Fruit growing
and viticulture of South Russia
Physiology and biochemistry of plants
Organic grape acids play a key role in sensory perception of wine and have a direct impact the formation of its organoleptic characteristics; contribute to the protection of wine materials and wines from the development of harmful bacterial microflora; affect the intensity of redox processes by inhibiting the action of oxidative enzymes; ensure the stability of wine products. The main grape berries acids (more than 90% of the total amount of acids) are tartaric and malic acids. Their content in grapes is due to a number of factors - grape variety, meteorological conditions during ripening, air temperature (cool conditions contribute to a higher content of malic acid in the ripe berries), water circulation in the plant stem, soil-microclimate complex, and agrotechnics of grape bush cultivation. The amount of these acids and their ratio largely determine the amount of titrated and active acidity of grapes. The purpose of this research was to study the composition of organic acids of grapes of European and Crimean aboriginal varieties from different soil and climatic regions of the Crimea. According to the results of research we have carried out the role of the grape variety in organic acid accumulation in the berries was confirmed. The similarity of grapes organic acids profiles was revealed between Pinot Blanc and Sary Pandas; Kokur Belyi, Rkatziteli and Muscat Belyi. The role of the soil and climatic conditions of grapes growing in the process of formation of composition of organic acids complex was shown. The possibility of using the organic acids complex as an indicator of the quality of grape raw material for the production of wines with geographic status as well as for optimization of technological methods of their production was confirmed.
The impact of cold stress is of great importance for scientific research in viticulture due to the relatively low cold resistance of grapes under the conditions of the viticulture zone of Russia, which leads to a significant decrease in yield. A better understanding of the physiological processes that influence the resistance of grapes to low temperatures is necessary for developing strategies to mitigate stress.The aim of this research was to study the changes in the antioxidant enzymes activity in grapes of different varietes with different cold- tolerance under the influence of the cold stress. Grapes shoots and buds of resistant and non-resistant varieties were chosen as research material. As the result of this work the different reactions of grape buds and shoots tissues to the low temperatures influence were observed. The resistant varieties were characterised by higher malonic dialdehyde content in vine tissues and buds than non-resistant varieties. For cold-resistant varieties the presence of high level oxidative processes are important for the activation of protective reactions. Influence of the cold stress resulted in elevation of antioxidant enzymes activity in the studied grape varieties. In the shoot`s tissues of resistant varieties the activity of these enzymes was higher than that of non-resistant varieties. Interestingly, that the relationships between cold-resistivity and antioxidant enzymes activity werent observed in studied buds, except for the peroxidase. n the studied varieties, there was no change in the number of peroxidase isoforms under conditions of low temperature stress, while its total activity significantly changed, which may be due to an increase in the expression of this enzyme. The activity of this enzyme changed drastically compared to the control. We suggest that the activity elevation of this enzyme is one of the defining protective reactions to the cold stress in grapes.
Under the conditions of the Krasnodar Territory, metabolic changes in apple varieties that differ in scab and drought resistance have been identified. Using physiological and biochemical methods with capillary electrophoresis the features of the apple tree`s leaves are studied in the summer growing season. According to the seasonal dynamics of some metabolites (malonic dialdehyde, chlorogenic acid, calcium ions), a comparative assessment of the response of apple varieties with different resistance to scab under influence of summer stressors was conducted. It was revealed that the smallest quantitative indicators of malon dialdehyde content under stressful conditions of August were observed in apple varieties, immune to scab, like Fortune, Soyuz and non-scab immune Rodnichok variety and were 0.123-0.192 mol / g dry weight of the substance and it is indicating of their resistance to oxidative stress. During the summer period, the highest content of chlorogenic acid were observed in scab-immune apple varieties. In the period of the greatest impact of stress factors, in August, its content significantly increased in the varieties not immune to scab (1.14-1.55 times), that is plants indicating the induction of protective reactions against the scab pathogen. According to the physiological and biochemical indexes the apple variety Fortuna and the Union was identified as varieties with high resistance to drought and scab pathogen in the South of Russia. Metabolic assessment of apple varieties according to physiological nd biochemical characteristics is a reliable criterion of plant resistance to summer stressors, and can be used as indirect diagnostics methods for adaptability of fruit crops varieties.
Tasty and technological qualities of raspberries depend not only on the genotype but also on their chemical composition, which is associated with soil and climatic conditions of plant growth. Long-term comparative study of raspberry samples on the main chemical characteristics in the foothills of Adygea allowed to determine the best among them. An assessment of more than 30 varieties of raspberries and one of the Rubus idaeus L. ecotypes (k-12897) was carried out. It is determined that, the content of dry substances in raspberries is about 13-19 %; sugars accumulate 4-10 %; acidity (malic acid) 1,4-2,6 %; vitamin C (ascorbic acid) 21-43 mg %. Increased amount of dry matter (about 18 %) were allocated the berries such varieties as Aly Parus, Magnificent Delbard, Lloyd George, Turner. The varieties of Aly Parus, Magnificent Delbard and Carolina (9.6%) have a high sugar content in this zone. According to the amount of vitamin C in raspberries, the varieties of Alenushka, Aly Parus, Arbat, Generalissimus, Lloyd George, Mestnaya is Astrakhani, Meteor, Olathe, Turner (40-45 mg %) stood out. When tasting jam and raspberry compote, the appearance of the product, color, consistency, taste, aroma of jam, as well as the color, transparency and taste of the syrup were determined. Samples of raspberries, received the maximum overall score (4,9-5,0 points) Aly Parus, Skromnitsa, Kompanion, Prude, Shuntukskaya can be used to prepare the high-quality jam. All compotes were characterized by high taste qualities of berries, color of syrup and transparency. According to the general technological assessment (5.0 points), compotes from Hussar and Tarusa varieties were stand out.
To assess the endurance of plants to oxidative stress, a wide range of indicators characterized the functional state of plants is used. As one of the most informative indicators, along with other enzymes (peroxidase, superoxide dismutase, etc.), catalase is considered. The aim of this work was to study the effect of root application of calcium and magnesium-containing substances on the activity of catalase in the leaves of a tea plant. In the humid subtropical zone of Russia on tea plantations under the conditions of a field experiment with fertilizers, the activity of the antioxidant enzyme catalase in young shoots and mature leaves of Kolhida tea was studied. The dynamics of the concentration of cell sap of young shoots and the catalase activity of tea plant leaves during different periods of vegetation, including those covering drought in combination with short-term hyperthermia due to day dynamics, is shown. It was found that an increase in the concentration of cell sap of young shoots under stressful conditions was accompanied by an increase in the activity of mature leaf catalase (r = 0.60) and inhibition of catalase activity in young shoots (r = -0.59). The effect of the root use of calcium in the form of a natural substance (100 kg / ha CaO) and magnesium in the form of MgSO4 (60 kg / ha Mg) on the activity of the antioxidant enzyme catalase in young shoots and mature tea leaves was studied. It is shown (in comparison with the control) an increase in the activity of catalase in mature leaves in certain periods against the background of the use of calcium-containing natural material. The use of magnesiumcontaining fertilizers reduced the resistance of plants to stress, which was recorded by a significant increase in the concentration of cell sap in young shoots and lower catalase activity in young and mature leaves.