RESISTANCE TO DROUGHT OF GRAPE VARIETIES

The work is devoted to the study of the resistance of grape varieties to high-temperature and water stress, which is very important due to climate change and the increasing weather anomalies.  The studies are aimed at solving the problem related to the disclosure of the physiological and biochemical mechanisms of the adaptation of grape plants to the climatic stress factors of the summer period against the background of changing environmental conditions.  The objects of research are technical grape varieties of various ecological and geographical origin.  It has been established that under conditions of high-temperature stresses, the inter-specific hybrids of the Crystal (Euro-Amur-American origin), Vostorg (Amur-American origin), Dostoiny (Euro-American origin), increased resistance characterized by a smaller change in the ratio of the content of bound and free water,  which is associated with a high content in the leaves of the stress hormone abscisic acid, narrowing stomatal gaps and reducing water loss.  The varieties Kristall and Vostorg were also characterized by greater peroxidase activity, which increases in their resistance to oxidative stress.  In general, the Kristall, Dostoiny, Vostorg and Aligote varieties (interspecific hybrid of Western European origin) showed complex resistance to high temperature and water stress, which is also due to a higher content of proteins with peroxidase activity – of molecular mass 80, 70 and 60 kDa.  Comprehensive assessment of physiological and biochemical characteristics allows to obtain a reliable assessment of the genotypes of grapes for resistance to adverse climatic conditions of the summer period and can be used as an indirect method of diagnosing varieties for drought tolerance.