About diagnostic features of Polygonum L. genus. Perianth

Abstract The genus Polygonum is quite difficult to define due to its inherent biological characteristics. Purpose of the work: to analyze the shape of the perianth of representatives of different subsections of the section Polygonum of the genus and to determine its diagnostic value.For diagnostic purposes, in addition to the known signs, it is proposed to use the shape of the perianth, which is determined by the following indicators: the ratio of the length and width of the perianth; the presence and position of the greatest width (in the lower, middle, upper part) of the perianth; the position of the perianth lobes, characterizing the degree of its openness - closed (closed), converging (half-open), erect and diverging (open). Siberian representatives of the genus Polygonum have 8 perianth forms: tubular, water lily, oblong-ovate, ovate, funnel-shaped, bell-shaped, goblet, and cupped. The perianth forms correspond to the subsections of the Polygonum section: tubular - Salsuginea, water lily - Polygonum, funnel-shaped - Arenaria, bell-shaped - Oxysperma, goblet - Humifusa. The presence of an oblong-ovoid perianth in the representatives of the subsections Acetosa, Patula and some species of the subsection Arenaria can be explained by their genetic proximity, and the goblet shape in some species of the subsections Polygonum, Patula - by their hybridogenic nature. The results of the performed analysis of the perianth forms reflect the system of the river. Polygonum. Both the distribution of perianths by subsections of the typical section, and deviations from the typical perianth forms for subsections are explained in the materials on the system and phylogeny of the r. Polygonum, obtained by the methods of factorial and discriminatory analyzes, RAPD-analysis of populations and in the results of the analysis of nucleotide polymorphism of the ITS 1-2 region of nuclear rDNA by the methods of maximum economy (MP) and maximum likelihood (ML).