Numerous functional traits have been identified as key contributors to plant performance under drought. However, many of these traits, specifically root traits, are rarely considered in the development of native plant cultivars. In this study, we assessed whether cultivars of the perennial grass Elymus trachycaulus (Slender wheatgrass) developed for drought differ in (a) drought resistance (i.e. a plant's ability to maintain aboveground biomass productivity under water deficit), (b) aboveground and belowground traits, and (c) trait responses to drought from other accessions (i.e. other cultivars, wild accessions). We also evaluated trait plasticity, assessed whether multivariate trait relationships varied between control and drought conditions, and determined which suites of traits are related to drought resistance. We worked with seedlings at two developmental stages to assess whether patterns vary ontogenetically. E. trachycaulus cultivars developed for drought did not differ from other accessions in drought resistance or traits related to drought-coping strategies. The effects of drought and accession on drought resistance, traits, and trait plasticity varied by developmental stage, but relationships among traits varied little between the two developmental stages. A primary axis of functional variation related to resource acquisition (plant height, root length, root tips) was consistently associated with drought resistance. However, which secondary axes were related to drought resistance varied by developmental stage and moisture condition. Our results suggest that traits and performance of commonly used cultivars ought to be reexamined to determine whether they are actually the best candidates for revegetation projects in specific contexts.

中文翻译：

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为干旱而开发的流行恢复草品种没有更高的抗旱性，并且与其他种质的干旱相关性状没有差异

许多功能性状已被确定为干旱条件下植物性能的关键因素。然而，许多这些性状，特别是根性状，在本地植物品种的开发中很少被考虑。在这项研究中，我们评估了多年生草皮Elymus trachycaulus 的品种为干旱而开发的（细长小麦草）在 (a) 抗旱性（即植物在缺水情况下保持地上生物量生产力的能力）、(b) 地上和地下性状以及 (c) 其他种质对干旱的性状响应（即其他栽培品种、野生种质）。我们还评估了性状可塑性，评估了控制条件和干旱条件之间的多元性状关系是否有所不同，并确定了哪些性状套件与抗旱性相关。我们使用处于两个发育阶段的幼苗来评估模式是否在个体遗传上有所不同。 E. trachycaulus为抗旱开发的品种在抗旱性或与抗旱策略相关的性状方面与其他品种没有区别。干旱和加入对抗旱性、性状和性状可塑性的影响因发育阶段而异，但两个发育阶段之间性状之间的关系变化不大。与资源获取（植物高度、根长、根尖）相关的功能变异主轴始终与抗旱性相关。然而，哪些次轴与抗旱性有关，但因发育阶段和水分条件而异。我们的结果表明，应该重新检查常用品种的性状和性能，以确定它们是否实际上是特定环境下重新植被项目的最佳候选者。