A.M. HASSAN, M.F. AHMED, and M.A. RASHED
SUMMARY
Drought is a severe causal factor of reduced crop yields than other abiotic stresses. Therefore, four sorghum genotypes underwent evaluation for their drought tolerance under three irrigation levels (100%, 70%, and 40% from evapotranspiration) under three sowing dates at the Higher Institute for Agricultural Cooperation Farm, Regwa region, Alexandria Desert Road, Egypt, to study the mean performance of grain yield plant-1 and transcriptomic analysis. The performance results reported that Shandaweel-6 and Hybrid-306 revealed the highest drought-tolerant hybrids, while Dorado and Giza-113 cultivars showed the lowest. The transcriptomic profiling of sorghum under normal and drought stress used the RNA-Seq method. Two differentially-expressed genes (DEGs) in leaves respond to drought. In the DREB2 case, the greatest average fold change showed 10.7 and 9.3 for the tolerant hybrids, Hybrid-306 and Shandaweel-6, respectively. Both genotypes performed significantly higher than the average fold change calculated for the sensitive genotypes Dorado and Giza-113 cultivars. This study contributes to a better understanding of the molecular basis of drought tolerance of sorghum and promotes sorghum improvement.
Keywords: Sorghum bicolor, DREB2, CBF4, transcriptomic, cDNA, transcription factors, drought stress
Key findings: Sorghum hybrids Shandaweel-6 and Hybrid-306 received classification as drought-tolerant because of their best performance under drought stress and normal conditions. Both hybrids possess resistance genes for drought and other abiotic stresses. However, the cultivars Dorado and Giza-113 proved susceptible to drought stress due to their weak performances under drought-stress conditions.
Date of publication: October 2022
DOI: http://doi.org/10.54910/sabrao2022.54.4.12