Source of Raspberry bushy dwarf virus in Rubus in New Zealand, and the infectibility of some newer cultivars to this virus

Abstract

An investigation of how the common or Scottish strain of the pollen transmitted Raspberry bushy dwarf virus (RBDV) became established in New Zealand indicates that ‘Canby ‘, a red raspberry cultivar (Rubus idaeus L.), introduced in 1965 and released for field evaluation in 1966, would be the most likely source. At the time of its introduction, all plants of ‘Canby’ grown in other countries are thought to have been infected with RBDV, and this same infection is likely to have been present in plants imported into New Zealand. ‘Canby’ was subsequently found to be infected with RBDV in New Zealand field plantings and commonly showed leaf yellows wherever it was grown. Testing of a number of Rubus cultivars either recently introduced from other countries, or obtained from the New Zealand Rubus breeding programme, showed four ('Glen Rosa, ‘Lewis’, ‘Malahat’, and ‘Summit') to be RBDV infected. Graft inoculations with the New Zealand source of RBDV to other cultivars showed three of the imports ('Glen Ample’, ‘Qualicum’, and Tulameen') and one of the locally bred selections ('HR 104') to be infectible with the common strain of RBDV.

Keywords:

• Rubus
• red raspberries
• Raspberry bushy dwarf virus
• infection source
• infectible cultivars