Biocontrol of Soft Rot of Chinese Cabbage Using an Endophytic Bacterial Strain.

Xingyu Li,Biao Wang,Lijuan Yang,Yixin Wu,Yueqiu He,Wenyan Cui,Pengbo He,Pengfei He,Pengjie He,Shahzad Munir

doi:10.3389/fmicb.2019.01471

Abstract

Soft rot caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) is a major constraint in the production of Chinese cabbage. The objective of this study was to demonstrate that the causative agent Pcc may be successfully managed by Bacillus amyloliquefaciens KC-1, both in vitro and in vivo. Chinese cabbage seedlings were cultivated in organic substrate termed bio-organic substrate using a floating-seedling system with B. amyloliquefaciens KC-1. This approach was applied in a greenhouse to evaluate the management of soft rot. The results showed that the extent of soft rot, as well as the transmission of Pcc to the stem progeny and its survival in the rhizosphere, was reduced following inoculation with B. amyloliquefaciens KC-1. In contrast, the population diversity of B. amyloliquefaciens KC-1 persisted in the Chinese cabbage stems after germination. These findings revealed that B. amyloliquefaciens KC-1 was able to survive and suppress the growth of Pcc in Chinese cabbage and its rhizosphere, protecting the host from the pathogen. The use of B. amyloliquefaciens KC-1 throughout the growth period of plants may be an effective strategy for the prevention of soft rot in Chinese cabbage.

Highlights

Pectobacterium carotovorum subsp. carotovorum (Pcc) is a common cause of soil-borne soft rot, in a broad range of vegetable and flower hosts such as Chinese cabbage, tomato, potato, cucumber, Amorphophallus konjac, and Zantedeschia hybrida (Des Essarts et al, 2016; Kang et al, 2016; Shao et al, 2016; Garge and Nerurkar, 2017; He et al, 2018)
The results of the present study clearly demonstrated that B. amyloliquefaciens KC-1 competes with the pathogen in the rhizosphere by significantly decreasing the pathogen copies in the rhizosphere soil and leaves of inoculated Chinese cabbage
We introduced a new biocontrol product – termed bio-organic substrate – by mixing the traditional organic substrate with B. amyloliquefaciens KC-1

Summary

Introduction

Pectobacterium carotovorum subsp. carotovorum (Pcc) is a common cause of soil-borne soft rot, in a broad range of vegetable and flower hosts such as Chinese cabbage, tomato, potato, cucumber, Amorphophallus konjac, and Zantedeschia hybrida (Des Essarts et al, 2016; Kang et al, 2016; Shao et al, 2016; Garge and Nerurkar, 2017; He et al, 2018). Carotovorum (Pcc) is a common cause of soil-borne soft rot, in a broad range of vegetable and flower hosts such as Chinese cabbage, tomato, potato, cucumber, Amorphophallus konjac, and Zantedeschia hybrida (Des Essarts et al, 2016; Kang et al, 2016; Shao et al, 2016; Garge and Nerurkar, 2017; He et al, 2018). Chemical methods – though generally effective – are not desirable due to concerns regarding the development of resistance and environmental pollution (Gill and Garg, 2014). Effective and environmentally friendly methods for controlling these diseases are required to reduce the use of chemical pesticides. Biocontrol is one of the most effective and promising approaches for the control of soft rot and other plant diseases

Objectives

Methods

Results

Discussion

Conclusion