Breeding report of a new superior quality and early-maturing plum cultivar Jizaofeng

Abstract: Jizaofeng plum is a new cultivar bred by a crossing between Jihong and 88-5-14. The crossing was made in 2009. The seeds were sown in the spring of 2010. The hybrid trees beared fruits in 2013, the quality indicators of the fruits were investigated, including soluble solids content, aroma, taste, texture, and fiber. A superior strain was selected in 2014. The regional trials were carried out in Jilin, Gongzhuling, Changchun, Huinan, in 2015, to test cold resistance, and to compare the fruit quality in different regions. The certificate of non-major crop variety was obtained in June, 2023. The tree posture of Jizaofeng was semi-spreading, with strong branching ability and moderate growth vigor. The one-year-old branches were yellow-brown, with an average length of 48 cm. The leaves were elliptical, with a length of 10.62 cm and a width of 5.18 cm. The leaf tip was long and acuminate, the leaf base was truncate, and the petiole was 1.60 cm long. The petals were white and obovate. The fruit shape was elliptical, with a single fruit weight of 45 g and a fruit length of 4.8 cm and a width of 4.4 cm. The suture line was shallow, the fruit top was low and flat. At maturity, the fruit peel was chartreuse and was covered with purplish red, the flesh was yellow, with abundant amount of juice, soft texture, free stone, and few fibers. The soluble solids content was 16.6%, reaching to 20% when fully mature, the soluble sugar content was 9.19% and a titratable acidity content was 0.92%. The flavor was sweet with a strong aroma, and the fresh quality was excellent. The flowering date was late April, with a flowering period of about a week, and the fruit maturing date was late July, with a fruit development period of about 85 days. The leaf buds bursted in early May, expanded in the mid of May, and fell in mid-to-late October (in Gongzhuling). According to the field investigations, it had strong resistance to cold, red spot disease, bacterial canker disease and rot disease. The fruit quality was better and yield was higher than the main early maturing cultivars in the local area. It could be introduced to the areas of Jilin Province with an effective accumulated temperature of ≥10 ℃ above 2800 ℃ and a frost-free period of ≥130 days.