Micropropagation of Rhynchostylis gigantea (Lindl.) Ridl. (Chang Phueak) through protocorm like-bodies: effects of plant growth regulators, characteristics of protocorm and strength culture media
Chang Phueak orchids (Rhynchostylis gigantea (Lindl.) Ridl.) are among the ThailandRSQUOs most popular wild orchids due to their impressively beautiful flowers. Propagation of these orchids has been hampered by the naturally slow growth rate of the plant, which renders it very difficult to be propagated through conventional methods. In vitro culture techniques have provided a useful alternative technology for propagating this recalcitrant species. In this study, the propagation of R. gigantea was achieved through the in vitro formation of protocorm-like bodies (PLBs) from protocorms that developed from a 6-month-old green capsule. The characteristics of protocorms (full-protocorms and half-protocorms) were cultured on MS agar medium supplemented with different concentrations (0, 1, 2 and 3 mg L-1) of 6-benzyladenine (BA) and (0 and 1 mg L-1) of 1-napthaleneacetic acid (NAA) for the induction of PLBs. After culturing for 3 months, half-protocorms were cultured on MS agar medium supplemented with 1 mg L-1 BA and 1 mg L-1 NAA gave the highest percentage of PLBs at 4.22 and average number of shoots at 2.89 shoots protocorm-1, respectively, The PLBs were cultured on different strength-MS media (MS, ½ MS and ¼ MS) and with/without 0.2% activated charcoal for the multiplication of PLBs. After culturing for 3 months, it was found that MS medium gave the highest no. of PLBs at 4.75 (PLBs explant-1). While ¼ MS medium gave the highest average number of shoots at 4.88 shoots explant-1. In addition, ½ MS medium gave the highest number of leaves (4.75 leaves explant-1) and average length of leaf (0.87 mm explant-1), respectively.
Ramasoot, S. 2017. Micropropagation of Rhynchostylis gigantea (Lindl.) Ridl. (Chang Phueak) through protocorm like-bodies: effects of plant growth regulators, characteristics of protocorm and strength culture media. Acta Hort. (ISHS) 1167:81-86
Rhynchostylis gigantea, Chang Phueak, micropropagation, PLBs