Development of an efficient protocol for Robiquetia spathulata (Bl) J.J. Sm. an Endangered Orchid Species Through in vitro Techniques

Abstract

Robiquetia spathulata (Bl) J.J. Sm. is an epiphytic endangered orchid species of Bangladesh and PM (Phytamax - Arditti, 1977) basal medium was best for seeds germination than KC (Knudson, 1946), MS (Murashige and Skoog, 1962), MVW (Modified Vacin and Went, 1949) media. Sucrose was highly favorable for germination as a source of carbohydrates than glucose and lactose. The highest mean increased length of seed originated seedlings (3.68 ± 0.22cm) and individual shoot bud (3.37 ± 0.18cm) were achieved on 0.8% (w/v) agar solidified MS medium fortified with 3% (w/v) sucrose +  0.5 mg/l IAA + 1.0 mg/l BAP. Nodal segments directly produced the highest average number of multiple shoot buds (8.36 ± 0.45/segment) via organogenesis sprouted on MS medium + 1.0 mg/l IAA + 2.0 mg/l BAP; Whereas, leaf segments underwent proliferation via embryogenesis and produced maximum percent of greenish PLBs on MS medium supplemented with 1.0 mg/l Pic + 2.0 mg/l BAP. The increase in length, as well as the number of roots, developed seed originated and shoot bud derived seedlings were best on half-strength PGRs free MS medium. The highest number of SPSs formation took place in liquid MS + 0.5 mg/l Pic + 1.0 mg/l BAP. This efficient protocol is a trustworthy way for the in vitro germination, micropropagation, development of seedlings, and SPSs production of Robiquetia spathulata.