EFFICIENT PLANT-REGENERATION THROUGH SOMATIC EMBRYOGENESIS FROM CALLUS INDUCED ON MATURE RICE EMBRYOS (ORYZA-SATIVA L)

To obtain a reproducible efficient procedure for regeneration of rice plants through somatic embryogenesis from callus four published method s of callus induction and regeneration were compared. Callus was initi ated from mature embryos of the Japonica cultivar Taipei 309 of rice ( Oryza sativa L.). The number, mass and morphology of the callus formed on the scutellum were dependent on the medium used. A limited humidit y and an optimal aeration of the culture vessels enhanced the frequenc y of embryogenesis and plant regeneration. A method described by Poons apaya et al. (1989) was found to be the most efficient and was slightl y modified. As a result 98% of the T309 embryos formed callus, of whic h 63% regenerated into plants. Each callus yielded an average of 6 pla nts. Plant morphology, fertility and seed set of the regenerants were found to be normal.