Evaluation of genetic diversity among some selected walnut by using morphological ‎and pomological characteristics

Identification and selection of superior genotypes in different regions of the country is a useful breeding method in walnut. This study was conducted to evaluate the genetic diversity among some selected walnut genotypes using 19 quantitative and qualitative traits related to morphological and pomological characteristics based on the IPGRI description (with some modifications) on 28 walnut genotypes during years of 2018 and 2019 in Reseach Station of Department of Horticulture, Unversity of Tehran. The results showed that the highest kernel percentage (69.12 and 67.14) belonged to UTW10 and UTW09 genotypes, respectively. The UTW05 and UTW07 genotypes were the latest leafing date. The UTW09 and UTW05 genotypes had the highest kernel weights of 8.05 and 7.87 g, respectively. UTW22 and UTW05 genotypes with 14.48 and 13.93 g, respectively, had the highest nut weight. Based on cluster analysis, genotypes with desirable traits were grouped from other genotypes. Among the factors that play a role in separating the main clusters were nut dry weight, kernel weight, length, diameter and width of nut, kernel percentage, Kernel plumpness, Kernel fillness and Leaf Abscission of genotypes. The results of simple correlation analysis of traits showed a significant positive and negative correlation between some important traits. In general, UTW01, UTW04, UTW06, UTW07, UTW08, UTW20, and UTW22 genotypes were selected as superior genotypes due to closed-shell seal, light kernel color, ease of kernel removal from nuts, lateral bearing, and high kernel percentage.