horticulturae

Communication Thai Orchid Genetic Resources and Their Improvement

Kanchit Thammasiri Department of Science, Faculty of Science, Mahidol University, Rama VI Road, Phayathai, Bangkok 10400, Thailand; [email protected]; Tel.: +66-891-327-015; Fax: +66-235-471-72

Academic Editor: Douglas D. Archbold Received: 1 December 2015; Accepted: 8 July 2016; Published: 28 July 2016

Abstract: Thailand is the origin of about 1300 species and 180–190 genera of orchids, comprising the major tropical orchids in the world. These wild Thai orchids grow naturally in various habitats and have unique flowers, stems, leaves, and roots. Many genera, including , , Ascocentrum, Aerides, Phalaenopsis, Doritis, Dendrobium, , , Spathoglottis, and , contribute significantly to the Thai orchid industry for cut-flowers and potted . The improvement of these orchids’ horticultural characteristics has been significant through breeding, tissue culture, and cultural practices, as well as by technological applications and extension. Orchids will continue to dominate other ornamental crops in Thailand due to their diversity, better technologies, know-how from research, suitable climatic conditions, and experienced and skillful growers and exporters, as well as their nationwide popularity.

Keywords: Thai orchid species; orchid diversity; breeding

1. Introduction Thailand is the origin of about 1300 species and 180–190 genera of orchids, comprising the major tropical orchids in the world. Although Thailand is a natural habitat for several diverse species of orchids, interest in growing cultivars for their economic value was first recorded in 1913 with the introduction of some exotic materials by a foreigner working in Thailand. Having a hobby of growing orchids, he brought cattleyas and some other genera to Bangkok, all of which were subsequently sold to a high ranking officer. Several other high rank and file individuals in the country also became interested in orchid growing as a hobby during the same period. Information concerning orchid growing, an expensive hobby suitable only for the rich and elite, was provided by a small group of high-ranking officials and older, wealthy people in Thailand. Orchids have the highest value among several tropical ornamental crops, especially among cut-flower crops which are important to Thai agriculture and the economy. Although orchid growing started as a hobby about 100 years ago, until 1966 only a small amount of orchid cut-flowers were exported from Thailand to Europe. The introduction of the Dendrobium cultivar “Pompadour” proved to be a landmark that also increased the popularity for orchid cultivation in Thailand. This hybrid was easy to grow and propagate by division, and was high yielding with a long vase-life. Thailand attained the status of the world’s leading producer and exporter of orchids in a little over a decade, and it has held the top rank since 1979. Orchid cultivation in Thailand has been confined to the Central Plain, mainly in Bangkok and its nearby provinces, where there are favorable climatic conditions, water, transportation and a marketing system. Orchid production takes place mainly in three provinces, Samut Sakhon, Bangkok, and Nakhon Pathom, followed by the nearby central provinces and those to the north and the south of Thailand. The estimated total area for orchid cultivation in 2012 was 3003 ha. The suitable environment, high orchid genetic diversity, efficient infrastructure, experienced growers, technological applications,

Horticulturae 2016, 2, 9; doi:10.3390/horticulturae2030009 www.mdpi.com/journal/horticulturae Horticulturae 2016, 2, 9 22 of of 13 13 technological applications, extension, training, teaching, and research, as well as business skills, have eachextension, contributed training, to the teaching, success and of orchid research, production as well as and business trade in skills, Thailand have [1]. each Many contributed farmers tohave the madesuccess orchid of orchid cultivation production their and main trade oc incupation, Thailand [ often1]. Many with farmers higher have returns made than orchid other cultivation crops. Commercialtheir main occupation, orchid production often with has higher been returnsfacilitated than by other over crops.10 tissue Commercial culture laboratories. orchid production Marketing has hasbeen been facilitated facilitated by overfor growers 10 tissue by culture over 50 laboratories. export organizations Marketing engaged has been exclusively facilitated in forexport growers of Thai by orchidsover 50 [2]. export organizations engaged exclusively in export of Thai orchids [2]. Thailand has a long history of orchid trade, especially for export. It It is is estimated estimated that that 54% 54% of of the the orchids produced in Thailand are currently exported, while the remaining 46% are are consumed in in the domestic markets. Exports Exports of of orchid orchid cut cut-flowers-flowers began began in in 1963 1963 with with a a few few hundred hundred thousand thousand sprays of mostly “ “Pompadour”Pompadour” sent to European markets. The The export export value value of of orchid cut cut-flowers-flowers has increased sharplysharply to to about about 60 60 million U U.S..S. $ in 2014. The export of orchid cut cut-flowers-flowers still predominates, but but the export of of orchid orchid plants plants has has also also rapidly rapidly increased increased to to about about 22 22 million million U U.S..S. $ $in in 2014 2014 (Figure (Figure 1)1 [2].)[2 ]. The imports imports of of ornamental ornamental plants plants and and flowers flowers into into Thailand, Thailand, especially especially orchid orchid plants plants and cut and- flowerscut-flowers,, has been has been relatively relatively low because low because there thereare a larg aree a variety large variety of indigenous of indigenous tropical tropical orchids orchids which arewhich relatively are relatively inexpensive inexpensive and good and quality. good quality. The success success of of Thai Thai orchid orchid cultivation cultivation and and trade trade of of cut cut-flowers-flowers and and potted potted plants plants was was a result a result of concertedof concerted national national efforts efforts with with respect respect to to germplasm germplasm resource resource mana management,gement, research, research, training, training, extension, technological applications, and communication networks [[3,43,4].

Figure 1. Orchid flower and plant export value from Thailand during 1987–2014. Figure 1. Orchid flower and plant export value from Thailand during 1987–2014. 2. Thai Orchid Genetic Resources 2. Thai Orchid Genetic Resources (Orchid family) is subdivided into six subfamilies [5], with Thailand as the origin of all sixOrchidaceae subfamilies. (Orchid They havefamily) distinguishing is subdivided characteristics into six subfamilies described [5], brieflywith Thailand [6] as follows: as the origin of all six subfamilies. They have distinguishing characteristics described briefly [6] as follows: 1. APOSTASIOIDEAE: This subfamily is sometimes separated into a new family, named 1. APOSTASIOIDEAE: This subfamily is sometimes separated into a new family, named Apostasiaceae by some authors as it is quite different in size and shape of sepals and petals Apostasiaceae by some authors as it is quite different in size and shape of sepals and petals with with two or three fertile stamen and an ovary with three locules. In Thailand, it is represented by two or three fertile stamen and an ovary with three locules. In Thailand, it is represented by two two genera and five species, and is mainly confined to moist evergreen lowland forests. genera and five species, and is mainly confined to moist evergreen lowland forests.

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2. : The well-known slipper orchids belong to this subfamily. Their common characteristic feature is a deeply saccate or slipper-shaped lip. The unusual structure includes a column with two lateral stamen, a large shield-like median staminode, and lateral sepals connate along the inner margin forming one sepal mostly hidden behind the lip. The Paphiopedilum is only found in Thailand with about 14 species. 3. NEOTTIOIDEAE: This orchid group is mainly terrestrial in moist evergreen forests with more or less fleshy rhizomes or tubers. There are about 24 genera and 68 species in Thailand. 4. ORCHIDOIDEAE: This subfamily is very close to the subfamily Neottioideae in general habit, as well as in habitat, but differs in having tubers or root-stem tuberoids, an anther usually basally attached to the viscidium (or visidia), and with the apex of the rostellum often protruding between the thecae. There are about 10 genera and 65 species recorded in Thailand. Habenaria is the most well-known one. 5. : This is the largest subfamily, growing in various habitats. Their soft, waxy pollinia, normally without stipe and viscidium, is very characteristic of this group. There are about 63 genera and 692 species found in Thailand. Many of them are very attractive in floral size, color and longevity. Thus, they are very popular among orchid growers. 6. VANDOIDEAE: This subfamily is very close to the Epidendroideae and has recently been included in the latter subfamily. The difference is mainly in the hard or cartilaginous pollinia which usually has a stipe and viscidium. There are about 78 genera and 289 species in Thailand. Many of them are also very popular, as are those in the Epidendroideae.

3. Cultivated Thai Orchid Genera and Their Improvement Among 180–190 genera and 1300 species of wild Thai orchids, about 11 genera are cultivated as a hobby and for commercial purposes. In addition, they have been improved through breeding and production technologies. The details of these genera are as follows:

3.1. Vanda The genus Vanda is an epiphyte and monopodial orchid with large stems. There are about 40–50 species in this genus. They grow in tropical Asia from East India to Southeast Asia, Indochina, New Guinea, Australia, Solomon Islands, the Philippines, Taiwan and nearby islands. In Thailand, 9 species are found. They are popular for growing, and are used as parents, especially Vanda coerulea (Figure2) because they give large flowers, and a long spray with a good arrangement of flowers. Flower colors of the hybrids are blue to red-purple (Figure3). Vanda can be crossed with other monopodial genera, such as Rhynchostylis, Aerides, Ascocentrum, etc., and produce many outstanding cultivars for cut-flowers and potted plants. Horticulturae 2016, 2, 9 4 of 13 Horticulturae 2016, 2, 9 4 of 13

FigureFigure 2. 2. VariationVariation in flower flower colors of Vanda coerulea.

Figure 3. Vanda hybrids.

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Horticulturae 2016, 2, 9 5 of 13 HorticulturaeHorticulturae 20162016,, 22,, 99 55 ofof 1313 3.2. Rhynchostylis 3.2. Rhynchostylis 3.2.3.2. RhynchostylisRhynchostylis ThisThis genus genus is is epiphytic, epiphytic, monopodial, monopodial, and and has has medium medium to large to large stems stems with with thick thickleaves. leaves. In ThisThis genus genus is is epiphytic, epiphytic, monopodial, monopodial, and and has has medium medium to to large large stems stems with with thick thick leaves. leaves. In In InThailand, Thailand, there there are are 3 species 3 species in this in thisgenus, genus, namely namely R. giganteaR. gigantea (Figure(Figure 4), R. 4retusa), R. (Figure retusa (Figure5) and 5 ) Thailand,Thailand, therethere areare 33 speciesspecies inin thisthis genus,genus, namelynamely R.R. giganteagigantea (Figure(Figure 44)),, R.R. retusaretusa (Figure(Figure 55)) andand andR. R.coelestis coelestis (Figure(Figure 6).6 ).The The flower flower colors colors of ofRhynchostylisRhynchostylis gigan giganteatea areare white, white, white white with with red red-purple-purple R.R. coelestiscoelestis (Figure(Figure 66)).. TheThe flowerflower colorscolors ofof RhynchostylisRhynchostylis gigangiganteatea areare white,white, whitewhite withwith redred--purplepurple spots,spots, red-purple red-purple andand orange.orange. This genus genus is is popularly popularly grown grown as as potted potted plants plants and and as asparents parents for for spots,spots, redred--purplepurple andand orange.orange. ThisThis genusgenus isis popularlypopularly growngrown asas pottedpotted plantsplants andand asas parentsparents forfor producingproducing interspecific interspecific hybrids hybrids (Figures(Figures7 7 and and8 8).). producingproducing interspecificinterspecific hybridshybrids (Figures(Figures 77 andand 88).).

Figure 4. RhynchostylisRhynchostylis gigantea gigantea. . FigureFigure 4.4. RhynchostylisRhynchostylis giganteagigantea..

Figure 5. Rhynchostylis retusa. FigureFigureFigure 5.55.. RhynchostylisRhynchostylis retusaretusa retusa.. .

Figure 6. Rhynchostylis coelestis. FigureFigureFigure 6.66.. RhynchostylisRhynchostylis coelestiscoelestis coelestis.. .

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FigureFigure 7. 7..A A hybridhybrid ofof RhynchostylisRhynchostylis gagantea gagantea andand VandaVanda coerulea coerulea.. .

Figure 7. A hybrid of Rhynchostylis gagantea and Vanda coerulea.

FigureFigure 8. 8..A A hybrid hybrid ofof RhynchostylisRhynchostylis coelestis coelestis andand SeidenfadeniaSeidenfadenia mitrata mitrata.. . Figure 8. A hybrid of Rhynchostylis coelestis and Seidenfadenia mitrata. 3.3.3.3. Ascocentrum Ascocentrum 3.3. Ascocentrum ThisThis genus genus is is a a small small epiphyte epiphyte andand monopodialmonopodial orchid orchid with with 3 3typestypes types ofof of flowerflower flower color,color, color, purplepurple purple-red--red This genus is a small epiphyte and monopodial orchid with 3 types of flower color, purple-red ((A. ampullaceum),), redred ((A. curvifolium),), andand orangeorange ((A. miniatum)) (Figure(Figure 99).). (A. ampullaceum(A. ampullaceum), red), red (A. ( curvifoliumA. curvifolium),), and and orange orange ((A. miniatum ) )(Figure (Figure 9).9 ).

FigureFigure 9. 9. AscocentrumAscocentrum miniatum miniatum. Figure 9.. Ascocentrum miniatum.. .

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Horticulturae 2016, 2, 9 7 of 13 Horticulturae 2016, 2, 9 7 of 13 3.4. Aerides 3.4.3.4. Aerides Aerides This genus (Figure 10) is a small epiphyte and monopodial orchid and can grow in strong ThisThis genus genus (Figure (Figure 10 10) ) is is a a small small epiphyte epiphyte and and monopodial monopodial orchid orchid and and can can grow grow in in strong strong sunlight. It has beautiful flowers and sprays, so it is popular for hobbyists to grow and use for sunlight.sunlight. It Ithas has beautiful beautiful flowers flowers and and sprays, sprays, so it is popularpopular for for hobbyists hobbyists to to grow grow and and use use for for orchid orchid orchidimprovement.improvement. improvement.

Figure 10. Aerides odorata. Figure 10. Aerides odorata. Figure 10. Aerides odorata. 3.5. Phalaenopsis 3.5. Phalaenopsis 3.5. PhalaenopsisThis genus (Figure 11) is a short epiphyte and monopodial orchid with long leaves. It has one to ThismanThisy genus flowers genus (Figure (Figureper spray, 11 11) ) isand is a a short someshort epiphyte continuouslyepiphyte andand bloom monopodial one at a orchid orchidtime. Thiswith with genus, long long leaves. espec leaves.ially It Ithas for has one its one to to manymanhybrids flowersy flowers (Figure per per spray, 12 spray,), is economically and and some some continuously continuously important in Taiwan. bloom one at at a a time. time. This This genus, genus, espec especiallyially for for its its hybridshybrids (Figure (Figure 12 12),), is is economically economically important important inin Taiwan.Taiwan.

Figure 11. Variation in flower color of Phalaenopsis cornu-cervi.

FigureFigure 11. 11.Variation Variation inin flowerflower color of PhalaenopsisPhalaenopsis cornu cornu-cervi-cervi. .

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Figure 12. Phalaenopsis hybrids. Figure 12. Phalaenopsis hybrids. Figure 12. Phalaenopsis hybrids. 3.6. Doritis Figure 12. Phalaenopsis hybrids. 3.6. Doritis 3.6. DoritisThis genus (Figure 13) is terrestrial and can grow in sand or rock. Its sprays are straight and hard 3.6.with Doritis This5–15 genus flowers (Figure which 13 continuously) is terrestrial bloomand can for grow 5–6 inmonths. sand or It rock. grows Its easilysprays as are a straightpotted plant and hard and This genus (Figure 13) is terrestrial and can grow in sand or rock. Its sprays are straight and hard withhas been This5–15 crossedgenus flowers (Figure with which Phalaenopsis 13 continuously) is terrestrial to get bloomand a medium can for grow 5–-sized6 inmonths. sand straight or It rock. grows flower Its easilysprays spray as are(Figure a straightpotted 14). plant and hard and with 5–15 flowers which continuously bloom for 5–6 months. It grows easily as a potted plant and has withhas been 5–15 crossed flowers with which Phalaenopsis continuously to get bloom a medium for 5–-sized6 months. straight It grows flower easily spray as (Figure a potted 14). plant and been crossed with Phalaenopsis to get a medium-sized straight flower spray (Figure 14). has been crossed with Phalaenopsis to get a medium-sized straight flower spray (Figure 14).

Figure 13. Doritis pulcherrima. Figure 13. Doritis pulcherrima. Figure 13. Doritis pulcherrima. Figure 13. Doritis pulcherrima.

Figure 14. Doritis hybrids. Figure 14. Doritis hybrids. Figure 14. Doritis hybrids. Figure 14. Doritis hybrids.

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HorticulturaeHorticulturae 20162016,, 22,, 99 99 ofof 1313 3.7. Dendrobium 3.7.3.7. DendrobiumDendrobium This genus (Figure 15) is a sympodial orchid with diversity in size and shape of stems, leaves, ThisThis genusgenus (Figure(Figure 1515)) isis aa sympodialsympodial orchidorchid withwith diversitydiversity inin sizesize andand shapeshape ofof stems,stems, leaves,leaves, its habitats and growth habits. They are over 1000 species in the genus around the world. They are itsits habitatshabitats andand growthgrowth habits.habits. TheyThey areare overover 10001000 speciesspecies inin thethe genusgenus aroundaround thethe world.world. TheyThey areare popularly grown and used in breeding to get outstanding hybrids (Figure 16). popularlypopularly growngrown andand usedused inin breedingbreeding toto gegett outstandingoutstanding hybridshybrids (Figure(Figure 1616).).

Figure 15. Dendrobium cruentum. FigureFigure 1515.. DendrobiumDendrobium cruentumcruentum..

FigureFigureFigure 16. 1616.. Dendrobium DendrobiumDendrobium cruentum cruentum hybrids.hybrids.hybrids.

3.8.3.8.3.8. Bulbophyllum BulbophyllumBulbophyllum This genus (Figure 17) is a small sympodial orchid. Pseudobulbs always have angles with thick ThisThis genus genus (Figure (Figure 17 17) is) is a a small small sympodial sympodial orchid.orchid. Pseudobulbs always always have have angles angles with with thick thick leaves. They are easy to propagate by division with only one pseudobulb and are popular for growing leaves.leaves. They They are are easy easy to to propagate propagate by by division division withwith only one one pseudobulb pseudobulb and and are are popular popular for for growing growing asas pottedpotted plants.plants. as potted plants.

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FigureFigure 1717 17... BulbophyllumBulbophyllum putidumputidum ..

3.9.3.9. CirrCirr Cirrhopetalumhopetalumhopetalum ThisThis genusgenus (Figure(Figure 1818)) waswas separatedseparated fromfrom BulbophyllumBulbophyllum becausebecause itsits dorsaldorsal sepalsepal isis smallersmaller thanthan thethe laterallateral sepals.sepals. TheThe flowerflower flower sprayspray isis umbellateumbellate andand the the pseudobulb pseudobulb is is cone cone shaped. shaped.

FigureFigure 1818 18... CirrhopetalumCirrhopetalum lepidumlepidum ..

3.10.3.10. SpathoglottisSpathoglottis ThisThis genusgenus (Figure(Figure 1919)) isis aa terrestrialterrestrial orchidorchid with with aa pseudobulb pseudobulb andand rhizome.rhizome. TheyThey areare are usedused forfor landscapinglandscaping since since theythey cancancan growgrowgrow well wellwell in inin the thethe soil. soil.soil. In InIn Thailand, Thailand,Thailand, there therethere are areare 5 55 species. species.species.Spathoglottis SpathoglottisSpathoglottis plicata plicataplicatais isisused usedused to toto make makemake hybrids hybridshybrids (Figure (Figure(Figure 20 20)20 with)) withwith many manymany colorful colorfulcolorful orchids. orchids.orchids.

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Figure 19. Spathoglottis plicata. Spathoglottis plicata FigureFigure 19.19. Spathoglottis plicata. .

Figure 20. Spathoglottis hybrids. FigureFigure 20.20. Spathoglottis hybrids.hybrids.

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3.11. Paphiopedilum 3.11. Paphiopedilum This genus is called “Lady’s slipper” because the lip looks like lady’s shoes. There are 15 species reportedThis in genus Thailand. is called They “Lady’s are popular slipper” to because grow from the lip seeds looks as like potted lady’s plants. shoes. The There popular are 15 species reportedused for trade in Thailand. are P. bellatulum They are (Figure popular 21 toa), grow P. concolor from, seeds P. exul as (Figure potted 21 plants.b). P. godefroyae The popular, P. niveum species, usedP. callosum for trade, P. parishi are P. bellatulumand P. hirsutissimum(Figure 21. a), P. concolor, P. exul (Figure 21b). P. godefroyae, P. niveum, P. callosum, P. parishi and P. hirsutissimum.

(a) (b)

Figure 21. Paphiopedilum bellatulum (a) and Paphiopedulum exul (b). Figure 21. Paphiopedilum bellatulum (a) and Paphiopedulum exul (b).

In addition to the breeding of cultivated Thai orchid genera, Thai orchidists from both the public and private sectors have improved the orchid production technologies for sustainable use, modifying greenhouses, water resources, planting material and containers, pest control, plant breeding, tissue culture [[7]7] and postharvest management.management. These improvements have resulted in increased yield and quality and have thereby directly enhanced production and increased quantity of orchids for for export export [8]. [8]. 4. Conclusions 4. Conclusions Thai orchid production has a bright future where export values are expected to remain high and Thai orchid production has a bright future where export values are expected to remain high and stable. Orchids will continue to dominate other ornamental crops in Thailand due to high orchid stable. Orchids will continue to dominate other ornamental crops in Thailand due to high orchid diversity, better technological know-how, suitable climatic conditions, and experienced and skillful diversity, better technological know-how, suitable climatic conditions, and experienced and skillful growers and exporters, as well as their popularity with the public. growers and exporters, as well as their popularity with the public. The success story of orchids in Thailand is a good example of the development of an ornamental The success story of orchids in Thailand is a good example of the development of an ornamental crop through its diversity in natural habitats to become a major crop. The development of the Thai crop through its diversity in natural habitats to become a major crop. The development of the Thai orchid industry has taken a long time to develop, but it is now a high-income business and an important orchid industry has taken a long time to develop, but it is now a high-income business and an part of the national economy. important part of the national economy.

ConflictsConflicts ofof Interest:Interest: TheThe authorauthor declaresdeclares nono conflictconflict ofof interest.interest.

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