低温胁迫下2个‘竹柳’品系的抗寒性

Cold Resistance of Two ‘Zhuliu'Varieties under Low Temperature Stress

‘竹柳’（Salix‘Zhuliu’）为杨柳科柳属（Salix）植物，是被优选、驯化出来的一个优良品种，其密植时形似竹子，故取名为‘竹柳’。‘竹柳’树干修长，叶色浓绿，树形美观；生长快，抗性强，材质好，适应性广，在防护林建设、纸浆造纸业和园林绿化上具有广阔的应用前景。目前，‘竹柳’作为盐碱地绿化、速生经济林和农田防护林新品种被广泛使用，已在四川、安徽、山东、北京、河北等地大面积栽植，并取得良好的经济效益和生态效益。目前有关‘竹柳’的研究主要集中在耐盐碱（杨升等，2012；王文成等，2011）、繁殖技术（蒋海月等，2010）等方面，并在此基础上进行新品系的培育与筛选。‘竹柳’3号品系和‘竹柳’5号品系就是在‘竹柳’品种基础上培育的枝色不同的新品系。‘竹柳’作为优良品种引种推广到东北地区，其抗寒性研究尤为重要。

Under natural and artificial low temperature stress, the relative electric conductivity, SOD activity and soluble sugar content of varieties of ＇ Zhuliu＇ No. 3 and ＇ Zhuliu＇ No. 5 were determined, with hankow willow （Salix matsudana） served as control. The cold resistance of the plants was comprehensively evaluated by the method of subordinate function with the measured data. Results showed that under natural low temperature stress, relative electric conductivity, SOD activity and soluble sugar content of selected twigs first increased and then declined with the decrease and increase of natural temperature. Under artificial low temperature stress, relative electric conductivity of the twigs increased with the decrease of temperature, SOD activity and soluble sugar content presented first increased and then dropped. The semi-lethal temperature of hankow willow, ＇ Zhuliu＇ No. 5, and ＇ Zhuliu＇ No. 3 was - 42.87, - 37.27, and - 31.60 ~C ,respectively, and the cold resistance of the varieties was as the follows ： hankow willow 〉 ＇ Zhuliu＇ No. 5 〉 ＇ Zhuliu＇ No. 3. The ＇ Zhuliu＇ No. 5, with relatively stronger cold resistance, grew well and overwintered successfully in 2011 in Harbin, Daqing, Qiqihar, and Heihe of Heilongjiang Province. The study showed that ＇Zhuliu＇ No. 5 could be applied to the region where winter temperature is above - 37.27 % through introduction and overwintering acclimation at the seedling stage.