Eucalyptus grandis , in its native Australian range, varies resistance to Austropuccinia psidii (syn. Puccinia ). The biotrophic rust fungus, A. is the causal agent of myrtle and poses a serious threat biodiversity. pathogen produces yellow pustules urediniospores on young leaves shoots, resulting shoot tip dieback, stunted growth, death. Dissecting underlying mechanisms against this will contr...