Uji Antagonisme Bakteri Endofit dengan Cercospora oryzae Miyake dan Bipolaris oryzae (Breda de Haan) Shoemaker

ABSTRACTAntagonism test between Endophytic Bacteria and Cercospora oryzae Miyake and Bipolaris oryzae (Breda de Haan) ShoemakerCercospora oryzae Miyake dan Bipolaris oryzae (Breda de Haan) Shoemaker are the causal agent of major disease for rice, which called Cercospora leaf spot and rice brown spot. Cercospora leaf spot and rice brown spot control using a bio-control agent in a form of endophytic bacteria is one of the eco-friendly alternative method. This research aimed to test the potential of the endophytic bacteria isolates which have the antagonism ability and able to reduce the growth of the diseases. The research was carried out in the Laboratory of Biotechnology Plant Protection of the Department of Plant Pests and Diseases, Faculty of Agriculture, Universitas Padjadjaran. The experiments were carried out using dual culture method. The experiments were performed using a completely randomized design (CDR)which consisted of 10 treatments with 4 replications. The antagonism experiments used 9 endophytic bacteria isolates from some parts of the rice plant. The result of antagonism of endophytic bacteria test showed that all of the isolates had antagonistic activity towards C. oryzae dan B. oryzae. Os6 isolate demonstrated the best result to inhibit C. oryzae growth with the radius of its colony reached only 85 mm and the inhibition growth percentage reached 85.83%. Os3 isolate showed the best result to inhibit B. oryzae growth with the radius of its colony reached only 147.5 mm and the inhibition growth percentage reached 75.41%.Keywords: Inhibition growth, Cercospora leaf spot, Rice brown spotABSTRAKCercospora oryzae Miyake dan Bipolaris oryzae (Breda de Haan) Shoemaker merupakan penyebab penyakit utama Padi, yaitu bercak daun Cercospora dan bercak coklat. Pengendalian C. oryzae Miyake dan B. oryzae (Breda de Haan) Shoemaker dengan menggunakan agens hayati berupa bakteri endofit merupakan salah satu alternatif pengendalian yang ramah bagi lingkungan sekitar. Penelitian ini bertujuan untuk mengetahui potensi isolat bakteri endofit yang mempunyai kemampuan antagonis dan mampu menekan pertumbuhan penyakit. Penelitian ini dilaksanakan di Laboratorium Bioteknologi Proteksi Tanaman Departemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Padjadjaran. Prosedur yang dilakukan adalah dual culture method. Percobaan dilakukandengan menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari 10 perlakuan dengan masing-masing perlakuan diulang sebanyak 4 kali. Uji Antagonisme pada penelitian ini menggunakan 9 isolat bakteri endofit yang berasal dari beberapa bagian tanaman padi. Hasil penelitian menunjukkan bahwa 9 isolat bakteri endofit yang diujikan, semuanya bersifat antagonis terhadap C. oryzae Miyake dan B. oryzae (Breda de Haan) Shoemaker. Isolat Os6 paling baik menghambat C. oryzae Miyake dengan jari-jari koloni sebesar 85 mm dan persentase penghambatan mencapai 85,83%. Isolat Os3 paling baik menghambat B. oryzae (Breda de Haan) Shoemaker dengan jari-jari koloni sebesar 147,5 mm dan persentase penghambatan mencapai 75,41%.Kata kunci: Penghambatan pertumbuhan, Bercak daun cercospora, Bercak coklat.