Growth regulators and cold pretreatment on in vitro androgenesis of Solanum iopetalum L.

An evaluation was made of the effect of three concentrations of indoleacetic acid (AIA; 0.0, 0.2, and 1.0 mg L-1), benzyl aminopurine (BA; 0.0, 1.0 and 3.0 mg L-1) and their respective combinations, as well as the effect of previous exposure to 4 degreesC for 48 and 96 h on callus induction on anthers of Solanum iopetalum. The effects of each factor, as well as their interactions, were highly significant and, therefore, are needed to stimulate callus formation from anthers. The most efficient combination (AIA, 1.0 mg L-1; BA, 1.0 mg L-1 and 48 h pre-treatment at 4degreesC) resulted in 27.5% of the anthers with calli. This undifferentiated tissue was transplanted to several morphogenic-inducing media, where the effect of 2,4-D, AIA, BA and gibberellic acid (GA(3)) was studied. The best medium (0.05 mg L-1 AIA; 0.05 mg L-1 BA; and 0.1 mg L-1 GA(3)) induced roots in 40% of the explants; this medium also induced plantlet differentiation.