Breeding report of a new mutation apple cultivar‘Hongguang No. 2'

‘Hongguang No.2'is a late maturing table apple with excellent appearance. The variety is a red rind bud mutant selected from‘Ralls' tree which grown in Yan Zhuangzi village, Huailai county. The mother tree was planted in an old orchard for 20 years. It was initially selected in 2007 for its bright colors and excellent quality. The scions were collected from‘Ralls' mather tree, grafted to the Malus robusta Rehd. Based on four years evaluation of the major characteristics, these lines were identified as superior trees in 2011. Based on the comparison research in Zhangjiakou and Chengde areas, 22 excellent‘Red Ralls' apple trees with red bud mutant were finally selected out. After regional adaptability testing at three sites(including Huailai county, Chengde county and Kuancheng county) for years from 2007 to2014, it was finally selected in 2014. The variety adaptability is strong, the tree potential, high yield and good fruit quality, etc. Plant variety registration was achieved in December 2014 in Hebei(No. hebei SSV-MP-012-2014). The selection cycle is 20 years, the diameter at breast heigh is 16 cm, attaining a height of 3.5 m, skin index is 0.95. The tree is vigorous with ramose crown and upright tree gesture. Young branches are densely pubescent, then glabrous, dull grey-brown in color. Leaf is ovate to elliptic, 4.0-8.5cm long, 3.0-5.0 cm wide sharply serrated. Flower is pink to white, trumpet, pedicel villous, five petals,quincunx, 3-4 cm across, the flowering time is late april(in Huailai county). It is a spur-type variety, the fruit of the flower bud at the top branch. Fruit growth uniformity, the mature period is in early October.Fruit is mainly oblate, has full red peel and light ware surface. The surface base color is yellow-green.The surface dot is median size and sparse. Its flesh is yellowish-white, crisp, rich juice, fine texture and aroma. The average fruit weight is 138.1 g, maximum fruit weight is 245.0 g, fruit shape index is 0.75; the average seed numbers of per fruit is 3.8. The fruit skin has thick waxy cuticle. There is rich fruit aroma.The juice yield is 81%, the content of soluble solid is 17.0%, the content of soluble acid is 0.73%, the sugar-acid ratio is 23.3, and the hardness is 10.51 kg·cm-2. Quality is excellent. The fruit development period is 170 d and it matures at the middle October in Huailai area; the number of inflorescence is 5.5, proportion of fruit branches is 25%, with a 78.0% branch-pulling pruning and carving on the sprout the germination rate. It is resistant to cold, drought and saline. The short, medium and long branches all can result, give priority to with short shoot. The species can be planted in the plain and hilly areas. Suitable cultivation area is Zhangjiakou and Chengde areas, this variety can bear fruits third year after planted, has a high yield potential of 22.5 t·hm-2. The row and column space are 3 m×4 m, the configuration of pollinizer is‘Fuji'; on the primary fruit stage, promote flower and results in order to slow growth. The adult tree must set production limits for 22.5 t·hm-2, leaving one fruit for each 15-20 cm.