Sedum mexicanum 'Gold Mound' exhibits better adaptive characters in contrast to S. spurium 'Coccineum' when subjugated to sustained waterlogging stress
Waterlogging is becoming a critical threat to plant growth and landscape visual effect. A comparative study was performed to investigate the morphological and physiological differences between S. mexicanum Gold Mound and S. spurium Coccineum plants in response to simulated waterlogging. The experimental design was completely randomized with two water conditions (control and waterlogging) combined with five evaluation times (0, 7, 14, 21 and 28-days waterlogging conditions). After 4 weeks of waterlogging, S. mexicanum Gold Mound showed better response towards waterlogging in comparison to S. spurium Coccineum. The stress-induced wilting, leaf chlorosis and abscission showed in both cultivars, but symptoms were more apparent and occurred earlier in S. spurium Coccineum. Although both of two test accessions showed outgrowth of adventitious roots to assist in waterlogging tolerance, the survival rate of S. spurium Coccineum was only 30%, which was significantly lower than that of S. mexicanum Gold Mound (76%). Waterlogging negatively affected plant growth vigor, above- and below-ground biomass and significantly decreased the relative water content of leaves compared to controls. The reduction of these factors was less pronounced in S. mexicanum Gold Mound. In addition, chlorophyll content, soluble protein and antioxidative enzyme activities were comparatively more salient in S. mexicanum Gold Mound during this hypoxia treatment while S. mexicanum Gold Mound showed a lower content of malondialdehyde (MDA) throughout the duration of waterlogging. It was indicated that S. mexicanum Gold Mound is relatively waterlogging-tolerant depending on a combination of morphological, physiological metabolic and biochemical adaptions.
Zhang, J., Yin, D., Li, X., Fan, S., Wu, F. and Dong, L. (2019). Sedum mexicanum 'Gold Mound' exhibits better adaptive characters in contrast to S. spurium 'Coccineum' when subjugated to sustained waterlogging stress. Acta Hortic. 1263, 141-148
waterlogging, stress response, osmotic regulation, antioxidant enzymes