Structural and functional content of xerophytic plants of Elytrigia repens L. genus

Abstract In the modern conditions of the ecological crisis, the study of adaptive changes in xerophyte plants, which form natural and cultural phytocenoses, has important theoretical and practical significance. Steppe phytocenoses of the Zaporizhia region, especially the Melitopol city and the Melitopol district, are represented by xerophytic associations. The research aim was to find out the histological and physiological rearrangements of the organs of the genus Elytrigia L. to determine adaptation features at the tissue level to water and temperature stresses. The subject of the study was the study of the structural and functional features of plant organs of the genus Elytrigia repens L. during adaptation to environmental factors (on the example of the Zaporizhzhia region, in particular the Melitopol city). The theoretical and methodological basis of the work was the synergistic use of a systemic approach, which led to a transparent approach to the choice of research methods, in particular: general scientific (analysis, synthesis, systematization, generalization of literary sources); general biological (experimental method, quantitative-anatomical, physiological and system-structural analysis, methods of mathematical statistics. It was established that the adaptation of xerophytes of the genus Elytrígia L. to arid habitats is characterized by structural and functional rearrangements of vegetative organs, in particular, the presence of unicellular trichomes, which ensures a decrease in transpiration, an increase in the share of storage tissues in the leaf and conductive and mechanical elements in the stem, as well as a decrease in intensity photosynthesis under drought conditions. As a result of finding out the functional disturbances in the leaf under the influence of drought, in particular the intensity of photosynthesis and the specificity of the pigment composition of the experimental plant, it was proved that the experimental plants under normal conditions have a parabolic curve of photosynthesis, and under the influence of atmospheric drought these indicators have a hyperbolic shape, and the analysis of the results of daily of the dynamics of photosynthesis established that the most intense photosynthesis occurs in plants under normal conditions, and under the influence of drought in plants there is a decrease and inhibition of the process of photosynthesis.