Abstract：
OBJECTIVE: Salt tolerance has rarely been investigated regionally in the neotropics and even more rarely in Orchidaceae, one of the largest families. Therefore, investigating local adaptation to salt spray and its physiological basis in Epidendrum fulgens, a neotropical orchid species, brings important new insights.
METHODS: We assessed the degree of salt tolerance in E. fulgens by testing whether coastal populations are more tolerant to salt, which could point to local adaptation. To understand the physiological basis of such salt tolerance, we exposed wild-collected individuals to salt spray for 60 days, then measured leaf expansion, osmotic potential, sodium leaf concentration, chlorophyll leaf index, chlorophyll fluorescence, relative growth rate, and pressure-volume curves.
RESULTS: There is no local adaptation to salt spray since both inland and coastal plants have a high tolerance to salt stress. This tolerance is explained by the ability to tolerate high concentrations of salt in leaf tissues, which is related to the high succulence displayed by this species.
CONCLUSIONS: We showed an unprecedented salt tolerance level for an orchid species, highlighting our limited knowledge of that trait beyond the traditional studied groups. Another interesting finding is that salt tolerance in E. fulgens is linked to succulence, is widespread, and is not the result of local adaptation. We suggest that E. fulgens and its allied species could be an interesting group to explore the evolution of important traits related to tolerance to salt stress, like succulence.
METHODS: We assessed the degree of salt tolerance in E. fulgens by testing whether coastal populations are more tolerant to salt, which could point to local adaptation. To understand the physiological basis of such salt tolerance, we exposed wild-collected individuals to salt spray for 60 days, then measured leaf expansion, osmotic potential, sodium leaf concentration, chlorophyll leaf index, chlorophyll fluorescence, relative growth rate, and pressure-volume curves.
RESULTS: There is no local adaptation to salt spray since both inland and coastal plants have a high tolerance to salt stress. This tolerance is explained by the ability to tolerate high concentrations of salt in leaf tissues, which is related to the high succulence displayed by this species.
CONCLUSIONS: We showed an unprecedented salt tolerance level for an orchid species, highlighting our limited knowledge of that trait beyond the traditional studied groups. Another interesting finding is that salt tolerance in E. fulgens is linked to succulence, is widespread, and is not the result of local adaptation. We suggest that E. fulgens and its allied species could be an interesting group to explore the evolution of important traits related to tolerance to salt stress, like succulence.
摘要：
目的：耐盐性在新热带地区很少进行区域调查，在兰科则很少。最大的家庭之一。因此,调查局部适应盐雾及其生理基础，一种新热带兰花，带来重要的新见解。
方法：我们通过测试沿海人群是否更耐盐来评估E.fulgens的耐盐程度，这可能指向本地适应。了解这种耐盐性的生理基础,我们将野生采集的个体暴露在盐喷雾中60天，然后测量叶片膨胀，渗透势，钠叶浓度，叶绿素叶指数,叶绿素荧光，相对增长率，和压力-体积曲线。
结果：由于内陆和沿海植物对盐胁迫都有很高的耐受性，因此没有局部适应盐雾。这种耐受性可以解释为能够耐受叶片组织中高浓度的盐，这与该物种表现出的高肉质有关。
结论：我们显示了兰花物种前所未有的耐盐水平，突出了我们对这一特征的有限了解，超越了传统的研究群体。另一个有趣的发现是E.fulgens的耐盐性与肉质有关，是广泛的，而不是局部适应的结果。我们建议E.fulgens及其相关物种可能是一个有趣的群体，以探索与盐胁迫耐受性相关的重要性状的进化，像多汁。
方法：我们通过测试沿海人群是否更耐盐来评估E.fulgens的耐盐程度，这可能指向本地适应。了解这种耐盐性的生理基础,我们将野生采集的个体暴露在盐喷雾中60天，然后测量叶片膨胀，渗透势，钠叶浓度，叶绿素叶指数,叶绿素荧光，相对增长率，和压力-体积曲线。
结果：由于内陆和沿海植物对盐胁迫都有很高的耐受性，因此没有局部适应盐雾。这种耐受性可以解释为能够耐受叶片组织中高浓度的盐，这与该物种表现出的高肉质有关。
结论：我们显示了兰花物种前所未有的耐盐水平，突出了我们对这一特征的有限了解，超越了传统的研究群体。另一个有趣的发现是E.fulgens的耐盐性与肉质有关，是广泛的，而不是局部适应的结果。我们建议E.fulgens及其相关物种可能是一个有趣的群体，以探索与盐胁迫耐受性相关的重要性状的进化，像多汁。
