Analysis of Rhizosphere Bacterial Community in Suppressive and Conducive Soil to Basal Rot of Garlic Based on PCR-RISA

Basal rot (Fusarium oxysporum f.sp. cepae) is an important disease ofgarlic in Tawangmangu Karanganyar Central Java Indonesia. Diseasesuppressive could be found in some lands around disease-conducive lands in Tawangmangu. The role of rhizosphere bacterial cammunity to induce disease-suppressiveness has been studied extensively on many soil born pathogen. Among the many groups of such organisms are root-associated bacteria, which generally represent a subset of soilbacteria. Ribosomal Intergenic Spacer Analysis (RISA) is a Polymerase Chain Reaction (PCR)-based method as an usefulassessment tool for the diversity analysis of microbes in theenvironment. Currently, the diversity analysis of rhizospere bacterialcommunity of garlic planted on suppressive and conducive soil hasbeen conducted. Conducive soil is the land where the diseaseincidence of basal rot of garlic at 1% or lower, whereas suppressivesoil at 40% or higher. The diversity analysis was done throughindependent cultureable approach of PCR-RISA using universalprimers of operon gene region of rRNA between small subunit (16S)and large subunit (23S) called intergenic spacer region (ISR). Thediversity of rhizosphere bacteria from suppressive soil was differentfrom that of conducive soil. The rhizosphere bacteria in suppressivesoil was more diverse than those of conducive soil and the bacteria inhealthy garlic rhizosphere was also more diverse than those in thediseased one.