Biocontrol of eucalypt bacterial wilt by culturable endophytic bacteria from non-host plants of Ralstonia solanacearum

The effective endophytic bacteria against eucalypt bacterial wilt were selected by determining antagonism between endophytic bacteria of non-host plants and Ralstonia solanacearum,and assessing control effect in three kinds of bioassays and endogenetic characteristics.The results indicated that fourteen bacterial strains were isolated from Allium sativum,A.fistulosum,A.cepa and Vitis vinifera,in which only four strains,designated as SH,SB,PT,C1 and C2,respectively,had inhibition against R.solanacearum.In the interactive inhibition test,strain C2 had strong growth inhibition against SH,and strain SH had slight inhibition against C1.SH had the best control effect in the test of hydroponic growing system,while PT had better effect than others in a potting soil system.The non-host endophytic bacterial strain SH had the colonization ability in eucalypt seedlings and they are capable of moving to the upper part of the stem,when the seedlings were inoculated with 108 CFU/mL of SH suspensions.