Estimation of Gene Effect for yield, yield Components and Foliar Diseases of Two Faba Bean Hybrids at Nubaria Region

Abstract

Two crosses of faba bean (Giza716xGiza40) and (Giza716xNubaria2), each represented by six population (P1, P2,F1, F2, BC1 and BC2) were tested for yield, yield components, growth attributes and two diseases (chocolate spot andrust). Heterosis in F1, which exhibited highly significant positive effects were detected for number of branches /plant,number of pod /plant, number of seed /plant, seed yield /plant and plant height in the two crosses over mid and betterparents. Significant negative Heterosis effects were obtained for chocolate spot and rust diseases in the two crosses overmid parents. Highly significant positive values of inbreeding depression were detected for number of branches/ plant,number of pods/plant, number of seed /plant, seed yield /plant, 100-seed weight and plant height in both crosses.However, highly significant negative values of inbreeding depression were found for chocolate spot and rust diseases inthe two crosses. Over dominance towards the higher parent were detected for number of branches/plant, number ofpods/plant, number of seeds/plant, seed yield /plant and plant height in both crosses. It was also found that overdominance controls spot and rust diseases in the second cross. Additive gene effects were significant for all characters,excepted number of seed/plant and seed yield/plant in both crosses. Dominance effects were highly significant for alltraits, excepted, seed yield/plant and plant height in both crosses and rust disease in second cross. Additive x additive,additive x dominance and dominance x dominance types of gene action were significant for most traits in both crosses,except, chocolate spot and rust disease. In both crosses, high heritability values in broad sense were detected for all traitswhich, ranged between 63.20 for rust disease and 85.32 % for reaction to chocolate spot and for cross (Giza 716 X Giza40). However, cross (Giza 716 X Nubaria2) had values ranged from 60.7% for reaction to rust to 70.93% for seedyield/plant in (Giza 716 x Nubaria2). The values of heritability in narrow sense were detected for all traits which, rangedbetween 60.19 to 80.36% for resistance to rust and chocolate spot disease in first cross, respectively and between 59.36and 68.42% for number of pods/plant and seed yield / plant in the cross (G.716 x Nubaria.2).The estimates of expectedgenetic advance from selection in F2 generation reflected low or moderate values for all studied traits in both crosses thatranged between 7.78 cm for plant height to 1.8 for rust disease in cross (Giza 716 X Giza 40) and between 8.13 cm forplant height to 1.84 for number of branches/plant in (Giza 716 X Nubaria2) cross.