Myrtaceous rust in Brazil

Myrtaceous rust (MR) belongs to the rust complex that was reported at the end of the 19th century in several species of the Myrtaceae family. The pathogen was first described by Winter (1884) on Psidium guajava in Brazil. This fungus had already been reported on ten other genera of the Myrtaceae family in Brazil. It was formally described in Eucalyptus citriodora by Hook and Joffily (1944). The first serious outbreak of MR occurred in 1973 in Espírito Santo State, where large-scale damage was observed in nurseries and young plantations of E. grandis established based on South African seed sources. The other big outbreak was in 1993-96 in São Paulo State, where 50% of the eucalypt plantations were severely attacked. The pathogen has been dispersed and adapted to different Mirtaceae species around the world and it is now considered a serious threat to the biodiversity of these countries. The life cycle of Puccinia psidii remained unknown until 1984. When it was this fungus was discovered, it was autoecious and had a macrocyclic life cycle. Spermacia (state 0) is not found in nature and aecia also have uredinia functions like hemi-forma rusts. Teliospores are amphigenous, bicellular, spindle-shaped, dark brown color with deciduous pedicel, in the same pustules as urediniospores, with 35-43-51 µm length and 14-18-22 µm large. The molecular study reclassified it into the genus Austropuccinia psidii (2017). In this work several trials we intend to review etiology, epidemiology and management.