Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate
Article first published online: 24 JUL 2012
© 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 3, pages 641–651, September 2012
How to Cite
Li, C.-H., Shi, L., Han, Q., Hu, H.-L., Zhao, M.-W., Tang, C.-M. and Li, S.-P. (2012), Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate. Journal of Applied Microbiology, 113: 641–651. doi: 10.1111/j.1365-2672.2012.05371.x
- Issue published online: 14 AUG 2012
- Article first published online: 24 JUL 2012
- Accepted manuscript online: 25 JUN 2012 02:35AM EST
- Manuscript Accepted: 18 JUN 2012
- Manuscript Revised: 28 MAY 2012
- Manuscript Received: 20 FEB 2012
- Natural Science Foundation of China. Grant Number: 31071459
- endophytic bacteria;
- Verticillium dahliae Kleb
To explore biocontrol potential of 39 DAEB isolates (doubly antagonistic towards both Verticillium dahliae Kleb and Fusarium oxysporum) against verticillium wilt of cotton and to elucidate colonization and category characteristics of an endophytic bacterium with significant biocontrol activity.
Methods and Results
Thirty-nine antagonistic endophytic bacteria strains were tested for their ability to control verticillium wilt in cotton plants caused by a defoliating pathotype of V. dahliae 107 in cotton under controlled conditions. The biocontrol trial revealed that an endophytic bacterium, designated HA02, showed a significant biocontrol activity to V. dahliae 107. After cotton seedlings were inoculated with a gfp gene-tagged HA02 (HA02-gfp), HA02-gfp populations were higher in the root than in the stem; in addition, the HA02-gfp was distributed in the maturation zone of cotton root. Furthermore, HA02-gfp also colonized seedlings of maize, rape and soybean after the bacteria inoculation. Phylogenetic trees based on 16S rDNA sequences combined with morphological, physiological and identification showed that the bacterium belongs to the Enterobacter genus.
Our results showed that only 1 of 39 DAEB isolates demonstrated more efficient biocontrol potential towards V. dahliae 107 in greenhouse and field trials. HA02-gfp mainly colonized cotton in roots. In addition, we quantitatively observed HA02 colonization in other hosts. HA02 belongs to the Enterobacter genus.
Significance and Impact of the Study
This is the first study on biocontrol to defoliating pathotype of V. dahliae Kleb by endophytic bacteria. The HA02 showed effective biocontrol to V. dahliae 107 in greenhouse and field trials. Furthermore, we assessed the quantitative and qualitative colonization of HA02 in cotton seedlings. Our study provides basic information to further explore managing strategies to control this critical disease.