Effects of Bio-compound Fertilizer on Banana Wilt and Soil Bacterial Community Based on Analysis with RFLP

In this study,PCR-RFLP was adopted to investigate the effect of bio-compound fertilizer and chemical fertilizer treatments on banana wilt and soil bacterial community.Total microbial genomic DNA was extracted by a direct method from four different soil treatments,respectively.The 16S rDNA of the extracted DNA were amplified using bacterial universal primers 27F and 1492R and a 16S rDNA clone library was constructed.A total of 50 positive clones were randomly chosen from the clone library to be examined.The PCR products were digested by Msp I and Rsa I,and their fingerprints were analyzed.Results indicated that disease indexes among the all treatments were as follow: no fertilizer and pathogen(CK1)bio-compound fertilizer plus pathogen(BF) chemical fertilizer plus pathogen(CF)pathogen only CK2.The fingerprints of 16S rDNA positive clones were analyzed using cluster analysis,CK1,CK2,CF and BF were clustered into 29,21,11,and 25 classes when the similar value was 1.00.Indicating that banana wilt could reduce soil bacterial community,bio-compound fertilizer could increase bacterial community.The bacterial diversity indexes of Shannon-Wiener,Simpson and Richness were lower in CF treatment compared to other treatments,but the evenness was higher.The type of operational taxonomic units and richness were lower in BF treatment in comparison to CK1 and higher in comparison to CK2,and the bacterial diversity indexes of Shannon-Wiener and Simpson were higher than those of other treatments.This revealed that CF could induce specific bacteria enrichment and loss of some other bacteria.Most importantly,BF could increase soil bacterial community and induce 4 kinds of dominant species in soil.The four dominant species had a higher proportions which were 12%,12%,10% and 8% respectively.16S rDNA analysis results showed that these 4 dominant species had separately high homology with uncultured delta proteobacterium,uncultured actinobacterium,Sphingomonas sp.and Streptomyces griseoruber strain.Bio-compound fertilizer could change the structure of soil bacterial community and these dominant species induced by bio-compound fertilizer might play an important role in control of banana wilt.