Genotype X environment interaction on bread wheat grown over multiple sites and years in Pakistan

The stability for yield performance and genotype x environment (GxE) intera ction was studied in 12 wheat genotypes grown at 13 contrasting sites (12 i n Sindh and one in NWFP) over two years. The combined analysis of variance over all environments revealed a highly significant (P less than or equal t o 0.01) difference for genotypes, environments and genotype x environment i nteraction. An adaptation analysis was applied to estimate the b. s.e. (b) and deviation from regression coefficients (S(2)d) for each genotype. The g enotype SI90157 produced the highest mean yield over all the environments s howing wide adaptation and stability. Genotypes PN90111; Anmol 91, SP89126 and SH8921 gave the lower mean yield over all environments with high value of s.e (b) and s(2)d. The line SI88126 gave higher yield particularly in hi gh yielding environments showing weak stability. The utilization of stable genotype SI90157 in the breeding programme fur dir evolution of new high yi elding variety has been suggested.