Breeding of a very early ripening apricot cultivar Longxing No. 3

Abstract: Longxing No. 3 is a very early ripening apricot cultivar, which was selected from natural hy-bridization with Caoxing as the female parent. Longxing No. 3 is round with an average fruit weight of 60.4 g. The fruit peel is yellow and reddish in the sunny side when it ripens. The surface of the fruit is fluffy and the fruit peel is medium thick. The fruit of Longxing No. 3 has orange flesh with delicate tex-ture and little fiber. Longxing No. 3 is an attractive with excellent flavor and quality, abundant juice, in-tense fruity aromas, pleasant sweetness and sourness, a soluble solids content of 12.4%, a total soluble sugar content of 5.79%, a total acid content of 1.02%, and a vitamin C content of 4.20 mg·100 g^-1. The fruit stone of Longxing No. 3 apricot is round, brown and separated easily from the flesh, and the kernel is sweet. The flower is showy and the anther is lightly yellow. In Anning district of Lanzhou, China, the flower bud of Longxing No. 3 starts to break in the late March; initial blooming mostly occurs in the late March to the early April; the full blossom stage generally takes place in the early April; and the flowering period can last about 8-9 days. The ovary gradually bulged after the flowers wither; the fruit matures in the mid to late June, about 65 days after blooming. The leaf buds break in mid-April and expand in the late April. The leaves start falling in mid-October and completely fallen in the early November, and the vegetative growth of the tree lasts for about 215 d within a year. The tree vigor of Longxing No. 3 is moderate, with a semi-open canopy. and the cultivar produce flowers easily. T Self-pollination rate for Longxing No.3 apricot is very low and suggested to be a self-incompatible cultivar. Only by planting suitable pollinizers can it set fruit well, and Golden-sun and Zhanggongyuan are suitable polli-nizer cultivars for Longxing No. 3. The rate of pollen germination increases with the increase in temper-ature with the range of 10-25 ℃. Pollen begins to germinate in 4-8 hours at 15 ℃. Longxing No. 3 mainly bore on the short and cluster branches in the fields, although various types of branches can flow-er and fruit. It has such characteristics as early ripening, high yielding and good quality, it can be stored for 4-5 days under ambient temperature. It is suitable for both protected field and open field cultivation. Longxing No. 3 has strong adaptability to adverse environments, high and stable output, and high-quality fruit, which has nice appearance. It is suitable to be cultivated in Gansu and surrounding plains, hills and mountains, and other regions suitable for apricot planting in China.