Aetiology of the rosette and decline disease of peach and interactions between Prunus necrotic ringspot, prune dwarf, and dark green sunken mottle viruses

Abstract

Rosetted peach trees were indexed for dark green sunken mottle virus (DGSMV). Although no cv. Pullars Cling trees and only 30% of trees of cv. Golden Queen were infected with DGSMV, all cv. Levis Cling trees tested were infected with it. Both Prunus necrotic ringspot (PRSV) and prune dwarf (PDV) viruses reduced shoot elongation in Elberta peach seedlings, but the viruses together reduced shoot elongation more than was expected from the effects of the viruses alone. A similar interaction occurred between mixed cultures of PRSV and PDV, that had passed through peach seed together, and an isolate of DGSMV from peach. PDV alone caused severe recurrent rosette and decline symptoms in cvv. Golden Queen, Levis Cling, and Pullars Cling, but had no significant effect on cv. Elberta.