Abstract:

Alfalfa (Medicago sativa) seeds of 23 cultivars (strain) were treated with different concentrations of NaCl solution (0, 0.20%, 0.40%, 0.60%, 0.80%, 1.00%, 1.20% and 1.40%) with 3 replicates. Salt tolerance of 23 alfalfa cultivars (strain) during germination was compared by measuring germination rate, seedling height, root length, germination potential, germination index and vigor index. The results showed that 1.20% NaCl was the critical point of salt tolerance of alfalfa, and was the best salt concentration for salt tolerance identification. Twenty-three alfalfa germplasms were divided into 3 groups based on cluster analysis. Among them, 34.78% were strongly salt tolerant, the middle salt tolerant germplasm accounted for 47.83%, and the weak salt tolerant germplasm accounted for 17.39%. Membership function analysis showed that ‘Eureka’ was the most salt-tolerant, and ‘Magna No.801’ was the weakest salt-tolerant. The comprehensive evaluation showed that ‘Magna No.2’ was the most salt-tolerant, and ‘L3003’ was the weakest salt-tolerant.

Key words: Alfalfa, Salt stress, Germination characteristics, Comprehensive assessment

摘要：

为确定不同苜蓿（Medicago sativa. L）品种及品系的耐盐能力，明确不同盐浓度对苜蓿种子萌发的影响规律，从而为苜蓿耐盐性早期鉴定和筛选提供科学依据，试验对23个苜蓿品种及品系种子在不同浓度NaCl'溶液下进行胁迫处理，NaCl浓度分别为0.20%，0.40%，0.60%，0.80%，1.00%，1.20%和1.40%（以蒸馏水为对照），观察发芽率、根长、苗高，计算发芽势、耐盐系数、发芽指数、活力指数，并通过隶属函数和聚类分析，对苜蓿品种及品系进行耐盐性综合评价。结果表明：质量分数为1.20%的NaCl是苜蓿耐盐性的转折点，是耐盐性鉴定的最佳盐浓度。聚类分析将23份苜蓿种质分为3类，强耐盐种质占34.78%，中等耐盐种质占47.83%，弱耐盐种质占17.39%。隶属函数分析表明，耐盐性最强的是‘游客’，最弱的是‘巨能801’。综合分析各项观测指标，23个苜蓿种质中耐盐能力最强的为‘巨能2’，最弱的为‘L3003’。

关键词: 苜蓿, 盐胁迫, 萌发特性, 综合评价