Fruit growing
and viticulture of South Russia
Physiology and biochemistry of plants
The questions of adaptative resistance of apple-tree varieties of various ecological-geographical origin to hydrothermal conditions of the winter and summer periods of plants development in the North Caucasian region of Russia are considered in the article. In the process of carried out research the comparative data characterized a physiological condition of apple-tree studied varieties during the winter and summer periods of 2013-2016 are obtained. The modern physiological-biochemical and anatomical-morphological methods of research with use of highly effective ana-lytical equipment are used in the work. It is noted that tree ploidy apple varieties of the Souys and the Rodnichok of native breeding, and also the diploidy varieties of the Aydared (USA) and Precubansko-ye (native breeding) in a winter time on physiological and biochemical parameters show themselves as high winter-hardy, in comparison with others studied varieties. It is shown that biochemical adaptation of apple varieties to a low-temperature stress is reached due to synthesis of the increased amount of proline, su-crose, the phenolcarbonic, chlorogenic, ABA acids and peroxidase. It is established that during the summer vegetative period of 2013-2016 the tree ploidy apple varieties of the Soues and the Rodnichok, and also the diploidy of Precubanskoye (all varieties of native breeding) have the best ability to adapt to a high-temperature stress and a drought, in comparison with other studied varieties. In the leaves of these apple varieties under the condition of summer extremal temperatures it is accumulated, more form of water, proline, sucrose and ABA, made the protective function, are accumulated. The adaptation features of plants revealed in the course of the research prove the necessity of use of potential opportunities of native apple varieties for breeding process as sources of signs of winter hardiness and drought resistance.
In the Anapa-Taman conditions (the summer period of 2014-2016) it is considered the questions of adaptation of various ecological and geographical origin grapes to abiotic and biotic stresses, and also the problem of formation mecha-nisms of their productivity. As a result of the carried out research the comparative data are obtained that characterizing a physiological condition of grapes plants when strengthening action of stressful factors. In the work the modern physiological and biochemical methods of research with the highly effective analytical equipment, and also methods of light microscopy have been used. The results of the carried out research have shown that the studied grapes varieties of various ecological and geographical origin under the influence of stressful factors made active the different systems and it is confirmed by change of key physiological and biochemical and anatomical and morphological indicators of plants. The various mechanisms of adaptation of the studied grapes varieties during vegetation to a drought and a high-temperature stress caused by their different ecological and geographical origin are revealed. The varieties with economical valuable properties perspective for use in the breeding and cultivation in the production orchards in the South of the Russian Federation are selected. In the process of studying of stability of grapes varieties to biotic stresses of the vegetation period it is established that at bigger content in the plants leaves of chlorogenic acid, that is metabolic precursor of a lignin and create of the adverse conditions for develop-ment of phytopathogens, the Crystal grapes are defected by mildew less, than plants of Krasnostop of AZOS and Dostoyny (Kcorrel. = 0,92). The high inverse correlation is revealed between intensity of development, percent of defeat of grapes plants by mildew and the content of chlorogenic acid in the leaves of grapes plants of the studied varieties (Kcorrel. = - 1).
Winter hardiness of fruit plants must be regarded as genetically determined property, the implementation of which depends on the physiological state of trees in the process of cultivation, and also from photosynthetic activity of leaves. The development of frost resistance and the loss of this property is significantly associated with changes of water state in the fruit plants tissues. For assessment of changes in water balance are increasingly using a differential thermal analysis (DTA) of ice formation processes in the organs and tissues of plants. The aim of our work is to analyse a number of cherry cultivars for winter hardiness using the DTA meth-od providing for the thermal analysis of ice formation in the tissues of studied plants. The objects of our study were one-year shoots and buds on the trees of 10 cherry cultivars in the orchards of 1997 planting. Definition of exothermic processes in the shoots of cherry trees with generative buds was carried out in the different periods of winter. The data obtained of the analysis of ice formation by thermographic method allowed to clearly identify the features of heat dissipation in the shoot's tissues of cherry cultivars with different frost resistance. It is noted, when the plants are going from dormancy, there are changes of water and physical parameters of the tissues, accompanied by a deepening of the front of ice formation in the most varieties at 1-6 C. The carried out comprehensive analysis al-lowed us to divide the studied cherry varieties into groups for winter hardiness: highly resistant varieties are the Alpha and the Turgenevka, the varieties with intermediate resistance Radost, Favorit, Nochka, North Star, Podbelskaya, and varieties with low winter hardiness Rebetskaya Krasavitsa, Donetskiy Velican and Chudo-Vishnia.
Plant defense reaction are produced in response to the perception of the stress factor and one of the earliest responses is the generation of reactive oxygen forms by the plant. This forms cause the for-mation of a secondary stress state in the plants, which activates and intensifies a cascade of signaling events. This leads to the manifestation in the plants of a series of biochemical changes that form a protective answer. Strengthening a number of protective anti-stress reactions is possible through the use of stimulating substances elicitors, which include the components of the plants themselves, as well as chemicals of pathogens, such as chitosan and exogenous phytohormones. The purpose of this research is to study the peculiarities of the change in the antioxidant response in two grape varieties, contrasting in resistance to mildew, in the process of treatments with inductors of immunity of different directions of action. For the experiment, in vitro plants of contrasting mildew-resistant grape varieties of Muscat Bely (susceptibility 4 points) and Vostopg (susceptibility 1 point) were selected. The non-bearing plants of the first year planting are used. The effect of immunity inducers the development of oxidative stress and antioxidant reactions in grape plants with different resistance to mildew has been studied. It was shown that the reactions of the Muscat Bely varie-ty unstable to the mildew were manifested in some of the used treatments, while the resistant Vostorg variety showed similar reactions to all types of immunity stimulation. This may indicate a great abil-ity to perceive various types of signals and quickly coordinate them to react, which does not lead to oxidative damage of plants.
Climate change on the planet is characterized by increased aridity in the regions where grapes are traditionally cultivated, the grapes is one of the most important crop in the world. Grapes vegetation takes a place at high temperatures, soil and atmospheric drought. Under such conditions, the plants are affected by a combination of abiotic and biotic stresses, causing the defensive reactions that are unique to each combination of stress factors. The aim of the research is to study the changes in the activity of antioxidant enzymes of various grape varieties under the influence of osmotic and high-temperature stresses. The objects of study were the leaves of different grape varieties, under the influence of simulated drought and high temperature. To simulate a drought, the leaves were dried for 2 hours at room temperature. To simulate the high-temperature stress, the grape leaves in the glasses with distilled water were kept n a thermostat for 2 hours at a temperature of +50 º. Different enzyme isoforms have different activity when the environmental conditions change, so the formation of several isoenzymes with differtnt molecular weights may show the adaptive response of plants to stress. It is found that for the most of the studied grape varieties, short-term exposure to stress led to decrease in the number of peroxidase isoforms, and decrease in the activity of superoxide dismutase and a phenolic oxidizing peroxidase. The activity of ascorbate peroxidase changed less than the activity of the other two enzymes. The content of MDA, which indirectly characterizes the development of secondary oxidative stress, was markedly increased in all studied grape varieties. This reaction may be associated with the activation of signaling cascades in the grape plants, which requires an increase in the level of secondary oxidative stress, for the further formation of protective reaction. Our study have shown that different grape varieties are sensitive to different types of stress. These research will continue to study the reactions of grape plants at a longer exposure time of studied stress factors.