STM Article Repository

Two field experiments were conducted at Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt. The first experiment was in a naturally Orobanche- free field and the second one was in a naturally Orobanche-infested field. In each experiment sixteen F2 crosses and their parents were sown. The sixteen F2 crosses were produced by a 4 x 4 factorial mating design in F1 and selfed to give F2-crosses. The data were then analyzed using a line x tester design. The main objective of this study was to develop new promising faba bean genotypes that are able to produce high yield, resistance to foliar diseases and broomrape tolerance. Significant differences among all genotypes mean square were observed for all studied traits under both growth conditions. The parents, crosses and their interaction mean squares were detected for all traits in the two environments. The mean squares of lines were significant and/or highly significant for flowering date and 100-seed weight under both conditions, while number of pods per plant was significant under normal condition, in addition to the number of seeds per plant and broomrape dry weight per plant under infested broomrape condition were significant and highly significant, respectively.

Mean squares of testers were significant for chocolate spot at the two conditions; rust disease, plant height, number of pods and seeds, seed yield per plant and 100-seed weight under normal condition. Lines x testers mean squares were significant for all traits in both conditions, except for number of branches and 100-seed weight. L1 and L4 and the parental testers T4 were considered more resistance parents to foliar diseases under both environments. The crosses; L2 x T3, L2 xT4, L3 x T2, L3 x T4 and L4 x T4 were considered resistant to foliar disease and had an earlier flowering date. The testers, T3 and T4 showed significantly the highest values of number of seeds per plant, seed yield per plant and 100-seed weight under both conditions, while the crosses; L3 x T4 and L4 x T4 had the highest values for seed yield per plant and 100-seed weight under both conditions. The parental L2 and T4 were considered good combiners for chocolate spot and rust diseases under both environmental conditions, while L1 and T4 performed as good combiner parents for number of seeds and seed yield per plant. The cross; L2x T3 performed as good specific combiner cross for foliar diseases under both conditions. The crosses; L2x T3, L3xT4, L3 x T1and L4 x T4 had highly significant (sij) values for the No. of seeds and seed yield per plant under infested soil condition. The phenotypic coefficient of variation (PCV) values ranged from 5.52% to 84.01% and genotypic coefficient of variation (GCV) values ranged from 3.18% to 79.21%. Broad-sense heritability (H) ranged from 72.98% to 99.29%, and narrow sense heritability (h2) ranged from 2.3% to 21.38%. Expected genetic advance (Ga) ranged from 0.03 to 0.71, and predicted genetic advance (Ga%) ranged from 8.21% to 10.86%.