updated classification of Orchidaceae Chase, Mark W; Cameron, Kenneth M; Freudenstein, John V ...
Botanical journal of the Linnean Society,
February 2015, Letnik:
177, Številka:
2
Journal Article
Dienia ophrydis is an endangered terrestrial orchid used for its ornamental and therapeutic purposes. This orchid possesses an anti-malarial alkaloid known as Malaxin. There is ongoing exploitation ...in the wild due to illegitimate herbal collection and climate change. To control the potential risk of extinction, there are no conservational measures or in vitro protocols established in this genus. The study focuses on addressing a germination protocol and enhancement of protocorm-like bodies (PLB) proliferation by optimizing the basal media and vitamins. It also aims to improve the misinterpretation of tetrazolium viability results in orchid testa along with a permeability test. Further, the seeds were subjected to 1% TTC staining to perform embryo viability test and 0.4% trypan blue (TB) dye for testa permeability. Ten basal media such as Gamborg's medium, Mitra medium, Thomale GD medium, Vacin and Went medium, Knudson C medium, Knop's medium, MS medium and ½ MS medium, ¼ MS medium, and modified MS medium (MMS) were tested for seed germination. The Half-strength MS medium responded with 92% of the highest germination and T-GD medium is not suitable for seed germination. The seed viability and permeability result showed 93% of permeability, 72% viability, and 9% dead seeds. Protocorms were transferred to the modified mMS medium containing half-strength macronutrients, full micronutrients, and 10 ppm of thiamine in vitamin formulation. PLB proliferation was observed and 12 shoots emerged from a single protocorm explant. Subsequently, the seedlings were acclimatized with 8-0-24 ratios of nitrogen, phosphorus, and potassium (NPK) as determined by soil testing. The study contributes in experimenting with seed germination of terrestrial orchid seeds asymbiotically and to establishing a protocol for conservation programs, especially in this genus.
•The present study is the first report for invitro study in the entire genus Dienia.•The effect of various basal media on seed germination of Dienia ophrydis was studied.•Simple method to improve protocorm like bodies proliferation was initiated.•Analyzing soil minerals from natural habitats guides in acclimatizing the in vitro plants to their natural environment.
Malaxis acuminata D. Don., a small, terrestrial orchid, is endemic to tropical Himalayas at an altitude of 1200–2000m asl. The dried pseudobulbs are important ingredients of century old ayurvedic ...drug ‘Ashtavarga’ and a polyherbal immune-booster nutraceutical ‘Chyavanprash’, known to restore vigour, vitality and youthfulness. Considering tremendous medicinal importance of this threatened orchid species, a detailed study was undertaken for the first time to address its antioxidant potential, secondary metabolite contents and biological activities against skin-aging related enzymes (anti-collagenase, anti-elastase, anti-tyrosinase and xanthine oxidase) and anti-inflammatory activity (5-lipoxygenase and hyaluronidase) in different plant parts of wild and in vitro-derived plants of M. acuminata. Methanolic leaf and stem extracts were further evaluated for in vitro photoprotective activity against UV-B and UV-A radiations. Furthermore, secondary metabolite profiling of various plant parts was carried out by Gas Chromatography Mass Spectrometry (GC–MS). A significantly higher antioxidant potential (DPPH, metal chelating and ABTS•+) with a comparative higher yield of secondary metabolites was observed in in vitro-derived plantlets as compared to the wild plants. Among various solvent systems used, methanolic leaf and stem extracts showed promising inhibitory activity against major skin aging-related enzymes and anti-inflammatory potential. Methanolic leaf and stem extracts of both wild and in vitro-derived plants showed promising photoprotective activity against UV-B and UV-A radiations in vitro with comparatively higher sun protection factor (SPF). Furthermore, GC–MS analysis of methanolic extracts of leaves and stems of wild as well as in vitro-derived plantlets revealed presence of many bioactive metabolites such as, dietary fatty acids, α-hydroxy acids, phenolic acids, sterols, amino acids, sugars and glycosides which substantially explain the use of M. acuminata as one of the potential rejuvenator and anti-aging ingredient in many Ayurvedic formulations.
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•Malaxis acuminata showed promising anti-inflammatory anti-aging activity in vitro.•Enhanced photoprotective activity with higher sun protection factor was reported.•Metabolite profiling exhibited higher antioxidant and secondary metabolite levels.•GC–MS based phytochemical profiling revealed compounds related to its anti-aging potential.
Malaxis nana C. Schweinf. se conoce de dos especímenes recolectados en 1925 en San Ramón, provincia de Alajuela, y tres especímenes adicionales sin datos de localidad detallados y recolectados en los ...finales de los 1800’s, todos de Costa Rica. Esta especie no había sido registrada desde entonces. Aquí informamos por vez primera sobre la existencia de Malaxis nana en la Estación Biológica Las Cruces, provincia de Puntarenas, en el sur de Costa Rica. Se presenta una descripción actualizada, ilustración, fotografías y mapa de distribución para este taxón.
A new species, Malaxis nilgiriensis, is described and illustrated based on the material collected from the Nilgiris of Western Ghats, southern India. It superficially resembles Malaxis versicolor but ...differs by the presence of a pseudobulb and stolon, a short inflorescence, and a lip slightly bilobed with four retuse teeth. The taxonomic phenology of the new species as well as its etymology, conservation status, and diagnostic features are discussed.
Malaxis ybytus is proposed as a new species from the wetlands of the Campos de Altitude of the Atlantic rainforest of south Brazil, Serra do Araçatuba\Papanduva mountain chain. It is described, ...illustrated, and compared with other similar species. The new species is similar to Malaxis cipoensis and Malaxis sertulifera, but it is recognised by its flat to slightly conduplicate leaves, densely congested inflorescence with small flowers bearing free lateral sepals and four foveas in the lip. Due to the high degree of endemism in this environment, the few collection records and the anthropic pressure in the region, we infer that the species is critically endangered (CR) based in criterium D of the IUCN.
Populations of
Polygonatum cirrhifolium
(Wall.) Royle and
Malaxis muscifera
(Lindl.) Kuntze are restricted to small pockets and are subject to destructive harvesting (rhizomes/pseudobulbs) from wild. ...Being under high threat categories considering habitat specificity, population size, utilization and extraction trends, both the species need conservation interventions. This study in Kumaun West Himalaya reveals that in the case of
P. cirrhifolium
the maximum density (6.33 individual/m
2
) was reported for the Burphu population, whereas for
M. muscifera
the maximum density (1.75 individual/m
2
) was reported for Kathaliya population. No significant (
p
< 0.05) relationship was found between altitude and studied phytosociological parameters and morphological parameters in both the targeted species. Principal component analysis-based analysis identified population of Gagar (
P. cirrhifolium)
and Kathaliya (
M. muscifera
) to be best performing populations and moist habitat is appropriate for the growth and development of these species. These populations can, therefore, be used for mass propagation and cultivation to meet the demand for commercial purposes.
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