In arid and semiarid regions, salinity may affect alfalfa (Medicago sativa) productivity and survival due to either cultivation on salt‐affected soils or the use of salinized irrigation water. Exploiting germplasm evolved under salt‐stress conditions offers opportunities for crop tolerance improvement. In the first phase of the current study, four reportedly salt‐tolerant landraces originated from stress‐prone areas of West Asia or North Africa and two reference commercial cultivars underwent three evaluation trials according to different methods, namely, seed germination in saline water, in vitro testing of young plants, and greenhouse evaluation of adult plants in Cone‐tainers. Experimental populations obtained by intercrossing landrace genotypes selected according to each evaluation method were subsequently evaluated under stressful field conditions in two regions featuring different salt stress type, namely, southern Tunisia (irrigation with saline water) and northwestern Argentina (rainfed cropping in saline soil). Landrace ranking for salt tolerance differed somewhat depending on the evaluation method, and the proportion of selected plants per landrace depended accordingly on the method. In each field experiment, there were two evaluation phases, and the second phase corresponded in both cases to harsher conditions. The in vitro evaluation and selection resulted in potentially more useful selected germplasm than the other evaluation methods. The field experiments highlighted the large specific adaptation effects that affected the response of salt‐tolerant germplasm across the two regions.

中文翻译：

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苜蓿地方品种耐盐性评价和选择程序的比较

在干旱和半干旱地区，盐分可能会影响苜蓿（苜蓿）由于在受盐影响的土壤上耕作或使用盐化灌溉水而导致的生产力和生存率。利用盐胁迫条件下进化的种质为提高作物耐受性提供了机会。在当前研究的第一阶段，四种据报道来自西亚或北非易受胁迫地区的耐盐地方品种和两种参考商业品种根据不同的方法进行了三项评价试验，即种子在盐水中发芽，在对幼苗进行体外测试，并对圆锥容器中的成年植物进行温室评估。根据每种评价方法选择的地方品种基因型杂交获得的实验群体随后在突尼斯南部（盐水灌溉）和阿根廷西北部（盐渍土雨养作物）两个具有不同盐胁迫类型的地区的胁迫田间条件下进行了评价。地方品种的耐盐性排名根据评价方法的不同而有所不同，每个地方品种的选择植物的比例也相应地取决于方法。在每个现场实验中，都有两个评估阶段，第二阶段都对应于更恶劣的条件。体外评估和选择比其他评估方法产生了潜在更有用的选定种质。田间实验强调了影响两个地区耐盐种质响应的巨大的特定适应效应。