[Soil microbial community composition and diversity in Panax quinquefolius rhizosphere]

The objective of this work was to analyze the soil microbial community diversity and structure in Panax quinquefolius rhizosphere and elucidated the rules of the ecology shift. Two community-based microbiological measurements, community level physiological profiling (CLPP) using Biolog sole C source utilization tests and phospholipid ester-linked fatty acid (PLFA) profiles, were used to evaluate soil microbial community function and composition of different Panax quinquefolius cropping soils. The properties, pH, N, P, K and organic matter were analyzed also. There were many differences in soil properties such as lower pH (5.82) in Jilin soil but higher pH (8.27) in Beijing soil and there were significant higher content of organic matter, available N, P, K in Jilin soil than those in Beijing soil. The analysis of soil microbial ecology showed a similar result in AWCD, Biolog and PLFA pattern. According to the PC1 score in principal analysis of Biolog and PLFA, the soils in 2, 3 and 4 years cultivated P. quinquefolius rhizophere were distinguished from the control and 1 year soils. The result indicated that the metabolism function reduced and the structure shifted in rhizophere soil microbial community after P. quinquefolius cropping. These may be the primary reason of the disease occur severely in P. quinquefolius field.