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Poster: Biology & Disease Mgmt: Biological Control


Biocontrol of Tubakia leaf blight by Paenibacillus peoriae(HB774)
H. YUN (1), Y. Kim (1) (1) Seoul National University, South Korea

South Korea has shown decreasing proportion of coniferous plants and increasing proportion of deciduous plants due to the effect of global warming. With the growing significance of deciduous forests, the national forest damage by ongoing Tubakia leaf blight of the oak is more severe than before. In response to the current critical forest situation of Korea, this study aims to develop the efficient biocontrol agent of the Tubakia leaf blight. Among 30 bacteria isolated from soil and plants, HB774 showed the highest inhibition rate (85.8%) of the fungal mycelial growth, which was selected as a potentially effective biocontrol agent. As a result of the 16S ribosomal DNA sequence analysis, a gram-positive bacterial isolate was identified as Paenibacillus peoriae and deposited as a patent strain in Rural Development Administration of Korea. This isolate inhibited the mycelial growth by 69.7% and 75.6 % at the bacterial concentrations of 1 x 106 CFU/ml and 1 x 108 CFU/ml, respectively, of which the inhibitory rates were identical to or significantly higher than those of the fungicides, propiconazole and iminonctadine-triacetate. In the simultaneous treatment and pre-treatment of HB774, its control efficacies were high with 80-90%, showing no significant differences from those of propiconazole and iminonctadine-triacetate. This suggests P. peoriae HB774 has a high potential to be developed as an efficient biocontrol agent against the Tubakia leaf blight on oaks.