Breeding report of a new pomelo cultivar Yunqing 1 with green skin and red pulp

Abstract: Yunqing 1 is a new pomelo cultivar selected by Honghe Tropical Agricultural Science Institute of Yunnan. In September 2007, the researchers purchased a batch of pomelo with green skin and red pulp from the market of Hekou county, Honghe Prefecture, Yunnan province. Finally, 104 maternal trees were obtained through seedling breeding. Those trees began to bear fruit in 2013. After two consecutive years of observation, an optimized strain with early flowering, medium ripening, large fruit juice content, high sweetness, long fruit retention time and resistance to granulation of flesh was selected. In 2014, local sour pomelo was used as the rootstock for top- grafting and the observation experiment was conducted. In 2016, the flower and fruit were tested. After two consecutive years of investigation on the botanical characteristics of the top-worked Qingpi red pomelo, no atypical plant appeared in the investigation. In 2018, the application for protection of new varieties was submitted to the Ministry of Agriculture and Rural Affairs. After years of continuous observation, the variety performance was stable in Hekou of Yunnan province. In October 2021, it passed the on- site examination of experts. On March 7, 2023, it was authorized by the Ministry of Agriculture and Rural Affairs for the protection of new varieties of plants (Code of Plant variety rights: CNA20184826.0) and named Yunqing 1. The cultivar has strong growth vigor, open tree gesture, medium bud breaking rate and strong branching ability. It enjoys sunlight and high temperature environment. It begins to produce in third year, and enters the fertile period in fifth year. The fruit shows long water droplet shape. The average weight of single mature fruit is 1.56 kg and the edible rate of fruit is 68%. The soluble solid content is 11.3%, the total acidis 0.47 g·100 g-1 , the solid/acid ratio is 24.04, the content of vitamin C is 56.7 mg·100 g-1 , and the content of vitamin E is 0.407 mg · 100 g-1 , all of which were superior to the control variety Chandler pomelo. In Hekou area of Yunnan, the bud break appears in early February, flowers bloom in March, fruits mature in late September, and the fruit growth period is about 190 d. After the fruits mature, the main color of the fruit surface is green and the flesh is red. The juice cell is three-dimensional slice crystal and clear without bitter hemp taste and the juice sac is not granulated. Seedless or less seeded pomelo fruits can be obtained under monoculture conditions. The plant of this variety is resistant to barren, high temperature and high humidity, which is suitable for cultivation in hot areas, and can be planted in southern hot areas and low hot valley areas of Yunnan.