Abstract:
The current work was done during the two successive summer seasons 2016 and 2017 at
Experimental farm of Agricultural Research Center, Ismailia, Egypt. Five genetically diverse
sesame genotypes namely; A1B5(P1), H133A4(P2), line 363(P3), Shandaweel -3(P4), and
Sohag(P5) were crossed in a half diallel breeding pattern to obtain ten F1 hybrids excluding
reciprocals and were evaluated during summer season of 2017. The 15 genotypes viz, the 5
parents and 10 F1s were raised in a randomized complete block (RCB) design with three
replications. Highly significant differences were observed among genotypes for all studied traits.
The performance of the parents P3, P4, P5, and the crosses P3*P4, P3 * P5, P4*P5 and P2*P3 were
the best genotypes for yield and its components. Mean squares for both general (GCA) and
specific (SCA) combining ability were significantly higher for all the studied characters. The
ratios of GCA/SCA were less than unit for plant height; capsules weight plant-1
, 1000-seed
weight and seed yield plant-1
. While, in case of remaining characters the magnitude of SCA was
higher than GCA. This indicates presence of adequate amount of variation in parents and crosses.
The three parentsP3, P4 and P5 could be considered as the best general combiners for seed yield.
However, the crosses P2*P5, P3*P4, and P3*P5 had the most desirable SCA effects for seed yield
plant-1
and the most studied traits and the same crosses also showed the highest heterosis
percentage over the mid-parent values for seed yield. The association between seed yield and its
contributing characters indicated that the seed yield had positive and significant association with
the most studied traits. Path coefficient analysis revealed maximum positive direct effect of
1000-seed weight per plant (0.781), number of seeds per capsule on seed yield followed by seed
oil content (0.442), capsules weight per plant (0.427) and plant height (0.414) showed high
positive direct effects on seed yield. Selection for the traits with positive association and direct effects will be useful for the improvement in yield of sesame through breeding program. High
heritability in broad sense was observed for all studied traits. |
