Breeding of a new melon cultivar Zhongtianxueqiong with low temperature tolerance

Abstract：The new melon cultivar Zhongtianxueqiong is a medium- maturing variety, developed by crossing inbred line J37 as female parent and F763 as male parent. J37 is an inbred line selected by 12 generations after crossing a hybrid offspring line（Sibuloto from Japan as female parent and Baizhuogua as male parent）with the female parent of a melon cultivar Xuehong. F763 is also an inbred line select-ed by 12 generations after crossing between Baipicui and the male parent of Guangzhoumi. More than 1200 hybrid combinations including J37×F763 were selected in autumn 2018 at Zhengzhou, and twice combination selection tests were conducted in winter 2018 and in spring 2019 at Sanya and Zhengzhou, respectively. J37×F763 was eventually selected for its excellent comprehensive characteristics. After regional adaptability testing at three sites (including Xinxiang, Anyang and Kaifeng in Henan Province) over two years from 2020 to 2021, it was finally selected and named Zhongtianxueqiong. Its whole growing period from sowing to harvest is 105 to 115 days and its fruit development period is 35 to 38 days under plastic greenhouse in spring in Henan Province. The fruit is oval shape with white peel color. The average single fruit weight is about 1.7 kg and the per-acre yield is about 2400 kg. The pericarp color of the melon is white and the taste is soft without residue. The flesh thickness is about 4.0 cm, and the soluble solid content of central and edge flesh is about 16.5% and 10.0%, respectively. It has high tolerance to low temperature and poor light. It is suitable for cultivation in plastic shed or greenhouse in Northern China. It has been registered as non-major crop variety by the Ministry of Agriculture and Rural Affairs of the People’s Republic of China in June 2022. In vertical cultivation, the optimal density is 1600 to 1800 plants per 666.7 m2 with the 40 cm of two plants and 75-100 cm of row spacing. Base fertilizer is mainly used for fertilization, including organic fertilizer and N, P, K compound fertilizer. The water content must be strictly controlled during flowering stage and irrigation should be stopped one week before harvest. And it also needs to focus on the prevention and controlling of various plant diseases such as soft rot and powdery mildew.