Breeding report of a new Actinidia arguta Planch. cultivar Danyang

Abstract:  Danyang is a middle-late kiwi berry cultivar which selected from wild relates of Actinidia ar-guta Planch. It was initially selected in 2009 for its large fruit size and tasted sweet with sour. After re-gional adaptability testing at four sites (including Dandong, Dalian, Shenyang, Chaoyang) over eight years from 2010 to 2018, it was finally selected in 2019. The tree grows vigorously and the branches are thick and strong. Buds germinated at the lower part of the annual branch is easy to die, which result-ing in bare branches phenomenon in the lower part of the branch. The leaves were dark green, broad-ovate, umbrella-shaped inflorescences, 1-3 flowers in each inflorescence and the corolla were green white, the sepal was green. Fruits begin to set at the 4th-7th nodes of the new shoots and continue for 5-10 nodes with 1-3 fruits per node. The fruit is mainly oblate, has green peel and with slightly ridge in the fruit surface. Its flesh is green, rich juice, moderately sweet and sour in flavor. The average fruit weight is 20 g, maximum fruit weight is over 46 g. The yield was more than 15 000 kg·hm^-2. The con-tent of soluble solid is 20.1%, the content of total acid is 0.99%, the sugar-acid ratio is 20.3, the content of Vitamin C is 2.86 mg·g^-1. Fruit containing 18 amino acids with total content of 18.03 mg·g^-1. The fruit development period is about 110 d and it matures at the middle and late September in Dandong ar-ea. 1-3 flowers per inflorescence, germination rate is 50%, branching ability is 90%. This cultivar is re-sistant to grape gall mites. The fruit has long storage-life. It can be stored for 5-10 days at room temper-ature and more than 70 days at 1-3 ℃, when the soluble solid content reaches 6.5%. It was suitable for cultivation in areas where the annual average rainfall was 450-1200 mm, frost-free period was more than 120 d, annual average temperature was 5.4- 10.0 ℃ , effective accumulated temperature above  10 ℃ was more than 2500 ℃ and the minimum temperature in winter was more than -30 ℃. It likes the loam or sandy loam soil with good drainage and weak acid or neutral soil. Orchard should choose sandy loam soil or loam soil which is flat or hilly mountains and with character of loose and good permeabili-ty. Orchard should close to the water source and with good drainage, without late frost and wind dam-age, with sufficient light and convenient transportation. 2-year seedlings were better chosen to establish orchard. Spacing in the rows and spacing between rows are 3 m×4 m or 2 m×5 m, and the ratio of fe-male to male was 8∶1. Scaffolding cultivation is required and scaffolding and T-frame were general used. Pruning includes bud picking, thinning, pinching and shoot-twisting, aiming at controlling tree size and maintaining tree vigor.