Evaluation of Genotypic Variation of Sorghum Varieties in the Southwestern Niger

Abstract

Background: Sorghum (Sorghum bicolor L. Moench) is grown in semi-arid regions, valued for its adaptation and drought tolerance. Understanding genotype × environment interactions is essential for developing stable, high-yielding cultivars. Methods: Eight sorghum genotypes were evaluated during the 2019 and 2020 growing seasons using a randomized complete block design with five replications. Data were collected on plant height, days to flowering, biomass, panicle weight, grain weight, 1000-grain weight. Data underwent ANOVA, Tukey's HSD (p<0.05), and mixed-model analysis. Results: Significant (p < 0.001) genotypic variation was observed for all traits. Genotype × year interaction was significant for most traits, indicating differential performance across year. PCA captured 63.6% variance (PC1 37.9%, PC2 25.7%), revealing trade-offs like taller plants with heavier grains but later flowering. These results highlight exploitable genetic diversity for Sahelian breeding, prioritizing stable, early-maturing, high-biomass/yield genotypes to boost productivity amid rainfall variability. Conclusion: Substantial genetic variability exists among the evaluated sorghum genotypes. High heritability for key traits suggests good potential for genetic improvement through selection. Identified stable genotypes provide valuable genetic resources for sorghum breeding programs targeting yield improvement and stability.