TESTING OF ISSR PRIMERS AND GENOTYPING OF NATURAL POPULATIONS OF HAZELNUT (СORYLUS L.)

Natural hazel populations in the border zones of the range are of considerable interest as potential sources of unique adaptive traits. These genotypes, formed under the pressure of stressful abiotic factors, are of critical importance for breeding cultivars resistant to adverse climatic conditions. The purpose of this work was to test ISSR-markers for the analysis of the genetic diversity of hazel natural populations (Corylus L.) in the Western Caucasus, the northern border of the distribution of some subtropical species. Three populations located at different heights above sea level were studied: 250 m (Tulsky village), 500 m (Novosvobodnaya station) and 1 500 m (Azishskaya cave). Of the 10 primers initially tested, five were selected for subsequent analysis, which demonstrated high reproducibility and clear amplification profiles. It has been shown that multilocus ISSR-markers are highly effective for population analysis, demonstrating an average polymorphism level of 64 % and high information content (PIC = 0.4–0.5). It was found that the highest level of genetic polymorphism is typical for populations from the extreme points of the altitude gradient: the lower (250 m above sea level, 74.6 %) and the highest (1 500 m above sea level, 71.2 %), while the population from the middle point (500 m above sea level showed significantly lower polymorphism (47.5 %), which indicates an increased adaptive potential of marginal populations due to the action of multidirectional selection. The data obtained confirm the expediency of using ISSR markers to assess the genetic diversity and structure of hazel populations. The approved set of primers is relevant for further study of the genetic resources of hazel and identification of valuable genotypes.