Combination of endophytic bacteria and resistant cultivars improves control of Ralstonia wilt of tomato

Abstract

The aim of this study was to evaluate the combined effect of endophytic bacteria and tomato cultivars with different resistance levels to Ralstonia solanacearum in the control of tomato bacterial wilt. Endophytic bacteria were successfully introduced into tomato seedlings by three methods: cutting of the hypocotyl, substrate drenching and seed microbiolization. One hundred and fifty endophytic bacterial isolates were screened in greenhouse assays. Two isolates, identified as Bacillus sp. and Serratia marcescens by 16S rDNA sequencing were the most promising. These isolates, when combined with tomato cultivars Drica, Caraíbe, Yoshimatsu, and Santa Clara, reduced the area under the disease progress curve (AUDPC) of bacterial wilt by 16 to 65%. Additionally, it was shown that antibiosis is not involved in the control of R. solanacearum by Bacillus sp. and S. marcescens. This study adds new isolates of endophytic bacteria as potential agents to control Ralstonia wilt in tomato and emphasizes the importance of combining these bacteria with host resistance in the management of the disease.

Recent Trends in Control Methods for Bacterial Wilt Diseases Caused by <i>Ralstonia solanacearum</i>

“…A previous study reported that the combination of endophytic bacteria ( Bacillus sp. and Serratia marcescens , both of which had no antibiosis) with resistant cultivars of the tomato reduced the incidence of bacterial wilt ( 18 ).…”

A Review on Solanaceous Plant Diseases Caused by Ralstonia Solanacearum Having Serious Economic Impact

“…A prior study found that the prevalence of bacterial wilt was decreased when resistant cultivars of the tomato were combined with endophytic bacteria (Bacillus sp. and Serratia marcescens, both of which displayed no antibiosis) (Barretti et al, 2012). In IPM for soil-borne diseases, grafting is a key tactic.…”

Diversity and antagonistic potential of apoplastic bacteria against Ralstonia pseudosolanacearum race 4 causing bacterial wilt of ginger

“…Since organic farming is gaining momentum, ecofriendly biological control measures are highly preferable to chemical control which poses serious environmental threats. Several rhizobacteria, endophytic bacteria, actinomycetes, phages etc were evaluated for bacterial wilt management in many economically important crops ((Lemessa and Zeller, 2007;Yamada et al, 2007;Ramesh et al, 2009;Barretti et al, 2012;Achari and Ramesh, 2014;Yuan et al, 2014)). In ginger, the common strategies adopted for bacterial wilt management include selection of disease free rhizomes, selection of fields with no history of bacterial wilt, seed treatment using chemicals, strict phytosanitory measures to avoid the carryover of pathogen inoculum through field workers or irrigation water and crop rotation with non-host plants (Kumar and Hayward , 2005).…”