A.N. FARHOOD, M.Y. MERHIJ, and Z.H. AL-FATLAWI
SUMMARY
The study comprised two experiments that were carried out for two consecutive years (2019–2020 and 2020–2021) at the Agricultural Research Station, Babil Governorate, Iraq. In the first experiment, seven wheat (Triticum aestivum L.) cultivars, viz., Iraq, Ezz, Abba-99, Furat, Sham-6, N-70, and Tamoz, were studied for most drought- tolerant genes in 2019–2020. During this year, three droughttolerant wheat cultivars, i.e., Iraq, Tamoz, and Abba-99, were selected having the most droughttolerant genes. In the second experiment, the three selected drought-tolerant wheat cultivars under three different drought stress conditions (D-1, D-2, and D-3) were studied during 2020–2021 in a randomized complete block design (RCBD) with three replications using a split-plot arrangement. The study aimed to determine the impact of drought effects on the expression of drought-resistant genes, growth, and yield traits in wheat. The results showed that wheat cultivars differed in their possession of drought-resistant genes (ABC4, GPAT, GBSS1, and umc1283), and the bands appeared in cultivars, Iraq, Tamoz, and Abba-99, while the rest of the four cultivars had lost one or two genes. Cultivar Iraq was distinguished as the most drought-tolerant genotypes, by having an increased relative expression of genes, ABC4 and GPAT, compared with other cultivars. The D-3 – drought stress condition caused a significant reduction in the biological and grain yield, and harvest index, with a decrease of 38.85%, 12.60%, and 29.83%, respectively. Cultivar Iraq was the least affected for plant height, flag leaf area, tillers meter2, biological and grain yield, and harvest index when increasing drought severity, and these traits decreased by 16.96%, 24.08%, 44.17%, 28.08%, 15.10%, and 15.29%, respectively. Results authenticated wheat cultivars differed in the expression of drought-resistant genes, and drought resistance is largely controlled by genes.
Date published: September 2022
Keywords: Wheat (Triticum aestivum L.), drought stress, drought-resistant genes, genes expression, growth traits, grain yield, and related traits
DOI: http://doi.org/10.54910/sabrao2022.54.3.5