Read: an article on this research in Agricultural Research.

Raspberry Virus May Thwart Itself

Consumers, growers and the environment would benefit if raspberry plants could naturally resist bushy dwarf virus. Scientists with ARS in Corvallis, Ore., and Agritope, Inc., in Portland, are genetically modifying the most popular raspberry variety grown in the Pacific Northwest to give the plants this resistance.

Raspberries with the virus develop small, crumbly fruit that is unsuitable for use as whole berries. The infection spreads rapidly through a field, and growers must frequently remove the plants, fumigate the soil and start over within five years. That means fewer domestic raspberries and higher costs for consumers.

The scientists are using the genetic material from the virus itself to induce resistance in the raspberry plants. They're trying three strategies to find the best approach. The first interferes with the virus' ability to replicate by inserting a specific protein from the virus into the raspberry.

A second approach is to alter the viral gene that makes it possible for the virus to move from cell to cell inside the plant, and then insert that altered gene into the raspberry plants. With this altered gene present in the plant, the virus would able to infect one cell of the plant, but couldn't spread to any other cells.

The third method they're trying is to have the plant make a small piece of viral RNA, or genetic material, that does not make any protein. Through a natural plant mechanism, this viral RNA then gets targeted by the plant for degradation.

They hope to refine the best strategy and provide breeding lines to growers within three years. They should also be able to use the results to incorporate virus resistance into other cultivars of raspberry, blackberry or black raspberry.

An article on this research appears in the October issue of Agricultural Research, the agency's monthly magazine.

ARS is the chief research agency of the U.S. Department of Agriculture.

Scientific contact: Robert R. Martin, ARS Horticultural Crops Research Laboratory, Corvallis, Ore., phone (541) 750-8794, fax (541) 750-8764, martinrr@bcc.orst.edu.