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

Abstract

Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases.

Ralstonia solanacearum: A Threat to Potato Production in Bangladesh

“…Among them soil borne diseases are considered to cause a yield loss of as much as 10-20% annually. Ralstonia solanacearum formerly called Pseudomonas solanacearum (Yabuuchi et al, 1995) is the most destructive soil-borne pathogen (Yuliar et al, 2015) that affects potatoes in temperate, subtropical and tropical regions throughout the world by causing bacterial wilt or brown rot disease (CABI, 2017a;Champoiseau et al, 2009). It is a vascular disease, which is fatal in infected plant and has been ranked as one of the most important bacterial plant pathogens identified to date, commonly known as bacterial wilt (in case of infected plant) and brown rot (in case of infected tubers).…”

“…The disease appears as rapid and fatal wilting symptoms in host plants (Yuliar et al, 2015) and infected potato plants die rapidly within 3-4 days. Older plants first show wilting of the young leaves, or partial one sided wilting of the plant and stunting, and finally the plants wilt permanently and die.…”

Desempenho de cultivares de batata sob diferentes espaçamentos em solo naturalmente infestado com Ralstonia solanacearum

“…Embora o uso de cultivares resistentes seja considerado o método mais eficiente de controle de doenças, principalmente por ser de fácil adoção pelos agricultores e não onerar os custos de produção (Yuliar & Toyota, 2015), ele praticamente não tem sido utilizado no caso da murcha bacteriana da batata. Isso se deve ao fato de a genética da resistência no germoplasma já explorado ser complexa, devido ao nível de ploidia da batata (tetraplóide), e porque os níveis de resistência encontrados são baixos e pouco estáveis, no tempo e no espaço, em virtude da alta variabilidade do patógeno (Silveira et al, 2007;Muthoni et al, 2012).…”

Impact of transgenic cotton expressing cry1Ac and cry2Ab genes on soil rhizosphere bacterial and fungal populations in soils of central Kenya

“…Indigenous microorganisms, in general, have higher competence for survival in their own habitat than introduced ones. Other cultural methods, such as mulching and crop rotation, also induce microbial increases in soil (Yuliar et al, 2015).…”