Estimation of heterosis combining and ability in faba bean (Vicia faba L.)‎ by line X tester technique

الملخص EN

The present study was conducted at Sakha Research Station during 2014/2015 and 2015/2016 growing seasons.

Line x Tester analysis was used, five lines and four testers were crossed in all possible cross combination according to factorial mating design producing twenty hybrids of Faba Bean in the first season.

All genetic materials were tested under two sowing dates, i.e.

October 20 (early date) and November 20 (late date) each in one experiment arranged in a randomized complete block design with three replications in the second season.

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.

Regarding yield and its components traits, the most crosses exhibited significant positive heterosis values relative to better parent for total dry seed yield, three, six and four crosses exhibited significant positive heterotic effects relative to better parent for number of seeds/plant, seed yield/plant and 100-seed weight respectively, under the two sowing dates.

Both general (GCA) and specific (SCA) combining ability were significant for the most studied characters revealing the important role of both additive and dominant components in the inheritance of the studied characters.

The parental genotype (Giza716) was a good combiner for seed yield/plant and100-seed weight under the two sowing dates.

Several crosses exhibited significantly positive SCA effects for the most studied characters especially the crosses (Sakha 4 x Qahera 4, Cross 957 x Giza 843 and Giza 716 x Qahera 4) and the crosses (Sakha1 x Misr 1, Sakha 4 x Misr 1 and Giza 40 x Giza 843) which exhibited highly significant and positive SCA effects for seed yield/plant and 100-seed weight respectively under the two sowing dates.

Heritability in broad sense estimates (Hb %) were higher than their corresponding of narrow sense heritability (Hn %).

The estimates of narrow sense heritability ranged were (37.7-40.4 %), (33.7-46.8 %) and (45.5-48.3 %) for number of seeds/plant, seed yield/plant and 100-seed weight, respectively under the two sowing dates.