Fruit growing
and viticulture of South Russia

Annotation

Most of the widespread grape varieties belonging to the European species Vitis vinifera L. are not highly resistant to environmental stress factors. On the contrary, American species are characterized by immunity to many pathogenic organisms, and are also able to grow under the influence of various abiotic stresses. Thus, the use of scion-rootstock combinations, where resistant varieties of American grape species act as a rootstock, makes it possible to increase the production and adaptation potential of a more susceptible scion. This work presents the results of a three-year study of the influence of scion-rootstock combinations of grapes on the resistance of grape plants to abiotic stress factors in the summer period in the conditions of the North-Western Ciscaucasia. Two varieties � Kishmish vengerskiy and Kishmish luchistyi � were studied on rootstocks Ferkal and Paulsen, as well as own-rooted plants. To assess the adaptive potential of grapes, the physiological and biochemical parameters of the leaves were analyzed, namely, the water regime, chlorophyll content and the level of electrolyte leakage. The weather conditions were obtained from a stationary weather station in the grape growing zone. The results showed that the scion-rootstock combinations Kishmish vengerskiy - Paulsen and Kishmish luchistyi - Paulsen are characterized by the highest values of the water and chlorophyll content in the leaves. The weather conditions of the summer period during three years were characterized by the presence of extremely high air temperatures and insufficient amount of moisture compared to long-term averages. To such conditions, the grafted forms of varieties Kishmish luchistyy and Kishmish vengerskiy proved to be the most adapted than own-rooted control plants. The obtained data allow to conclude that it is expedient to use the Paulsen rootstock for Kishmish luchistyy and Kishmish vengerskiy varieties in the conditions of the North-Western Ciscaucasia in order to increase the adaptive potential of these varieties to the stress factors of the summer period.

Annotation

The search for new promising pear varieties with high adaptation and production potential is an important aim of modern breeding for the southern regions of the Russian Federation. In present study, the results of the physiological characteristics of four pear varieties during the summerautumn season 2022-2023 are presented. Pear trees were planted in the territory of the Prikubanskaya fruit growing in the Krasnodar Region. Three varieties Leven, Lyuberskaya, Flamenco of Russian breeding and the American variety Devo were used. The pear leaves were selected three times during the summer months and in September. The content of soluble sugars and total phenols, as well as the activity of antioxidant enzymes � superoxide dismutase and peroxidase � were determined in the plant material. It was established that an increase of the level of the primary and secondary metabolites accumulation and an increase of enzymatic activity by ~20-75 % occurred in the hotter and drier 2023. The content of soluble sugars significantly increased to ~12.0 mg/g fresh weight in the leaves of the varieties Devo and Leven. The accumulation of phenolic compounds increased in all pear varieties by more than 30 % with values exceeding 27,0 mg/g fresh weight. The level of superoxide dismutase activity in 2023 averaged 13.4 unit/mg protein, which is slightly higher than the values of 2022. Peroxidase activity increased 2-4 times with maximum values of more than 8,0 unit/mg protein per min. in the varieties Leven and Lyuberskaya. In conclusion, the data obtained indicate that the drier and hotter conditions of 2023 were not critical for the normal growth and development of the studied pears varieties, but only initiated the activation of the defense antioxidant system in plant cells.