非寄主植物可培养内生细菌防治桉树青枯病研究

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

为筛选对桉树青枯病有防治效果的内生细菌,采用抑菌圈法,测定从青枯菌的非寄主植物中分离的内生细菌对青枯菌的拮抗作用,并分别在水培和土壤系统中测定其防治作用以及内生特性。结果表明:从蒜、葱、洋葱和葡萄内分离的14种可培养内生细菌中,只有菌株SH、SB、PT、C1和C2对青枯病菌具有拮抗作用;SH对C1具有拮抗作用,C2对SH有拮抗作用;在水培系统中,菌株SH对桉树青枯病的防治效果最好;在土壤系统中菌株PT、SH具有防治作用;菌株SH具有内生性,将桉苗浸于SH菌液中24 h,内生菌能侵入到桉苗茎部。

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.