Abstract: By the field simulation drought method with rain-proof shed,we selected 12 alfalfa materials with different drought resistance at seedling stage to study the drought environment setting,identification indices and evaluation method selection. The results showed that the stress state started from the seedling stage,the stress cycle was the entire annual growing season. The selected evaluation indices were biomass,plant height and the number of plant branch. The methods of membership function and drought resistance index were adopted to evaluate the drought resistance of alfalfa materials. Compared with those evaluation methodsat seedling stage,the result showed better consistency with the methods of membership function during the whole growth period while a certain difference with the method of drought resistance index. The drought resistance identification at seedling stage has advantages such as short evaluation period,easy to operate,suitable for large number of materials and is of scientific to some extent. But the results of drought resistance identification during the whole growth period were more intuitive,accurate and reliable,which was suitable for evaluating the actual drought resistance of alfalfa.

Key words: Alfalfa, Whole growth period, Drought resistance identification, Evaluation methods

摘要： 本试验选取苗期抗旱性表现不同的12份紫花苜蓿（Medicago sativa L.）材料，采用防雨棚田间模拟干旱法，开展了苜蓿全生育期抗旱性鉴定中干旱环境的设置、鉴定指标与评价方法选取的研究。结果显示：紫花苜蓿从苗期开始进入胁迫状态，胁迫周期为全年生长季；筛选出适宜的鉴定指标为：生物量、株高和分枝数；采用抗旱指数法对苜蓿全生育期抗旱性进行评价的结果与苗期评价结果一致性较好，采用隶属函数法对全生育期进行评价的结果与苗期的评价结果存在一定的差异性。苗期抗旱性鉴定周期短，便于操作，适合大量材料的抗旱性鉴定，有一定的科学性。而全生育期鉴定评价结果更直观、准确，可靠性强，可用于苜蓿实际抗旱能力的评价。

关键词: 苜蓿, 全生育期, 抗旱性鉴定, 评价方法