Evaluation of Traits' Performance Contributing to Drought Tolerance in Sorghum

Sorghum (Sorghum bicolor [L.] Moench) is an important food crop for people in semi-arid Africa. The crop is affected by post-flowering drought; therefore, the study was conducted to screen traits contributing to drought tolerance using BC2F4 sorghum genotypes in stressed and unstressed water conditions in a split-plot design. Water stress (0 mm/day) was applied at post-flowering to plant maturity in water-stressed treatment. The genotype SE438 produced the highest grain yield (2.65 ton ha(-1)) in water-stressed environment and NA316C yielded highest (3.42 ton ha(-1)) under well-watered (7 mm/day) environment. There were significant differences of most traits evaluated at p < 0.01 across environments. The mean squares of traits for genotypes by environments revealed interactions at p < 0.05 and p < 0.01. The indices geometric mean productivity (GMP) and mean productivity (MP) were highly correlated with yield under well-watered (YP) and water-stressed condition (YS) and each other. The first principal axis (PC1) explained 59.1% of the total variation. It is the best indicator of yield potential and drought tolerance of sorghum genotypes in this study. Therefore, further improvement is needed to strengthen drought tolerance and yield in sorghum.

Automated summary

Sorghum is an important food crop in semi-arid Africa, but is affected by drought. This study identified traits contributing to drought tolerance in sorghum genotypes, with SE438 showing the highest grain yield in water-stressed environment and NA316C yielding highest under well-watered conditions, indicating sensitivity of sorghum to water availability.