Breeding sesame for resistance to charcoal rot caused by Macrophomina phaseolina

Abstract

To assess the combining ability, heterosis, and heritability of growth traits, yield and its attributes, seeds oil content (%), and disease infection percentage in sesame, a half diallel set comprising five diverse parental genotypes was studied at the Experimental Farm of the Agriculture Faculty, Suez Canal University, Ismailia, Egypt. The experiment was laid out using a Randomized Complete Block Design with three replications. Highly significant mean squares were found for both general combining ability (GCA) and specific combining ability (SCA) for all studied traits. The narrow sense heritability ranged from low to high, with values ranging from 3.3 to 76.43% across the studied traits. In addition, these findings suggest that both dominance effects and environmental factors have a major impact on the traits under study. Shandaweel 3 (P4) exhibited positive and highly significant general combining ability (GCA) effects for all studied traits. This suggests that this parent could be a valuable source of genes for improving yield potential. It showed a highly significant negative effect on disease infection percentage, indicating its potential to contribute genes for disease resistance. Based on its performance as the best general combiner and possessing desirable genes for decreasing charcoal rot infection while increasing resistance to charcoal rot. Furthermore, the parent M1A38 (P3) demonstrated positive and highly significant effects for most of the studied traits, along with a highly significant negative effect on disease infection percentage. The crosses (P1 x P4), (P3 x P5), (P2 x P4), and (P4 x P5) exhibited desirable specific combining ability (SCA) effects and significant heterosis values for most of the studied traits. The cross (P3 x P4) displayed significant heterosis values for most of the studied traits as well. These crosses might be used in sesame breeding programs to produce high-yielding ability and highly resistant pure lines.