Evaluation of the drought resistance of 66 alfalfa clones at the seedling stage

To identify the most accurate index for evaluating drought resistance in alfalfa and to select for drought tolerance in alfalfa, 66 alfalfa varieties from clones of diverse geographical origins were used in drought stress experiments in a greenhouse in this study. The sensitivity of different alfalfa varieties to drought stress was analyzed by measuring plant height, fresh weight, dry weight, root length, and leaf relative water content. Drought resistance was comprehensively evaluated using the drought resistance coefficient, fresh weight drought resistance index, comprehensive drought resistance coefficient, and the membership function approach. The results indicated that plant height, fresh weight, dry weight, root length, and leaf relative water content were viable metrics for assessing the drought resistance of alfalfa under water-deficit conditions. Through a comprehensive comparison, cultivars such as ‘Dryland’ ‘Permanent 101’ ‘Befo’ ‘Ondaka’ ‘Lanrelaiende’, and ‘Keshanshaertu’ were selected as drought-tolerant alfalfa cultivars, rendering them suitable for cultivation in arid regions.