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Ecological Study On Arbuscular Mycorrhiza Fungi Of Phragmites Australis In Sugan Lake Wetland

Posted on:2009-11-05Degree:MasterType:Thesis
Country:ChinaCandidate:J Z YanFull Text:PDF
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Arbuscular mycorrhizal fungi(AMF)is a kind symbiotic fungi of plants,plays an important role in wetland ecosystem in the aspects of nutrition absorption,growth, anti-salt stress and anti-pollutant,thus,it becomes hotspot of research.Util now,there is no convictional result of the factors influence wetland AMF in complex circumstance has gained.We experiment on spatial distribution(hydrophyte, halophyte,psammophyte),seasonal dynamic(July and October)of reed(Phragmites australis)AMF in Sugan Lake wetland,which lies on the edge of Chaidamu basin, and probe into relationship between AMF and its host,the main results showed:1.Reed,a kind of monocotyledon,has a low AMF hyphal and vesicular colonization rate.In July,AMF colonization rate(6.67%)is higher than that in October (2.73%).The colonization rate between ecotype was:hydrophyte(10.28%)>psammophyte(3.84%)>halophyte(3.21%),indicates AMF colonization was not affected by soil moisture.AMF hyphal colonization rate was positive correlate with reed wet weight(R~2=0.480,P<0.01),reed mean height(R~2=0.614,P<0.01). Multiple linear regression analysis results shows,AMF is mainly affected by its host.2.In July,mean AMF spore density is 1159 per 100g soil.Among ecotypes,the highest is halophyte(1688),psammophyte followed(635),halophyte is the lowest (532).There has a great amount of spore density in alkaline-saline soil,even in the depth of 1.0m.It suggests AMF may form a special structure with its host's aerenchymatous to get enough oxygen to survive.Via PCA analysis,the component deputy of soluble ion(R~2=0.727,P<0.05)and species richness (R~2=-0.422,P<0.05)was positive correlate with AMF spore density.Using multiple linear regression analysis,we get the equation: Sd=-1943.618+1723.587Pbi+4.146Tpd(R~2=0.490,P<0.001,Sd:spore density; Pbi:plant species richness;Tpd:total plant density).The partial correlation coefficient of Pbi and Tpd is 0.574 and 0.757;it means plant density was the most important factor to AMF spore density.Plant species richness affects AMF spore density too.May be secretion of different plants could increase sporulation of AMF,thus increase AMF spore density.3.We got 28 kinds of spores by phenotype.We use Simpson index as species richness,and find out the value in October(1.9882)is higher than July(1.7673). Values among 3 ecotypes is:hydrophyte(2.1562)>halophyte (1.7829)>psammophyte(1.6247).AMF spore richness is correlation with reed density(R~2=0.598,P<0.01),total plant density(R~2=0.393,P<0.05),soluble ion (R~2=0.383,P<0.001).Using multiple linear regression analysis,we get the equation:Ssi=1.067+0.291Hf~2+0.290Si(R~2=0.567,P<0.001,Ssi:spore spices richness;Hf:host factor,which was constructed by PCA analysis;Si:soluble ion). Partial correlation coefficient of Hf and Si is 0.728 and 0.510,indicates host is main factor affect AMF species richness,and then soluble ion.With the increasing of soluble ion,AMF species richness increasing too,it was the result of AMF long live in the alkaline-saline soil.4.Graph of AMF primary component shows,plots of same ecotype stand nearby, whereas plots of same season stand far from each other,indicates ecotype factor affect more to AMF than seasonal factor.
Keywords/Search Tags:Arbuscular mycorrhizal fungi(AMF), ecological function, wetland, Phragmites australis, Multiple regression analysis
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