Penapisan Bakteri Filosfer Penghasil Senyawa Bioaktif Anti Xanthomonas oryzae pv. oryzae Penyebab Penyakit Hawar Daun Bakteri pada Padi

Abstract

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the important diseases in rice crops. The disease is difficult to control because it attacks the rice plant at different growth stages ranging tillering, flowering and ripening. One alternative that can be used to control the spread of BLB is using the biocontrol agent which can be obtained from phyllosphere. This study aims to isolate, characterize and screen the rice phyllosphere bacteria producing bioactive compounds anti Xoo causes BLB in rice. Phyllosphere bacteria isolated from rice leaves Ciherang healthy age of 2.5 months using 4 different media obtained 285 bacterial isolates, the 65 isolates of King’s B agar, 86 isolates of nutrient agar, 81 isolates of Luria-Bertani agar, and 53 isolates of trypticase soy agar. Antagonist test using double layer method showed 58 isolates phyllosphere bacteria potential as a biocontrol agent producing bioactive compounds Xoo. Pathogenicity test showed 18 isolates not potentially pathogenic to rice plants. Among the 18 non-phytopathogenic isolates, 14 isolates including Gram-positive bacteria, 4 isolates Gram-negative bacteria, and 5 isolates of Bacillus suspected. Three of the 18 isolates (BFSGb 8, BFSGb 55, and BFSGb 99) has the largest index value inhibition of in-vitro against Xoo is 1.33, 1.67, and 1.33 respectively to isolate BFSGb 8, BFSGb 55, and BFSGb 99.