First report of rust on Alnus in New Zealand is Melampsoridium betulinum, not M. hiratsukanum

Abstract

A rust disease was first observed in New Zealand on leaves of alder (Alnus viridis) in North Canterbury in 1980, then on Alnus spp. in Nelson in the 1990s and Auckland in 2012. The causal agent was determined by molecular techniques to be Melampsoridium betulinum and not M. hiratsukanum, a species that is currently spreading throughout the northern hemisphere. A rust on Betula nigra and B. populifolia, and earlier specimens from B. pendula, were also confirmed as M. betulinum.