Breeding report of a new early-maturing fresh jujube cultivar 'Xinzhenghong No.9'

Abstract: 'Xinzhenghong No.9'is a new early-maturing fresh jujube cultivar selected from the bud variations of the natural population of Xiaobaizao. In 2005, when the jujube germplasm resources were collected in Zhongliu Village, Mengzhuang Town, Xinzheng City, it was found that a young shoot on one Xiaobaizao tree which is about 100-year-old bearing fruits with excellent fresh-consume traits. The mutant shoots were collected for scion in 2005-2010, and comparative experiments were carried out in the experimental garden of Xinzheng Jujube Science Institute. From 2010 to 2018, regional trials were arranged in Xinzheng and Minquan County, Henan Province. After many years of observation, the cloned trees show superior and stable traits. December 2018, the clone were examined by Henan Provincial Forest Cultivar Examination and Approval Committee, and approved as a new cultivar named'Xinzhenghong No. 9'. The cultivar has an open tree shape, and strong vigor. The leaves are lanceolate, yellow-green, with an average leaf length of 7.0 cm and width of 3.2 cm. The amount of flowers is large, the flower buds are oblate, each order has 5-15 flowers. The flower disk is yellow, with plenty honey, blooming in daytime. The fruit is oval, crisp, juicy, sweet, and has a good taste. The average fruit mass is 5.83 g and the maximum fruit mass is 14.65 g. The soluble solids were 25.8%, the soluble total sugar content was 21.43%, the total acid content was 0.35%, the Vc content was 212 mg·100 g-1, and the edible rate was 97.8%. In the Xinzheng jujube producing area, germination in mid-April, beginning flowering in late May, full-flowering period in early June, crisp ripening period in early August, mature period in mid-August, and deciduous in late October, the fruit growth period is about 80-85 days.'Xin Zhenghong No. 9'has wide adaptability, strong disease resistance, drought tolerance and salt and alkali resistance. Fresh dates can stored at room temperature for 3-5 days. Suitable for planting in the main jujube producing areas of Henan Province. According to the soil and fertilizer conditions and management level, the intercropping type jujube garden adopts the row spacing of (4-6) m × (8-12) m, and the dwarf dense planting can choose the row spacing of 2 m×3 m, 1.5 m×4 m or 3 m×4 m. The tree shape of the dwarf dense planting jujube garden is generally selected from the small crown layered shape or the open-center shape, the tree height is controlled at 2.5 to 3 m, and the crown width is 3 to 3.5 m.