STUDIES ON THE CALLUS INDUCTION EFFICIENCY OF RICE (ORYZA-SATIVA L) ANTHERS

The callus induction efficiency of rice anthers is high when spikelets are yellowish green in colour and tips of anthers at the middle of the spikelet corresponding to mid-uninucleate stage of the microspores. Dark incubation of anthers showed a mean of 7.04% callusing ability (CA) compared to 2.24% under continuous illumination. The best duration of cold pre-treatment was observed to be 9-18 days in semi-solid and 9-15 days in liquid media suggesting a cold shock of 9 days at 8 +/- 1C to be enough for induction of calli. The callusing ability of japonicas ranged from 15.5 to 375 with regeneration ability of as high as 62.5%. In indica, a wider range of 0.5-34.6% callus induction was observed with regeneration of plants of up to 71.4%, most of which, however were albino. The variable response of indicas and japonicas indicates that cultivar and media differences exist in terms of callus induction and regeneration.