Breeding report of a new walnut cultivar Nongheduanzhi

Nongheduanzhi is an excellent new walnut (Juglans regia L.) variety selected from the seedling population of Fenyang-mian walnut. The nut was oblong with smooth shell surface and the suture lineis tightly combined. The average single fruit mass was 16.5 g. The average of longitudinal diameter, transverse diameter and lateral diameter of nuts were 39.32 mm. The shell thickness was 1.08 mm. The whole kernel could be taken out, and the kernel rate was 57.3%. The fat content in the kernel was 55.0%, the crude protein content was 20.0%; the sugar content was 2.34%; the starch content was 1.52%. The kernel was full, light in color, strong in flavor. In the central region of Shanxi Province, budbreak occured in the end of March and beginning of April; the female flower bloomed in the beginning of April; the male flower bloomed in the middle April, the nut matured in the early to mid-September, and leaves fall at the beginning of November. The variety in Shanxi, following extensive multi-sites and multi-generation grafting, exhibited stable performance characteristics. These characteristics included moderate tree vigor, a pronounced advantage in branch apices, shorter branch internodes, a high sprouting rate, and a relatively weak branching force. Additionally, the rate of fruiting from lateral buds was elevated, contributing to a high overall fruiting rate and robust productivity. This variety was officially recognized by the Forestry Variety Validation Committee of the Shanxi Province Forestry and Grassland Bureau on January 22, 2024. According to the regional test and production trial planting, it was preliminarily believed that it could be planted in Jinzhong and southern areas of Shanxi Province and similar climate regions.