Objective To investigate the influence of Panax ginseng continuous cropping on the carbon substrate metabolic activity of microbes in soils sampled from Dafang,Huangni,and Wulidi in Jilin Province,China.Methods Soil metabolisms of soil communities were characterized by community level physiological profiles using BIOLOGTM EcoPlate.Results Soils sampled from the three sites were analyzed and their metabolic activities were compared.Principal component analysis explored the significant variance in metabolic function of microbial communities in soils,though the Shannon index and the evenness index of them were similar.Futhermore,two principal components(PC1 and PC2),which contributed 67.83% and 10.78% of total variance,were extracted respectively.And also,substrates significantly correlated with PC1 and PC2 at the three sampling sites were identified.Conclusion Characteristic of soil is the primary factor influencing microbial communities,and P.ginseng continuous cropping has significant influence on microbial community.Though soil samples show similar microbial metabolic profiles,microbial communities in rhizosphere soil are changed obviously during the cultivation of P.ginseng,which would finally result in the unbalance of microbial community.Phytopathogens would gradually be the predominants in rhizosphere soil and make P.ginseng sick.
YING Yi-xin1,DING Wan-long1,ZHOU Ying-qun2,LI Yong1 1.Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100193,China 2.China National Corporation of Traditional and Herbal Medicine,Beijing 100195,China
Objective To study the influence of allelochemicals such as benzoic acid, diisobutyl phthalate, diisobutyl succinate, palmitic acid, and 2,2-bis-(4-hydroxyphenyl) propane on the microbial community of ginseng cultivating soil. Methods Soil samples were sprayed with five allelochemicals(100 mg/L) and their mixture(20 mg/L), respectively. Carbon metabolic ability variances were analyzed by Biolog method and genetic polymorphism variance was analyzed by RAPD method. The Nei's genetic diversity index and Shannon's information index were calculated. Results Significant differences in carbon metabolic activity were found between allelochemical-treated soils and control. Further analysis indicated that although the carbon-utilizing ability and genetic polymorphism of soils treated with di-isobutyl phthalate, di-isobutyl succinate, and allelochemical mixtures were lower than those of the other treatments, genetic similarities of soils treated with di-isobutyl phthalate, diisobutyl succinate, and allelochemical mixtures were much higher than those of the other treatments. Conclusion Allelochemicals significantly declined the genetic diversity and carbon metabolic activity of microorganisms in newly reclaimed forest soil for ginseng cultivation.
