Abstract: Young panicles, immature embryos, stem nodes, stem tips, leaf segments, root tips and anthers from Hubei Photoperiod Sensitive Genie Male-Sterile Rice (Oryza sativa subsp, japonica) “Nongken 58” (abbr. 58s) and fertile “Nongken 58” (abbr. 58f) were examined for callus induction, plant regeneration and direct plantlet formation on differentiation medium. 58s and 58f had equal ability in all explants cultures except anther cultures. The induction frequency of the anther callus and the regeneration frequency of the green plant in 58s were much lower than those in 58f, and such differences were not affected markedly by the change of fertility of 58s donor plants. Young panicle, immature embryo, stem node, stem tips showed direct plantlet formation when cultured on differentiation medium containing NAA and kinetin. Different explants produced various types of responses. Young panicles could produce callus and then regenerate plantlets. Evidences from histological observation showed that the plant regeneration in direct plaatlet formation of young panicles were mainly organogenetic, bowever, somatic embryogenesis was also possible.

Key words: Photoperiod Sensitive Genic Male-sterile Rice, Explants, In vitro culture