Protocorm-like body formation and plant regeneration of Dendrobium huoshanense, an endangered medicinal plant

A procedure was developed for protocorm-like bodies (PLBs) formation and proliferation and subsequently plant regeneration from stem segments of Dendrobium huoshanense Tang et Cheng, an endangered medicinal plan. PLBs were formed on Murashige and Skoog (MS) medium containing a-naphthaleneacetic acid (NAA) alone or in combination with kinetin (KIN). The highest frequency (79.9%) of PLB formation occurred on MS medium supplemented with 7.5 Lmol L-1 NAA and 0.5 pmol L-1 KIN. Growth regulator-free MS medium at half strength was optimum for PLB proliferation and liquid suspension culture gave the maximum increase in fresh weight after culture of 4 weeks in the dark. Upon transfer to solid MS medium without growth regulators in the light, the proliferated PLBs developed into shoots. Potato extract enhanced the regeneration and elongation of shoots and approximately 420 shoots were obtained from one gram PLBs. High frequency of shoots (90.7%) were rooted on MS medium supplemented with 10% banana extract and complete plantlet with 3-5 roots were obtained after 7 weeks of rooting initiation.