Assessment of genetic stability of micropropagated plants of Rhynchostylis retusa (L.) using RAPD markers

Abstract Rhynchostylis retusa (L.) is an epiphytic orchid having both medicinal and ornamental value. The present study aimed to develop a protocol for mass propagation of R. retusa and evaluate the genetic stability of in vitro regenerants. The immature seeds obtained from capsule of mother plants (wild type) were cultured on different strength of MS medium viz. full (FMS), half (HMS), quarter (QMS) supplemented with BAP (0.5 mg/L), NAA (0.5 mg/L), and 5% or 10 % coconut water (CW). The earliest germination and protocorm development were observed on HMS and QMS media. Mature protocorms produced higher number of shoots (12.8) and longest shoots (5.3 cm) on FMS supplemented with 10 % CW. The maximum number of roots (7.3) and root length (5.0 cm) were observed on FMS when supplemented with fungal elicitor CVS4 (extracted from the stem of Vanda cristata). Ten RAPD primers were used to analyze genetic stability among six samples (five in vitro and one mother plant) produced a total of 23 fragments ranging from 275bp to 1100bp. The polymorphic information content (PIC) values ranged from 0.28 to 0.50. The amplified bands of all the samples of in vitro plants were similar to bands of mother plant. The result demonstrated the genetic stability of the micropropagated plants of R. retusa. Research reported here is indicating the applicability of tissue culture for true-to-type plant production and conservation of R. retusa.