Investigation of morphological diversity among native populations of walnut (Juglans regia) in Golestan province, of Iran

Walnut is a plant belongs to Juglandaceae family. Among 21 species, of the Juglans genus, the Persian walnut (Juglans regia L.) is recognized as the best species. The main aim of the current research work was identification of genetic diversity among Persian walnut species in Golestan province, of Iran. Morphological traits used as an approach to evaluate 96 trees which belonged to the five native populations. All morphological characters of leaf, flower and fruits were recorded. There were observed sSignificant differences was bseen among these populations for thein respect to character of nut with husk and without husk. This range was between 14.88 to 55.88 gr for the earliest former and 5.64 to 25.91 gr for the latest one. Also the percent of kernel was in a range from of 19.95 to 50.19. Further results indicated a negative correlation between high altitude with protogeny and percent of age oil of kernels. Reversely, there was a positive correlation between altitude and protein content of the kernels. Other phenological traits such as seed biophysics and seed morphology (according to IPGRI and UPOV descriptors) were evaluated within this study.