‘From Snowy River, up by Kosciusko’s side’: a virus, a beetle, and a PhD

A chance discovery early in 1980 led to a body of work on a virus and a rare species that lasted until the end of the decade. The discovery and characterisation of turnip yellow mosaic virus (TYMV-Cd) infecting one-fifth of the fragmented population of Cardamine robusta at Mt Kosciuszko, New South Wales, revealed a puzzle that remains unresolved. There is no clear explanation as to why there is a population of TYMV here in the Southern Hemisphere whose sequence has only diverged from Northern Hemisphere TYMV by a few percent. Adding to the mystery is the fact that TYMV-Cd only infects one of the rarest and geographically most restricted species in Australia, while it is surrounded by potential hosts known to be infected in the Northern Hemisphere. This article reviews research published on TYMV at Mt Kosciuszko during the 1980s and 1990s. While human agency cannot be ruled out, indications are that TYMV established without human intervention. The work is set in a historical context and highlights some of the changes around how plant virology is done.