Breeding report of a new mid-ripening sweet cherry cultivar Changhuazicui

Changhuazicui (Prunus avium L.) is a new mid-ripening sweet cherry cultivar developed by the Changli Institute of Pomology, Hebei Academy of Agriculture and Forestry Science. 107 hybrid seedlings were selected by embryo rescue of the naturally pollinated seeds of the sweet cherry Rainer in 2000. The hybrid seedlings were planted in the breeding nursery of the Changli Institute of Pomology in the spring of 2001, and started to bear fruit in 2004. The fruit indicators including maturity period, fruit weight and firmness, soluble solids content, and titratable acidity, were investigated for three years from 2004 to 2006. The offspring coded 3-20 was selected as a final superior strain for its good taste and firmness, large size and stable high yield from 2007. It was grafted on Heishanying (P. maximowiczii) as rootstock in 2009 and planted in three different areas in Hebei Province for variety evaluation trial from 2010. The variety was examined and approved by Hebei Forest Tree Variety Evaluation Committee and named Changhuazicui in 2020. The tree vigor of Changhuazicui is moderate. The height of 6- year-old tree is 4.04 m. The canopy size is 4.52 m×4.78 m. The perennial branch is grayish brown in color, and the 1-year-old branch is grayish brown with the short internode. The leaves are long obovate, with 16.71 cm in length and 8.52 cm in width. This variety has a large fruit size, with an average fruit weight of 9.50 g and a maximum single fruit weight of 16.00 g. The fruit is broad kidney-shaped, with a purple red skin and a glossy appearance. The flesh is red in color, thick and juicy, with an edible rate of 94.80%. The flesh is hard and crispy, with a peel hardness of 2.2 kg·cm-2 , and is resistant to storage and transportation. The fruit has a strong sour and sweet flavor, with a soluble solids content of 20.5%. The flowers of Changhuazicui open on April 10-11, with a flowering period of about a week, and fruits mature in early June, with a fruit development period of about 55 days in the Changli area (119°9'45", 39° 43'7") of Hebei Province. There is not special disease and pest for Changhuazicui. The fruit has very good shelf-life for 20 days under cold storage condition. It is suitable for planting in Qinhuangdao and Tangshan areas such as Changli County and Luannan County in Hebei Province. This variety begins to bear fruits in the third year after planted, and then in the eighth year it can produce a yield of over 770 kg per 666.7 m2 . Changhuazicui is a self-incompatible variety with the S- genotype S1S9, but it would be productive if the pollinizer assignment is suitable. The recommended density is 3-4 m×5 m for vigorous rootstock such as Heishanying (P. maximowiczii) and P. mahaleb L. and 2.5-3 m×4 m for the dwarf rootstock such as Gisela 6. The slender spindle and tall spindle axe systems should be recommended, and summer pruning should be paid attention to enhance flower bud differentiation.