Native plant genetic resources have evolved from long processes of natural selection and adaptation to specific environments, and have developed tolerance to various stresses prevailing in their natural habitats via adaptive morphophysiological features. The associations between environmental stress conditions (aridity degree and salinity) prevailing in the original habitat of Argentine native Trichloris species (T. crinita and T. pluriflora) and various biometric and physiological traits were evaluated. Trials were carried out in hydroponics in a growth chamber. Components of initial plant growth, oxidative stress expression and antioxidant activity under drought and salt stress were measured in ecotypes of both species, as well as Na⁺ and K⁺ leaf tissue concentration and excretion rates under salinity. Ecotypes from arid and semiarid origin of both species had higher drought tolerance. Regarding salt stress, T. crinita ecotype from alkali soil showed stimulated growth under salinity and an ecotype from saline soil kept high root and shoot biomass production. Although the ecotypes of T. pluriflora were not significantly salt-sensitive, none stood out. Many active salt glands on the abaxial leaf surface, high Na/K excretion ratio and high leaf tissue concentration of sodium were found for salt-tolerant ecotypes. This study identified ecotypes with tolerance to prevailing stressful conditions of natural habitat of native forage species to be introduced to plant breeding programmes for restorations purposes. Trichloris pluriflora is an unexplored genetic resource for semiarid rangeland, thus this study is the first report of drought tolerant ecotypes.

中文翻译：

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不同生境的Trichloris生态型对干旱和盐胁迫的差异响应

天然植物遗传资源已从长期的自然选择和适应特定环境的过程演变而来，并已通过适应性形态生理特征发展了对自然栖息地中普遍存在的各种胁迫的耐受性。评估了阿根廷原生三毒种类（T. crinita和T. pluriflora）的原始栖息地中普遍存在的环境胁迫条件（干旱度和盐度）与各种生物特征和生理学特征之间的关联。在生长室中以水培法进行试验。在两个物种的生态型以及Na ⁺中测量了植物初始生长，干旱和盐胁迫下的氧化应激表达和抗氧化活性的成分盐度下K ⁺叶组织浓度和排泄率。两种物种的干旱和半干旱来源的生态型都具有较高的耐旱性。关于盐胁迫，碱土的T. crinita生态型在盐分下显示出受刺激的生长，而盐土的生态型保持了高根和芽生物量的生产。尽管紫锥花的生态型对盐的敏感性不高，没有一个脱颖而出。耐盐生态型在叶片背面有许多活性盐腺，高的Na / K排泄率和高的钠叶组织浓度。这项研究确定了可以耐受天然草料物种自然栖息地主要胁迫条件的生态型，将其引入植物育种计划中以进行恢复。多头chlor草是半干旱牧场的未开发遗传资源，因此该研究是抗旱生态型的首份报道。