Effect of combined waterlogging and salinity stresses on euhalophyte Suaeda glauca

Salinity and waterlogging are abiotic stresses that have a significant impact on agricultural production and ecosystem conservation. The response of euhalophyte Suaeda glauca to waterlogging and salinity stresses was investigated. The results revealed that waterlogging markedly decreased seedling emergence. Compared to drained conditions, waterlogging inhibited the shoot dry weight, net photosynthetic rate, stomatal conductance, maximal efficiency of PSII photochemistry and chlorophyll content at salinity. Salinity decreased these values in both waterlogged and drained conditions, while the opposite trend was found in intercellular CO2 concentrations. Waterlogging increased Na+, Cl−, O2-, H2O2 and MDA content in the leaves compared with those in drained conditions, but this was not the case for K+ content and SOD and APX activity. Salinity increased these values except that salinity decreased K+ content in both waterlogged and drained conditions. In conclusion, S. glauca is not tolerant to combined waterlogging and salinity stresses during both seedling emergence and seedling growth stages, and this trait may limit the distribution of the species in lowland saline areas.