Modulation of Morphological and Several Physiological Parameters in Sedum under Waterlogging and Subsequent Drainage

A comparative study was undertaken to investigate the morphological and physiological differences between tolerant Sedum spectabile Boreau Carl and susceptible S. spectabile Rosenteller in response to simulated waterlogging for 36 days and subsequent drainage for 12 days. Although the stress induced visible leaf stress symptoms in both cultivars, symptoms occurred earlier and severe in the susceptible cultivar. In the S. spectabile Carl, adventitious roots emerged earlier from leaf scar. Waterlogging induced more acute decrease of plant height, canopy, leaf area, root length, shoot/root biomass in S. spectabile Rosenteller. Leaf chlorophyll, relative water content and water soluble carbohydrate concentration were comparatively more salient in S. spectabile Carl. The activities of SOD (superoxide dismutase), CAT (catalase), APX (ascorbate peroxidase) increased in both accessions after suffering of the stress, and all activities of them were more pronounced in S. spectabile Carl. In addition, the lower MDA content of S. spectabile Carl was lower than that of S. spectabile Rosenteller demonstrated that less oxidative damage was induced by waterlogging and drainage. All these results suggest that the greater relative waterlogging tolerance to withstand waterlogging stress up to 36 days and better recovery capacity after soil drainage of S. spectabile Carl appears to depend on the combination of morphological and metabolic responses.