Deciphering Genetic Diversity and Geographical Structuring of Xanthomonas citri pv. citri Strains: Implications for Sustainable Control Strategies in Burkina Faso Citrus Production

A comprehensive understanding of the genetic diversity among strains of Xanthomonas citri pv. citri (Xcc), the causative agent of citrus bacterial canker, is crucial for unraveling the pathological nature, structure, and evolution of populations, thereby facilitating the adoption of sustainable control measures. In a collection of 48 strains isolated in 2012, 2020, and 2021 from citrus production areas in Burkina Faso, polymerase chain reaction (PCR) tests utilizing specific primers were conducted to investigate the distribution of type 3 effectors (T3E) and the structuring of strains based on their geographical origins. The analysis of the distribution of type 3 non-transcription activate like effectors (TALE) reveals a more extensive repertoire in strains isolated in 2020 and 2021 compared to those isolated in 2012. Nevertheless, all strains share a common repertoire of three genes, namely XopE2, XopN, and AvrBs2. Additionally, all screened effectors were observed in the Bobo-Dioulasso locality. Concerning the characterization of TALEs, two profiles consisting of two to three TALEs were identified. Profile 1, with two TALEs, was present in 37 Xcc strains, while Profile 2, with three TALEs, was identified in 11 strains. Among the three TALEs (A, B, and C) identified, TALEs B and C were common to all strains. The correlation matrix revealed a positive correlation between the T3E content of strains and the years of their isolation. Multiple component analysis indicated a weak structuring of the tested strains.