紫花苜蓿种质耐盐性综合评价及盐胁迫下的生理反应

A comprehensive evaluation of salt-tolerance and the physiological response of Medicago sativa at the seedling stage

以中苜1号为对照,对来自俄罗斯的18份紫花苜蓿种质的耐盐性进行了综合评价,并对盐胁迫下的生理反应进行了初步研究。结果表明,运用标准差系数赋予权重法进行综合评价,不但考虑了不同指标的权重,还定量的鉴定出了每份材料的耐盐能力,比聚类分析的结果更具科学合理性,试验共筛选出M7、M9、M15、810共4份耐盐性强的种质;在此基础上,进一步探讨了盐胁迫下的生理反应,除叶水势随着盐浓度的增加呈下降趋势外,游离脯氨酸含量、可溶性糖含量、细胞质膜透性、丙二醛含量、水分饱和亏缺则呈上升趋势,且不同材料变化幅度不同。可溶性糖含量、细胞质膜透性、丙二醛含量、水分饱和亏缺和叶水势等指标很好的反映了材料间的耐盐性,可直接作为耐盐评价的鉴定指标。

A comprehensive evaluation of salt tolerance and the physiological response of 18 Medicago sativa. germplasms from Russia was studied under different NaC1 concentrations （0.3%, 0.4%, 0.5% and 0.6%） in the green house at the seedling stage. They were compared with Zhongmu 1. The standard deviation coefficient allocation weighted method not only considered different indexes allocation weight, but also evaluated drought resistance of all the materials. Four strong salt tolerant germplasms, M7, M9, M15, and 810, were screened using this method. Free proline content, soluble sugar content, relative electrical conductivity, MDA content and water saturation deficit were considerably increased by an increase of salt concentration, while leaf water potential decreased. The soluble sugar content, relative electrical conductivity, MDA content, water saturation deficit and water potential in the leaf at the seedling stage responded sensitively to the level of salt stress and this can be used as an identification index of salt tolerance.