Evaluation of Genetic Diversity of Mature Walnut (Juglans rejia L.) Genotypes in the North of Hamadan Province, Iran

Persian walnut (Juglans regia L.) has a long history of cultivation in Iran and Persia (include Iran) consider as origin center of walnut in the world. Among different region of walnut production, Hamedan is the leading province for walnut culture and has the largest walnut plantations in Iran. Due to this high genetic diversity, identification of superior walnut genotypes the first step of walnut breeding program. Therefore, 84 preselected walnut genotypes in the north of Hamedan were morphologically evaluated based on IPGRI descriptor in 2017. Based on the results, a high diversity was observed in the studied population. The results showed that nut and kernel weight and kernel percentage varied 6.-4-23.5 g, 2.73-11.7 g and 27.02-78.35%, respectively. Based on morphological data, 11 out of 84 genotypes were selected as superior genotypes. The selected superior genotypes had lateral bearing habit, heavy nuts (13.14-21.62 g) and kernels (7.12-10.71 g) with thin shells and light to extra light kernel colors. Correlation analysis revealed that a positive and strong correlation between phenological data especially leafing and harvest date. There were strongly positive correlations between nut and kernel weight with nut size.

Keywords:

Persian walnut , Lateral bearing , Germplasm , Nut weight , Correlation analysis