核桃优良单株幼苗对干旱胁迫的生理响应及抗旱性评价

Physiologic Response and Evaluation of Walnut Seedling in Superior Individual Plants under Drought Stress

为了解不同核桃优良单株幼苗间抗旱差异,筛选高抗旱性良种。以新疆阿克苏地区采集到的8种核桃优良单株幼苗为试验材料,采用自然干旱法,测定干旱胁迫期间叶片可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量、超氧化物歧化酶活性与过氧化物酶活性等生理指标,研究优良单株幼苗对干旱胁迫的生理响应及抗旱能力。随着干旱胁迫的持续,各核桃优良单株幼苗的游离脯氨酸含量均呈现增长趋势,而可溶性糖含量、可溶性蛋白含量、超氧化物歧化酶活性与过氧化物酶则呈现为两种趋势,即持续增长趋势与先升后降趋势,且同期不同优良单株的生理指标之间存在差异。因此,采用抗旱系数结合隶属函数法综合评价其抗旱能力,结果为:YZ-1>YZ-7>YZ-5>YZ-4>YZ-3>YZ-8>YZ-6>YZ-2。进一步对优良单株幼苗进行系统聚类分析,在欧式距离为5.0时,YZ-1归类为强抗旱品种,YZ-5、YZ-7归类为中抗旱品种,YZ-2、YZ-3、YZ-4、YZ-6、YZ-8归类为弱抗旱品种。YZ-1具有较强的抗旱性,可作为核桃砧木使用,适合在西北干旱地区应用。

This paper aims to learn the drought resistance difference between different varieties of walnut seedling in superior individual plants and provide a high drought resistance varieties for Xinjiang.Eight varieties of walnut seedling in superior individual plants collected in Akesu of Xinjiang were taken as the test materials and natural drought method was used to test soluble sugar content in leaf,soluble protein content,free proline content,superoxide dismutase activity,peroxidase activity and other physiological indexes during drought stress and study the physiological response of walnut seedling in superior individual plants to drought stress and the drought resistance ability of walnut seedling in superior individual plants.As drought stress continued,the free proline contents of all varieties of walnut seedling in superior individual plants showed increased,while soluble sugar content,soluble protein content,superoxide dismutase activity and peroxidase activity showed two trends of continuous increase and decrease after increase,and different indexes had different physiological effects.Therefore,the method of combing drought resistance coefficient with subordinate function was used to comprehensively evaluate the drought resistance ability.The result was YZ-1>YZ-7>YZ-5>YZ-4>YZ-3>YZ-8>YZ-6>YZ-2.A hierarchical cluster analysis was done for the eight varieties of walnut seedling in superior plants.When Euclidean distance was 5.0,YZ-1 was classified as a high drought resistance variety,YZ-5、YZ-7 was classified as a medium drought resistance variety,and YZ-2、YZ-3、YZ-4、YZ-6、YZ-8 was classified as a low drought resistance variety.YZ-1 with strong drought resistance ability can be used as walnut rootstock and be applied in arid area of Xinjiang.