In vitro Morphogenic Responses of Different Explants of Stevia ( Stevia rebaudiana Bert.)

摘要

Leaf segments, internode and nodal segments of Stevia were cultured on MS medium supplemented with varying concentrations (1, 3, 5 and 7 mg L-1) of growth regulators (2,4-D, BAP and NAA) along with coconut water for observe morphogenic responses (mainly formation of callus). Ninety five percent aseptic cultures were obtained when sterilized with 0.1% HgCl2 for 10 min. Nodal segment initiated callus earlier than leaf segments and internode explant. Higher amount of callus were obtained from leaf segments than internode and nodal segment. Interaction effects of explant and growth regulators were significant for days of callus initiation, fresh weight and dry weight of the callus per culture. Among the twelve treatments the highest amount of callus was obtained in MS medium supplemented with 7 mg L-1 BAP followed by 3 and 5 mg L-1 NAA, respectively. On the other hand, 7 mg L-1 2,4-D showed lowest performance followed by 5 mg L-1 2,4-D and 5 mg L-1 BAP, respectively among the twelve treatments.