Breeding of a new high-quality and mid-late maturing mango variety Qianshan Mango No. 2

Qianshan Mango No. 2 is a high-quality mid-to-late maturing variety. The seedling was derived from a cross between female parent (Jinhuang Mango) and male parent (Red Mango No. 6) in 2002 at the experimental field. It was initially selected in 2002 for its bright colors and quite late ripening time. Through artificial hybridization pollination, 18 hybrid seeds was gotten. From 2013 to 2015, the phenological period, botanical characteristics, agronomic traits, fruit quality, yield and stress resistance of QSM-02 were observed and recorded for three consecutive years. The results show that QSM- 02 is late-maturing, with a fruit development period of 130 days. The mature fruit has yellow skin with a red tinge and yellow flesh. It has strong stress resistance and stable comprehensive traits, and is thus designated as a preliminary selected strain. After regional adaptability testing at three sites over three years from 2017 to 2019, it was finally selected in 2020. The tree vigor is moderate with a relatively open canopy. The leaves are elliptical and thick, with a leaf shape index ranging from 3.71 to 5.88. The inflorescence is conical, measuring 30.6-43.6 cm in length and 13.5-23.6 cm in width, with a hermaphrodite flower ratio of 32.3%. The fruit is ovate. The skin of the green ripe fruit is green with a hint of red, while that of the fully ripe fruit is yellow with a hint of red. The fruit surface is smooth with a waxy texture. The flesh is yellow, fine and tender, with few fibers and abundant juice. It has a good appearance. The average single fruit weight is 542.6 g, and the maximum single fruit weight is 664.0 g. The fruit shape index is 1.58. The edible rate of the fruit is 71.5%- 82.3% , the soluble solids content is 12.0%-15.3%, the total sugar is 83.21 mg·g-1 , the fructose is 22.04 mg·g-1 , the sucrose is 10.13 mg·g-1 , and the glucose is 9.76 mg·g-1 . Total acid is 0.20%, vitamin C is 0.30 mg·g-1 , and crude fiber is 0.47%, with sweet taste and nitrogenous aroma; The quality is above the average. The fruit development period is 130 days. In the low-heat river valley area of Guizhou Province, it matures at the middle and late August. The yield per plant is 14 to 16 kilograms after four years of planting. Generally, it sprouts 3 to 4 times a year. The flowering period is from mid-March to mid and late April. The inflorescence is conical, with a length of 30.6 to 43.6 cm and a width of 13.5 to 23.6 cm. The ratio of bisexual flowers is 32.3%. It is suitable for cultivation in the dry and cool climate areas below 800 meters in altitude in Guizhou. It has strong resistance to bacterial angular leaf spot and powdery mildew. The planting holes should be dug according to the specifications of 70 cm in length, 70 cm in width and 70 cm in depth. The planting density is 4 m×3 m. It is advisable to perform the trunk pinning in the second or third year (when the tree trunk height is 80-100 cm). The pruning of the bearing tree is carried out in two stages. The first stage is during the early fruiting period (May-June), to remove the dense branches and leaves, diseased and pest-infested branches and the top flower stalks of the fruit clusters that do not bear fruit. The second stage is in mid-August, to short-trim the borne branches, summer shoots and overly long spring shoots after the harvest; and to remove the diseased and pest-infested, crossing and overlapping branches.