Isolation, screening and identification of endophytic antagonistic bacteria toPotato ring rotbacteria

Two hundred and forty bacterial strains were isolated from three potato (Solanum tuberosum) cultivars from eight different sources. On the basis of antagonistic bacteria examinationin vitro, greenhouse and field tests, 22.9% of isolated bacteria were endophytic and antagonistic. Three strains, namely A-10', T3(Bacillussp.) and H1-6 (Pseudomonas fluorescens), were chosen for their suppressive effect on bacterial ring rot (Clavibacter michiganensissubsp.sepedonicus) and their growth promotion. The strain A-10' was an endophytic bacterium with the effects of colonization, plant growth promotion and suppression of the pathogenic bacteria, showing good prospects for commercial use.