The Potential Biological Agent Bacteria Against for Controling Important Pathogens on Rice

The Potential Biological Agent Bacteria Against for Controling Important Pathogens on Rice At present, biological control technology for the main diseases of rice continues to grow. In the development of biological control technology, inhibition mechanism of pathogens in the development of disease in a plant population in a certain area becomes important. The aim of this study was to obtain potential biological agent bacteria for controlling important rice diseases based on antagonistic mechanism, ability to induce plant resistance and support plant fitness, and their compatibility. The results showed that Ralstonia pickettii TT47, Pseudomonas fluorescens P12, Chromobacterium sp. T51118, Bacillus subtilis 451 and 154, and Streptomyces sp. T51105 have an antibiosis mechanism by producing secondary metabolites and volatile compounds. Additionaly, Chromobacterium sp. and Streptomyces sp. also have a lysis mechanism on the basis of the chitinolityc enzyme production test. The antibiotic activity of R. pickettii and P. fluorescens were strong to P. oryzae on dual culture test with the highest inhibition up to 79.68% and 77.59% respectively. Inhibition growth of P. oryzae and R. solani mycelium on volatile tests up to 100% by Chromobacterium sp. T51118. Generally, all of biological agents were able to induce plant resistance and support to plant fitness. Compatibility test obtained R. pickettii, P. fluorescens, and Chromobacterium sp. were compatible. Based on the results, three biocontrol agent bacteria, namely P. fluorescens P12, R. pickettii TT47, and Chromobacterium sp. T51118 were excellent. They were able to suppress the growth of pathogens, were able to induce plant resistance and support plant fitness, as well as they have more diverse target pathogens, and compatible.Saat ini teknologi pengendalian hayati penyakit utama padi terus berkembang. Dalam pengembangan teknologi pengendalian hayati, mekanisme penghambatan patogen dalam perkembangan penyakit pada suatu populasi tumbuhan dalam area tertentu menjadi hal yang penting. Penelitian bertujuan mendapatkan bakteri agens hayati potensial dalam pengendalian penyakit penting padi di antaranya yang disebabkan Pyricularia oryzae, Xanthomnas oryzae pv. oryzae, Rhizoctonia solani, Burkholderia glumae, dan Drechlera oryzae, berdasarkan mekanisme antagonisme, kemampuan menginduksi ketahanan dan mendukung kebugaran tanaman, serta kompatibilitas antaragens hayati. Ralstonia pickettii TT47, Pseudomonas fluorescens P12, Chromobacterium sp. T51118, Bacillus subtilis 451 dan 154, serta Streptomyces sp. T51105 dibuktikan memiliki mekanisme antibiosis dengan menghasilkan metabolit sekunder dan senyawa volatil. Berdasarkan uji produksi enzim kitinolitik Chromobacterium sp. dan Streptomyces sp. memiliki mekanisme lisis. Aktivitas antibiotik R. pickettii dan P. fluorescens tergolong kuat terhadap P. oryzae dengan penekanan secara berurutan sebesar 79.68% dan 77.59% pada uji biakan ganda. Penekanan pertumbuhan miselium P. oryzae dan R. solani pada uji volatil mencapai 100% oleh Chromobacterium sp. Semua agens hayati umumnya mampu menginduksi ketahanan dan mendukung kebugaran tanaman. Uji kompatibilitas menunjukan R. pickettii, P. fluorescens, dan Chromobacterium sp. bersifat kompatibel. Dari hasil penelitian diperoleh tiga bakteri agens hayati dengan kategori unggul, yaitu P. fluorescens P12, R. pickettii TT47, dan Chromobacterium sp. T51118. Ketiganya mampu menekan pertumbuhan patogen, menginduksi ketahanan dan mendukung kebugaran tanaman, memiliki patogen sasaran yang lebih beragam, serta bersifat kompatibel