Isolation and half-diallel analysis of earliness in five (vicia faba l.) Genotypes

Abstract

The present investigation was carried out at Genetic Resources Department, Bahtim, Egypt, to evaluate five faba bean cultivars in Half-diallel crosses set. Ten crosses were constituted in 2014/2015 winter season, whereas, parents and crosses were evaluated in 2015/2016 winter season, in a randomized complete block design, with three replications. Results revealed highly significant variations within parents and F1 genotypes, indicating a wide genetic variability for the studied characters and the possibility of genetic improvement, using such genetic pools of faba bean. Some crosses recorded significant desired heterotic percentages relative to mid parent and better parents for all studied traits, except for plant height and numbe of branches per plant. Both general (GCA) and specific (SCA) combining abilities were significant for all studied traits, revealing the important role of both additive and dominant earliness in the inheritance of the studied characters. The ratio of general and specific combining abilities (GCA/SCA) indicated great additive effects for the majority of the studied characters. P1 and P5 were proved to be good combiners for all studied traits except for number of pods per nod and number of pods per plant. Several crosses exhibited highly significant positive SCA effects for the studied traits, especially P2×P3 and P4×P5 for number of seeds per plant, with high seed weight and number of pods per plant. Heritability, in the broad sense (H2bs%) estimates generally was, high for all studied traits, except for number of branches per plant and number of pods per nod. However, heritability, in the narrow sense, was high for 100-seed weight (72.25%) and pod length (51.03%), while, it was low for the majority of traits. High heritability values indicated that such traits would respond to selection.