Breeding of a new Actinidia arguta Planch. cultivar Lüjiaren

Abstract: Lüjiaren is a mid-maturing variety selected from a plant of wild Actinidia arguta in 2010. After the regional adaptability test in four locations in Liaoning province over ten years from 2011 to 2021, it was finally selected in 2021. The tree vigoris moderately weak. The new vine shows obvious anthocyanin coloration. The leaves are dark green and ovate in shape. Petiole is red and the flower is umbel with 1-3 flowers per inflorescence. The corolla is green and white and sepals are purplish red. Fruiting canes begin to bear fruit from the 3rd to 5th nodes, the canes set 1 to 3 fruits in each node, and the maximum number of fruit nodes is 10. The fruit is obovate with dark green peel, smooth, glabrous, non-waxy, green flesh, juicy texture and sweet flavor. The average weight of a single fruit is 17.6 g and fruit shape index is 1.37. Seed numbers per fruit are from 100 to 140. The total acid content is 1.07%. The average soluble solid content is 18.1% and the highest content is 22%. The vitamin C content per kilogram of fresh fruit is 1100 mg. It takes about 100 d from fruit setting to fruit ripening, and the ripening period is around September 10th at 124°23′ east longitude and 40°07′ north latitude. Bud break rate is 60%-80% and fruit cane rate is 50%-70%. The plant blooms in the third year, and enters into a high yield in the fifth year. The yield per hectare is over 15 000 kg. This cultivar is more resistant to speckly and sooty mould diseases. At room temperature, its shelf life is long, which can reach 10 days. When the fruit is refrigerated at 1-3 ℃, its storage life can reach more than 8 weeks. In areas suitable for cultivation, the climatic conditions are that the frost-free period lasts for more than 120 d, there is no harm of late frost and strong wind in the growing season, the average annual precipitation is 450-1200 mm, the lowest temperature in dormant period should be above -30 ℃, and the effective accumulated temperature should be above 2500 ℃. The loam or sandy loam with good soil drainage and pH 6.5-7.0 is required. Orchards should be established near water sources or with irrigation conditions. And it should be well drained with no frost and wind damage in later period, sufficient light and convenient transportation. The 2- year seedlings should be selected for starting a new orchard. The row spacing between plants and rows is 2 m×4 m. The female and male plants should be in a ratio of 5∶1. Lüjiaren is usually cultivated by supporting. Pruning measures in summer include bud picking, cane thinning, pinching and tip twisting, aiming at controlling the density of canes and the growth direction of new canes to ensure ventilation and light transmission on the trellis. Middle and long cane pruning are used in winter with fishbone pruning system. This cultivar is not suitable for heavy cut back in winter pruning. At present, the main pest control is thrips.