This study was performed for a better understanding of genotypic responses of a germplasm of tall fescue to different prolonged drought stresses and exogenously applied salicylic acid (SA) in terms of drought tolerance, postdrought recovery, persistence and root-related traits. Twenty-one diverse tall fescue genotypes were evaluated under three irrigation treatments (IT) (normal, mild and intense drought stress) and the presence of two SA concentrations (0 and 1 mM) during 2015–2017. In the fourth year (2018), irrigation was withheld in all treatments for two months in summer (severe drought) and then plants were rewatered to investigate the effect of previous treatments on the mentioned traits. Results indicated that recovery after severe drought and persistence in tall fescue depends on previous environmental conditions with clear differences in genotypic responses. Foliar application of SA improved forage production, drought tolerance, postdrought recovery and most of the root traits, while it had a negative effect on persistence and root length. Associations amongst traits under different treatments and selection of superior genotypes will be discussed.

中文翻译：

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外源水杨酸和水分胁迫交互作用下高羊茅种质持久性、干旱后恢复和根系特征的变化

本研究旨在更好地了解高羊茅种质对不同长期干旱胁迫和外源施用水杨酸 (SA) 在耐旱性、干旱后恢复、持久性和根相关性状方面的基因型反应。在 2015 年至 2017 年期间，在三种灌溉处理 (IT)（正常、轻度和强烈干旱胁迫）和两种 SA 浓度（0 和 1 mM）的存在下评估了 21 种不同的高羊茅基因型。在第四年（2018 年），所有处理在夏季（严重干旱）中停止灌溉两个月，然后对植物重新浇水以研究先前处理对上述性状的影响。结果表明，严重干旱后的恢复和高羊茅的持久性取决于先前的环境条件，基因型反应存在明显差异。叶面喷施 SA 提高了牧草产量、耐旱性、干旱后恢复和大部分根性状，但对持久性和根长有负面影响。将讨论不同处理下性状之间的关联和优良基因型的选择。