Concerning structure-functional features of the leaf apparatus of some stone crops varieties belonging to Prunus (Rosaceae Juss.) genus

For the Rosaceae family (Rosaceae Juss.), which is part of the group of families with the highest species abundance, one of the largest genera is the Prunus genus, which, according to the Catalog of Life, includes 395 species, 16 subspecies, 55 variations. Various sources for this genus indicate from 250 to 400 species of trees and shrubs widely distributed in the northern temperate zone, subtropical and tropical regions, from forests to deserts, in altitude ranges from sea level to alpine zones. In the Samara Oblast, among 67 species of woody Rosaceae, there are 30 native and 36 introduced species (adventitious and wild). The genus is most widespread in the temperate zone of the Northern Hemisphere, is widely represented in North America, Europe and Northern Asia, and includes a number of cultivated species of global economic importance. The active involvement of interspecific hybridization between representatives of the Prunus genus is considered by experts as a determining factor in the evolutionary development of its species diversity, which manifested itself in the appearance of a number of hybridogenic species that were able to overcome successfully the effects of abiotic stressors in the process of expanding ranges, the formation of cultigenic species of stone crops and their varietal diversity. In recent decades, the characteristics of leaves have gained special place in the research programs of plant ecologists as significant indicators of various aspects of growth, reproduction and functions of the plant organism, water use, nutrients, adaptation to environmental changes, including projected climatic changes. Leaf indicators are the most accessible for study throughout almost the entire growing season, they can be evaluated quickly enough, without involving expensive equipment, the screening procedure for leaf apparatus indicators is well standardized. The combined efforts of researchers led to the creation of large and complete databases of leaf apparatus features for various plant species. For the leaves of 15 varieties of stone crops (cherry Olechka, Chernookaya, Kalinka, Nyusha, Pervinka; apricot Samara, Yantar Povolzhya; Russian plum Dolgozhdannaya, Konservnaya, Velikansha, Naryadnaya, Kompotnaya, Lunnaya; domestic plum Dachnaya, Doch Eurasii) quantitative indicators determined for samples selected in July 2020, 2021 and 2022 are analyzed. In order to visualize the possible features of the leaf apparatus in groups of varieties of various fruit crops, the construction of dot diagrams with a limited area of location for each group of points was used. This technique made it possible to identify both the presence of separate groups of points corresponding to one indicator of the leaves of individual stone fruits, and the overlap of the corresponding ranges of other indicators of values. Probably, this picture is a reflection of a certain ecological and physiological heterogeneity in groups of stone fruit varieties, which are cultigenic hybrids of complex origin.