screening of some grape (vitis vinifera l.) genotypes responses to drought stress using physiological and biochemical traits in greenhouse condition

Purpose: grapes (vitis vinifera l.) are among the most significant agricultural products cultivated in various regions of iran, boasting high nutritional value. this study focuses on assessing the genetic diversity of grape genotypes from vineyards in the west azarbaijan province.  drought is an important environmental factor that limits plant growth and production. given the abundant grape germplasm in iran, there is potential to select cultivars and high-yielding genotypes possessing valuable genetic traits to use as resilient bases in commercial grape cultivars. research method: this research involved the evaluation of 16 grape genotypes in a single phase. for this purpose, 16 grape genotypes were grouped and compared in various dry conditions including (peg0%, peg2% and peg4%). findings: the results showed that vegetative traits, relative water content, and membrane stability decreased in all cultivars, but this decline was less pronounced in the »garashire, gezel, and fakhri genotypes«. protein content and the activity of protective enzymes in the roots and leaves increased significantly across all 16 genotypes, with particularly notable levels observed in the »garashire genotype«. drought stress had a marked effect on the accumulation of malondialdehyde and hydrogen peroxide in the asgari and reddish tabriz genotypes. the levels of these compounds were higher in these genotypes compared to others, indicating increased lipid peroxidation and reduced stability against drought. research limitations: there was no limitation. originality/value: the adverse effects of drought were more pronounced at the end of the stress period, especially under a high dose of peg (4%). overall, the »garashire genotype« exhibited the highest tolerance, while the asgari genotype was the most sensitive to drought.