Characteristics of the stomatal apparatus of Vigna (Vigna unguiculata) during introduction in the south of Western Siberia

Background. The stomatal apparatus of heat-loving legume species reflects the ecological features of its functioning in thе (sub) tropical conditions of the original range. To assess the morphometric parameters of leaves, the density of the arrangement and size of stomata on the adaxial and abaxial sides of the leaves were determined and their relationship with cold resistance in the mature male gametophyte phase in vitro was studied. Materials and methods. Fourteen accessions of cowpea (Vigna unguiculata) were used in the study. The Hitachi TM4000 plus scanning electron microscope was used to examine the stomatal apparatus. Pollen viability in vitro was assessed on a 20 % PEG 6000 solution at 25° / 3 hours (control) and at 6° / 24 hours (cold resistance assessment). The similarity of the accessions by the parameters of the stomatal apparatus was determined using cluster analysis. Correlation analysis was used to assess the relationship between the morphometric parameters of the leaves and the viability of pollen in vitro. Results. The morphological parameters of the stomata of different varieties of Vigna differed significantly. The stomatal density, stomatal long axis and stomatal short axis on the adaxial and abaxial side of Vigna were 74.0–230.0 / mm2, 231.0–439 / mm2, 14.7–20.8 μm, 14.3–20.1 μm, 4.0–6.3 μm and 4.3–8.4 μm, respectively. Correlation analysis showed that the density of stomata on the adaxial side of the leaf significantly correlated with pollen viability at 25°(r = 0.524), and the short axis of the stomata on the adaxial side of the leaf significantly correlated with cold resistance (r = ‒0.513). Conclusions. Systematic clustering divided the above varieties into three categories. Zinder, Kudesnitsa, Blaek Sid is a separate category with the highest stomatal density; Grafinya, Liliana, Niagara, k-802, Nezhnaya, and also Phaseolus vulgaris and adzuki (form RU-1-NOVB-vegYF-0061) are categories with medium stomatal density; the rest of the varieties were divided into one category, which had the lowest stomatal density.