Characteristics of chlorophyll-fluorescence parameters of Suaeda microphylla Pall.and their responses to soil factors in different water-salt habitats
[Objective]This project aims to study the photosynthetic response mechanism of halophyte in arid region in order to provide theoretical and scientific support for soil salinization bioreremediation technolo-gy.[Methods]In this paper,the typical halophyte Suaeda microphylla Pall.in the National Nature Reserve was studied and three types of habitats:high water salt(habitat Ⅰ)salt(habitat Ⅱ),low water and high salt water(habitat Ⅲ)were selected to measure and analyze its Suaeda microphylla Pall.chlorophyll fluorescence parameters under three habitat Suaeda microphylla Pall.characteristics of chlorophyll fluorescence parameters,thus clarifying the effects of soil factors on the fluorescence characteristics of the three habitats.[Results]The results showed that there were significant differences in chlorophyll fluorescence parameters among the three habitats(P<0.05).Fo,Fmand NPQ gradually increased with the change of habitat,with the maximum val-ues in the habitat Ⅲ(142.95,609.42 and 1.65)and the minimum values in the habitat Ⅰ(87.6,358.06 and 0.96).Fv′/Fm′increased first and then decreased,the maximum value occurs in environmentⅢ(0.53),the minimum value appears in scenarioⅡ(0.39),respectively;Fowas positively correlated with Fmand NPQ(P<0.01),the correlation coefficient of Fmwas the largest,which was 0.99;Three key chlorophyll fluores-cence parameters,Fo,Fmand NPQ,were screened out by principal component analysis,and their common factor variances were 0.947,0.969 and 0.824;Salt,available phosphorus and pH could explain 17.2%,24.2%and 13.5%of the variation of chlorophyll fluorescence parameters,while water did not.[Conclusion]In conclusion,in the high-salt habitat,the structure and physiological state of leaves PSⅡ were damaged,photosynthesis was blocked,and plant growth was inhibited eventually.