Stability analysis for physiological parameters and grain yield in bread wheat (Triticum aestivum L.)

A study was conducted at Indian Agricultural Research Institute, New Delhi using 36 diverse wheat genotypes and three sowing conditions (irrigated, restricted irrigation and rainfed conditions) to assess the stability of genotypes for yield and physiological parameters. The pooled analysis of variance with respect to all the traits indicated that the variance due to environment was significant for all the traits except canopy temperature depression at anthesis which showed the distinctly differential effect of the different sowing conditions in the name of environment. The variance for genotypic effect was also highly significant for all the traits under study indicating thereby differential response of all the genotypes selected for the study. The varieties BACANORA T 88, BHRIKUTI, BL 1804, CHIRIYA 3, CHIRIYA 7, CNO 79/PRULLA, GW 273, GW 326, HD 2189, HD 2819, KANCHAN, HD 2781, MP 4010, NEPAL 1, NL 623, HD 2987, C 306 and PBW 175 have shown higher mean values, desirable regression coefficient and deviation from the regression coefficient. Based on the mean performance, linear regression and S²d values, the above varieties can be said stable as per the criteria of the stability analysis. The environmental index for normal sowing was 498.25 which gradually decreased in the restricted irrigation and rainfed sowing. Stress susceptibility index can serve as an indication for selecting genotypes with higher yield and higher tolerance to stress. The higher the value of stress tolerance index (STI) of a genotype better is the stress tolerance. The STI had high positive correlation with the grain yield under normal and both the stress conditions.