Myrtus communis in Europe threatened by the pandemic and South African strains of the myrtle rust pathogen Austropuccinia psidii (Sphaerophragmiaceae, Pucciniales)

Austropuccinia psidii , the causal agent of myrtle rust, has emerged as a significant threat to Myrtaceae in planted and natural woody ecosystems. The first detection A. puccinia South Africa was from severely infected ornamental Myrtus communis. This raised concern that M. communis sole species native Europe an important component vegetation Mediterranean regions, could be threatened by rust. In light potential this unique species, seed collected 12 Italian provenances including mainland island (Sardinia Sicily) populations. We assessed susceptibility these both pandemic African strains . Colombia, where strain is native, seedlings rapidly became inoculum. Africa, preliminary screening artificial inoculation with single-uredinium isolate produced high levels disease. Finally, plants each were monitored Florence, Italy. To date, showed no signs disease, but will continue monitored. study highlights pose Europe.