YIELD STABILITY IN BREAD WHEAT GENOTYPES

Stability for grain yield performance and genotype x environment (GxE) interaction was studied in twelve (nine advance genotypes and 3 checks) wheat genotypes evaluated at various locations having different agro-climatic conditions in Sindh province of Pakistan over two years. The combined and individual analysis of variance for locations and years was conducted. Pooled analysis of variance revealed highly significant (p<0.01) difference for genotypes, environments and genotype x environment (GxE) interaction. A joint regression analysis was applied to grain yield data to estimate the stability parameters viz., regression coefficient (b), s.e. (b) and deviation from regression coefficients (S 2 d) for each genotype. Genotype MSH-14 produced the highest mean yield (5090 kg/ha) in all environments averaged for two years, and had regression coefficient (b) close to unity (0.86) and S 2 d close to zero (0.7923). This indicated wide adaptation and stability of performance of MSH-14 in all environments. Other high yielding genotypes MSH-03 and MSH-05 ranked 2 nd and 3 rd showing regression coefficient (b=0.78 and 0.69 respectively) and deviation from regression (S 2 d= 1.076 and 1.29 respectively) indicating specific adaptability of these genotypes to harsh (un favorable) environments. These findings suggested that both the genotypes could be used as stress tolerant genotypes under stressed environments (such as drought, heat and salinity stress).