Affiliation:
1. Departamento de Biologia Vegetal, Instituto de Biologia Universidade Estadual de Campinas (UNICAMP), Laboratório de Ecologia Evolutiva e Genômica de Plantas Campinas 13083‐862 SP Brazil
2. Departamento de Biologia Vegetal, Instituto de Biologia Universidade Estadual de Campinas (UNICAMP), Laboratory of Crop Physiology (LCroP) Campinas 13083‐862 SP Brazil
3. Organisms and Environment Division, Cardiff School of Biosciences Cardiff University Sir Martin Evans Building Cardiff CF10 3AX UK
4. Departamento de Bioloxía Funcional, Facultade de Bioloxía Universidade de Santiago de Compostela Lope Gomez de Marzoa s/n Santiago de Compostela 15782 Spain
Abstract
AbstractPremiseSalt 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.MethodsWe 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.ResultsThere 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.ConclusionsWe 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.