Fruit growing
and viticulture of South Russia
In condition of humid subtropical zone of Russia during 2002-2020, the degree of drought resistance of pear varieties and hybrids was assessed by anatomical, morphological and physiological parameters to study their adaptation mechanisms. Researchs objects different genotypes of genus Pyrus L. (varieties: Bere Zhiffar, Vega, Williams, Red Williams, Chernomorskaya Yantarnaya, Yuzhanka, Nektarnaya, Slavyanka, Verbena, Luchistaya, Bere Bosk, Rassvet, hybrid 8520, Kilchu). A set of physiological, anatomical and morphological indicators was used to assess the adaptability of the studied pear varieties to stress factor of the summer period (high temperature and low water-holding). It is established that change in the physiological processes affect the anatomical and morphological structure of the leaf. The assessment of drought resistance of the studied varieties and hybrids by the nature of changes in the parameters of the water regime is given. It was determined that water-holding capacity of the leaf blade in all genotypes has a high inverse dependence (r= -0,77) on the number of stomates on lower epidermis of the leaf. According to quantitative ratio of chlorophylls a and b, the varieties Bere Zhiffar, Bere Bosk and Chernomorskaya Yantarnaya were identified, confirming stability of the pigment system to water deficit at the most arid period. Continuous modification of the photosynthetic function of leaves associated with productivity and viability was noted. It was found that the influence of stressful weather conditions leads to the appearance of such xeromorphic traits in the genotype as increased development of the palisade parenchyma layer and a decrease in the number of stomates per unit surface. Varieties Red Williams, Chernomorskaya Yantarnaya, Vega and Rassvet are identified by the complex of the above characteristics as the most adaptive to the abiotic stress factors of the summer period of humid subtropics. Revealed adaptive features of these varieties allow to use them in breeding as sources of resistance to drought.
In connection with climate change, it is necessary to improve the assortment of grapes adapted to the conditions of the south of Russia. The purpose of the work is to identify physiological and biochemical indicators associated with the formation of protective reactions of various grape varieties to the effect of summer stressors; to identify adaptive varieties for cultivation in the Anapo-Taman zone of the Krasnodar region on the basis of them. Adaptive resistance of grapes to high temperatures was achieved by increasing the content of bound water and proline. It was found that the indicator of the ratio of bound water to free water, which determines the resistance to drought in the varieties Krasnostop AZOS, Kristall, Zarif, is higher than in other studied varieties and was 5.23-5.24 by the end of summer. The varieties Dostoynyi, Krasnostop AZOS, Aligote showed the maximum amounts of proline (52.41-66.14 μg/g raw weight), involved in the implementation of stress-protective mechanisms. Adaptive changes in water-soluble proteins and sugars played a decisive role in the formation of high-temperature stability in summer. A minimal decrease in the content of soluble proteins (by 1.3 times) during the summer was noted in the Dostoynyi and Kristall varieties, indicating their high adaptive ability. The unstable Aligote variety showed a maximum decrease in the content of soluble proteins by the end of summer (3.4 times). The Zarif variety showed the smallest changes in the content of soluble sugars (a decrease of 1.3 times), indicating increased adaptation to arid conditions. It was found that the induction of protective adaptive mechanisms is more pronounced in the varieties Dostoynyi, Krasnostop AZOS, Zarif, which proved to be more adaptive in comparison with other studied varieties in the conditions of the summer period 2019-2020.
Jasmonic acid and its methyl ester exhibit various physiological and biochemical effects in a wide range of plant cellular processes. However, there is no reliable available method for determining their mass concentration in complex biological objects. The objects of research were fresh leaves of Hibiscus rosa-chinensis, Sansevieria, Juglans regia L., Morus, Vítis. The aim of the research was to improve the analytical method for the quantitative determination of the mass concentration of jasmonic acid and methyl jasmonate, to develop the conditions for preparing samples for analysis. To carry out the work, a capillary ion electrophoretic analyzer "Kapel 104T", a gas chromatograph "Kristall 2000M", a gas chromatography-mass spectrometer GC-MS Perkin Elmer Clarus 600T were used. The approbation of the method of capillary electrophoresis and capillary gas chromatography for the quantitative determination of methyl jasmonate was carried out. The unsuitability of the method of capillary electrophoresis for the direct determination of methyl jasmont was established, and the possibility of determining methyl jasmonate after extraction with hexane by capillary gas chromatography was shown. An increased dosage of the hexane extract sample into the chromatograph was applied, which made it possible to achieve the required level of analysis sensitivity. Application of GC-MS method for identification of methyl jasmonate in hexane extract of leaves with a sensitivity threshold of 0.01 mg/dm3 is shown. The conditions of hydrolysis of plant samples exposure time and concentration of potassium alkali were found experimentally. For the subsequent quantitative determination of jasmonic acid, the method of capillary electrophoresis was used; an electrolyte based on boric acid was used. The completeness of hydrolysis of jasmonic acid esters was tested on solutions of methyl jasmonate. Data on the content of methyl jasmonate and jasmonic acid in biological objects were obtained.
The prospects of application biostimulants of growth to increase the resistance and stability of fruiting of fruit crops are discussed. Fruit crops are exposed to stress factors, both biotic and abiotic. Climate changes, especially regional weather conditions, characterized by a higher frequency of extreme manifestations of abiotic stress, strongly affect the growth and productivity, the quality of fruit plant products. Increasing the productivity of fruit crops is achieved by regulating the main factors of the production process. One of the promising areas of modern horticulture for increasing the resistance and formation of stable productivity of fruit agrocenoses is the development of a system for the application of biostimulants. Groups of biostimulants, their classification, characteristics and mechanism of action on plants are considered. The analysis of the influence of biostimulants on the stability and productivity of fruit crops is presented. It is shown that biostimulants in low concentrations have a growth-stimulating effect, enhance plant metabolism and increase the degree of absorption of nutrients from the soil. Their application makes it possible to increase the efficiency and reduce the amount of mineral fertilizers used in the management system for garden crops cultivated using intensive technologies. The role of biostimulants in the preservation of soil fertility of garden agrocenoses is revealed, since these drugs can stimulate the activity of useful soil microorganisms and optimize the absorption of nutrients from the soil by plants. The anti-stress properties of biostimulants were studied and analyzed to preserve the productivity level of fruit plants, the quality of fruits in conditions of drought, salinity, low and high temperatures. The available developments in the field of the application of biostimulants in horticulture indicate the prospects of applying the research results for further improvement of intensive technologies for cultivating fruit plantations based on methods of biologization and ecologization of production processes.
The article shows the results of the influence of gibberellin on the productivity of seedless grape varieties of the AZES breeding. The indicators of photosynthetic activity of leaves are considered: the content of pigments (chlorophyll a + b and carotene), the size of the leaf surface area and the accumulation of sugars in grape berries. Analysis of these studies showed an increase in the amount of chlorophylls during treatments with gibberellin of a grape plant, as well as an individual reaction depending on the dosage of the preparation and the grape variety. The obtained data indicate that the application of exogenous gibberellin leads to changes in the morphogenesis of grape plants. During the entire growing season, the plants treated with gibberellin showed more intensive growth than the plants of the control variant. An increase in the length of shoots due to the lengthening of internodes at increased doses of GA was revealed. At the same time, no effect on the number of stem nodes was noted; therefore, shoot elongation is associated with stretching of the stem cells. It was proved that under the action of the preparation the total area of grape leaves increased, leading to the formation of a more powerful leaf apparatus: at a dose of GA of 1 ml in the Lotos variety by 22.6 %; Zhemchug Anapy by 28.8 %; Kishmish rozovyi AZOS 16.9 % higher than the control indicator. It is known that the accumulation of sugars in grape berries is due to the photosynthetic activity of the leaf apparatus. As shown by laboratory and field analyzes, gibberellin affects the sugar content in grapes, accelerating the ripening and timing of the harvest. In the variety Lotos, Zhemchug Anapy with a dosage of 1 ml GA and Kishmish rozovyi AZOS with a GA 0.75 three times, the sugar content of berries exceeded the control variants.