| In the rigorous desert, there live some kinds of desert pioneer plants, such as Salix psammophila,They occupy ecological niche by root-sucker to resist wind, drought and salinity improving ecological environment.Arbuscular mycorrhizal(AM) fungi was an important composition in biological ecosystem with plant roots to improve stree tolerance. In this research, AM fungal ecological distribution and species diversity in the rhizosphere of Salix psammophila in Inner Mongolia desert, effects of soil factors on AM fungi were systemically investigated. Results were showed as follows:An abundant diversity of AM fungi was found in the rhizosphere of Salix psammophila in Inner Mongolia desert. 37 AM fungal species belonging to 4 genera were isolated from soil samples. Of them, there were 23 to the genus Glomus, 10 to Acaulospora, 3 to Scutellospore and 1 to Gigaspora. Ecological distribution of the diverse species is different. Glomus and Acaulospora were distributed in the three sites, Scutellospora occurred in Heichengzi and Zhenglanqi, Gigaspora found only in Zhenglanqi. Glomus reticulatum was the dominant species in the three sites. Some AM fungi only occurred in one sampling sites. The scanning electron microscopy(SEM) of the AM fungal spores provide a reliable scientific basis for observation ultrastructural, classification and identification of AM fungi.Salix psammophila can form well symbionts with AM fungi in Inner Mongolia desert, The average spore density reach 236.02/100g soil , and the average total colonization is up to 61.07%, The formed the intermediate type mycorrhizas.The AM fungi in the rhizosphere of Salix psammophila have a significant temporal and spatial distribution. August and October's spore density were significantly higher than that in May; the maximal value of spore density and colonization were observed at the 0-10cm layer; and then gradually decreased with soil depth. Spore density was different among sites, Heichengzi and Zhenglanqi sites were significantly higher than that in Yuanshangdu, vesicular colonization rate in Zhenglanqi is significantly higher than that in Heichengzi, arbuscular colonization of AM fungi differed significantly, with the value at Heichengzi ranking the first. Total glomalin(TG) and easily extractable glomalin(EEG) concentrations in the rhizosphere of Salix psammophila were maximal in the October, and the changing trend of them in the three sites was Heichengzi > Zhenglanqi > Yuanshangdu, they also decreased with layers deepened. TG and EEG accounted for 23.9%~27.9% and 14.7%~20.2% of soil organic matter. They were an important source and component of soil organic matter.AM fungal species diversity and distribution in the three months are different. Species richness and Shannon-Weiner index of AM fungi in August and October were significantly higher than those in May, AM fungal composition, species richness and species diversity index in Yuanshangdu were significantly different from other sites.AM fungal ecological distribution and species diversity were closely related to soil factors. Soil temperature, moisture and available P have a direct effort on spore density, soil acid phosphatase, moisture and urease have a direct effort on vesicular colonization and the soil available P, organic matter and urease were the important factors for hypha colonization and total colonization. Soil available N was the key factor affecting the diversityThe results showed that Salix psammophila establish well symbiosis with AM fungi in Inner Mongolia desert.AM fungal resources were rich, There have obvious spatio-temporal heterogeneity in ecological distribution and species diversity and affected by soil factors. This thesis enrich the basic theory of desert restoration ecology and elucidated the ecologic function of AM fungi and interaction between plants and soil factos, provided the scientific basis for the applications of AM fungal resources in vegetation restoration and ecology reconstruction of desert.
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