Breeding of a heat-tolerance yellow passion fruit cultivar Qinguo No. 9 (formerly name: Qinmi No. 9)

Ａbstract: Qinguo No. 9, which was formerly named as Qinmi No. 9, is a hybrid between Guava- flavored Golden Passion Fruit (♀) and Honey-flavored Golden Passion Fruit (♂). This hybrid was authorized as a new variety by the Plant New Variety Protection Office, Ministry of Agriculture and Rural Affairs, with a variety authorized code of CNA20211005004. The hybridization was conducted in early May of 2018, and the screening from 1010 hybrid seedlings in field was conducted from 2019 to 2020, and finally this hybrid was selected due to its excellent characteristics, such as heat-resistance, sweet fla-vor, long shelf-life and high yield. The color of vigorous vines is purplish-green. The leaves are papery, with serrated edges; There are three types of leaves in shape: entire, bilobatenon and trilobate. Generally, the lower nodes of the vine have entire leaves, while the middle and higher nodes have bilobatenon and trilobate leaves; The trilobate leaves have a length of 13.12 cm and a width of 16.63 cm. The fruit is pear-shaped, with a longitudinal diameter of 65.96 mm and a transverse diameter of 60.57 mm, and with the ratio of longitudinal diameter to transverse diameter being 1.09. The ripe fruit has golden color peel with white dots. The maximum single fruit weight is 142.5 g, the average single fruit weight is 69.17 g, and the average edible rate is 49.3%; The ripe fruit’s mesocarp and endocarp are easy to separate. The thickness of the peel is 5.40 mm, the color of the fruit juice is yellow; The content of soluble solids is 19.4%, the titratable acidity is 1.53%, and the ratio of soluble solids to total titratable acidity is 12.7; and the content of vitamin C is 78.8 mg·100 g-1 . This variety is very tolerant to high temperature, and blooms and sets fruit even at high temperature of 35-37 ℃ in July and August. According to field test in southern Guangxi, when planted in early March, it started to bloom in late May, and the flowering period lasted 7-10 days. And then, with an interval of 20-25 days, a new batch of flowers bloomed again. So from late May to late October, it set 6-7 batches of fruits, and the first 5-6 batches of fruits could fully mature, but the last batch could not fully ripen due to low temperature. The fruit ripening period is about 55-60 days in spring and summer, and about 65-70 days in autumn. The fruit can be harvested when the color of peel changes from deep green to light green and the peel becomes soft; and the skin can be stored at room temperature for 7-10 d in summer without wrinkling, and can be stored at 4 ℃ for 25 d. The recommended cultivation density is 150-200 plants per 666.7 m2 , with a yield of 1000- 1500 kg per 666.7 m2 . This variety is now widely cultivated in Guangxi, Hainan, Guangdong, Yunnan, Guizhou and Fujian due to its heat-tolerance and stable yield, and has become one of the main varieties in China.