Isolation and identification of phytopathogenic bacteria in vegetable crops in West Africa (Côte d'Ivoire)

Yield losses in food crops due to plant pathogenic bacteria are significant and increasing over the years. The increasing losses caused by bacterial plant pathology are explained by the emerging resistance of bacteria to the chemical agents used in plant protection. Moreover, these chemical agents harm the environment through residue accumulation leading to soil pollution and the perturbation of the soil's inner ecosystem. The most important bacteria causing plant pathology belongs to the genera of Pseudomonas, Ralstonia, Agrobacterium, Xanthomonas, Erwinia, Xylella, Pectobacterium, and Dickeya. However, in Côte d'Ivoire, only the Ralstonia species have been identified. Therefore, this study aims to identify plant pathogenic bacteria present in market garden plants in Côte d'Ivoire. Three sites in the cities of Anyama, Abidjan, and Bingerville were selected for the sampling and the detection of Pseudomonas syringea, Erwinia carotovora, Clavibacter michiganensis, Ralstonia solanacerum, and Xanthomonas campestris. The samples consisted of healthy and affected plant leaves and soils. In brief, 70 bacterial strains were isolated and phenotypically identified in this study. Among them, we noticed that 20% were isolated from the leaves and 80% from the soil. Regarding the bacterial species, C. michiganensis (37.14%), E. carotovora (18.57%), R. solanacerum (15.71%), X. campestris (14.28%), and P. syringae (11.42%) were identified. The molecular identification has confirmed the identification of the 5 plant pathogenic bacteria within all the studied sites. To the researchers' knowledge, this study is the first to describe the identification of P. syringea, E. carotovora, C. michiganensis, and X. campestris isolated in plant crops in Côte d'Ivoire.