Screening for resistance to Raspberry bushy dwarf virus via pollen transmission.

摘要

Raspberry bushy dwarf virus (RBDV) is a serious problem in all raspberry growing areas. Although there are sources of resistance to the common strain, it has been difficult to screen for resistance to pollen transmission. Susceptible raspberry plants may be exposed in the field for ten or more years and not become infected. A reliable method to screen selections and cultivars for resistance is needed. In 2001, four plants for each of 24 raspberry cultivars and selections were planted into 19 L pots. Eight of the clones were thought to be resistant to RBDV, nine were thought to be susceptible and the RBDV reaction of seven was unknown. Forty-eight RBDV positive plants were also planted into 5-gallon pots. These plants were placed outside in 2002 and arranged so every third plant was a known RBDV positive plant. All plants of the selections and cultivars tested negative for RBDV in the spring 2003. After one fruiting season, the spring of 2004, 13 plants tested positive representing seven clones. In the spring of 2005, after two fruiting seasons, 31 plants tested positive representing nine clones. Five clones had all four plants test RBDV positive in 2005. Two susceptible clones ('Coho' and 'Cascade Delight') still had all four plants test virus negative in 2005. Annual testing of these plants for RBDV will be continued.