Abstract

MICROPROPAGATION OF AN ENDANGERED TERRESTRIAL ORCHID GEODORUM DENSIFLORUM (LAM.) SCHLTR. OF KANYAKUMARI DISTRICT, INDIA

G.V. Gegi, Dr. B. Christudhas Williams & Dr. R. Mary Suja

Abstract

Geodorum densiflorum (Lam.) Schltr. is an endangered orchid with pharmaceutical importance. In vitro studies will immensely aid conservation measure of this orchid species. Seeds of Geodorum densiflorum (Lam.) Schltr. were aseptically cultured on 0.8% (w/v) agar solidified Murashige and Skoog (MS) media. Seeds germinated and formed light green globular structures directly produced tiny seedlings which underwent elongation in PGRs supplemented MS medium. The callus was friable, opaque and creamish to light yellow in colour. In the assessment of callus induction MS media supplemented with coconut water showed maximum number of PLBs (15.93 per callus) in BAP (1 mgL-1) + NAA (1 mgL-1) + 15% CW. The produced PLBs are converted into plantlets after 8 to 10 weeks of culture in only those cases regenerated on auxin and cytokinins combinations. 0.5mg/l KIN and 0.5mg/l BAP showed maximum number of shoots (4.4±0.4) and shoot length increased to 2.4±0.3cm. The combination of BAP +IAA showed maximum number of roots per plantlet (3.57) obtained from 0.5 mg/L each of BAP+IAA with charcoal supplementation and 1.0 mg/L each of BAP +IAA combination gave the highest number of roots (2.667 cm) with charcoal supplementation. Hardened plant was transferred to green house after ex vitro rooting techniques.

Keywords: Geodorum densiflorum, BAP, endangered orchid, micropropagation, MS media, green house, hardening, phytochemical analysis.