Implications of Parental Selection Procedures on Hybrid Performance and Adaptability

(1) Male parents selected at one location during summer resulted in hybrids of wide adaptation. The magnitude of male × environment interaction was considerably lower than female × environment interaction indicating that selected males have conferred greater stability of performance to hybrids.

(2) Further, estimates of σ²_gca (m), σ_2gca (m) × Env. were not significant indicating that the gca due to males is also stable while similar interactions with females were highly significant indicating their sensitivity. The σ²_sca × Env. interaction was also not significant indicating specific combining ability to be stable.

(3) The early test cross procedure, while capitalising largely on additive genetic variance also seem to usilise some non-additive genetic variance. In the present study, where test cross procedures were used 30 per cent of genetic variation used was of the non-additive type, while in other studies only 10 per cent of the variation was due to sca. The implications of early test cross procedures as breeding tools have been discussed.

(4) Studies on character association revealed that when seed numbers are not adversely effected, early flowering and seed weight were the most important attributes influencing yield. Selected males furnished greater diversity for seed size.