黄河三角洲滨海湿地水盐胁迫对盐地碱蓬幼苗生长和抗氧化酶活性的影响

研究黄河三角洲滨海湿地先锋植物盐地碱蓬在水盐胁迫下的生存机制能够为退化滨海湿地的修复提供重要的理论基础.通过温室控制模拟试验,研究了不同地下水位深度（0、-10、-20、-30 cm）以及不同盐浓度（0%、1%、2%、3%）的交互作用对盐地碱蓬幼苗高度、分枝数、生物量以及叶绿素含量和抗氧化物酶的活性的影响.结果表明,从...

Effects of Water-Salt Stresses on Seedling Growth and Activities of Antioxidative Enzyme of Suaeda salsa in Coastal Wetlands of the Yellow River Delta

The halophyte Suaeda salsa is the pioneer plant and is used for the degraded coastal wetland in Yellow River Delta. The water-salt stress is the most important factor for ecological restoration to degraded coastal wetland. To understand the adaptive mechanism of Suaeda salsa to water-salt stresses, the induced effects of different groundwater table depths (0, -10, -20, -30 cm) and salt stress (0%, 1%, 2%, 3%) on seedlings of Suaeda salsa plant were characterized by the growth parameters of plant height, branch number and biomass of different organs and biological indices of leaf chlorophyll content, the activities of SOD, CAT, the leaf content of MDA and protein. The results showed the significantly (p < 0.001) decreased height of the seedlings from -30 cm to 0 cm of groundwater table depth, together with the decreased the number of branches, the biomass of leaf, shoot and root. The highest total biomass of single plant was (1.09 +/- 0.15) g under the condition of -30 cm water table depth and 0% salt stress. However, the combination of 0 cm water table depth and 3% NaCl resulted in the biomass of (0.23 +/- 0.01) g, which was ca. 21% compared with the highest biomass. Similarly, the contents of leaf chlorophyll a, b and carotenoid were the highest under the condition of -30 cm water table depth and 0% salt stress and lowest under the condition of 0 cm water table depth combined with 3% NaCl. The activities of SOD, CAT were increased significantly (p < 0.05) depending on the increase of salt stress. At 0 cm water table depth, the activities of SOD were 55.00 U/mg with 0% NaCl and 151.58 U/mg with 3% NaCl, respectively. The activities of SOD were decreased when the water table depth increased. However, the activities of CAT achieved the highest level at -30 cm water table depth. At 0 and -10 cm water table depth, the MDA content increased with the increase of salt stress. The MDA content was 0.26 mmol/g at -30 cm water table depth with 3% NaCl, which was approx. 28%-40% of the MDA contents compared with that caused by other salt stresses. These results demonstrated that Suaeda salsa plant could change its morphological characteristics, biomass allocation, and the activities of antioxidative enzymes to adapt severe environment.