RICE TISSUE CULTURE AND APPLICATION TO BREEDING: I. Induction of high totipotent haploid and diploid callus from the different genotypes of rice (Oryza sativa L:)

Callus induction and plant regeneration from various explants (seed, plumule meriste, shoot apex, anther, and immature inflorescence) of rice were investigated. Plant regeneration from seed-derived callus was low (an average of 15,8%) and genotypic dependent. Plumule meristem produced high totipotent callus in all genotypes used on the meddium supplemented with 1,0 mg/1 2,4-D and 0,4 mg/1 kinetin. The frequency of plant regeneration increased from 37 % to 83 % when the concentration of 2,4-D was decreased from 2,0 mg/1 to 1,0 mg/1 at two levels of kinetin (0,4 and 0,6 mg/1) on the callus inducing and subculturing medium. Haploid immature inflorescence callus showed high regeneration capacity (90-97%) than those of anther and shoot apex and regenerated only green plants.