Interactive effect of genotype and environment on the paddy yield in Sindh province

The implication of genotype-by-environment (G x E) interaction is an important consideration in plant breeding programmes. A significant G x E interaction for a quantitative trait such as yield can seriously limit efforts in selecting superior genotypes for both new crop introduction and improved cultivar development. To determine the possible effects of environments and genotypic differences for yield, 7 advanced mutants of non-aromatic rice along with parent variety IR6 and 2 commercial checks were tested at 8 different sites in Sindh during 2004 and 2005 rice crop growing season. Genotypes, locations, genotype x environment interactions were highly significant (P less than 0.01) indicating genetic variability between genotypes by changing environments. Stability analysis showed that mutants IR6-15/A and IR6-15/E had the mean paddy yield with regression coefficient (b) less than or close to unity (1.10 and 0.85) and the lowest deviation from regression (S2d) (0.03 and 0.17) suggesting above average stability and adaptability over environments. IR6-15-18 produced low mean yields with the highest regression coefficient (b) and highest deviation from regression coefficient (S2d) had below average stability and is specifically adapted to favourable environments.