Crop production decreases because of water deficit stress conditions worldwide. Understanding genetic variation in enzymes and physiological responses of wheat genotypes under drought conditions is necessary to select tolerant genotypes for cultivation under drought conditions. These goals set 15 wheat genotypes for cultivation in the fall of 2022 with two irrigation interval regimes to evaluate their growth and yield-related traits for drought tolerance. The experiment had a randomized complete block design with three replications. Results showed highly significant differences among studied genotypes for all assessed traits. Genotype G11 gave the highest values in aldehyde dehydrogenase activity, spike per meter, grain yield, and biological yield (9.620 milliunits/mL, 975.8 spikes m^-1, 10.725 t ha^-1, and 29.568 t ha^-1, respectively). Genotype G1 emerges with the utmost value for glutamate dehydrogenase activity (9.62 milliunits/mL), G2 for tillers per meter (1030.0 tillers m^-1), G4 for spike length (11.17 cm), G6 for 1000-grain weight (40.8 g), G12 for grains per spike (40.9 grain spike^-1), and G14 for plant height (117.2 cm). Likewise, water level treatments exhibited a significant impact on the studied traits. However, genotype G11 was leading in grain and biological yields. The five-day irrigation interval treatment gave the highest values in all studied traits except for glutamate dehydrogenase activity. Therefore, the study concluded that wheat genotypes responded differently to water level treatments and water stress at 14-day irrigation intervals, which can benefit screening the wheat genotypes for water deficit stress.

Keywords: Wheat (Triticum aestivum L.), genotypes, genetic variation, irrigation intervals, drought conditions, growth and yield traits, aldehyde dehydrogenases

Key findings: Genotype G11 had the highest aldehyde dehydrogenase activity, spike count, grain, and biological yields (9.620 milliunits/mL, 975.8 spike m^-1, 10.725 t ha^-1, and 29.568 t ha^-1, respectively). Genotype G1 had the utmost glutamate dehydrogenase activity (9.62 milliunits Ml^-1), G2 for tillers per meter (1030.0), G4 for lengthiest spikes (11.17 cm), G6 for heaviest grains (40.8 g), G12 for grains per spike (40.9 grains spike^-1), and G14 the tallest plants. Furthermore, the 5-day water level treatment significantly affected the growth and yield-attributing traits.