An efficient in vitro propagation, antioxidant and antimicrobial activities of Aphyllorchis montana Rchb.f.

Abstract

An in vitro plant regeneration protocol was successfully established in Aphyllorchis montana, a saprophytic achlorophyllous orchid by culturing immature seeds. Among the six basal media evaluated for seed germination, BM-1-Terrestrial Orchid medium was found to be the best followed by Knudson C medium. Half-strength BM-1-Terrestrial Orchid medium was supplemented with different growth regulators either individually or in combinations for multiplication of shoots induction. Of the five cytokinins tested, thidiazuron at 6.8 μM was found to be most effective for multiple shoot induction yielding 17.24 ± 0.27 shoots after 10 weeks of culture. Addition of low concentration of α-Naphthaleneacetic acid (1.3 μM) in MS medium supplemented with the cytokinin thidiazuron (6.8 μM) favored shoot multiplication. The addition of organic additives to the medium containing thidiazuron enhanced the number of regenerated shoots. The plantlets were acclimatized, and the survival rate was 100%. Screening of the antioxidant and antimicrobial activities and estimation of total phenolics and flavonoid content of methanolic extracts of micropropagated plants were also carried out and compared with that of the wild-grown plants. In all the tests, methanolic extract from wild-grown plants showed higher antioxidant, antimicrobial activity, total phenolics and flavonoid content than in vitro propagated plants.