Genetic Studies of Heterosis and Combining Ability for Foliar Disease, Yield and Its Contributing Characters in Faba Bean (Vicia faba L.)

The present study was carried out in the farm of Sakha Agricultural Research Station, Kafr –El Sheikh, Egypt, during2019/20, 2020 /21seasons to produce seed hybrids (F1 seeds) which evaluated in 2021/22 season. Four parental genotypes namely; Almany, Giza 843, Misr 3 and Najeh were used as testers, while four material genotypes namely; Line 1, Line 2,Line 3 and Line 4 used as lines which crossed according to Line X tester mating system under insect free cages in the first and second seasons. In the third season the resulted F1, s sixteen crosses along with their parental genotypes were sown in a randomized complete blocks design with three replications during 2021/22 season. The data subjected to line x tester analysis. Highly significant of genotypes, parents and crosses were found for all traits. The magnitude of genotypes or any of its components i.e., parents, crosses and parents vs. crosses were several times large than corresponding mean squares of error. Mean squares of parent's vs. crosses as an indication to average heterosis over all crosses appeared to be highly significant heterotic effects for almost all traits. Partitioning the crosses mean squares to its components i.e., lines, testers and lines x testers revealed that, lines and testers mean squares seems to be not significant for all traits. While, lines x testers mean squares found to be highly significant for all traits. The ratio of s2gca/s2sca was less than unity for all traits, indicating that the non-additive gene effects were of greater important in the inheritance of these traits. The crosses; Line 1 x Tester 1, Line 1 x Tester 2, Line 2 x Tester 2, Line 3 x Tester 1, Line3 x Tester 4, Line 4 x Tester 1 and Line 4 x Tester 2 had significant and /or highly significant mid and better parents heterotic effects for many important traits a result of over-dominance in approximately all studied traits. Tester 4 considered as good combiner parent for plant height, No of pods/plant, No of seeds /plant, seed yield /plant and curd protein percentage. The cross; Line 1 x Tester 2 expressed significant (Ŝij) in favorable direction for rust disease reaction, flowering date, plant height and crude protein percentage. The cross; Line 2 x Tester 3 had significant (Ŝij) in favorable direction for chocolate spot diseases reaction, plant height and No. of branches/plant and the cross; Line 4 x Tester 2 had significant (Ŝij) in positive direction for No of branches/plant, No of pods/plant, No of seeds/plant, seed yield /plant and carbohydrate percentage. Brood sense heritability ranged from 24.6% for No. of seeds/plant to 77.90% for 100-seed weight. While, narrow- sense heritability (h2), ranged between 0.68% for 100-seed weight to 20.28% for chocolate spot diseases reaction. The predicted genetic advance ranged from 0.18% for 100- seed weight to 6.92% for chocolate spot diseases reaction.