Breeding report of a new apple cultivar Jinyu

Abstract: Jinyu is an early-season, table apple variety with excellent appearance. The variety was derived from a cross between Huamei and Hongro in 2006 in the experimental field. It was initially selected in 2010 for its early ripening time and good quality. After five years of consistent observations, it was finally selected in 2016. The regional adaptability test started in 2017 at five sites (including Zhengzhou, Xinxiang, Sanmenxia, Shangqiu, and Gongyi), the authorization was received from the Ministry of Agriculture and Rural Affairs for the protection of new plant varieties in 2019; and it was approved by the Henan Forest Species Certification Committee in 2023. The young trees of Jinyu were vigorous, with strong, fast-growing branches with slight short internotes. The leaves were 10.13 cm in length and 6.34 cm in width, medium green, and had acuminate (pointed) tips. The early flowering date was early April, full blooming date was from April 4 to 13. The fruit began to lose its astringency and acidity in mid-June, turned color from green to yellow in early July. The leaf fall occured in early November, with a vegetative growth period of 250-260 days. The fruit was cylindrical or long conical, with a regular shape. It had an average longitudinal diameter of 5.4 cm and a transverse diameter of 5.5 cm. The fruit size was small, weighing approximately 110 g on an average. The flesh was yellowish-white, fine, and crispy, with a peel firmness of 8.5 kg· cm^-2 . The solid content was 14.4%, titratable acid content 0.12%, and the quality was high. The fruits ripened in mid-to-late July in Zhengzhou, approximately two weeks earlier than Gala and its parent varieties. The flavor was similar to that of Gala. The axillary flower buds were easily formed on the young trees. To reduce the competition between these buds and overall tree growth, it was important to remove excess axillary buds during the early stage. Thinning flowersand fruits was crucial to ensure optimal fruit size. Typically, no more than two fruits were allowed per inflorescence. The distance would be 10-15 cm between the fruit clusters. The plants exhibited minimal occurrence of severe leaf diseases such as apple Alternaria mali roberts and powdery mildew. The fruit could be stored for 10-15 days at room temperature, and the cold storage life was 2 months. Jinyu was highly adaptable and had a wide planting range with dwarfing, semi-dwarfing, and standard rootstocks.