Abstract:

In order to find out the salt tolerance evaluation method of alfalfa (Medicago L.) at germination stage and screen the salt tolerant germplasms, 120 alfalfa germplasm were comprehensively evaluated using a method of weighted membership function and classified into different salt tolerance levels. Salt stress was carried out with 150 mmol·L^-1 NaCl solution. 13 traits such as germination potential were used to identify the responses of alfalfa to salt stress. Salt tolerant coefficient was used as the basis for evaluation. The results showed that both the seed germination and seedling growth were inhibited by 150 mmol·L^-1 NaCl solution, however, the germination potential, germination rate and germination index were more inhibited than seedling growth. The root was inhibited greater than the seedling by the salt stress. Correlation analysis suggested that the method of weighted membership function could give a comprehensive evaluation of the salt tolerance of alfalfa at germination stage. 120 germplasms were divided into 5 levels with different salt tolerance levels according to the value of weighted membership function and the cluster analysis. 11 germplasms were classified as high salt tolerance (level 1). 24 germplasms were classified as salt tolerance (level 2). 38 germplasms were classified as medium grade (level 3). 36 germplasms were classified as salt sensitivity (level 4). 11 germplasms were classified as high salt sensitivity (level 5).

Key words: Alfalfa, Germination stage, Salt tolerance, Comprehensive evaluation, Screening

摘要：

为探明苜蓿（Medicago L.）萌发期耐盐性评价方法并筛选耐盐种质，采用加权隶属函数法对120个苜蓿种质进行综合评价并划分为不同的耐盐级别。试验以150 mmol·L^-1 NaCl溶液进行盐胁迫，以发芽势等13个性状来鉴定苜蓿对盐胁迫的反应，以耐盐系数为评价依据。结果表明：150 mmol·L^-1的盐溶液对苜蓿种子萌发和幼苗生长均有一定的抑制作用，发芽势、发芽率、萌发指数比幼苗生长受抑制的程度更大；盐胁迫对根的抑制程度大于苗。相关分析表明，加权隶属函数法可以综合评价苜蓿萌发期耐盐性。根据加权隶属函数值和聚类分析，可将120个种质分为耐盐性不同的5个级别：11个种质高耐盐（1级）、24个种质耐盐（2级）、38个种质中等（3级）、36个种质敏盐（4级）、11个种质高敏盐（5级）。

关键词: 苜蓿, 萌发期, 耐盐性, 综合评价, 筛选