GENETIC TOOLS AND PROXY PLANT CHARACTERISTICS TO EXPEDITE GRAINYIELD IMPROVEMENT IN SORGHUM HYBRIDS FROM DIVERSE MALE STERILITYCYTOPLASM’S

Abstract

Correlation, path analytics, and genetic variability were investigated in this work, for yield and yield component traits in 280 sorghum F1 hybrids during Rabi 2021 and Summer 2022 seasons. Considerable amount of genetic variation was observed for all the traits studied, confirming the scope for further selection for superior and desirable hybrids. The broad sense heritability was high for all traits evaluated, and the correlation between genotypic coefficient of variation (GCV) and phenotypic coefficient
of variation (PCV) was almost perfect (r=0.99, p<0.001) and their means comparable (sample estimates mean difference = 1.3), implying the low level of the environmental effect, and a high level additive genetic factors effects on the measured traits. There was a high positive correlation between days to 50 % flowering (DFF) and days to maturity (MAT), MAT and number of leaves per plant (NLP), plant height (PH) and hundred seed weight (HSW), panicle width (PW) and panicle weight per hectare (PWt),
PWt and yield (YLD). The correlation coefficients between YLD and the rest of the traits evaluated were low except for PL, PW, and PWt that showed medium, medium, and high positive correlation, respectively. PL, PW, and PWt should therefore be considered in the indirect selection process to identify superior sorghum genotypes with higher grain yield potential. Since the three traits were favorably correlated with grain yield, selection can simultaneously improve all traits by tandem selection, or indirect
selection and index selection. The direct and indirect effects of PWt as revealed by path analytics were instrumental to the observed correlation between YLD and PL, PW and PWt. PWt was therefore the sole trait able to determine YLD along with the major component traits in this work. These findings are expected to expedite and enhance genetic gains in sorghum breeding.