Extensive field surveys and investigations have been made in Sylhet, Cox’s Bazar, Chittagong, and Chittagong Hill Tracts of Bangladesh to explore the orchid diversity which resulted in good collections of orchids including some new reports. The orchid specimens were critically examined and identified. Amongst them, four species, i.e. Chiloschista parishii Seidenf., Coelogyne ovalis Lindl., Conchidium extinctorium (Lindl.) Y.P.Ng & P.J.Cribb, and Dendrobium parcum Rchb.f., are being reported here as new angiospermic records for Bangladesh flora. Two genera i.e. Chiloschista and Conchidium are reported for the first time from Bangladesh. Detailed description flowering time, ecology, and geographical distribution of the species have been provided with illustration and photographs.
A species of Black Carpenter Ant (Camponotus pennsylvanicus) was observed to be a significant pollinator of Herminium lanceum (Thunb. ex Sw.) Vuijk. The present paper describes the pollination mechanism of a terrestrial and endangered orchid species, H. lanceum The flowers were observed as self-compatible but mainly cross-pollinated. As the flowers are nectarous, these were frequently visited by a variety of insects. The presence of a large number of flowers in H. lanceum enhanced the attraction of pollinators towards them. The pollinators visited the flowers many times for foraging. Four species of insects (1 species of black carpenter ant loaded with pollinia, 2 species of unknown fly, and 1 species of crab spider) were found visiting the flowers. Since, the transfer of pollinarium, from anther to stigma, took place through the dorsal surface of the head (occiput) of the pollinator ant, the mode of pollination is Nototribic. As a single individual of ant was observed to pollinate a large number of flowers in its single visit to the inflorescence, the rate of pollination and fruit set was very high in H. lanceum. Interestingly, it was observed that the frequency of insect visit decreased as the day passed by.
Present paper reports the regeneration competence of leaf segments in a commercially important orchid, Cymbidium eburneum Lindl., for its mass multiplication. Nearly 83.3% regeneration response could be evoked on M (Mitra et al., 1976) medium supplemented with 6 Benzyladenine (BA, 0.5 mgl-1) and a-Naphthaleneacetic acid (NAA, 2 mgl-1) within 5.25 wks, and 15.7 plantlets per explants could be regenerated after 30 wks of culture initiation. Cytological studies confirmed the uniform somatic chromosome number of 2n=40 in the regenerants. The protocol can be utilized for rapid mass multiplication of this orchid and aid in alleviating the collection pressures on its natural populations.
Dactylorhiza umbrosa (Kar. & Kir.) Nevski, a medicinal species of ground orchids, is reported as a new record for the Nubra valley of Ladakh region, India. In this communication, description along with photographs, flowering time, distribution, and relevant ecological notes of the species are provided.
Orchid cultivation in Thailand has been developed for over 50 years. The export value started from a few million baht to about three billion baht in 2019. Major growing factors in natural growing habitats are concerned for appropriate commercial cultivation. They are altitude light, temperature, relative humidity, nutrients, and air movement. At present, saran houses constructed with cement poles, cement benches, galvanized pipes for hanging orchid baskets, and black netted nylon roof with 50-60% shade and open sides are developed for low cost, long lasting, and suitability for growing tropical orchids for cut-flower and potted orchids. The cultivation is done mostly for many outstanding cultivars of pink-red, white, and yellow-green flowered dendrobiums and blue, pink, and yellow flowered vandaceous orchids which need hot and humid conditions. A complete cycle of orchid production which needs breeding programme, micropropagation, planting materials (mainly coconut husks, charcoal, and cement block), plastic containers, watering equipments, fertilizer, pest control, postharvest technology, and transport from farm to packaging houses are effectively implemented. Thailand is famous for exporting cut-flower orchids applying low-cost cultivation but high production. Orchids continue to dominate other ornamental crops in Thailand due to better technology know-how, suitable climatic conditions for dendrobiums and vandaceous orchids, experienced and skillful growers and exporters, as well as their nationwide popularity. Apart from all these, orchids are a symbol of Thailand that reflects the country’s pride internationally.
Dendrobiums are sympodial epiphytic orchids and popular potted flowering plants and cut-flowers around the world due to their floriferousness, wide range in flower colour, size and shape, year round availability, and lengthy vase life. Elite species of Dendrobium are used as parents for breeding programmes to develop outstanding hybrids of special merit. Native species are used as genetic resources for crop improvement programmes, potted plants, dry flowers, hanging baskets, tree mounting, and medicinal purposes Dendrobium hybrids are used as cut-flowers, pot plants, in bouquet arrangements, and for display in exhibition. In the present study,agricultural practices including post-harvest management and value addition of tropical, subtropical, and temperate species and hybrids of Dendrobium are discussed in details.
Orchids occupy top position amongst all the flowering plants and are valued for cut-flower production as well as potted plants due to their long lasting and bewitchingly beautiful flowers, which fetch a high price in the international market. Shimla, the capital of Himachal Pradesh with diverse climate and the varied environmental conditions supports diverse habitat to the flora and fauna including orchids of high therapeutic values. Ashtavarga (group of eight medicinal plants) is a vital part of Ayurvedic formulations like Chyavanprash and includes four orchids namely Riddhi, Vriddhi, Jeevak, and Rishbhak. These species are known to provide local medicine, food, and fodder thereby contributing to the livelihood and income generation within rural communities. Under existing climatic changes scenario, these orchids face greater risk of extinction and are listed under Appendix II of CITES. Hence, there is a strong need to take steps to conserve these valuable orchids in their natural habitats. Amongst many techniques, plant tissue culture has proved as one of the most promising alternative tools to minimize the pressure on natural population of medicinal as well as floriculturally important orchids and their sustainable utilization.
Orchid genotypes comprising of six genera i.e., Aranda, Aranthera, Kagawara, Mokara, Renanthera, and Vanda were evaluated using completely randomized design with five replications. The selected materials were evaluated by recording observations on their vegetative and floral characters. Parameters of variability, heritability, and expected genetic advance were calculated. The mean and standard errors were worked out as per standard methods and then coefficients of variation were computed. Genotypic and phenotypic coefficients of variation were high for thickness of leaf, leaf area, and number of aerial roots indicating high variability for these characters and scope for improvement through selection. High heritability (>70%) combined with genetic advance greater than 70 per cent was observed for number of aerial roots, leaf width, leaf thickness, leaf area, number of spikes per shoot, and number of flowers per inflorescence indicating additive gene action for these characters and providing thereby a greater scope for further improvement of these traits in advance generations.
An efficient and reproducible protocol for asymbiotic seed germination of an endangered and therapeutically important terrestrial orchid Herminium lanceum, commonly known as Jalya, has been established. Its leaves and stem are mainly used for curing fever, diabetes, and urinal disorders. With a view to enlarging its population base, an attempt was presently made to culture its mature seeds procured from dehisced capsules on modified Knudson C (KC, 1946) medium fortified with different concentrations of auxins (IAA, IBA, NAA; 1 mgl-1 each and cytokinins (KN, BAP; 1mgl-1 each) in different combinations. The aim of present investigation was to study the effect of different combinations of growth regulators on seed germination and their subsequent development into seedlings. Seeds showed initial signs of germination within 29±0.88 days of inoculation. The first visible sign of germination was the swelling of embryos followed by apical rupturing of seed coat so as to release the spherules. Within 95±3.05 days of inoculation, the spherules developed into oval, green protocorms with absorbing hair. The complete seedlings were obtained within 149±1.15 days of inoculation. The highest germination percentage (83.02%) and early development of healthy seedlings were observed on medium augmented with combination of IBA and KN.
Seeds obtained from mature green capsules (‘pods’) of a highly fragrant and floriculturally important epiphytic orchid, Dendrobium chrysotoxum Lindl. were aseptically grown on agar gelled KC, MS, MVW, and PM media with three different sources of carbohydrates i.e. glucose, lactose, and sucrose; high response was achieved on sucrose containing PM medium. Highest mean increased seedling length (2.95±0.19 cm) was achieved on agar gelled MS medium with 0.5 mgl-1 IAA + 1.0 mgl-1 BAP followed by next seedling length (2.93±0.14 cm) on liquid MS medium with 1.0 mgl-1 IAA + 1.0 mgl-1 BAP. The pseudobulb segments directly produced highest average number of multiple shoot buds (7.04±0.46/segment) on MS medium with 1.0 mgl-1 IAA + 2.0 mgl-1 BAP followed by next response of shoot buds (6.76±0.37 segment) on MS medium with 1.0 mgl-1 NAA + 2.0 mgl-1 BAP. Leaf segments showed proliferation and produced maximum per cent of greenish PLBs (Protocorm Like Bodies) on MS medium with 1.0 mgl-1 IAA + 2.0 mgl-1 KN followed by MS medium supplemented with 1.0 mgl-1 IBA and 2.0 mgl-1 BAP. The highest mean increased individual shoot bud length (2.73±0.21 cm) was achieved on liquid MS medium with 1.0 mgl-1 IAA + 1.0 mgl-1 BAP followed by next shoot bud length (2.65±0.17 cm) on agar gelled MS medium with 0.5 mgl-1 NAA + 1.0 mgl-1 BAP. The increase in length as well as the number of roots developed in seed originated seedlings and shoot bud derived plantlets were best on MS medium with 1.0 mgl-1 IAA followed by MS medium with 0.5 mgl-1 NAA. The highest number of shoot bud formation took place in agar gelled PM medium with 0.5 mgl-1 NAA + 1.0 mgl-1 BAP and liquid MS medium with 0.5 mgl-1 Pic + 1.0 mgl-1 BAP. This protocol is a reliable way for the in vitro germination, micropropagation, seedlings development, and multiple shoot bud production of Dendrobium chrysotoxum.
Orchids are known for their high ornamental value due to their magnificent and graceful flowers. Apart from their use as decorative materials and cut-flowers, they are being used for various purposes such as herbal medicines as a source of phytochemicals and in aromatic products due to their pleasant fragrance. As orchid extracts are considered a panacea for various ailments, studies have be initiated to explore the biological activities of orchid extracts, especially in cosmetology and cosmeceuticals. These have effective ingredients like retinoids, peptides, antioxidants, hyaluronic acid, and hence have become the foremost skin ageing fighters in the industry. The present review focusses on the cosmeceutical potential of orchids ensuing cognizance for their conservation, thereby raising scope for their flourishment in the cosmeceutical industry and bringing in new developments in skincare health.
A hybrid was raised between two species Cymbidium aloifolium (L.) Sw. and C. bicolor Lindl. from India. The variation in the floral morphology of the hybrid with respect to its parents was compared. Figures of the floral components and images of the flowers of these species are provided.
NorthEastern part of India including Northern part of West Bengal is a hotspot of most of the orchids which represents more than 70% Indian orchid species. Amongst 103 species of Dendrobium, 82 are found in this region. As we know, orchid populations are depleting day by day due to the anthropogenic activities and change in climate, a suitable measure is required to predict the current situation and to conserve the valuable species. Realizing the importance of this genus, efforts were presently made in estimating the species richness of Dendrobium collected from the different parts of NE Himalayan states and parts of Eastern Himalaya with the help of DIVA GIS (geographic information system) software. Morphological characters of the different species were correlated to the environmental factors. Most of the species of Dendrobium (approximately 80%) are available at 1000-2000 m altitude with a suitable temperature variation of 10-25°C and 1000-3000 mm rainfall zone. The species richness is higher in Central Meghalaya, parts of North Bengal, parts of Arunachal Pradesh, and parts of Upper Assam.
Shimla hills located at an altitude range 1600-2800 m amsl, are biodiversity rich zones in NorthWestern Himalayas. Terrestrial orchids have special preference for this area because of its vast vegetation ranges, forest cover, and favourable climate. Orchids are generally highly adapted to form specific biological interactions with other organisms; flowers are usually specialized to specific pollinators and all species rely on mycorrhizal symbiosis with specific groups of fungi. They have been used in many parts of the world in traditional healing system as well as in the treatment of a number of diseases since the ancient time. Orchids are considered as indicator species of habitat disturbances. Recently, these plants are listed amongst the most threatened taxa globally due to increasing anthropogenic threats inherent rarity, and specific conservation needs. The most commonly cited threats affecting orchids are deforestation, logging, forest fire road construction, and the expansion of forest plantations and agriculture, and their over-collection for the ornamental, medicinal, food, and trade. The present investigation deals with substratum analysis of some therapeutically significant and/or endangered orchids from Shimla and adjacent hills. It was observed that these plants grow in a variety of habitats, having different soil types with slightly acidic pH and with species specific nutrient requirements. The information obtained after soil analysis will indicate about the nutritional requirements of species, and this information can later be utilized for formulation of species specific nutrient media for their in vitro mass propagation and conservation programmes.
Coelogyne nitida is an important member of the genus Coelogyne, distributed throughout Himalayan region and SouthEast Asia. In this study, a total of 17 C. nitida germplasm collections were characterized for various morphological and floral characters during the flowering season of 2020 at ICAR-NRC for Orchids, Pakyong. Amongst the various characters studied, it was observed that the number of flowers per inflorescence was recorded upto 9-12 which is higher than the previously reported number (4-8 flowers per raceme). This character needs to be studied to a greater extent to confirm the expression for further usage.
The experiment was conducted at the Orchid house, Department of Botany, Panjab University, Chandigarh, during the period from February-April, 2018 to study the growth performance of a floriculturally important epiphytic orchid, Dendrobium chrysanthum Wall. Ex Lindl. under the influence of different NPK spray concentrations. In the present investigation, four spray formulations: spray formulation T1 (N:P:K=50:12.5:50), spray formulation T2 (N:P:K=100:25:50), spray formulation T3 (N:P:K=150:25:100), and spray formulation T4 (N:P:K=200:37.5:100) were used along with a control (water). The experiment was laid out in Completely Randomized Design (CRD) with three replications of each treatment. Spray formulations had significant influence on growth of presently tested species. Spray treatment T4 (NPK=200:37.5:100) showed highest number of leaves (20.42±0.41) while minimum number of leaves (7.95±0.19) were observed on use of spray of simple water. Spray treatment T3 (NPK=150:25:100) and spray treatment T1 (NPK=50:12.5:50) showed maximum (13.37±0.44 cm) and minimum (9.23±0.04 cm) length of leaves, respectively. Also, maximum width of leaves (3.53±0.35 cm) was observed in species treated with spray treatment T3 (NPK=150:25:100) whereas the minimum width of leaves (1.43±0.07 cm) was observed on the species treated by spray treatment T1 (NPK=50:12.5:50). Spray treatment T3 (NPK=150:25:100) showed maximum height of plant (38.93±0.45 cm), while the minimum height of plant (11.55±0.02 cm) was observed on spray treatment T1 (NPK=50:12.5:50). Spray treatment T4 (NPK=200:37.5:100) showed maximum stem width (10.99±0.20 cm), while the minimum stem width (5.39±0.27 cm) was observed on spray of simple water. In most of the parameters, control had shown the minimum results. Further investigation needs to be undertaken so as to find out the efficacy of different NPK spray formulations on both vegetative and reproductive stages of Dendrobium chrysanthum and other related species.