Department of Plant Breeding and Genetics, Agricultural College and Research Institute, Madurai-India-625104
A study was undertaken to know the genetic potentialities of genotypes belonging to three different races of Oryza sativa L. Fifteen wide compatabile genotypes including 11 tropical japonicas and four indicas were crossed with three each of indica and japonica genotypes in a ‘line x tester’ mating design. The resultant four types of hybrids viz., tropical japonica x indica (33), tropical japonica x japonica (33), indica x indica (12) and indica x japonica (12) were evaluated for mean performance and combining ability effects for different yield component traits. Based on mean performance and gca effects, four genotypes viz., IR 66154-48-1-3-1, IR 66159-23-2-2-1, ASD 16 and Langi were adjusted as best. Multiple crosses involving these four genotypes would yield good segregants with all economic traits along with wide compatabile genes, which could be used as improved varieties or parents in heterosis breeding programmes involving inter-racial crosses. The hybrid ASD 16 x Langi, with high additive effect, is suggested for recombination breeding to obtain better segregants with high grain yield and wide compatabile genes.
Rice, wide compatabile genotypes, inter-racial crosses, combining abilities
