الفهرس 
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Abstract
Five faba bean genotypes and 10 F1 faba bean crosses derived from a half diallel cross among these genotypes and their F2 generation, in addition to six populations of four faba bean hybrids (Triple white x GZA, Triple white x Spanish, GZA x Giza 716 and Giza 716 x Spanish were evaluated for earliness and seed yield as well as its attributes at the experimental farm of El-Gemmeiza, Agricultural Research Station, Egypt. Mean performance, heterosis; magnitudes and significancy of both general and specific combining ability, components of variances; heritability and gene action of the studied characters were estimated. The results indicated that the inbred lines P1, P3, P4 and P5 and their single crosses as well as F2 progenies were the best combiners for earliness, seed yield and most of its attributes.
The additive gene effects were larger in its magnitude than dominance ones in controlling earliness characters, 100 seed weight and seed yield/plant in both F1 and F2 generations. However, both additive and dominance gene effects were important in the inheritance of number of branches/plant. Moreover, the dominance was more pronounced in the genetics of plant height, number of pods/ plant, number of seeds / plant and number of seeds/ pod.
Negative and significant usefull heterotic effects relative to mid-parents had been detected in cross P3 x P5 for days to 50% flowering and P2 x P3 for first pod height in both generations. In addition to, positive and significant heterosis relative to mid-parents was recorded for number of seeds/ pod, 100 seed weight and seed yield/plant in cross P4 x P5 in both generations. Heritability in narrow sense was high for earliness characters and moderate to high for seed yield and its attributes in both F1 and F2 generations. Significant non-allelic interactions were detected for days to 90% maturity, first pod height, number of pods / plant, number of seeds/plant, 100 seed weight and seed yield/ plant in all crosses; days to 50% flowering in 2nd cross only; plant height in 2nd, 3rd and 4th crosses; number of branches/plant in 1st, 2nd and 4th crosses and number of seeds/pod in 1st and 3rd crosses.
The additive (d), dominance (h), additive x additive (i), additive x dominance (j) and dominance x dominance (l) gene effects were significant and involved in the inheritance of days to 50% flowering and first pod height in cross 2nd; first pod height and number of pods / plant in 1st one; number of pods / plant, number of seeds/plant and 100-seed weight in cross 4th; number of seeds/plant in crosses 1st and 3rd and 100-seed weight as well as seed yield / plant in cross 2nd .
The digenic interaction types additive x additive (i) and dominance x dominance (l) in cross 4th were involved in the inheritance of first pod height. Whereas, the additive gene action (d) and its digenic type, additive x additive were significant for plant height and number of pods / plant in cross 3rd; number of branches / plant in cross 2nd and seed yield / plant in cross 4th. Meanwhile, the additive x dominance (j) type of gene action was significant for days to 90% maturity in cross 2nd, plant height in cross 4th, number of branches / plant in crosses 1st and 2nd and 100-seed weight in cross 3rd.