Antagonistic Assay of Bacillus spp. for Eco-friendly Biological Control of Melon Powdery Mildew

Myung Soo Park¹ Moon Haeng Lee² Eun Mo Lee² Hae-Kuen Yun³ Sung Eok Kim⁴ Nak Beom Jeon^2,*

¹School of Biological Sciences and Institute of Microbiology, Seoul National University
²Fruit-Vegetable Research Institute, Chungcheongnam-do Agricultural Research and Extension Services
³Department of Horticulture and Life Science, Yeungnam University
⁴Sangmyung University

Abstract

Melon powdery mildew, caused by Podosphaera fusca, is one of the serious diseases of melon plant in Korea. In this study, we evaluated the effect of selected antagonistic bacteria on the inhibition of mycelial growth of various plant pathogens, and control of melon powdery mildew. Based on the 16S rDNA and gyrA gene sequences, the selected antagonistic bacteria, M09, M70, and M99-1, were identified as Bacillus velezensis. These bacteria not only inhibited the mycelial growth of 47~69% in various plant pathogens, but also significantly reduced the incidence of powdery mildew. The three strains selected in this study could be used as potential biological control agents for various plant diseases as well as melon powdery mildew.

Acknowledgements

This research was supported by a grant (Project No. LP0033982017) from Chungnam province, Republic of Korea.

Figures & Tables

Fig. 1. Neighbor joining trees inferred from 16S rDNA (A) and gyrase subunit A (gyrA) (B) gene sequences of Bacillus subtilis species complex. Bootstrap scores > 50 are presented at the nodes. The scale bar indicates the number of nucleotide substitutions per site. The selected antagonistic bacteria are indicated in bold.