Exploration Indigenous Bacillus Bumiaji-Malang Against Ralstonia solanacearum Causing Potato Bacterial Wilt

Abstract

Ralstonia solanacearum is a soil borne pathogen, which has a very wide host range and causes bacterial wilt. The use of biological agents, such as bacterial groups has been tried in several areas of potato plantations in Java. This study aims to obtain Bacillus isolates from the potato cropping area, Sumber Brantas, Bumiaji, Batu, which had the potential to suppress growth R. solanacearum. Bacillus was isolated from the soil rhizosphere of potato plants, while R. solanacearum was isolated from the base of potato stems showing bacterial wilt symptoms on tetrazolium chloride (TZC) selective medium. Bacillus spp. and R. solanacearum isolates were tested for hypersensitivity on the leaves of the KR-15 tobacco plant. Isolates that cause necrosis symptoms in tobacco leaves can be ascertained to be pathogenic. This study succeeded in obtaining 13 Bacillus spp. isolates with different colony morphologies. Three isolates of Bacillus spp. were selected from the 13 isolates obtained, based on their ability to suppress the growth of R. solanacearum and are expected to be potential as biological agents. Based on genetic analysis, the 3 bacterial isolates were identified as Bacillus mycoides and Bacillus weihenstephanensis.