Breeding of a new mid- late- maturing apricot cultivar——‘Longxing No. 1'

Abstract: ‘Longxing No.1'is a new mid-late-maturing apricot cultivar with attractive appearance and excellent quality. Originated from seedlings and artificial selection of‘Caoxing'(a local fine cultivar in Gansu province)as female parent in 1998 at experimental field. It was initially selected in 2002 for its large fruit,good quality and mid-late ripening time. Through seedling breeding technology,350 seeds were got in 1998. After regional adaptability testing at four sites(including Lanzhou area,Pingliang area,Tianshui area and Qingyang area,where are all apricot main producing areas in Gansu province) over four years from 2008 to 2012,it was finally selected in 2013. We applied for the new cultivar registration a in 2014 and got identification certificate from Crop Variety Approval Committee of Gansu province in 2015. The tree growth vigor is strong and tree gesture is half opened with the purple brown trunk and round crown under natural circumstances. One-year-old shoots has a red-brown skin and it's lenticels is white,oblong,medium size and medium density. The shape of leaf is nearly round,the surface of leaf is flat and smooth with dark green color. Leaf margin is tidy with blunt,medium deep sawtooth. The petiole is red with an average length is 4.1 cm. Leaf glands is round and the number is 1-2. The distance between two buds is short and the average length is only 1.9 cm. The color of the flower is light pink with 5 petals,1 pistil and 21-27 stamens. The fruit is round with an attractive appearance and the longitudinal diameter,transverse diameter and side diameter are 4.5 cm,4.5cm,4.4 cm,respectively. The new cultivar has a flat fruit top and the suture is shallow and not obvious,and both sides are symmetrical. The fruit peel is yellow and the sunny side is rosy red. The average fruit weight is 70.5 g,and the heaviest one is82.6 g.‘Longxing No.1'has light yellow flesh with delicate texture and less fiber,pleasant sweetness and sourness,abundant juice and intense fruity aromas. The content of soluble solids,soluble sugar,titratable acidity,vitamin C account for 14.50%,12.35%,1.42%,0.15 mg·g-1,respectively. In sammary,the quality of‘Longxing No.1'is excellent. The stone is oval with smooth surface,free to the flesh and the kernel is full and sweet. The average mass of a fresh stone is 2.75 g,so the edible rate can reach up to 96.1%. The fruit development period is 102 d and its maturity date at early August in Yuzhong area,where is belong to Lanzhou city,Gansu province,China. The main fruit branches are short and bouquet shaped branches,the proportion of fruit branches about short,medium and long are 51.6%,20.2% and 18.2%,respectively,the spindling fruit branches is only 10%. The quantity of fruit drop of physiological and before harvest are all slight. The new mid-late-maturing variety has strong suitability to adverse circumstance,such as drought,bitterly cold,barren soil,et al.‘Longxing No.1'has good disease resistance like it's female parent. Shelf life of the fruit is 5-6 days at room temperature,but reach to 10-11 days in a cooler environment and the fruit aroma get better.‘Longxing No 1'has a wide adaptability,it can be planted in most places in Gansu province,but the best suitable areas are Lanzhou,Pingliang,Qingyang and Tianshui,where belong to the middle,the eastern,the southeast part of Gansu province respectively. At the same time,it can also be introduced and cultivated in some places of China if the ecological conditions are similar to the best suitable areas of Gansu province. The new cultivar has some good characteristics of early fruit,high yield and stable yield. It can bear fruits 3 years after planted and the yield will reach 11 040 kg·hm-2with the planting density of 3 m×4 m in the orchard. The yield will reach 22 680 kg·hm-2in 5 years after planted. Orchard should choose neutral sandy soil which is flat and has ability of moisture and fertilizer retention. At the same time,orchard should choose convenient transportation and away from industrial pollution area and avoid continuous drupe planting with peach,apricot and plum. It is necessary to choose high standard seedling with apricot rootstock and no plant diseases and insect pests in planting. In order to improve the survival rate,some drought resistant technologies must be applied,such as cover with film around the tree,especially in dry land orchard. According to the different orchard,the spacing in the rows and spacing between rows are 3-4 m×4-6 m. In order to obtain high and stable yield,orchard should choose pollination tree and the configuration of pollinizer is 1:5. The best form of the tree is the evacuation of the hierarchical form,the main pruning technology includes pinching,bending and back pruning,aiming at controlling tree size and maintaining tree vigor. In order to improve the orchard income when the trees are young,some dwarf crops planting is allowable in rows.The main measures to improve the quality of apricot fruit is to increase the organic fertilizer and to use chemical fertilizer reasonably. Meanwhile,some drought resistant techniques must be used in the mountainous orchard. Grapholitha molesta,aphid and apricot spot are main plant diseases and insect pest in the orchard. These are all effective measures to spray 5 Be0 Lime Sulphur before bud,the removal of diseased leaves and fruits timely in the orchard.