Breeding report of a new mid-season peach cultivar Xiahui No. 10

A new mid- season honey peach cultivar Xiahui No. 10 was selected from a cross between Hakuho and nectarine Ruiguang 28 made in 2006. The seeds were sowed in a greenhouse in late winter 2006. 46 seedlings were planted in the Peach Experimental Field of Jiangsu Academy of Agricultural Sciences in Nanjing in spring of 2007. The seedlings started to bear fruits in 2009. Based on the germplasm evaluation of fruit quality and yield from 2010 to 2013, the strain 06-24-10 was identified as an excellent individual in 2013 for slow-softening flesh, attractive appearance, high degree of red blush, excellent peach flavor and stable and high yield. The selected plant was asexually propagated for field trials in Suzhou, Wuxi, Zhenjiang, Nanjing, Xuzhou and other places of Jiangsu Province in 2014 and 2015. From 2017 to 2019, the propagated plants maintained all characteristics of the original seedling without any phenotypic aberrations. It was officially named Xiahui No. 10 and applied for new variety certification from Office of Plant Variety Protection, Ministry of Agriculture in 2020. It was granted a plant variety protection certificate (No. CNA20201007515) and registered as GPD Peach (2024) 320065 in 2024. The tree exhinited middle vigor, with a moderate bud burst rate and branching ability. The leaves were long elliptic-lanceolate, green, with an average length of 19.9 cm, width of 4.4 cm, and petiole length of 1.0 cm. The average internode length was 2.6 cm. The leaf tips were acuminate, leaf bases cuneate, and leaf margins blunt-serrate. The reniform nectaries were present, with an average of 2.4 per leaf. The average branch diameter of 5- and 6-year-old trees was 0.7 cm. The flowers were pink with 5 petals, and the inner wall of the calyx tube was green-yellow The cultivar was self-fertile, with a flower density of 40.3 flowers per meter. The mature fruits were round in shape with symmetrical halves, a flat apex, a shallow central cavity, and a faint suture. The fruit skin was glabrous, with a white background color and over 80% red blush at maturity. The average fruit weight was 243.4 g, and maximum fruit weight was 397 g under fruit thinning condition. The flesh was white, firm, and slow-softening, with moderate juiciness. At 80% maturity, the fruit firmness was 22±3 N. The cultivar exhibited excellent fruit quality: the soluble solids content ranged from 12.8% to 14.7%, and titratable acid content averaged 0.19% at harvest. Compared with its maternal parent Hakuho, Xiahui No. 10 had a higher average soluble solids content and a slightly lower titratable acid content. In Nanjing, blooming occured in mid-March, with a flowering duration of 7-8 days. The fruit ripened from July 8 to July 19, with a total fruit development period of 116 d. The fruits matured slowly and had a long shelf life: over 7 days at room temperature and over 3 weeks at 4 ℃ when full mature, with no quality deterioration. Three scaffold limbs or Y shape training should be recommended. In full bearing period, the yield should be controlled at the level of 2000 kg per 666.7 m-2 . The cultivar had no particular susceptibility to the pests and diseases but showed mild sensitivity to bacterial spot. According to the conclusion from the Comprehensive Experiment Station of China Agriculture Research System of Peach (CARS-30), there would be a risk of frost damage when winter extreme low temperature drops below -20 ℃. It would be suitable for cultivation in Jiangsu province and other areas with similar climatic conditions.