Integrated Biological Control of Tobacco Bacterial Wilt (&amp;lt;i&amp;gt;Ralstonia solanacearum&amp;lt;/i&amp;gt;) and Its Effect on Rhizosphere Microbial Community

Yun Hu,Ji Feng,Yanyan Li,Xiaoqiong Yang,Shouwen Chen,Chunli Li,Yong Yang,Lin Wang

doi:10.4236/jbm.2021.93012

Abstract

Biological control agents and soil amendments have been applied to control tobacco bacterial wilt, but the mechanism is not well-known. In the present study, a field experiment was performed to investigate the soil physicochemical properties, disease index (DI) and disease incidence of tobacco bacterial wilt, and rhizosphere microbial community. The results show that the control efficacy of single application of antagonistic bacteria and calcium cyanamide was 46.43% and 51.92%, respectively. While the combined control efficacy of antagonistic bacteria and calcium cyanamide was 65.79%. Besides, the combined application of antagonistic bacteria and calcium cyanamide could increase soil pH, total N alkaline N, and exchangeable Ca, which were negatively associated with the microbial diversity, soil-borne pathogenic microorganisms, and incidence of tobacco bacterial wilt. Additionally, the combination of antagonistic bacteria and calcium cyanamide can improve the proportion of some antagonistic microbial species, and these antagonistic microbial species were inversely associated with the DI of tobacco bacterial wilt. In conclusion: The integrated measure may influence soil microbial communities through enhancing soil physicochemical properties and rebuild healthy soil microbial community structure to mitigate tobacco bacterial wilt. The current study presented valuable insights into the mechanisms enhancing soil health in the integrated measure.

Highlights

Tobacco bacterial wilt is a soil-borne bacterial infection triggered by Ralstonia solanacearum, which seriously damages the growth of tobacco [1] [2]
The results show that the control efficacy of single application of antagonistic bacteria and calcium cyanamide was 46.43% and 51.92%, respectively
The combination of antagonistic bacteria and calcium cyanamide can improve the proportion of some antagonistic microbial species, and these antagonistic microbial species were inversely associated with the disease index (DI) of tobacco bacterial wilt

Summary

Introduction

Tobacco bacterial wilt is a soil-borne bacterial infection triggered by Ralstonia solanacearum, which seriously damages the growth of tobacco [1] [2]. Tobacco bacterial wilt has received extensive attention, and many research studied have been reported about how-to restraint the tobacco bacterial wilt in breeding resistant varieties, agricultural control, and chemical control. These conventional approaches have a partial effect and are associated with many problems, such as lack of resistant varieties, easy loss of resistance, and the poor control effect of chemical agents, environmental pollution, and so on [4]. Studies show that culturing of antagonistic into bioorganic fertilizers has helped in control of tobacco bacterial wilt It can increase the population of beneficial microorganisms in soil and enhance the disease resistance of tobacco plants and improve the rhizosphere micro-ecological environment, promote root growth and nutrient absorption [11] [12]. An integrated approach based on the combination of biological control and soil amendments was proposed as a new method to control tobacco bacterial wilt

Methods

Results

Discussion

Conclusion