The Effect of Bacillus subtilis on in vitro Growth and Pathogenicity of Agrobacterium tumefaciens

Abstract

Five isolates of Bacillus subtilis isolated from the soil, were found to be antagonistic to 6 isolates of Agrobacterium tumefaciens in vitro. Inoculation of B. subtilis in wounded castor bean plants 30 min before or simultaneous inoculation with A. tumefaciens resulted in excellent control of the crown gall symptoms on the host within 50 days of inoculation. Application of B. subtilis 30 min after inoculation with A. tumefaciens did not result in appreciable disease reduction. Treatment of the tested plants by B. subtilis did not induce any phytotoxic injury or growth retarding side effects. It appears that B. subtilis could potentially be incorporated for crown gall control. However, further tests are needed to test this biological control agent with other plant species especially fruits, nuts and vine nursery stock.

The Effect of Bacillus subtilis on In Vitro Growth and Pathogenicity of Erwinia amylovora

“…It appears that B. subtilis which was proved in the present study to be effective in vitro tests against £. amylovora and which was also suggested as a biocontrol agent of brown rot of potato (HASSANEIN 1987) and the crown gall disease (HASSANEIN and EL-GOORANI 1991) did not exhibit any activity against E. amylovora in planta tests.…”

“…Many reports have dealt with B. subtilis as a biological control agent of certain plant diseases caused by fungi (UTKHEDE andRAHE 1983, WILSON andPUSEY 1985). However, very limited work has been reported on the control of bacterial diseases by the antagonistic activity of B. subtilis (HASSANEIN 1987, HASSANEIN andEL-GOORANI 1991).…”