Stability analysis over various filial generations in bread wheat.

Stability analysis on 7 parent varieties and all their possible crosses (excluding reciprocals) in generations F1 to F5 are reported. The regression coefficient (b) of the parents ranged from 0.66 ('Sonalika') to 1.34 ('Kalyansona'). On the average the 'b' value was lower in F3 (.87) and F2 (.88) followed by F1 (1.04), F4 (1.06) and F5 (1.16). Phenotypic stability appeared to be associated with genetic constitution of the parents as well as level of heterozygosity and heterogeneity of the populations. Distinct differences were observed in general combining ability values for regression coefficients among the parents, indicating transmissibility of this trait. However, no such trend was observed for deviation mean squares. The data on yield and stability parameters showed that high mean yield is not necessarily associated with average regression, indicating the possibility of combining high mean yield with high stability.