Abstract: In order to study the changes of germination state and response of different alfalfa varieties to salt stress. Ten domestic and foreign alfalfa varieties were used as experimental materials to investigate the effect of different concentrations of sodium chloride (50,100,150,200,250 mmol·L^-1)on salt tolerance of the seeds of those alfalfa varieties. The results showed that:the germination rate (GR),germination potential (GP),germination index (GI),vigor index (VI),radical length (RL),hypocotyl length (HL),fresh weight and dry weight of the different alfalfa varieties displayed different changing trends under different salt concentrations. Principal component analysis on salt resistance coefficients for seed germination indicators showed that the maximum eigenvalue of the first principal component was 4.803,with a contribution rate of 60.039%. GR,GP,GI,VI,and RL had eigenvectors with higher absolute values. GR was highly significantly positively correlated with the GP,GI,VI and RL. According to the analysis of membership function method,weight coefficient and comprehensive evaluation D-value,among the tested 10 alfalfa varieties,'Adina' 'WL343HQ' and 'WL319HQ' varieties the strongest tolerance to salt stress. The results in this study can provide theoretical reference for selecting suitable alfalfa varieties in alkali soil.

Key words: Alfalfa, Salt stress, Seed germination, Membership function method, Comprehensive evaluation

摘要： 为探讨盐胁迫下不同苜蓿品种种子萌发状况及抗盐胁迫响应变化规律，以国内外 10 种紫花苜蓿(Medicago satuva L.)品种为试材，研究不同浓度(50，100，150，200，250 mmol·L^-1)氯化钠对其种子耐盐性的影响。结果表明：不同苜蓿品种种子在不同氯化钠浓度胁迫下其发芽率(Germination rate，GR)、发芽势(Germination potential，GP)、发芽指数(Germination index，GI)、活力指数(Vigor index，VI)、胚根长(Radicle length，RL)、胚轴长(Hypocotyl length，HL)、鲜重和干重等 8项指标均表现出不同的变化趋势；种子萌发指标耐盐系数的主成分分析中第1主成分的特征值最大为 4.803，贡献率达 60.039%，GR，GP，GI，VI，RL具有绝对值较大的特征向量；GR与GP，GI，VI，RL均呈极显著正相关关系。利用隶属函数法、权重系数和综合评价D值分析可知，10 种苜蓿品种中'阿迪娜''WL343HQ''WL319HQ'盐耐受力比较强，可为盐碱地选择适种苜蓿品种提供理论参考依据。

关键词: 紫花苜蓿, 盐胁迫, 种子萌发, 隶属函数法, 综合评价