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Response Of Two Suaeda Species To Salt Stress Under Different Nutrition Supply

Posted on:2021-03-08Degree:MasterType:Thesis
Country:ChinaCandidate:Q H ZhangFull Text:PDF
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Due to its special geographical environment and location,coastal wetland is easily disturbed by many factors including seawater erosion,soil salinization and so on,so its ecosystem is very fragile.Moreover,in recent years,influenced by climate change and human development activities?the stability of coastal wetland ecosystem has been more threatened,its area shows a trend of accelerated shrinkage,and the environment of the existing wetlands has further deteriorated.In this context,more and more attention has been paid to the restoration and protection of coastal wetland ecosystem.In coastal wetland ecological restoration projects,the selection of suitable pioneer species for planting is a key step of restoration.The planted species can effectively help the wetland soil desalination and improve:the habitat condition.However,due to the severer environmental stress of coastal wetlands,the growth and reproduction of the plant are greatly threatened,so it is difficult to ensure that the pioneer species planted can exhibit the expected effect.Therefore,it is necessary to select the effective pioneer species reasonably as well as explore the scientific planting management technology.As a typical true halophyte,Suaeda is widely concerned because of its strong salt tolerance.S.salsa has been studied and planted as a pioneer species of coastal wetland vegetation restoration.At present,there are few studies on other species of the same genus,so it is difficult to judge whether other species of the same genus can also be used in vegetation restoration projects.In addition,in our previous field investigation in the Yellow River Delta,we found that two species of S.glauca and S.salsa grow together in the coastal area of the Yellow River Delta,but they show certain spatial differentiation,that is,S.salsa distributes in a large area near the coastline,while S.glauca only exists far from the sea The area.It is generally believed that the main factor driving the species zonation along the environmental gradient is the change of soil salinity.However,the soil conditions in coastal areas are complex,and whether soil salinity is the key driving factor of spatial differentiation needs further study.In addition,the situation of soil nutrition in coastal areas is complex,and whether the soil nutrition conditions will affect the salt tolerance of plants is also a question worth exploring.And it can serve as reference for the nutrition of fertilization and other technical means in vegetation restoration.Under the above background,different levels of salt addition and nutrition supply were set up in this study.Two kinds of plants,S.glauca and S.salsa,were used for pot experiments to compare their salt tolerance and the effect of nutrition on their salt tolerance.The purpose of this study was to explore the causes of spatial differentiation of the two plants in the Yellow River Delta,and explore the effects of nutrition and salt stress on the growth of S.glauca and S.salsa.Our results showed that there was no difference in salt tolerance between S.glauca and S..salsa.Under the lowest supply of nutrition,the growth of S.salsa does not change significantly with the increase of salinity,showing a strong ability of salt tolerance,and the nutrient promotion of the growth on S.glauca is more significant,especially under the condition of high salinity.In addition,the two species showed similar strategies to cope with stress.In the environment of low nutrition and high salinity,the two plants increase the root-to-shoot ratio to promote the absorption of nutrients and-water in the soil.In addition,the fleshy degree of leaves of plants under different treatments was basically unchanged,which indicated that keeping the leaf succulence was another important salt stress coping strategy shared by the two species of Suaeda.In addition,S.glauca and S.salsa use proline as an important osmoregulation substance,and the addition of nutrition will affect the synthesis of proline.The two plants showed similar mechanism of using metal ions for osmotic regulation.With the increase of salt treatment concentration,the content change of sodium,potassium,calcium and magnesium displayed regularity,which was the two plants accumulated a great amount of sodium ions,but inhibited the accumulation of other ions in the shoot.Our results reveal that the spatial segregation of the two Suaeda species is not driven by salinity.Different soil nutrient requirements and competition ability may be important reasons for the spatial differentiation,but the specific reason still requires further studyIn the experiment,the two plants have high salt tolerance,and S.glauca can also be used in the coastal wetland ecological restoration project,and can add fertilizer in planting S.glauca to promote plant growth and cope with the environmental stress.
Keywords/Search Tags:salt stress, nutrition, Suaeda glauca, Suaeda salsa, spatial distribution
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