Genetic Diversity Evaluation of Some Walnut (Juglans regia L.) Genotypes in Meshkin-Shahr by ISSR Marker

Abstract

Genetic resources are the most valuable national treasure of countries, being vital to identify, conserve and use them. The Persian Walnut (<em>Juglans regia</em>L<em>.</em>), a diploid species native to the mountainous regions of Central Asia, is the major walnut species cultivated for nut production and one of the most widespread tree nut species in the world. This research was conducted in Meshkinshahr in Ardabil Province. In this study, to determine the level of genetic diversity, a total of 31 walnut genotypes were analyzed using Inter Simple Sequence Repeats(ISSR) markers. Genotypes were evaluated using 10 ISSR markers and a total of 26 polymorphic alleles were identified.The average of the observed alleles was equal to 7 in each locus. The lowest and highest RP valueswere found ISSR5and ISSR9, respectivly.Cluster analysis based on Jacard similarity coefficient matrix using WARD method classified the genotypes into three main groups.The highest genetic distance was found between genotypes AK4 and RM2, and the lowest was among genotypes MZ4 and ES1.Both clustering and PCA divide genotypes with similar geographic origins.