Effects Of Funneliformis Mosseae On The Community Diversity Of Root Rot Pathogenic Fungi In Soybean Rhizosphere Soil

Soybean is one of the earliest economic crop in China,In recent years,due to the change of supply-demand relationship in the market,the number of soybean import presents the trend of quickly increase and lead-to the area of soybean cropping expanding,continuous cropping of soybean become a common phenomenon and cause the yield and quality of soybean shows the trend of gradually decrease.Heilongjiang province as the major area of soybean cropping in China,the area of soybean continuous cropping has reached 50%-70%.Continuous cropping can cause lots of soil-bome diseases,such as soybean root rot,which become more and more severely,however,people do not get a suitable solution that how to overcoming continuous cropping obstacles.AM fungi has a promote effect to improve the resistance of plant.This study mainly aims to analysis the change of the community compositions of root rot pathogenic fungi in the soil rhizophere of soybean continuous cropping through inoculated Funneliformis mosseae,explore the impact of inoculated F.mosseae on the soybean root rot pathogenic fungiand providetheoretical basis for using AM inoculums to prevent from occurring the soybean root rot.Therefore,the study has a significant importance for solving the continuous cropping obstacles.In this study,we analyze the community structure of root rot pathogenic fungi in three soybean varieties rhizosphere soil and root subject to continuous cropping during a season with a high incidence of root rot through PCR-DGGE technology,the DGGE bands show that:the abundance?dominance and diversity index is decrease in the different years and the different growth stage of per sample,and continuous cropping years of 2>continuous cropping years of 1,the community structure is more complex;the abundance?dominance and diversity index of HN48 is higher than other varieties in the different years and the different growth stage,HN48>KF16>HN44,and the different of soybean variety has different the dominance of fungi.Continuous cropping of soybean roots and rhizosphere soil of DGGE profiles that was showed that the thirteen bands are Pyhium ultimum,Fusarium sp.,Pleosporales sp.and Rhizoctonia solani,seven of them were uncultured fungi.In this experiment,13 DGGE bands had been sequenced.The dominant of soybean root rot pathogenic fungi in the experimental filed could be divided into Pythium ultimum andRhizoctonia solani,Phylogenetic analysis also showed that these unkown fungi had close relationship with the two main fungi.