Phenotypic variability analysis of key sorghum (Sorghum bicolor (L) moench) genotypes under dry lowland areas

Abstract

Sorghum is a climate-resilient food security and nutrition crop, which has been produced as a staple food in the semi-arid tropical regions of the world. However, moisture stress is increasingly affecting sorghum performance, especially at the flowering stage when water availability is critical for grain filling, thus reducing the sorghum grain yield. Therefore, the experiment was conducted to identify the best-adapted superior sorghum genotypes and quantify genetic variability, heritability and genetic advance as percent of mean for yield and yield components of sorghum genotypes. An alpha lattice experimental design with two replications was used to assess 42 sorghum genotypes in total at Mieso and Kobo. The combined analyses of variance revealed the presence of substantial genetic variation among sorghum genotypes for yield and agronomic traits. Among the traits with high genotypic coefficients of variation and heritability observed for plant height, panicle width and panicle yield were linked with higher values of genetic advance as a percentage of the mean. This result indicates that additive gene action governs the variability of these traits. High heritability and genetic advancement percentages were obtained for plant height (95.63 and 45.39 %, respectively), 1000-seed weight (77.98 and 23.86 %, respectively), panicle exertion (74.87 and 51.88 %, respectively), and panicle yield (65.43 and 37.32 %, respectively). The maximum grain yield was obtained from genotype 4x14 (6.32 tha^-1), followed by genotypes 8x15 (5.92 tha^-1), 1x15 (5.88 tha^-1), 13x14 (5.78 tha^-1) and 6x15 (5.57 tha^-1), with an average value of 5.00 tha^-1, which was greater than the mean value of the check (ESH-4) (4.77 tha^-1). In general, this study revealed wider genetic variability in the tested genotypes for different traits under moisture stress conditions. The selection and hybridization on these genotypes for a desired traits with high (H²) coupled with higher GCV and GAM will be effective to develop and select high yielding, stable and early sorghum genotypes. The results of this investigation would help determine the most pertinent genetic material and plan the subsequent breeding program to encourage efforts for varietal improvement. The most promising and potential genotypes that could be used commercially were identified by the study following an in-depth investigation of their superiority and yield stability over time across different parts of the country.