in vitro seed germination and micropropagation of a critically endangered terrestrial orchid Erythrodes humilis (Blume) J. J. Smith
Tapash Kumar Bhowmik, Md Mahbubur Rahman
Asymbiotic cultures were raised from seeds obtained from 65-70 days old green capsules of critically endangered orchid Erythrodes humilis (Blume) J. J. Smith. MS basal medium was best for seeds germination than PM, KC, MVW media respectively. Sucrose was enhanced for germination as source of carbohydrate than glucose and lactose. Maximum elongation of germinated seedlings was recorded on agar solidified MS medium with 1.0 mg/l NAA + 1.0 mg/l BAP (3.50 ± 0.23cm) followed by liquid PM + 1.0 mg/l IAA + 1.0 mg/l BAP (3.34 ± 0.19cm) medium. Rhizome segments directly produced highest average number of multiple shoot buds via organogenesis sprouted on MS + 1.0 mg/l Pic + 2.0 mg/l BAP (6.55 ± 0.43/segment) medium followed by MS + 1.0 mg/l IAA + 2.0 mg/l BAP (6.23 ± 0.38/segment) medium. Highest mean increased of individual shoot bud length was achieved on agar solidified MS with 1.0 mg/l NAA + 1.0 mg/l BAP (3.27 ± 0.21cm) followed by liquid PM with 1.0 mg/l IAA + 1.0 mg/l BAP (3.16 ± 0.18cm) medium. MS media supplemented with 0.5 mg/l IBA was best for rooting followed by MS + 1.0 mg/l IAA. The highest number of SPSs development in liquid MS + 0.5 mg/l NAA + 1.0 mg/l BAP followed by agar solidified MS + 1.0 mg/l Pic + 1.0 mg/l BAP medium. Rooted plantlets were transferred to ex vitro condition after a short period of acclimatization.