Breeding of a new litchi cultivar 'Beiyuanlü'

Abstract: Beiyuanlü', a new litchi cultivar with excellent characteristics, was selected through seed-ling selection. In 1998, maternal tree of'Beiyuanlü'was initially selected for its large fruit size, excel-lent appearance and high quality in Zengcheng city. After regional adaptability testing at four sites oversix years from 2009 to 2015, 'Beiyuanlv'was finally selected in 2017. For a 12-year-old tree on'Huai-zhi'rootstock, the average height of'Beiyuanlü'is 525.0 cm; the average trunk girth is 165.0 cm andthe average crown size is 210.0 cm × 230.0 cm. Tree of'Beiyuanlü'is vigorous with semicircularcrown. Leaves are lanceolate, 9.71 cm long and 2.87 cm wide. Inflorescence is conical; the main axis ofinflorescence is 15.8 cm long and 10.5 cm wide. Flower is white with medium size. The average lengthof style is 2.0 mm.'Beiyuanlü'can sprout new shoots all round year, with young tree shoot about 5-6 times while fruiting tree 3-4 times. Fruit is mainly heart-shaped and peel is red with yellow-green color.The flesh is white and crisp, with sweet flavor and aroma. The average fruit weight is 25.8 g; fruit hori-zontal diameter is 34.0-38.0 mm, fruit longitudinal diameter is 31.0-34.0 mm, the number of seeds is 1.The fruit eatable rate is 74.5%. The content of soluble solid is 17.9%; total sugar is 16.2%; soluble acidis 0.153%. The content of vitamin C is 178.0 mg · kg-1. The fruit quality of'Beiyuanlü'is excellent. Thefruit development period is about 76 d. And its maturity period is from the late June to early July inGuangzhou city in Guangdong province. It is resistant to drought and waterlogging.'Beiyuanlü'has astrong adaptability and suitable cultivation area includes the majority of the mid-late maturing litchi pro-duction areas in Guangdong province. The graft compatibility between'Beiyuanlv'and'Huaizhi', 'Guiwei'and'Nuomici'is high. Three years after high-grafting, this cultivar can bear fruits, and theyield potential is high. Orchard should be built in acid red loam which has the ability of moisture andfertilizer retention. Spacing in the rows and spacing between rows are 5 m×6 m. Main stem is 0.4-0.6 mhigh with 3-4 main branches which have uniform distribution and growth vigor. Pruning can be doneone month after harvest, including erasing redundant branches, dense branches and poor branches. Win-ter shoot should be controlled by girdling or spray paclobutrazol which aims to promote flower forma-tion. Prevention of insects should be taken seriously, especially control of Tessaratoma papillosa Druryand Conopomorpha sinesis Bladley.