Breeding of a new Juglans hopeiensis variety Jibaleng

Jibaleng is a newly selected Juglans hopeiensis Hu variety derived from the selection by seedling. The mother tree was discovered in 2002 on Fenghuang Mountain in Qianxi, Tangshan City. Its nuts are oblong with bold and twisted patterns, thick ribs, a flat base, a small umbilicus, eight prominent ridges converging at the top, and a star-shaped tip. From 2005 to 2010, systematic evaluation of botanical characteristics, growth and fruiting habits, and economic traits confirmed its phenotypic stability. In 2011, scions were collected for grafting in Laishui, Zanhuang, and Dingzhou. From 2021 to 2023, a systematic study was conducted on the tree growth, fruit shape, yield potential, and stress resistance under different ecological conditions. DNA fingerprinting analysis was carried out using SSR markers to confirm that there were differences among different cultivars. This variety was officially registered as Jibaleng in 2024 by the Hebei Provincial Forest Variety Approval Committee (ID: Hebei S- SV- JH- 012- 2024). Jibaleng trees are tall and vigorous, with a height of 7.6 meters, a crown diameter of 6.5 m×6.8 m, and a new shoot growth of 68 cm in a 12-year-old tree. There are thick branches, abundant buds, strong branching ability, and a high fruiting branch rate in Jibaleng trees, and the average yield per tree is 221 walnut fruits. The bark is grayish green when young and turns grayish white with shallow longitudinal fissures when old. The leaves are odd- pinnate with 9- 13 leaflets being elliptical, entire and smooth. Jibaleng is a typical protandrous variety. The male catkins are 12-19 cm long, and the female spikelets usually contain 1-3 flowers. The stigmas are light red. The fruiting spikes are short, with 1-3 fruits. The fruit is nearly round, with a longitudinal diameter of 5.37 cm, a transverse diameter of 5.18 cm, and a ridge diameter of 5.14 cm. The nut is oblong in shape, with a longitudinal diameter of 4.68 cm, a transverse diameter of 4.32 cm, and a ridge diameter of 4.36 cm. The suture lines are thick, and the patterns are rough and twisted like flowers. It has thick ribs, a large flat bottom, a small navel, eight ribs gathered at the top, and a cross-shaped tip. In Baoding, Hebei, the cultivar’s budbreak occurs in the end of March to early April. The male flowers reach their peak in mid-April, and the female flowers reach their peak in mid to late April. The fruit growth period is from mid-May to late June, the fruit-core-hardening period is from late June to early July, the fruit ripening period is from mid-August to early September, and the leaves fall from late October to early November. This variety has the characteristics of high yield potential and high price, which is suitable for promotion in the suitable areas of walnut growing in Hebei.