盐胁迫对美国黑核桃幼苗生长和生理特性的影响

Effects of salt stress on the growth and physiological characteristics of american black walnut seedlings

【目的】研究美国黑核桃(以下简称黑核桃)在盐胁迫下幼苗生长和生理特性变化规律,综合分析不同黑核桃幼苗的耐盐性,为选育黑核桃耐盐品种、抗盐性机制及其在新疆核桃种植区耐盐性砧木的筛选提供参考依据。【方法】以黑核桃品种小果黑核桃(Juglans regia.microcarpa)、北加州黑核桃(Juglans regia.hindsii)、东部黑核桃(Juglans regia.nigra)和魁核桃(Juglans regia.major)实生苗为材料,分析4种黑核桃幼苗在不同NaCl浓度胁迫下地上干重、地下干重、主根长、侧根数、MDA含量等9项生长指标和生理响应,采用相关性分析、隶属函数分析法综合评价幼苗耐盐性。【结果】在盐胁迫下,4种黑核桃幼苗生长均受到抑制,盐胁迫40 d后,地上干重、地下干重、主根长和侧根数均有不同程度的下降,不同材料的变化幅度不同;随着盐浓度增加,丙二醛含量上升,SOD活性、POD活性、脯氨酸含量和可溶性糖含量总体呈先增加后降低的趋势。【结论】4种黑核桃耐盐能力由强至弱为东部黑核桃>小果黑核桃>魁核桃>北加州黑核桃。

【Objective】Study the growth and physiological changes of American black walnut under salt stress and a comprehensive analysis of the salt tolerance of different seedlings,with a view to providing a reference for the selection and breeding of salt-tolerant varieties of black walnut,salt resistance mechanisms and the screening of salt-tolerant rootstocks in Xinjiang walnut growing areas.【Methods】The growth and physiological responses of seedlings of small-fruited black walnut(Juglans regia.microcarpa),northern California black walnut(Juglans regia.hindsii),eastern black walnut(Juglans regia.nigra)and quebracho black walnut(Juglans regia.major)were analyzed by correlation analysis and subordinate function analysisgrowth and physiological responses of above-ground dry weight,below-ground dry weight,main root length,lateral root number and MDA content of the four black walnut seedlings were analyzed.【Results】After 40 d of salt stress,above-ground dry weight,below-ground dry weight,main root length and number of lateral roots all decreased to different degrees,with different magnitudes of change for different materials;with increasing salt concentration,malondialdehyde content increased,and SOD activity,POD activity,proline content and soluble sugar content generally showed a trend of first increasing and then decreasing.【Conclusion】A comprehensive analysis of the affiliation function values yielded four species of black walnuts in descending order of salt tolerance:eastern black walnut>small-fruited black walnut>quebracho black walnut>northern California black walnut.