早熟欧李新品种‘夏日红’的选育

Breeding report of a new early ripening Chinese dwarf cherry cultivar‘Xia Ri Hong'

‘夏日红’是2006年从自然杂交实生后代中选育而成的早熟型欧李新品种。果实扁圆形,果皮红色,果肉黄色,味酸甜;平均单果质量6.74 g,半离核。果实可溶性固形物达含量10.9%,总糖含量8.20%,总酸含量1.81%,糖酸比4.53,可食率94.51%。果肉含钙219.7 mg·kg^(-1),铁4.4 mg·kg^(-1),锌1.09 mg·kg^(-1),维生素C 182 mg·kg^(-1)。果实发育期96~101 d,北京地区7月下旬成熟。货架期3~5 d,冷藏20 d左右,冷冻可达1 a,果实不失味。适合北京地区栽培,第二年开花结果,丰产性较强。

‘Xia Ri Hong’is a new early-ripening variety selected from seedlings of Chinese dwarf cherry（Cerasus humilis Bunge）in 2006. The seeds were sowed in Spring of 2003, and one selection were made from this population for its perfect appearance and high quality in 2006. Regional adaptability testing of this optimal system was at Huairou district, Pinggu district and Tongzhou district of Beijing over three years from 2009 to 2012. Finally,‘Xia Ri Hong’was selected out in 2012. Trees of‘Xia Ri Hong’are moderately vigorous with an tufted growth habit.‘Xia Ri Hong’is dwarf with height of 0.5-0.8 m. The characteristics of one year shoots are thin with the length of 89.1 cm and the rougness of 0.74 cm. Leaf is long obovate, emerald green and luster with serrate leaf margin. The average length and width are 6.71 cm and 3.17 cm, respectively. The flower is white with ovoid and white petals. The diameter of corolla is 0.92 cm with 24 stamens. The fruit is flat round with red skin color and semi-free stone, and the average length to diameter ratio is 0.80 and the average weight is 6.74 g. The flavor is aromatic, sweet and sour taste with a soluble solid substance content of 10.9%, a total sugar of 8.20%, and a total acid content of 1.81%. The flesh is yellow and semi-free stone with calcium content is 219.7 mg·kg-1, iron is 4.4 mg·kg-1, zinc is1.09 mg·kg-1, and vitamin C is 182 mg·kg-1. Full bloom date of‘Xia Ri Hong’in Beijing area is April and the mature date is late-July to early-August and the ripening period is 40 days earlier than‘Nongdagaiguo 4’. The fruit development period is 96-101 d, the natural fruiting rate is over 60%, without preharvest fruit dropping. The resistance to plant diseases and insect pests are similar to that of‘Nongdagaig-uo 4’. It keeps fresh quality for 3-5 days at room temperature, 20 days at cold temperature, and 1 year under the condition of frozen. This variety can bear fruits after planted for one year. The ability of yielding was 0.8-1.5 kg per plant in the 2-3 year. The variety has the cultivation characteristics of simply management, with high and stable yield. At the same time, the comprehensive properties are superior to‘Nongdagaiguo 4’. The ornamental period of flowers and fruits of‘Xia Ri Hong’is long and beautiful which is suitable for using in landscape beautification and bonsai production. Orchard should choose neutral sandy soil. Spacing in the rows and spacing between rows are 1.0 m×1.0 m or 0.5 m×2.0 m and the tree form could be tufted, upright or shaped after top grafting. Pruning includes pinching and back spune, aiming at growing and fruiting alternately overyear.