Substantiation of the adaptability of Zizyphus jujuba varieties to the climatic conditions of the Volgograd region

Abstract

The relevance is due to the introduction of the subtropical fruit crop Zizyphus jujuba (unabi) to the Volgograd region. For the first time in the conditions of the Volgograd region, the material on the biochemical properties of various varieties of unabi fruits was analyzed and generalized. The aim of the research is to study the adaptive reactions of subtropical plants of Zizyphus jujuba in the northern points of cultivation on the basis of their biochemical and physiological parameters. The objects are plant genotypes of Z. jujuba: large-fruited, medium-fruited and small-fruited. Experimental plantings with their participation are cultivated at the collection site of the Federal Research Center of Agroecology of the Russian Academy of Sciences (Volgograd, Russia). The study of adaptive reactions to changing environmental conditions is based on the fixation of environmental factors and bioecology of plant individuals based on their physiological and biochemical parameters in the field and laboratory conditions. The objectives of the research included: identification of limiting factors limiting development; analysis of critical periods of plant development by changes in water metabolism and temperature regime; comparative assessment of the biochemical characteristics of fruits in the northern point of the cultivation area, taking into account adaptation to stress factors (genotype-environment). It was revealed that the lack of water leads to an increase in the concentration of soluble substances. Dehydration leads to a violation of the integrity of the membranes and affects the composition of the pigment complex. The variability of ascorbic acid content by years was established: in large-fruited and medium-fruited plants from 31.9 to 66.5 mg%. In small-fruited plants under cultivation, the variability over the years is less pronounced. During the dry period (the total moisture reserve in the soil is up to two meters 130-141 mm), the content of ascorbic acid decreases. Small-fruited plants showing a high degree of adaptation have high levels of ascorbic acid (up to 740.3 mg%). Limiting factors are temperature increases and a decrease in air humidity in summer with low rainfall and moisture reserves in the root layer of the soil. The productivity of plants under stress strongly depends on maintaining the water status of plants. Any assessment of the water status should take into account the reaction of plants to environmental conditions and the characteristics of these conditions