Genetic analysis for seed germination, callus induction and survival of rice under salt at in vitro conditions

The genetics of salt tolerance in rice was investigated both at seed germination and in seed/seedling derived calli using six parents diallel analysis., excluding reciprocals. Test materials involved tolerant (CSR-5 and CSR-10), moderately tolerant (NDR-501 and SAR-41) and susceptible (IET12860 and IET 11149) genotypes. Rate of germination index (RGI), germination stress index (GSI) at seedling phase, fresh and dry weight (FW and DW) of calli, corresponding survival ratio of callus were studied for their combining ability and gene action. Analyses revealed both additive and non-additive gene effects for most of the traits: the former being more pronounced than later, especially under stress medium: for fresh and dry callus weight and callus survival under controled condition, both additive and non-additive gene effects were equally important. The genotypes like CAR-10, CSR=5 (tolerant) and NDR-501 (moderately tolerant) were found to be the best combiners under both Control (CM) and salt medium (SM). The crosses like CSR-10 x CSR-5, CSR-5 x NDR- 501, NDR-501 x IET 12860 and NDR-501 x IET 11149 exhibited maximum SCA effects for fresh and dry weight of calli in control medium and salt medium and its terminal survival under CM.