Isolation of endophytic bacteria from nodule of Sophora alopecuroides and effect of biological control against Fusarium wilt

Abstract:

Lots of endophytic bacteria strains isolated from healthy Sophora alopecuroides were studied by using surface spread plate experiment, confront antibiotic culture experiment, antagonistic activities of extracellular secretions determination and disease-control experiment in greenhouse. The results indicated that there were a lot of endophytic bacteria resources isolated from nodule of Sophora alopecuroides antagonized against Fusarium oxysporum. 48 strains with the relative inhibition rate more than 50% of total 60 endophytic bacteria were selected with surface spread plate method. 48 antagonistic strains were then screened in confront antibiotic culture trial. The results showed that 40 strains had inhibits against Fusarium oxysporum with more than 20 mm inhibition zone, and 26 strains with more than 5 mm in extracellular secretions inhibitory activities testing experiment on 40 antagonistic strains. In disease-control experiments with Fusarium oxysporum carried out in greenhouses, two isolates (KDRE12 and KDRE41) gave satisfactory results, with 67.11% and 72.65% average control effect, respectively, which have good applied potential.