避晚霜型早实核桃新品种‘云林7号’的选育

Breeding of avoiding late frost walnut variety of early-fruiting ‘Yunlin 7'

云南省东北区域晚霜危害严重,严重缺乏避晚霜能力强的核桃品种。云南省林业科学院和鲁甸县林业局在鲁甸县通过实生选育,选育出了早实核桃新品种‘云林7号’。通过2010—2016年5 a(年)的观测结果表明,定植1 a生嫁接苗第3年开花结果,高枝嫁接第2年开花结果。坚果三径平均3.40 cm,壳厚1.03 mm,果质量14.66 g,仁质量8.51g,出仁率58.05%,含油率69.4%,蛋白质含量(w)18.9%,取仁易,仁黄白,肥仁,饱满,食味香无异味。2016年12月通过云南省林木良种审定委员会良种认定。该品种避霜性好,适合在云南省东北区域、贵州、四川、湖北、重庆等地区栽培。

Northeast Yunnan have severe late-frost and lack of the walnut varieties which have ability to avoid the late-frost damage.‘Yunlin 7＇, a new early-bearing walnut variety with excellent characteristics,was selected from seedings in Ludian county by Yunnan Academy of Forestry and Ludian county forestry bureau in 2016. It was initially selected out in resources investigation in 2009 for its large fruit size, excellent quality, high yield, no obvious stem diseases and good continuously fruiting ability. By the method of top grafting, variety comparative testing orchard of 1 200 square meters was built in Sanba state farms in Ludian Forestry Bureau of Ludian county, Yunnan province in 2010. Through five years＇ investigation and comparison about graft compatibility, nut quality, bearing habit and yield, it was identified as superior line in 2016. Regional adaptability testing of this superior line was carried out at three sites（Kunming, Dali and Lijiang, Yunan） over one years in 2012, using Juglans sigillata as control varieties. Results showed that this superior line had stable characters and outstanding economic value, which meet the breeding objective of big nut, suitable shell thickness, easily taken kernel. It was name as‘Yunlin 7＇in 2012 and audited through the Committee for Forestry Varieties in Yunnan province in 2016. The bud of the tree is round with a tip on the top. Leaflet is broadly lanceolate and the number of it is five to eleven. Male flowers bloom earlier than female ones. The nut has an elliptical shape, slightly tip on the top, flat and tight suture line, with average of vertical, transverse and lateral diameters of 3.40 cm. The average fruit weight is14.66 g, shell thickness is 1.03 mm. The oil content is 69.4%. The protein content is 18.9%. The kernel rate is 58.05%. The kernel is light yellow and plump with strong aroma. In Ludian county, Yunnan province, the tree germinates in late March. Male flowers bloom from the end of April, and female flowers bloom in 4 to 5 days later than male flowers. So, the variety of‘Yunlin 7＇is protandrous. Fruit rapid growth period is from June to August. Nut ripens in early September. The fruit bud rate is 93.3%. The flo-ral bud rate is 88.7%. The top of fruit bud rate is 34.2%. The lateral bud rate is 65.8%. The fruit setting rate is 84.6%. Juglans sigillata walnut suffered serious frozen injury in the winter of 2007. So the trees of‘Yunlin 7＇have higher resistance to frost. The northeastern region in Yunnan,Guizhou, Sichuan, Hubei and Chongqing are the suitable cultivation area for the variety of‘Yunlin 7＇.