新疆沙冬青AM和DSE真菌空间分布研究

Abstract

Ammopiptanthus nanus is the only endangered evergreen broadleaf shrub endemic to the deserts and plays all vital roles,which is thought to be the prefect plant at improving arid desert area and in putting off desertification. To elucidate the colonization rule of AM and DSE fungi and the ecological function of soil factors on Ammopiptanthus nanus,The paper studied the ecological distribution of AM and DSE fungi,and symbiosis with Ammopiptanthus nanus. We sampled from four different sites including Kang Su,Biao Ertuokuoyi( yang),Biao Ertuokuoyi( yin) and Shang Etushi in XinJiang in June2012. Soil samples were collected from the rhizosphere of Ammopiptanthus nanus,and were divided into five depth intervals,0—10,10—20,20—30,30—40 and 40—50 cm respectively. The results indicated that the average total colonizations of AM and DSE fungi were 83. 2% and 53. 22% respectively. AM and DSE fungi could establish well symbiosis with the roots of Ammopiptanthus nanus. Ammopiptanthus nanus could be highly infected by AM fungi and form a classical type of arbuscular mycorrhizal,most of which is arum type( A-type). The spatial distribution of AM and DSE fungi had significant spatial differences. The total colonization of AM fungi in Kang Su and Shang Etushi was highest and reached the peak at the 20—30 cm layer. There were no significant differences in the total colonization of DSE among different soil layers. However,it was higher in Biao Ertuokuoyi( yang) than that in the other three sites. and it was thelowest in Shang Etushi. The relativity of analysis showed that the colonizations of hyphened,Vesicular colonization and total colonizations of AM fungi had significantly negative correlations with each structures of DSE,such as hypha,microsclerotia and total colonizations. The hypha and total colonizations of DSE had negative correlations with the colonization intensity of AM fungi,and extreme positive correlations with arbuscule colonization. That showed the presence of niche competition between AM and DSE fungi. The infecting of AM and DSE fungi were significantly affected by soil factors. The total colonizations of AM fungi were extreme positive correlations with available P,TG( total glomalin) and acid phosphatase,significant positive correlations with soil urease,and significant negative correlations with soil pH. The hypha colonization were extreme positive correlations with soil urease,TG and acid phosphatase,and significant positive correlations with organic matter and available P. The vesicular colonization was extreme positive correlations with acid phosphatase. The arbuscule colonization was extreme positive correlations with TG,but extreme negative correlations with soil pH,and significant negative correlations with alkaline phosphatase. There were extreme positive correlations between the hypha colonization of DSE and soil urease,and extreme negative correlations between hypha colonization and available N and soil pH. The total colonizations were extreme positive correlations with soil urease,and extreme negative correlations with soil pH,and significant negative correlations with available N. The microsclerotia correlations were extreme positive correlations with available N,TG and acid phosphatase,and significant positive correlations with soil urease. The study provided basis for making good full use of AM and DSE fungi resources to promote the growth of host plant and vegetation restoration on desert sand.