Breeding report of a new Actinidia arguta cultivar Xiangmizao

Abstract: Xiangmizao is a new tara vine cultivar, which was selected from the wild tara vine population growing at Dawei Mountain, Liuyang city, Hunan province. In early May of 2011, this single individual was propagated via cuttings or grafting, and cuttings were grafted on individuals of Actinidia deliciosa collected from Dawei Mountain. After 6-year field trial, clones of this individual showed stable performance for all horticultural attributes. The tree vigor is moderate and most new shoots grow out in spring. These new shoots are purple red with dense white lenticels distributing on the surface. Newly formed leaves are yellowish green with red tips. Mature leaves are dark green with red petioles and ovate blades with serrated edges. The inflorescence is dichasium. The long columnar berry shows green skin and flesh just after harvest. Berry skin becomes purplish red after storage and berry flesh near seeds is purplish-red. Berry skin is smooth and covered with fruit wax. The berry shape index is 1.37, the average berry weight is 25.18 g, and the maximum berry weight is 28.33 g. Soluble solids content of berry is 13.13% at just harvest time. The total acid content is 1.13%, the soluble solids content could reach up to 26.50% after storage, and the average soluble solids content is 23.34% and the dry matter content is 22.28%. The average seed number is about 130 per berry. The vitamin C content is 36 mg per 100 g fresh weight, and the fruit stalk is 11.14-26.29 mm in length. The proper harvesting period is mid to late August, which is slightly earlier than early season and red- fleshed A. chinensis cultivar Hongyang. This individual performs consistently and stably through six- consecutive- year field trial from 2017 to 2023. The individual is mainly propagated by asexual propagation methods such as hardwood cuttings, softwood cuttings and grafting. This desirable individual prefers growing environment with shading and cool climate. This new cultivar is suitable to be planted in areas with higher altitudes andrelatively cool climate. Xiangmizao is mainly planted in a terraced orchard at Dawei Mountain Scenic Area with 650 meters altitude in Liuyang city. The proper male pollinator has been selected for this new cultivar, which is a male individual collected from Dawei Mountain. This male pollinator shows the overlapped blooming time with Xiangmizao and produces relatively large number of flowers with quality pollen resulting in the best fruit quality for this female cultivar. Irrigation mainly adopts drip irrigation and soil is covered with grass residuals to collect rainfall. Irrigation needs to be carried out according to rainfall and fertilizer application schedule. The vine of Xiangmizao is trained into an open-heart system without supporting trellis. In spring and summer, actively growing shoots are required to be pinched in time to maintain the balance of vegetative-reproductive growth. Protection facilities or practices from possible low temperature are not required in winter at the Dawei Mountain growing area and the new cultivar could naturally live through the winter at 650 meters in altitude. This new A. arguta cultivar has showed resistance to various biotic and abiotic environmental factors, and particularly its resistance to kiwifruit bacterial canker is better than Miliang No. 1, a major kiwifruit cultivar grown in Hunan province. Xiangmizao is suitable for both fresh-eating and processing.