In vitro induction of callus from cotyledon and hypocotyl explants of Glycine wightii (Wight & Arn.) Verdc.

Abstract

With the objective to promote in vitro callus induction, cotyledon and hypocotyl segments of "perennial soybean" (Glycine wightii (Wight & Arn.) Verdc.) were inoculated in basal medium MS supplemented with sucrose (1.5 e 3%) and 0.8% agar and different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-furfurylaminopurine (kinetin). The explants were maintained in a dark growth room at 28ºC. The best callus induction was observed in explants (cotyledon and hypocotyl) maintained in medium containing the combination of 2,4-D (1 mg.L-1), kinetin (0.1 mg.L-1) and 3% sucrose. To promote callus subculture, the MS medium was supplemented with different combinations of 2,4-D (0.5 to 4.0 mg.L-1), with or without kinetin (0.1 mg.L-1) and sucrose (1.5 e 3%). The calli were maintained 35 days in a dark growth room at 28ºC. The results indicated that the use of 2,4-D 1.0 mg.L-1 + kinetin 0.1 mg.L-1 + sucrose 3% provided the highest average weight of cotyledons calli fresh matter, whereas the use of 2,4-D 2.0 mg.L-1 + kinetin 0.1 mg.L-1 + sucrose 3% provided the highest average weight of hypocotyl calli fresh matter. High concentrations of 2,4-D, independent of kinetin and sucrose concentrations, promoted oxidation and reduction in fresh weight from calli of cotyledon and hypocotyls.