Molecular characterization, pathogenicity and copper sensitivity of Xanthomonas citri pv mangiferaeindicae, the causal agent of mango bacterial black spot disease in Ghana

Abstract

Recent outbreak of the mango bacterial black spot disease has resulted in massive damages to the Ghanaian mango industry. Research was carried out to confirm the etiology of the disease. Diseased mango fruits and leaves were collected from Greater Accra (Asutuare and Dodowa), Eastern (Akuse, Somanya) and Volta (Juapong) regions, and the sus pected causal bacterium was isolated. The pathogen was identified as Xanthomonas citri pv mangiferaeindicae based on cultural and morphological characteristics and sequence analysis of the cpn60 gene. The pathogenicity of the bacterial pathogen on mango and cashew was determined and its sensitivity to some selected copper based fungicides available in Ghana was evaluated by the agar diffusion bio-assay. All strains of the pathogen were able to cause disease symptoms on artificially inoculated mango and cashew leaves. The pathogen was highly sensitive to Copper oxychloride, Copper hydroxide and Coprous oxide at very low concentrations.