Fuchigami'. In March 1978, we remade the cross registered as D. Mini Pearl by Ralph Yagi in 1974, using as parents D. bigibbum var. compaction K 3 8 8 - 2 4 and D. canaliculatmn D 1 7 3 - 2 . In November 1980,

Dendrobium Mini Pearl 'Elaine F u c h i g a m i 4 N ' . W h i l e mericloning 'Elaine Fuchigami' for release to growers, we treated some protocormlike bodies with colchicine in aseptic culture to induce tetraploids (amphidiploids) for use in future breeding. The amphidiploids were found to be more vigorous and generally superior to

Figure 12.24. Dendrobium Autumn Lace 'Florida Twist'.

Figure 12.25. Dendrobium Autumn Lace 'Uniwai Sunset'.

118

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BREEDING

POTTED

PLANT

CULTIVARS

their diploid counterparts, although spray yield

potted plant cultivars developed by and grown

was lower than that of the diploids. Sprays of the

at the University of Hawai'i at Manoa. It should

amphidiploids were more erect and upright. Indi-

be noted thai

vidual flowers and flower parts were substantially

affected by environmental conditions within a

larger in the amphidiploids. N o difference in

location, variation among environments within

pseudobulb height was observed and both aver-

the

aged under 2 7 . 0 cm (1 1 inches). T h e flowering

weather.

state,

and

flowering

of any cuitivar can ue

year-to-year

variation

in

the

season for both was similar. A selected amphidip-

'Lynne Horiuchi' and 'Elaine Fuchigami' have

loid (Fig. 1 2 . 2 7 ) was remericloned and plantlets

a favorable winter-spring blooming season. Sev-

were released to dendrobium growers (Kamemoto

eral cultivars flower from fall through winter,

et al. 1991a).

and several others display peak flowering during fall. A few cultivars, 'Pua'ala', 'Caesar', and 'Samarai', produce flowers throughout the year. Gener-

SEASONALITY

ally, with the exception of 'Susan Takahashi' and

One of the objectives of our breeding program is to produce cultivars with more than one flowering period per year. In addition it is desirable for flowering peaks to coincide with major florist holidays—Christmas and New Year, Valentine's Day ( 1 4 February), Easter (late March to midApril), and Mother's Day (sccond Sunday in May). Thus flowering potted plants should be in greater demand during winter and spring months. However, if potted dendrobium plants are to be used tor interiorscaping hotels and other commercial establishments, an established practice in Hawaii, then there is a need for flowering dendrobium potted plants throughout the year.

'Samarai', summer production is low. Fortunate-

Figure

12.28

ly, many of the cut-flower cultivars (chapter 11) flower during the summer, thereby alleviating any shortages during that period.

shows the seasonality of the

Figure 12.26. Dendrobium Mini Pearl 'Elaine Fuchigami'.

Figure 12.27. Dendrobium Mini Pearl 'Elaine Fuchigami 4N'.

BREEDING

PRESERVATION OF BREEDING PLANTS

POTTED

PLANT

CULTIVARS

/

119

Tammy Wakasugi to produce Sandy Kunimoto (Fig. 1 2 . 2 9 Q . Sandy Kunimoto has entered into

it is an absolute necessity to maintain breeding

crosses with Lady Claire to give Mae Teramoto

parent plants for the production of seed-propa-

(Fig. 12.29D)-, with Kairnuki Beauty to produce

gated cultivars. However, it is extremely difficult

the

to maintain some breeding plants (Table 12.1)

K 4 0 4 - 2 (Fig. 1 2 . 2 9 £ ) ; and with Field K i n g to

in a healthy condition, especially the tetraploid

yield Evelyn Nakasato (Fig. 1 2 . 2 9 F ) , a parent of

valuable

breeding

parent

Manoa

Beauty

hybrids, primarily

'Susan Takahashi'. Mae Teramoto also has served

because of the accumulation of cymbidium mosaic

as a valuable parent. Crossed to Merle Sado, it

virus, but also because of insect and disease pests

produced Catherine Cavaletto (Fig. 1 2 . 2 9 0 , and

and

to Manoa Beauty to give K 1 4 1 7 (Fig. 1 2 . 2 9 H ) .

D. pbalaenopsts-type

(PPPP)

phytotoxicity

of

chemical

sprays.

D. Jaquelyn Thomas-type amphidiploids

The (PPCC)

Manoa Beauty K 4 0 4 - 2 is a valuable breed-

are more vigorous and easier to maintain. Also,

ing parent. It has produced 'Miyoko Azuma'

androgenesis provides a vehicle to eradicate the

and 'Sharon

virus, as discussed in chapters 8 and 9.

Manoa Beauty have somewhat degenerated. To

Dendrobium

Claire (Fig. 1 2 . 2 9 A ) was one of

the early PPPP-type

Sewake'.

Recently

the

plants

of

rejuvenate this clone, it was micropropagated.

dark purple selections used

As a hedge against losing the valuable germ

in our breeding program. It was crossed to Lady

plasm, K 4 0 4 - 2 was crossed to Mae Teramoto

Hay (Fig. 1 2 . 2 9 B ) to give Lady Claire, and to

to produce K 1 4 1 7 (Fig. 12.29H). Several selec-

Figure 12.28. Seasonality of Dendrobium indicates moderate flowering.

potted plant cultivars. Solid bar indicates peak flowering; shaded bar

Figure 12.29A.

Figure 1 2 . 2 9 0 .

Figure 1 2 . 2 9 6 .

Figure 12.29£.

F i g u r e 12.29C.

Figure 12.2 9F.

Figure 12.29- Breeding plants: A, Dendrobium Claire; B, Dendrobium Lady H a y ; C, Dendrobium Sandy K u n i m o t o ; D, Dendrobium Mae Teramoto; E, Dendrobium Manoa Beauty; F, Dendrobium Evelyn Nakasato.

120

Figure 12.29G.

Figure 12.29/.

Figure 12.29 H.

Figure 12.29 K.

Figure 12.29/.

Figure 12.29L.

Figure 12.29- Breeding plants: G, Dendrobium C a t h e r i n e Cavaletto; H, Dendrobium K1417—17; I, Dendrobtum phalaenopsis W 1 5 -6;J, Dendrobium Doreen; K, Dendrobium K 1 4 0 5 - 16; L, Dendrobium J o a n n a Mesina.

121

122

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BREEDING

POTTED PLANT

Table 12.1. Dendrobium

CULTIVARS

phalaenopsis—type tetraploids maintained or developed for breeding purposes

Hybrid

Parentage

Registrant

Claire

B o n n i e X A m e r i c a n Beauty

K. K a m e m o t o , 1968

Lady Hay

Lady Fay X Lady H a m i l t o n

Kushima, 1968

Lady Claire

Lady H a y X Claire

U H , 1984

Sandy K u n i m o t o

Claire X T a m m y W a k a s u g i

U H , 1984

Mae T e r a m o t o

Lady Claire X Sandy K u n i m o t o

U H , 1984

C a t h e r i n e Cavalecto

Mae T e r a m o t o X Merle Sado

U H , 1984

M a n o a Beauty

K a i m u k i Beauty X Sandy K u n i m o t o

U H , 1996

K1417

Mae T e r a m o t o X M a n o a Beauty

—

Evelyn N a k a s a t o

Field K i n g X Sandy K u n i m o t o

D. phalaenopsis

D. phalaenopsis 3 N x D , phalaenopsis

W15-6

J o a n n a Mesina

Debi Debra X Drake K u b o

Doreen

T h e o d o r e T a k i g u c h i X D.

K1405

K 1 H 1 - 4 4 x K1263-60

tions f r o m K 1 4 1 7 have been used in crosses, and it is hoped that a d d i t i o n a l desirable a d v a n c e d g e n e r a t i o n PPPP-type b r e e d i n g p l a n t s will emerge. O t h e r i m p o r t a n t b r e e d i n g parents are tetraploid D. phalaenopsis W 1 5 - 6 (Fig. 12.29/), a

U H , 1984 2N

—

Kamiya, 1979 phalaenopsis

Takiguchi, 1961 —

p a r e n t of t h e PPPC c u t - f l o w e r cultivar 'Joan K u s h i m a ' ; t e t r a p l o i d w h i t e D o r e e n (Fig. 1 2 . 2 9 / ) ; K 1 4 0 5 , a relatively recent w h i t e PPPP h y b r i d (Fig. 1 2 . 2 9 ^ 0 ; and J o a n n a Mesina (Fig. 1 2 . 2 9 ^ ) , a p a r e n t of PPPC c u t - f l o w e r cultivars ' N e l l i e Sugii' and 'Tessie A m o r e ' .

CHAPTER i 3

Breeding Yellows and Novel Characters

ONE OF THE objectives of our breeding program has been the development of improved yellow cut-flower cultivars. Unfortunately, the mode of utilizing amphidiploids to produce yellow seedpropagated cut-flower and potted plant cultivars discussed in the previous two chapters has not been useful, primarily because of the lack of a yellow-flowered species comparable with Dendrobium [¡halaenopsis and D. bigibbum. A colchicine-induced tetraploid, D. May Neal 'Srisophon', crossed to diploid D. helix produced a fairly uniform progeny, but lacked the desirable horticultural characteristics for cutflower production. It appears that for the present, breeding yellow cultivars, as well as blue and novelty cultivars, has to rely on the traditional selection and clonal propagation of outstanding individuals.

P O L Y P L O I D Y IN Y E L L O W

received the Award of Merit from various orchid societies were triploid. Two hybrids that gained popularity as cutflower cultivars in Southeast Asia are D. Mary Mak and D. Sri Siam (Fig. 13.1), both of which are triploid (Table 1 3 1 ) . The relationships among several clones involving both of these hybrids are obscure. Dendrobium Mary Mak was produced in Thailand and registered by Mak Chin On in Singapore in 1977 (Royal Horticultural Society 1981). Either a single or a few clones were mericloned by one or more propagation laboratories, and plantlets were widely distributed. Our two accessions of Mary Mak, one from Thailand and the other from Hawaii, were triploid. The local acquisition, 'Dream City' (Fig. 13.2), received an Award of Merit from the American Orchid Society. 'Dream City' originated as a mericlone in

CULTIVARS

Chromosome counts of 15 Dendrobium species belonging to the section Spatulata (Ceratobium) that contained some yellow pigments were determined to be 2n = 38 (Kamemoto et al. 1987). The counts are listed in chapter 3 (Table 3-1). Table 13.1 gives chromosome numbers and descriptions of flower colors of cultivars. Among 30 accessions, 21 were triploid, six were tetraploid, and only three were diploid. The high percentage of triploids among the mericloned selections and cultivars evaluated reflects the significance of triploidy in breeding improved yellow cultivars. Also the majority of the accessions that

Figure 13 • 1 • Dendrobium

123

Sri Siam

Table 13-1. Chromosome number and flower color of Dendrobium (from Kamemoto et al. 1987) Accession no.

cultivars with yellow pigments

Chromosome Plant name'

Source

no.

(2n)h

Flower colorc

D269

Alice Queen

O r c h i d nursery, H o n o l u l u

38

Y e l l o w g r e e n ( 1 5 0 B ) p e t a l s and sepals, p u r p l e

D211

Amy 'Orange'

O r c h i d nursery, H o n o l u l u

57

G r e y e d o r a n g e ( 1 7 2 B ) p e t a l s a n d sepals

D227

Betty Ho 'Kamiya'

O r c h i d nursery, H o n o l u l u

57

Y e l l o w ( 5 A ) p e t a l s and sepals, w i t h g r e y e d o r a n g e

( 7 7 A ) lip

b l u s h ( 1 6 4 B ) on b a c k o f sepals, y e l l o w (5 A ) lip with light lavender keels D186

Betty Ho

Waimea'

D312

Boonchoo Gold

O r c h i d nursery, H o n o l u l u

57

Y e l l o w ( 2 D ) p e t a l s and sepals

O r c h i d nursery, I n d o n e s i a

57

Y e l l o w g r e e n ( 1 5 I B ) p e t a l s and sepals wirh red p u r p l e ( 7 2 B ) at base, red p u r p l e ( 7 1 A ) l i p , k e e l s red p u r p l e ( 7 2 B )

D393

Boonchoo Gold

57

O r c h i d nursery, H o n o l u l u

'Brightest Yellow'

p u r p l e ( 7 2 B ) at base, red p u r p l e (7 1 A ) lip, red

CR/HOS D234

C . K . Ai ' O k a '

Y e l l o w g r e e n ( 1 5 I B ) p e t a l s and sepals w i t h red

purple ( 7 2 B ) keels 57

Garden shop, H o n o l u l u

G r e y e d o r a n g e ( 1 7 8 A ) p e t a l s and sepals w i t h y e l l o w ( 5 B ) t o w a r d base, b a c k o f sepals and

AM/AOS, H O S

petals yellow ( 5 A ) D270

D. disco/or

O r c h i d nursery, H o n o l u l u

57

(= D. undulatum)

Y e l l o w g r e e n ( 1 5 1 A ) p e t a l s and sepals, y e l l o w green m i d l o b e with white keels

var. broomfteldu 'Shimonishi' AM/AOS, H O S D209

Esther Zane Shigaki

57

O r c h i d nursery, H o n o l u l u

'Butterfly'

Y e l l o w (5 A ) p e t a l s and sepals, red p u r p l e ( 7 1 A ) lip, red p u r p l e ( 7 2 B ) keels

AM/AOS, H O S D245

Field K i n g AM/ 9th

D267

Dr. C h a r a n a s r i , T h a i l a n d

57

Y e l l o w ( 5 A ) p e t a l s and sepals, g r e y e d o r a n g e

O r c h i d nursery, H o n o l u l u

57

G r e y e d p u r p l e ( 1 8 7 B ) p e t a l s a n d sepals, b a c k o f

WOC

Garnet Beauty

( 1 6 6 C ) lip w i t h p u r p l e ( 7 8 B ) k e e l s

'Suzuki'

sepals y e l l o w ( 1 2 B ) w i t h g r e y e d p u r p l e e d g e s , g r e y e d p u r p l e m i d l o b e w i t h y e l l o w s p o t at t i p of keel

D 2 16

Imelda Romualdez

Garden shop, H o n o l u l u

76

G r e y e d p u r p l e ( 1 8 3 B ) p e t a l s and sepals, b a c k sepals y e l l o w g r e e n ( 1 5 1C), g r e y e d p u r p l e ( 1 8 3 C ) lip w i t h y e l l o w ( 4 A ) b l o t c h e s , p u r p l e ( 7 8 A ) keels

D384

Kasem Gold

O r c h i d nursery, T h a i l a n d

76

Y e l l o w g r e e n ( 1 5 1 C ) p e t a l s and sepals, lip s t r i p e d

D380

Madame Chuli

O r c h i d nursery, T h a i l a n d

38

Y e l l o w ( 7 A ) p e t a l s and sepals, red p u r p l e (7 1 A ) l i p

D373

Madame Chuli ( 4 N )

O r c h i d nursery, T h a i l a n d

76

Y e l l o w ( 7 A ) p e t a l s and sepals, red p u r p l e ( 7 1 A ) l i p

D244

Mary Mak

Dr. C h a r a n a s r i , T h a i l a n d

57

Y e l l o w ( 8 A ) p e t a l s and sepals, p u r p l e ( 7 7 C ) k e e l s

D398

Mary Mak

O r c h i d nursery, H o n o l u l u

57

Y e l l o w ( 8 A ) p e t a l s and sepals, p u r p l e ( 7 7 C ) k e e l s

Dr. V a j r a b h a y a , T h a i l a n d

76

Y e l l o w ( 7 A ) p e t a l s and sepals, lip g r e y e d o r a n g e

w i t h b r o n z e , red p u r p l e ( 7 2 B ) k e e l

AM/OST

'Dream City' AM/AOS D179

May Neal 'Srisophon'

( 1 7 6 C ) on g r e e n y e l l o w ( 1 A ) base, k e e l red purple ( 7 2 B ) with prominent white tip

(continued)

124

BREEDING

YELLOWS AND N O V E L CHARACTERS

/

125

( continued) Accession no. D215

Plant nameMilroy

Source G a r d e n shop, H o n o l u l u

Chromosome n o . (2n)h 76*

F l o w e r color 1 G r e y e d o r a n g e ( 1 6 6 B ) petals and sepals, greyed red ( 1 7 8 A) lip, back of petals and sepals greyed orange ( 1 6 3 B )

D232

N g Eng Cheow

O r c h i d nursery, H o n o l u l u

76'

Yellow green ( 1 5 0 D ) petals and sepals, s l i g h t l y

D265

Pakanoa ' W a i a n a e

O r c h i d nursery, H o n o l u l u

57

Yellow green ( 1 5 1 A) petals and sepals

D154

Prince K u h i o X

G a r d e n shop, H o n o l u l u

57

Yellow green ( 1 5 4 A ) petals and sepals, light

O r c h i d nursery, H o n o l u l u

57

Yellow (2A) petals a n d sepals, greyed orange

darker lip ( 1 5 0 C ) Beauty' b r o w n m a r k i n g s on yellow green lip

Liholiho D405

Robsan 'Velma' AM/HOS

( 1 6 4 A ) m i d l o b e , p u r p l e ( 7 8 A ) t o w a r d base, t i p of keels w h i t e

D388

Robsan ' W a i m e a '

O r c h i d nursery, H i l o

57

Yellow (2A) petals and sepals, yellow (2A)

D290

Sharifah F a t i m a h

O r c h i d nursery, H o n o l u l u

57

Yellow (8A) petals a n d sepals, side lobes of lip

D325

Sharifah F a t i m a h

O r c h i d nursery, S i n g a p o r e

57

Yellow (8A) petals a n d sepals, side lobes of lip

D378

Sri Siam

O r c h i d nursery, T h a i l a n d

57

Yellow green ( 1 5 3 B ) petals and sepals, red p u r p l e

m i d l o b e , light p u r p l e ( 7 8 D ) throat striped w i t h p u r p l e (77C), p u r p l e (77C) keels striped w i t h p u r p l e (77C.), p u r p l e (77C) keels (72B) at base, red p u r p l e ( 7 1 A ) lip b l o t c h e d w i t h yellow green ( 1 5 3 B ) , red p u r p l e (72B) keels D326

Sri Siam N o . 2'

O r c h i d nursery, Singapore

57

Yellow green (15 IB) petals and sepals, red p u r p l e (72B) at base, red p u r p l e (71 A) lip, red p u r p l e (7 2B) keels

D210

Ukio

O r c h i d nursery, H o n o l u l u

57

Yellow green ( 1 6 4 D ) petals and sepals

D385

Uraiwan

O r c h i d nursery, T h a i l a n d

38

Yellow green (15 I B ) petals and sepals, d a r k red p u r p l e (7 1 A) lip

;,

CR, Certificate of R e c o g n i t i o n ; A M , Award of M e r i t ; A O S , A m e r i c a n O r c h i d Society; H O S , H o n o l u l u O r c h i d Society; W O C ,

W o r l d O r c h i d Conference; OST, O r c h i d Society of T h a i l a n d . '' + Indicates accuracy of p l u s or m i n u s one c h r o m o s o m e . ' C o l o r d e s i g n a t i o n s are f r o m the Royal H o r t i c u l t u r a l Society Colour C h a r t .

Southeast Asia and was subsequently introduced into Hawaii.

YELLOW P I G M E N T S Thammasiri et al. (1986) examined carotenoids and chlorophylls in petals of 14 Dendrobium species from five sections of the genus by highperformance liquid chromatography. Identification of the pigments was based on retention times and spectral characteristics in comparison with known compounds isolated from spinach leaves. Six carotenoids—neoxanthin, violaxanthin, anther-

axanthin, lutein, zeaxanthin, and P-carotene— and chlorophylls a and b were identified. Dendrobium aggregatum of section Callista has bright yellow flowers. Zeaxanthin and antheraxanthin in relatively high concentrations, and neoxanthin and violaxanthin in low concentrations, were detected. P-carotene and chlorophylls were absent. Considerable variation in visual color existed among the nine species examined in section Ceratobium. With the exception of D. strebloceras and D. discolor var. broomfieldii, the species contained all six carotenoids and the two chlorophylls.

126

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BREEDING

YELLOWS

AND

NOVEL

CHARACTERS

Dendrobium schulleri showed relatively high concentrations of all eighi pigments. Lutein concentrations were high in all species except D. stratwtes. (3-carotene was abundant in D. conanthurn. D. schulleri, and D. discolor. The petals of D. canaliculatum of section Eleutheroglossum (Spatulata) were yellow green at the proximal portion and white at the axial portion. All eight pigments present in the Ceratobiuni section were also observed in this species. Dendrobium moschatum in section Dendrobium (.Eugenanthe) has bright yellow orange ( R H S C C 2 1 C ) flowers. The highest carotenoid concentration was observed for zeaxanthin. As in D. aggregatum, (3-carotene and the chlorophylls were absent. Both D. macrophyllum and D. spectabile of section Latouria have pale yellow flowers. All eight pigments were found in relatively lower concentrations than in those species in the Ceratobiuni section with darker yellow flowers. The degradation of flavonoids, carotenoids, and chlorophylls in Dendrobiutn flowers at different stages of maturity within a raceme was examined for three progenies (Thammasiri et al. 1987): K 5 2 8 (pale yellow), K 6 3 7 (white with purple lip), and K 6 5 0 (bright yellow). T h e amounts of carotenoids and chlorophylls in crosses K 5 2 8 and K 6 3 7 decreased rapidly after blooming, but cross K 6 5 0 maintained a high carotenoid content in all stages of maturity. Flavonoid content in all three crosses showed no change over time. Carotenoid and chlorophyll changes in growth and

Figure 13.2. Dendrobium Mary Mak 'Dream City' AM/AOS.

development from the bud stage to flower maturity were deteimined qualitatively and quantitatively by high-performance liquid chromatography in crosses K 5 2 8 and K 6 3 7 . All six carotenoids and two chlorophylls in both crosses declined continually from the bud stage to two to four weeks after blooming. T h e presence of six carotenoid pigments and chlorophylls a and b, along with the degradation of these carotenoids and chlorophylls in flowers, complicate breeding for improved yellow cultivars.

YELLOW CULTIVAR AND SELECTIONS 'Carey Miller' (K487-118) To produce a good yellow cut-flower cultivar, we crossed a white amphidiploid D. Jaquelyn Thomas Y 1 6 6 - 1 with tetraploid light bronze D. Field King D 1 6 7 . T h e offspring were predominantly light lavender. By crossing a selected offspring to tetraploid D. May Neal 'Srisophon', several promising yellows were obtained, one of which was selection K 4 8 7 - 1 1 8 (Fig. 13.3). T h e natural spread of flowers is about 5.7 cm (2'A inches). Petals and sepals are yellow green ( R H S C C 1 5 1 B ) and the lip is purple ( R H S C C 8 I B ) . This selection was registered with the Royal Horticultural Society as D. Carey Miller in 1 9 8 3 , and mericloned plants were released to cooperating growers in 1 9 8 6 . K1005-11 It was shown earlier that the majority of yellow cultivars are triploid (Table 1 3 1 ) . Because triploids are generally poor breeders, we attempted to produce tetraploid plants for breeding purposes by crossing the outstanding triploid cut-flower cultivar D. Mary Mak (Fig. 1 3 . 2 ) to the diploid species D. helix (Fig. 2.6). Among weak aneuploid offspring, several tetraploid individuals were obtained through the functioning of unreduced triploid D. Mary Mak eggs and normally reduced D. helix sperm. An individual selection, K 1 0 0 5 - 1 1 (Fig. 13-4), was utilized in several crosses, and promising offspring (Figs. 13.5, 1 3 . 6 ) were selected for observation and evaluation.

BREED

NG YELLOWS

AND

NOVEL

CHARACTERS

/

127

Figure 13.5. K 1 3 3 6 - 2 1 ( K 8 7 0 - 2 0 X K 1 0 0 5 - 1 1).

Figure 1 3-3- Dendrobunn Carey Miller.

Figure 13.6. K 1 3 6 3 - 9 ( K 1 0 0 5 - 1 1 x K 8 7 0 - 2 0 ) .

with variable flower color. A light lavender selection, K1 377-42, was self-pollinated. T h e resulting offspring segregated into 3 normal-lip to 1 pansy-lip (See Fig. 10.6). T h e offspring also segregated into various shades of lavender, semi-alba, and alba. Figure 13.4. K 1 0 0 5 - 1 1 (D. Mary Mak X D. helix).

PANSY-LIP CULTIVAR In chapter 10 we discussed the mode of inheritance of a unique floral character, pansy-lip (Amore and K a m e m o t o 1997). T h e cross between D. D ' B u s h Pansy D 4 2 7 - 1 and D. Theodore Takiguchi D 3 8 3 produced normal-lip individuals b u t

T h e cross K 1 3 7 7 (D. Theodore Takiguchi X D. D ' B u s h Pansy) was registered as D. Ethel K a m e m o t o . Selection K 1 3 7 7 - 4 2 that was used to produce the F, progeny is a vigorous grower and very floriferous, and therefore it was given the varietal designation 'Splendor' (Fig. 13.7) and micropropagated ( K a m e m o t o et al. 1998). A m o n g the F 2 offspring, two segregants, K 1 4 4 9 - 2 5 and K 1 4 4 9 - 3 0 , w i t h paper white pansy-lip flowers were selected. Flowers are round

128

/

BREEDING

YELLOWS

AND

NOVEL

CHARAC

ERS

Figure 13.7. Dendrobium Ethel Kamemoto 'Splendor'.

Figure 13.8. Dendrobium Ethel Kamemoto 'White Cascade'.

with overlapping sepals and petals, and measure about 2.5 cm (1 inch) across. N u m e r o u s longlasting sprays were produced from September to February. Because the F, progeny, K 1 4 4 9 , resulted from self-pollination of D. Ethel K a m e m o t o , 1377-42, the name Ethel K a m e m o t o must be

retained for the selfed progeny based on the rule of orchid nomenclature and registration. However, to distinguish the unique white pansy-lip selection K 1 4 4 9 - 3 0 (Fig. 13.8) from K 1 3 7 7 - 4 2 , it was given the cultivar name ' W h i t e Cascade'.

CHAPTER 14

Breeding by Genetic Engineering

improvement programs are supplementing genome breeding methods with molecular breeding approaches. This is because genetic engineering, coupled with tissue culture techniques, has successfully introduced traits such as improved protein quality, novel flower color, and pest resistance into various crops in relatively short periods of time. For slow-growing orchids, with their long generation times, limited available gene poo!, and unknown genetics, it can be difficult to modify certain desirable traits such as flower color or disease resistance through sexual hybridization. Also, increased demand for florist products worldwide portends substantial economic gains to be made by the creation of new or improved orchid hybrids.

ments, is also capable of plant regeneration and may be suitable in some cases. To satisfy the second step, we tested several gene transfer methods—microparticle bombardment, seed imbibition, pollen tube—mediated D N A delivery, and electroinjection—with Dendrobium seed, protocorms, PLBs, and etiolated shoots (Table 14.1; Fig. 14.1) (Kuehnle and Sugii 1992; Nan and Kuehnle 1995a,b). W e also laid groundwork for application of two additional and popular gene transfer methods, Agrobacteriummediated transformation and protoplast electropo ration. For evaluating these methods, and to satisfy the third step in molecular breeding, two selectable markers were used for identification of trans-

M A N Y CHOP

OVERVIEW OF METHODOLOGY Several steps are necessary for molecular breeding to be feasible with a given orchid: (1) the tissue to be genetically engineered must give rise to plants; (2) the gene transfer method and gene expression vectors used must be compatible with the plant's genotype and the tissue to be treated; (3) there should be a means of identifying and selecting shoots arising from engineered tissue (also referred to as transformed or transgenic tissue). To satisfy the first step for Dendrobium, meristematic tissues such as excised shoot tips and lateral buds, seeds, protocorms, and protocormlike bodies (PLBs) can be used. A nonmeristematic tissue of Dendrobium, namely etiolated shoot seg-

Figure 14.1. Dendrobium tissues grown in vitro for use in genetic engineering experiments. A, Seed; B, Protocorms from germinated seed; C, Protocormlike bodies from bud explants; D, Etiolated shoots from seed germinated in darkness.

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Table 14.1. Five m e t h o d s of g e n e transfer tested w i t h Dendrobium (based o n K u e h n l e and Sugii 1992; Ghia et al. 1994; N a n and K u e h n l e 1995a, b; N a n et al. 1998) Transformation Method Microparticle

efficiency

Description g o l d or t u n g s t e n s p h e r e s of a b o u t l p . m d i a m e t e r a n d c o a t e d w i t h D N A are

1 1 . 7 % for one gene;

bombardment

accelerated u n d e r partial v a c u u m into p r o t o c o r m s , p r o t o c o r m l i k e bodies

4 % for two

(gene g u n )

o r e t i o l a t e d s h o o t s e c t i o n s ; t i s s u e s are c u l t u r e d o n p l a n t d e v e l o p m e n t

plasmid-linked

m e d i u m w i t h s e l e c t i o n of t r a n s f o r m a n t s b y m e d i u m a m e n d m e n t s or

genes

e x p r e s s i o n of r e p o r t e r g e n e s Protocorm elecrroinjection

D N A in s o l u t i o n e n t e r s t a r g e t cell u n d e r t h e i n f l u e n c e of an e l e c t r i c p u l s e ;

1.4%

p r o t o c o r m s are s c r e e n e d o n p l a n t g r o w t h m e d i u m c o n t a i n i n g s e l e c t i o n agent Seed i m b i b i t i o n

D r y seeds r e m o v e d f r o m c a p s u l e s are i m b i b e d in D N A s o l u t i o n , t h e n

0.005%

s c r e e n e d on g e r m i n a t i o n m e d i u m c o n t a i n i n g s e l e c t i o n a g e n t ; d e s p i t e recovery of T r a n s g e n i c t i s s u e , no p l a n t s s u r v i v e d a f t e r m o r e t h a n o n e year on s e l e c t i o n m e d i u m

Agrobiicteriuw-meòvàtcò D N A transfer

Nontumorigenic

Agrobaiterium tumefaciens,

i n d u c e d by acetosyringone to

Undetermined

i n i t i a t e g e n e t r a n s f e r , a r e i n c u b a t e d w i t h p r o t o c o r m l i k e b o d i e s for t w o t o t h r e e d a y s ; t h e b a c t e r i a a r e k i l l e d a n d t i s s u e s are s c r e e n e d o n p l a n t g r o w t h m e d i u m c o n t a i n i n g selection agent; transgenic shoots were recovered after m o r e t h a n o n e year of s e l e c t i o n

Pollen t u b e - m e d i a t e d D N A transfer

In p l a n t a : s t i g m a t i c s u r f a c e of a p o l l i n a t e d f l o w e r is sliccd a n d a D N A

0.03-0.08%.

solution applied In v i t r o : c a p s u l e s are h a r v e s t e d , sliced at t h e c o l u m n e n d a n d e x p o s e d to D N A solution, and c u l t u r e d on o v a r y - m a t u r a t i o n m e d i u m ; r e s u l t i n g seeds are s c r e e n e d o n g e r m i n a t i o n m e d i u m c o n t a i n i n g s e l e c t i o n a g e n t ; s o m e r e c o v e r y of t r a n s g e n i c t i s s u e b u t no p l a n t s s u r v i v e d a f t e r m o r e t h a n o n e year o n s e l e c t i o n m e d i u m

formed Dendrobium plants following t r e a t m e n t . K u e h n l e and Sugii (1992) used the ability of plants to grow on antibiotic as one selectable trait. A near 100% phytostatic level of antibiotic was recommended for use d u r i n g the first few m o n t h s of plant regeneration. Levels we later found adequate for PLBs were 1 0 0 - 2 0 0 mg/liter kanamycin sulfate, 2 5 - 5 0 mg/liter geneticin sulfate, or 5 15 mg/liter hygromycin sulfate in solidified m e d i u m ; and 50 mg/liter geneticin or 10—20 mg/liter hygromycin for several weeks in liquid m e d i u m . An alternative to antibiotic selection in Dendrobium is the use of the firefly luciferase gene luc (Chia et al. 1994). Tissue w i t h an active gene produces light upon reaction with luciferin, which can be detected with a camera-photomultiplier. Dendrobium gene transfer methods have also been evaluated using the reporter gene gusA (also referred to as uidA). It produces the enzyme G U S

(^-glucuronidase) with a strong color (indigo or dark blue) reaction when an appropriate gene p r o m o t e r is used. However, Dendrobium has been observed to produce detectable color in G U S reactions w i t h o u t addition of gusA (i.e., Dendrobium tissues have low to moderate endogenous activity). This endogenous activity may sometimes be difficult to distinguish from transgenic G U S expression if a relatively weak gene p r o m o t e r is being used, such as the single C a M V 35S p r o m o t e r of gusA in plasmid p B I 1 2 1 ( N a n 1994). Effectiveness of genetic engineering systems can be measured by the transformation efficiency, calculated as: [Total n u m b e r of transformed shoots/Total n u m b e r of explants] X 1 0 0 % . Plants whose shoots have chromosomal integration of the foreign D N A sequences are t e r m e d stable transformants. Transformation efficiency thus refers to stable transformation events. Introduced

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genes can also be expressed by a host tissue for a iimited period of time, without being incorporated into the host chromosomes; this is called transient gene expression. Transient expression data can be used to assess appropriateness of the gene expression vector and the delivery m e t h o d , independent of subsequent stable transformation and plant formation. Table 14.1 gives examples of transformation efficiency rates for four of five gene transfer methods tested with Dendrobium. T h e most effective method thus far appears to be microparticle b o m b a r d m e n t (A grobacteri urn-mediated transformation efficiency is not yet known).

GENE TRANSFER BY MICROPARTICLE B O M B A R D M E N T There are few published reports of stable transformation in Dendrobium. The first such report described use of microparticle b o m b a r d m e n t , or the so-called "gene g u n " Kuehnle and Sugii (1992) reported stable transformants of Dendrobium Jaquelyn Thomas recovered from protocorms bombarded by microparticles coated with the plasmid p G A 4 8 2 G G / c p P R V 4 , which contains the plant expressible N O S - N P T I I (for antibiotic resistance) encoded by the gene neo and papaya ringspot virus coat protein genes. The microparticle bombardment method involves high-velocity delivery into cells of tiny spheres coated in D N A (Klein et al. 1987). Approximately 280 protocorms from four crosses were b o m b a r d e d and potentially transformed tissues were identified by growth and green color on m e d i u m supplemented with 5 0 - 1 00 mg/liter kanamycin. Southern blot analyses of enzyme-digested genomic D N A and also polymerase chain reaction (PCR)— amplified D N A sequences 21 m o n t h s after treatm e n t showed that 13 of 13 plants from two hybrids, which appeared kanamycin-tolerant, contained the N O S - N P T II gene, b u t only one of these plants carried the vector-linked PRV C P gene. Using the same m e t h o d , Chia et al. (1994) b o m b a r d e d PLBs of Dendrobium W h i t e Angel w i t h tungsten microparticles coated with p U C 1 9 LUC. or p M O N 5 3 Q - L U C carrying luc. Every 21

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days, chopped PLB sections were screened for emission of light, for a total of three rounds of manual screening. Individual sections positive for light emission were then collected under a dissecting microscope for further culture in liquid m e d i u m . Transgenic plants were obtained from a total of 27 lines created from PLB tissue selection. O f these lines, 6 3 % gave plants that showed rearrangement or recombination of luc; 9 3 % gave rise to plants with normal g r o w t h habit. Alt h o u g h the tranformation efficiency of this system was not reported, the visual selection system appears highly effective. T h e recovery rate of stably transformed orchids was improved by N a n and K u e h n l e ( 1 9 9 5 b ) after examining five parameters affecting microparticle b o m b a r d m e n t and gene expression: helium gas pressures, plasmid constructs, size and sources of gold particles, and target plant genotype and type of tissue. A m o n g other results, the gusA gene promoter (duplicate CaMV 35S plus A M Y

Figure 14.2. Genetically engineered Dendrobium plant recovered from protocormlike bodies two years after gene transfer by microparticle bombardment. (Photograph by G. L. Nan)

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translational enhancer sequence) in p B l 4 2 6 was shown to produce at least 1.5 times as many transient transformants as the single 35S promoter in pBI121. Differences in plant genotype, tissue source, and microparticles also significantly affected transient GUS activities following bombardments. Nan and Kuehnle ( 1 9 9 5 b ) estimated a transformation efficiency of 11.7% (Table 14.1) following analysis of transgenic plants (Fig. 14.2) recovered from Dendrobium J a q u e l y n Thomas 'Uniwai Mist' ( U H 8 0 0 ) PLBs bombarded with pBl426-coated tungsten particles using an earlymodel gunpowder-driven apparatus. PGR analysis showed that eight of nine regenerated U H 8 0 0 plantlets contained a neo fragment, and three of nine contained both neo and gusA fragments. This suggests that the plasmid D N A may be fragmented or rearranged during this procedure, similar to that reported in Dendrobium W h i t e Angel (Chia et al. 1994). DNA analysis of two plantlets using the restriction enzyme BamHI, with a unique cutting site on p B ! 4 2 6 , gave rise to iden-

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D 1

2

3 -