Breeding report of a new apple cultivar ‘Ruixue'

Abstract: ‘Ruixue'is a new late ripening yellow apple cultivar selected from a cross‘Qinfu No.1'and‘Pinklady'. Firstly, after artificial pollination, 4 176 hybrid seeds were got in 2002. The seeds were sowed in 2003, and 1 294 seedlings were got. Subsequently, the progeny plants were transfered to Baishui Apple Experiment Station in 2005. Seven selections were made from this population for its perfect appearance and high quality in 2008. Regional adaptability testing of those selections was at Baishui county, Xunyi county and Fufeng county of Shaanxi province over three years from 2008 to 2010. Finally,‘Ruixue'was selected out in 2010. Trees of‘Ruixue'are moderately vigorous with a upright growth habit. The central axis of tree becomes obvious with taupe colour while the perennial branch is auburn. The characteristics of annual shoots are upright, thick, and the internode is very short with an average length is 1.8 cm.Axillary bud is medium size, triangle and hairy. Flower bud is full, heart-shaped, compact and hairy. Leaf is spindle, dark green and luster. The average length and width are respectively 9.7 cm and 6.4 cm. The flower is pink with ovoid and white petals. The diameter of corolla is 4.10 cm with 20 stamens. The fruit is cylindric, large size with an average length to diameter ratio of 0.90 and an average weight of 296 g, the biggest one is up to 339 g. It has a beautiful appearance with yellow color. The skin is smooth, waxy with small dots. The flesh is yellowish white, delicate tender, juicy and crispy with a firmness of 8.84 kg·cm-2.This variety has 10 seeds per fruit. The flavor is aromatic, sweet and sour taste with a soluble solid substance content of 16.0%, a total sugar of 12.10%, and a total titratable acid content of 0.30%. Vitamin C is68.2 mg·kg- 1. The quality is excellent. Full bloom date of‘Ruixue'in Shanxi Weibei area is April and the mature date is mid-October. The fruit development period is 180 d, without pre-harvest fruit dropping. The germination rate is 55%, branching ability is medium. Foliage and fruits are resistant to powdery mildew, stronger than that of‘Golden Delicious'. The resistance to brown spot is similar to that of‘Golden Delicious'. In order to investigate the storability of‘Ruixue', the fruit are stored at room and cold temperature, respectively. These results indicate that it can store for 5 month at room temperature,and it keeps fresh quality for 8 month at cold temperature. This variety can bear fruits after planted for three years. The ability of yielding was 21 900 kg·hm^-2 in the fourth year. And this variety has the cultivation characteristics of Spur type with high and stable yield, and easy initiation of floral bud with precocious fruit bearing. At the same time, the comprehensive properties are superior to‘Golden Delicious' and‘Orin'. It has stronger competition for the market and a wide application prospect.