Changing climates and associated increased variability pose risks to alfalfa (Medicago sativa L.) cultivation, with the requirement to establish, survive, and maintain production under water stress. Crop wild relatives (CWR) of alfalfa include populations that have evolved to survive in a number of different, extreme environments, but until recently have had limited use in breeding programs. Here we report on the phenotypic diversity of alfalfa crop wild relatives that were selected to represent extremes in drought tolerance (by sourcing germplasm from environments with extremes in low rainfall, high temperature, shallow soils, and winter freezing) with the aim of providing germplasm with drought tolerance and improved forage yield traits for breeding programs in both warm and cool dry temperate environments. Newly formed hybrids created between M. sativa, M. arborea L. (a woody shrub), and M. truncatula Gaertn. (an annual species from the Mediterranean region) were developed or acquired to introduce new genetic diversity from the tertiary genepool. Preliminary characterization and evaluation was used for taxonomic classification, and to identify wild accessions and pre‐bred (hybrid) lines that offer new diversity for growth habit, seed size, fall dormancy, and forage yield. The accessions and pre‐breeding lines described have been donated to the Australian Pastures Genebank for conservation and distribution.

中文翻译：

---

来自干旱胁迫环境的各种苜蓿野生近亲的特征和繁殖

气候变化和相关的可变性增加给苜蓿（紫花苜蓿）带来风险L.）种植，要求在水分胁迫下建立，生存和维持生产。苜蓿的野生野生近缘种（CWR）包括已经进化成可以在许多不同的极端环境中生存的种群，但是直到最近在育种计划中的用途仍然很有限。在这里，我们报道了苜蓿作物野生近缘种的表型多样性，这些野生近缘种被选为代表极端干旱耐受性（通过从低降雨，高温，浅土和冬季冰冻的极端环境中采购种质），旨在为种质提供抗旱性。在温暖和凉爽的干燥温带环境中，都可以为育种计划提供耐旱性和改良的牧草产量特征。在苜蓿，木本植物之间产生新近形成的杂种L.（木质灌木）和M. truncatula Gaertn。（来自地中海地区的一年生物种）被开发或获得，以从第三级基因库引入新的遗传多样性。初步表征和评估用于分类学分类，并鉴定野生种和预育（杂种）品系，它们为生长习性，种子大小，秋季休眠和牧草产量提供了新的多样性。所描述的种质和预育系已捐赠给澳大利亚牧场种质库进行保存和分配。