A new Chinese chestnut cultivar Qiuhong with high quality, high yield, and strong stress resistance

Chinese chestnut (Castanea mollissima) is a woody food crop included in the national food security strategy. However, the Chinese chestnut industry in China has long been constrained by challenges such as a narrow range of dominant cultivars and shortage of high-quality, high-yield, and stressresistant varieties, which severely hinder its high- quality development. Qiuhong, a new mid-maturing cultivar developed by the Chestnut Breeding Team of Hebei Normal University of Science & Technology through seedling selection, exemplifies such desirable traits. Its mother tree, nearly 200 years old, is located in Xiaolugou Village, Louzhangzi Town, Qinglong County, Qinhuangdao Municipality, Hebei Province. In 2005, the breeding team identified it as a primary elite selection from 170 seedling-grown trees due to its high yield, excellent quality, and tolerance to barren conditions. In the spring of 2006, 1- year-old branches of the mother tree were collected for top-grafting in the on-campus experimental station, with Yanzi as the control for secondary selection evaluation. Through systematic observation, it showed stable and excellent comprehensive traits, and was confirmed as the secondary superior strain in 2012, temporarily named“Qiuhong”. Since 2012, regional trials have been carried out in three locations (Qinglong, Kuancheng and Funing), with Yanzi as the control, to systematically evaluate indica-tors such as phenology, traits, yield, quality, and stress resistance. The results of the regional trials showed that this superior strain had obvious characteristics of strong bearing capacity and high yield, with sweet and fragrant flavor, strong drought resistance, and no significant diseases or pests. In January 2025, it was certified as a forest variety by Hebei Province and officially named Qiuhong. Qiuhong has a tall tree body and an open tree posture. Its 1-year-old branches are brown, with small, moderately dense, round lenticels and no pubescence. The leaves are long elliptical, with an average length of 20.41 cm and an average width of 6.87 cm, presenting green color, dense pubescence on the abaxial surface of the leaves, and horizontal leaf posture. The fruiting branches have a length of 34.33 cm, a diameter of 0.86 cm, and a terminal branch length of 9.37 cm. The burs are oval, and the nuts are purple-brown and glossy, with oval- shaped lateral nuts, inconspicuous veins, a medium- sized base, and a smooth base line. The average single nut weight is 10.7 g. The soluble solid content is 22.29% , starch content 52.08%, protein content 9.19 mg·g-1 , moisture content 50.23%, fat content 0.89%, and Vc content 39.68 mg·100 g-1 . The fruit growth period of Qiuhong is approximately 95 days, and it ripens in mid-September in Qinglong County, Hebei Province. It starts bearing fruit in the 2nd year after grafting, and enters the stage of high and stable yield after 5 years. The average yield per 7-year-old tree can reach 10.35 kg. It has strong continuous fruiting ability, with no alternate bearing pattern. Qiuhong has strong stress resistance to drought and barren soil. When planted in dry granite and gneiss steep mountainous areas where existing cultivars often show weak growth and premature senescence, it does not exhibit premature senescence, making it suitable for planting in steep mountainous areas with barren soil. Planting should be carried out around the time of tree germination in spring. The recommended planting density is 2 m×3 m or 3 m×4 m, and pollinator trees should be arranged at a ratio of 10% in the same row. Suitable tree shapes include open-center shape, multi-main-branch open-center shape, or layered main-stem shape. For young trees, summer pruning with multiple pinching operations are conducted throughout the year to increase the number of branches and accelerate tree shaping. For mature trees, pinching is practiced on the vigorously growing new shoots to moderate their growth. Integrated pest and disease management should be adopted, with special attention to the damage caused by red spiders, peach fruit moth, and chestnut weevils.