Phyllosphere bacteria as a candidate of biocontrol agents against Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight disease

Abstract

Abstract. Prabawati A, Susilowati A, Sugiyarto. 2019. Phyllosphere bacteria as a candidate of biocontrol agents against Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight disease. Pros Sem Nas Masy Biodiv Indon 5: 256-262. Rice production is often threatened by bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo). Biocontrol is one of alternative plant disease management. Living organism, such as microorganism, take a role as a biocontrol agent. The aims of this research were to isolate, to select, to identify and to know the relationship of phyllosphere bacteria against Xoo. The antagonist bacteria can be a candidate of biocontrol agent. Bacteria were isolated from paddy fields in Klaten, Sragen, and Surakarta. Screening process was done by plug agar method. The research was conducted at Laboratory of Biology Department, Faculty of Mathematics and Natural Sciences, Sebelas Maret State University, Surakarta. Selected bacteria identified by characterizing cell and colony morphology and 16S rRNA gene sequencing. Sequencing was done in 1st BASE, Singapore. Phylogenic tree was made by MEGA 7.0. This research successfully collected 52 isolates, 7 of them had antagonist activity against Xoo. Antagonist bacteria were identified as Bacillus OBA1, Bacillus OBA8, Bacillus OBA14, Bacillus OCA7, Bacillus ODA1, Bacillus OIA8, and Arthrobacter OIA10. The phylogenic tree showed that the bacteria were Bacillus and Arthrobacter groups.