Identification And Antibacterial Activity Of Antagonistic Endophytic Bacteria From Cowpea

In order to clarify the potential bio-control value of 20 strains of endophytic bacteria isolated from cowpea leaves and the evolutionary relationship between them.Twenty strains of biocontrol bacteria were studied by morphological method,plate confrontation method,PCR technique and bioinformatics method.The pathogenic fungi were tested for their inhibitory effects against various pathogenic fungi.The results showed that 20 strains of endophytic bacteria were identified as Bacillus subtilis,Pseudomonas sp.And Bacillus amyloliquefaciens,11 strains of 20 endophytic bacteria were identified as Bacillus subtilis,4 strains were Pseudomonas sp.,5 strains were Bacillus amyloliquefaciens,1 strain was B.subtilis.All of the biocontrol bacteria were found to inhibit the growth of 4 tested plant pathogens antagonism produced by fungi.Among all of them,the highest inhibition rate was No.18 Bacillus subtilis against fungus B(C.gloeosporioides),the antibacterial rate was 80.28%,and the worst effect was Bacteria No.2 against the fungus A(C.gloeosporioides),the antibacterial rate was 29.58%,some strains had significant biocontrol effects.We measured the minimum inhibitory concentration(MIC)of the crude butanol extract from No.7 strain,which had good biocontrol effects anmog all 4 pathogenic fungi.Afterwards,we carried out gene sequence analysis and protein structure prediction for sfp and lpa related to the synthesis of non-ribosomal pathway lipopeptide antibacterial substances,laying a certain theoretical foundation for the further exploration of the mechanism of biological defense and the development of biological agents.