Genetic diversity of an endemic medicinal orchid, Coelogyne nervosa, from southern India using morphological and molecular markers

Genetic diversity of Coelogyne nervosa A. Rich. was investigated using SDS-PAGE, RAPD markers and morphological characters. C. nervosa grows as an epiphyte as well as a lithophyte in the Eastern and Western Ghats of India. Leaf samples collected from these two reference sites were taken for RAPD and protein profile analysis. Vegetative parts such as leaves, pseudobulbs and roots were fixed in FAA. Free-hand and microtome sections were cut and stained with safranin-fastgreen. The objective of this study is to assess the genetic diversity of endemic orchid C. nervosa distributed in southern India. The six populations collected from these two geographical regions exhibited significant variation in their morphological and molecular characters. The stomata are tetracytic and hypostomatic in distribution. The maximum thickness of cuticle and midrib region in leaf and, extensive lignification in exodermis and endodermis of root were recorded in populations located in the Western Ghats as compared to those of the Eastern Ghats. It is interpreted to be associated with the greater need to conserve water. RAPD and protein profile data showed the inter population diversity between these two reference sites. This can be attributed to the different ecological and climatic conditions prevailing in the Eastern and Western Ghats of India.