Genetic Diversity and Pathogenicity of Species Associated with Symptomatic Citrus Plants in Europe.

This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA), translation elongation factor 1-alpha () and β-tubulin () genes, nine species were identified as belonging to the genera , , and . Isolates of and were the most frequently detected, while had the widest distribution, occurring in four of the five countries sampled. Representative isolates of the nine Botryosphaeriaceae species used in the pathogenicity tests caused similar symptoms to those observed in nature. Isolates assayed were all re-isolated, thereby fulfilling Koch's postulates. Isolates of and are recorded for the first time on citrus and all species found in our study, except , are reported for the first time on citrus in Europe.