Abstract
To create a new biological control technique for soil-borne diseases on pepper caused by the Pepper mild mottle virus (PMMoV), we examined 253 microorganisms isolated from soils of plant-cultivated fields and inactivating pathogenic fungi. The screening was carried out by evaluating the suppression degree of PMMoV infection to pepper root. Three isolates, M-21, C-176, and BS-17, were selected from two hundred and fifty-three rhizosphere microorganisms. The isolates M-21 and C-176, selected as the most effective bacteria throughout the second screening by pot-inoculation tests, were identified as Bacillus megaterium and Ralstonia pickettii, respectively, on the basis of several biological properties and the identity of their 16S rDNA sequence. In the isolation field of a green house, the sole application of M-21 suppressed soil-borne PMMoV diseases. Furthermore, the combination of M-21 soil incorporation and root dipping into the C-176 suspension suppressed soil-borne PMMoV diseases more effectively.
