Abstract:

Plant regeneration from soybean hypocotyl explants has already been reported many times but the regeneration rates were always low, and in all the cases adventitious buds were obtained on media containing cytokinin, which causes the production of excessive amount of callus on the explants and hinder the further growth of the regenerated buds. To tackle these problems, experiments were designed where surface-sterilized mature seeds of soybean were placed on two kinds of germination media, one contained 2 mg/L benzyl adenine (BA) but the other not, and hypocotyl explants were obtained from six days old seedlings and inoculated on two regeneration media, one contained 2 mg/L BA but the other not, for the induction of adventitious bud formation. With all the 12 soybean cultivars tested including 9 local, 2 from USA and 1 Brazilian, the best results were all obtained from the treatment using hypocolyl explants from seedlings germinated on medium containing BA and cultured on the BA-free regeneration medium without any exception. By this treating method, the regeneration rate was significantly increased with the highest of 72% from a local cultivar Guangdali, and the quality of the regenerated buds was also improved.

Key words: Soybean, Hypocotyl, Organogenesis, Hormone, Callus