Native Orchid Species Research Articles

Distribution areas, morphologial and phenologicial characteristics of some native orchid species in Bucak (Burdur) Province

In this study, distribution, morphologic and phenologic characteristics of some Orchid species which are used for producing sahlep in Burdur region were determined. Data were obtained from 26 stands of Bucak province where orchids species mostly distributed. As a result of field studies which were conducted in 2015 (March to July) of flower, 13 taxa were found. Morphologic and phenologic measurements such as number, color, stem length and bloom period, plant height, tuber weight, width, length, number and maturation period were made on the studied taxa. The first flowering species is Ophyrs mammosa (beginning of March) and the last ones are Orchis purpurea (mid-April) and Orchis simia (mid-April). Ophyrs mammosa is the first full flowering species (mid-April) and the last taxon is Ophrys reinholdii subsp. leucotaenia (mid-June). The first maturing bump belongs to Ophyrs mammosa (end of April) and the last one to Himantoglossum comperianum (end of July). The stands where the orchids densely occured are the forests openings, steep rocky slopes and edge of cultural areas. Productivity of flower and tuber are the highest on south and south-western aspects. Slopes of these stands varied between 5-40%. Orchid taxa were distributed between 300 and 1451 m.

Phalaenopsis flowering locus VE regulates floral organ maturation.

PaFVE is low ambient temperature-inducible and acts as a systemic regulator in the early stage of floral development in Phalaenopsis. Phalaenopsis aphrodite: subsp. formosana, a native orchid species of Taiwan, is an economically important ornamental crop that requires low ambient temperature for floral transition. Currently, limited genetic information about such orchid species hampers genetic manipulation for specific or improved floral traits, and the control of flowering time independent of temperature regulation. In this study, the sequence of the full-length of Phalaenopsis flowering locus VE (PaFVE) gene was determined. Spatial and temporal expression studies showed that mRNA transcripts of PaFVE were inducible by low ambient temperature, and high levels of expression occurred after spiking initiation and remained high throughout the early stage of floral development. Further investigation revealed that floral organ development was impeded in PaFVE-silenced P. aphrodite, but flowering time and floral organogenesis were not compromised. Analysis of the downstream flowering genes suggested that the delay in floral maturation is associated with a corresponding decrease in the expression of downstream flowering genes, PaSOC1, PaSOC1L and PaAGL24. The ectopic expression of PaFVE in Arabidopsis resulted in an accelerated flowering time, accompanied by an increase in the expression of AtSOC1, thus revealing the functional role of PaFVE as a floral regulator. Overall, our results demonstrate that PaFVE has evolutionarily diverged and conserved functions, and serves as a regulator of floral organ maturation in Phalaenopsis and a regulator of flowering time in Arabidopsis.

In vitro propagation of Catlleya Lindl. and Laelia Lindl. species

Nowadays many wild species of South American’s orchids are under threat of extinction from over-col- lection and habitat destruction. Many tropical native orchid species were propagated in the National Botanical Garden of National Academy of Sciences of Ukraine through a range of asymbiotic seed germi- nation techniques and tissue culture procedures aimed to preserve a number of individuals under artificial conditions in glasshouses in the temperate zone, with the aim to protect these species from complete extinc- tion. Our orchid collection includes plants of Cattleya and Laelia species. Some of these species are rare in the wild. To protect them from extinction the meth- ods of propagation should be developed.

Photosynthetic Light Utilization Efficiency, Water Relations and Leaf Growth of C3 and CAM Tropical Orchids under Natural Conditions

Native orchid species of Singapore in their natural conditions experience stress from high irradiance, high temperatures and periods of extended low rainfall, which impact orchid plant physiology and lead to reduced growth and productivity. In this study, it was found that there was a reduction in photochemical efficiency of photosystem II (PSII) in 6 native orchid species under high light (HL) and Bulbophyllum membranaceum under low light (LL). There was chronic photoinhibition in these 6 orchid species over a period of 3 months after transplanting onto the tree trunks without watering and fertilization, especially in Coelogynes mayeriana and Bulbophyllum membranaceum under both HL and LL. This chronic photoinhibition caused by sustained period of water deficit in their natural conditions was later reversed by natural re-watering conditions from higher rainfall. These results indicate that water deficit has a greater impact on photosynthetic light utilization efficiency than excess light. The present study also showed that after natural rewatering, relative water content (RWC) of leaves and pseudobulbs generally increased. During the natural re-watering, total leaf area also gradually increased and reached maximum expansion after 7 weeks under both HL and LL, with some exceptions due to leaf abscission or decline in total leaf area, possibly a strategy for water conservation.

Desiccation tolerance, longevity and seed-siring ability of entomophilous pollen from UK native orchid species.

Pollinator-limited seed-set in some terrestrial orchids is compensated for by the presence of long-lived flowers. This study tests the hypothesis that pollen from these insect-pollinated orchids should be desiccation tolerant and relatively long lived using four closely related UK terrestrial species; Anacamptis morio, Dactylorhiza fuchsii, D. maculata and Orchis mascula. Pollen from the four species was harvested from inflorescences and germinated in vitro, both immediately and also after drying to simulate interflower transit. Their tolerance to desiccation and short-term survival was additionally assessed after 3 d equilibration at a range of relative humidities (RHs), and related to constructed sorption isotherms (RH vs. moisture content, MC). Ageing of D. fuchsii pollen was further tested over 2 months against temperature and RH, and the resultant survival curves were subjected to probit analysis, and the distribution of pollen death in time (σ) was determined. The viability and siring ability, following artificial pollinations, were determined in D. fuchsii pollen following storage for 6 years at -20 °C. The pollen from all four species exhibited systematic increases in germinability and desiccation tolerance as anthesis approached, and pollen from open flowers generally retained high germinability. Short-term storage revealed sensitivity to low RH, whilst optimum survival occurred at comparable RHs in all species. Similarly, estimated pollen life spans (σ) at differing temperatures were longest under the dry conditions. Despite a reduction in germination and seeds per capsule, long-term storage of D. fuchsii pollen did not impact on subsequent seed germination in vitro. Substantial pollen desiccation tolerance and life span of the four entomophilous orchids reflects a resilient survival strategy in response to unpredictable pollinator visitation, and presents an alternative approach to germplasm conservation.

The Status and Future of Orchid Conservation in North America1

The status and trends of issues related to the conservation of orchids native to the United States, Canada, and Greenland are considered. We focus on nine of the 16 Targets of the Global Strategy for Plant Conservation (GSPC). The first two targets, which all other targets rely upon, appear to have been adequately achieved, in addition to Target 11. Limited progress has been made on six other GSPC targets. Three case studies of efforts to conserve the native threatened orchids, Platanthera leucophaea (Nutt.) Lindl., Isotria medeoloides (Pursh) Raf., and Tolumnia bahamensis (Nash) Braem, are presented to demonstrate the difficulties as well as the issues associated with effective conservation. We describe our efforts to establish an international program to conserve all native orchids in the United States and Canada. The North American Orchid Conservation Center (NAOCC) is an internationally focused effort that is based on public-private partnerships. The goal of NAOCC is to conserve the genetic diversity of all native orchids through efforts to develop an international collection of seeds and orchid fungi. The NAOCC also focuses on the cultivation of all native orchids in an international network of botanic gardens, and they partner with private and public landowners to develop techniques to conserve and restore all native orchid species.

Present Ecological Status and Diversity of <i>Zeuxine</i> Lindl. a Botanically Less Known Orchid of Dibrugarh District of Assam, North East India

Assam is the second largest state of North-East India and treasure trove of Indian orchids. Dibrugarh District is in the located in the eastern part of the state with rich native orchid species. This report is the outcome of our intensive field studies carried out during 2006 - 2011. We have chosen opportunistic method to cover all representative areas of different habitat. We have surveyed the area covering all the seasons of the year. For microhabitat structure randomly selected quadrat of 5mx5m were laid in the field and noted down all the features. In this study a total of 114 Orchid species under 54 genera have been recorded from the district. The study revealed 29 species as terrestrial and the rest 85 species are epiphytic. Among the terrestrial genus Zeuxine is found as ecologically and taxonomically co mplex group of Orch idaceae. During this field study, 6 species of the genus Zeuxine were recorded viz. Z. clandestine; Z. glandulosa; Z. goodyeroides; Z. longilabris; Z. nervosa and Z. Strateumatica. The present study envisages the threat and status of these species with conservation recommendation. Moreover, this is the first attempt to establish the taxonomic identificat ion to workout currently accepted botanical names of the genus with its ecological status, voucher specimen numbers, habitat, phenology and distribution in this district.

In vitro plant regeneration of Esmeralda clarkei Rchb.f. via protocorm explant

Esmeralda clarkei is an epiphytic native orchid species of Nepal growing under medium amount of light with fragrant flowers. Reliable protocols for in vitro plant regeneration of E. clarkei via protocorm explants were developed. Protocorms obtained from in vitro germinated seeds cultured on Murashige and Skoog's (MS) medium supplemented with 6-benzylaminopurine (BAP) and a-naphthalene acetic acid (NAA) individually and in combinations responded positively by induction of multiple shoots. The cultures were maintained at 25 ± 2°C under a 16/8h light/dark cycle photoperiod provided by fluorescent lamps (Philips, India). BAP increased from 0.5 to 2.0 mg/l individually induced the maximum number of shoots (11 to 14 shoots per treatment) which is followed by combinations of BAP (0.5, 1.0 and 1.5mg/l) and NAA (0.5mg/l) which induced 7 to 8 shoots per treatment. The highest number of roots (3 roots per treatment) was observed in NAA (0.5 and 1.0 mg/l) supplemented medium among the other tested medium. Key words : 6-Benzylaminopurine, Esmeralda clarkei, in vitro, a-naphthalene acetic acid, protocorm.

Conservation and reintroduction of native orchids of Singapore – the next phase

Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways to conserve their germplasm, and increase their number for subsequent re-introduction into appropriate habitats, including roadside trees, parks and nature areas. From 1999 to 2008, we carried out experiments and have successfully propagated and re-introduced 5 species of native orchids, namely Grammatophyllum speciosum Blume, Bulbophyllum vaginatum Rchb.f., Bulbophyllum membranaceum Teijsm. and Binn., Cymbidium finlaysonianum Lindl. and Cymbidium bicolor Lindl. spp. pubescens (Lindl.) Du Puy and Cribb. More than 80% of the plants are growing well and all that have survived have flowered. From 2009 to 2012, we expanded our reintroduction efforts by planting fifteen species: Bulbophyllum blumei (Lindl.) J.J.Sm., Bulbophyllum medusa (Lindl.) Rchb.f., Bulbophyllum membranaceum Teijsm. and Binn., Bulbophyllum purpurascens (T.andB.) J.J.Sm., Bulbophyllum vaginatum Rchb.f., Coelogyne mayeriana Rchb.f., Coelogyne rochussenii De Vr., Cymbidium finlaysonianum Lindl., Dendrobium aloifolium (Blume) Rchb.f., Dendrobium leonis (Lindl.) Rchb.f., Grammatophyllum speciosum Blume, Phalaenopsis cornu cervi (Breda) Bl. and Rchb.f., Cymbidium bicolor Lindl. spp. pubescens (Lindl.) Du Puy and Cribb, Thrixspermum amplexicaule Rchb.f., and Vanilla griffithii Rchb.f. is scheduled to be planted. One of our goals is that the reintroduced species would act as catalysts for the restoration of at least part of the original ecosystem. For example, pollinators may be attracted to sites where orchids have been re-introduced. Subsequently, orchid seeds that are produced from naturally pollinated flowers may be blown to the safe sites where appropriate mycorrhizal fungi are present; thus making germination and subsequent establishment of natural populations in areas beyond those in which the re-introductions occurred!

EX SITU ORCHID CONSERVATION - A CASE STUDY FROM THE SINGAPORE BOTANIC GARDENS

Some 226 species of native orchids have been recorded in Singapore. Of these, 178 are considered to be extinct, 40 are critically endangered, one is endangered (Bulbophyllum vaginatum), two are vulnerable (Vanilla griffithii, Bulbophyllum trifolium), and only five are considered to be common (Arundina gramminifolia, Bromheadia finlaysonianum, Dendrobium crumenatum, Eulophia graminea, Spathoglottis plicata). The orchid conservation program at the Singapore Botanic Gardens aims to monitor existing species, explore ways to conserve their germplasm, and increase their number for subsequent re-introduction into appropriate habitats, including managed parks and roadsides. Thus far, we have successfully re-introduced Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. A special designated area at the National Orchid Garden has been set up to showcase the rich diversity of native species. The Orchid Cryo-Seed Bank began several years ago and is showing some promising results. We have successfully stored seeds of several native species including Cymbidium finlaysonianum, Cymbidium bicolor, Grammatophyllum speciosum, Dendrobium crumenatum, Spathoglottis plicata, Bulbophyllum vaginatum, and Dendrobium anosmun.

Studies of Mycorrhizal Fungi of Chinese Orchids and Their Role in Orchid Conservation in China—A Review

China has over 1,200 species of native orchids in nearly 173 genera. About one fourth of native species are of horticultural merit. Some species are of Chinese medicinal value. In fact, the demand on orchid species with high Chinese medicinal values such as Gastrodia elata, Dendrobium offcinale, along with demands on species of cultural importance, such as those in the genus of Cymbidium, is a major factor causing wild populations to diminish and in some cases, drive wild populations to the brink of extinction. These market demands have also driven studies on the role of mycorrhizal fungi in orchid seed germination, seedling and adult growth, and reproduction. Most of these mycorrhizal studies of Chinese orchids, however, are published in Chinese, some in medical journals, and thus overlooked by the mainstream orchid mycorrhizal publications. Yet some of these studies contained interesting discoveries on the nature of the mycorrhizal relationships between orchids and fungi. We present a review of some of these neglected publications. The most important discovery comes from the mycorrhizal studies on G. elata, in which the researchers concluded that those fungi species required to stimulate seed germination are different from those that facilitate the growth of G. elata beyond seedling stages. In addition, presence of the mycorrhizal fungi associated with vegetative growth of post-seedling G. elata hindered the germination of seeds. These phenomena were unreported prior to these studies. Furthermore, orchid mycorrhizal studies in China differ from the mainstream orchid studies in that many epiphytic species (in the genus of Dendrobium, as medicinal herbs) were investigated as well as terrestrial orchids (mostly in the genus Cymbidium, as traditional horticultural species). The different responses between epiphytic and terrestrial orchid seeds to fungi derived from roots suggest that epiphytic orchids may have a more general mycorrhizal relationship with fungi than do terrestrial orchid species during the seed germination stage. To date, orchid mycorrhizal research in China has had a strongly commercial purpose. We suggest that this continuing research on orchid mycorrhizal relationships are a solid foundation for further research that includes more rare and endangered taxa, and more in-situ studies to assist conservation and restoration of the endangered orchids. Knowledge on the identities and roles of mycorrhizal fungi of orchids holds one of the keys to successful restoration and sustainable use of Chinese orchids.

Conservation of the Native Orchids Through Seedling Culture and Reintroduction—A Singapore Experience

Singapore is located near the equator, off the southern tip of the Malay Peninsula. The whole country consists mostly of lowland. It has many interesting types of natural habitats such as primary rain forest, freshwater swamp forest, mangroves, secondary forests, shrub, grasslands, and urban parks and fields. The climate is equatorial with relatively uniform temperature and high humidity. Unfortunately, many of the natural habitats and the native orchids which thrive there have disappeared due to habitat destruction. Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways to conserve their germplasm, and increase their numbers in natural, semi-natural, and urban environments through ex-situ seedling culture and subsequent re-introduction into appropriate habitats, including roadside trees, parks and natural areas. In the first phase of the programme, we have successfully propagated and carried out experiments of re-introduction on five species of native orchids, namely, Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. Survival percentages 8-yr after the reintroduction events ranged from 10 to 95 for G. speciosum, the target species of the earliest re-introduction experiments. Size of the seedlings at reintroduction, host trees, and relative humidity seemed to play significant roles in the success rate of the reintroductions.

Symbiotic seed germination of Habenaria macroceratitis (Orchidaceae), a rare Florida terrestrial orchid

The rapid loss of native orchid habitat throughout ecologically important areas (e.g., Florida) has prompted researchers to develop appropriate plans for the propagation and reintroduction of many native orchid species. Ideally, symbiotic orchid seed germination methods are utilized in the production of orchid seedlings to be used in plant reintroduction programs. In the current study we (1) describe an efficient symbiotic seed germination protocol to germinate seeds of the rare sub-tropical terrestrial orchid Habenaria macroceratitis; (2) discuss the in vitro fungal specificity demonstrated by this species; and (3) describe the effects of three photoperiods (0/24 h, 16/8 h, 24/0 h L/D) on in vitro symbiotic seed germination of H. macroceratitis. Six fungal mycobionts were isolated from both vegetative and flowering plants of H. macroceratitis from two geographically distinct sites. Symbiotic seed germination percent was highest (65.7%) and protocorm development was most advanced (Stage 2) when seeds were cultured with fungal mycobiont Hmac-310. Seeds of H. macroceratitis demonstrated a degree of specificity toward fungal mycobionts isolated from plants originating from the same site where seed was collected. Continual darkness (0/24 h L/D) inhibited initial seed germination (Stage 1; 17.1%), but stimulated subsequent protocorm development (Stage 2; 53.5%). These findings will aid in developing an efficient symbiotic seed germination protocol for the conservation of this rare Florida terrestrial orchid, and may prove useful in the conservation of other sub-tropical terrestrial orchid species.

Distribution of crassulacean acid metabolism in orchids of Panama: evidence of selection for weak and strong modes.

Crassulacean acid metabolism (CAM) is one of three metabolic pathways found in vascular plants for the assimilation of carbon dioxide. In this study, we investigate the occurrence of CAM photosynthesis in 200 native orchid species from Panama and 14 non-native species by carbon isotopic composition (δ13C) and compare these values with nocturnal acid accumulation measured by titration in 173 species. Foliar δ13C showed a bimodal distribution with the majority of species exhibiting values of approximately -28‰ (typically associated with the C3 pathway), or -15‰ (strong CAM). Although thick leaves were related to δ13C values in the CAM range, some thin-leaved orchids were capable of CAM photosynthesis, as demonstrated by acid titration. We also found species with C3 isotopic values and significant acid accumulation at night. Of 128 species with δ13C more negative than -22‰, 42 species showed nocturnal acid accumulation per unit fresh mass characteristic of weakly expressed CAM. These data suggest that among CAM orchids, there may be preferential selection for species to exhibit strong CAM or weak CAM, rather than intermediate metabolism.