Halting Black Raspberry Decline

A new virus associated with black raspberry decline has been identified by Agricultural Research Service (ARS) scientists in Oregon, the nation's primary producer of black raspberries.

According to research leader and plant pathologist Robert Martin, with the ARS Horticultural Crops Research Unit at Corvallis, Ore., decline is generally a symptom of a virus complex. However, plants infected with the newly identified black raspberry decline-associated virus (BRDaV) will show symptoms even if the plant has no other diseases.

Black raspberries are a delicious source of ellagic acid, vitamin C, antioxidants, anthocyanins and other important nutrients. In affected plants, BRDaV causes yellow, puckered and spotted leaves, yield reduction and cane dieback—the gradual death of shoots, branches and roots, from the tip inward.

Decline shortens a plant's life expectancy from several decades to three to four years, with severe economic repercussions. Identifying BRDaV as a cause of decline is an important step towards controlling the disease. Martin and his colleagues have obtained genetic information on 17 berry viruses, including BRDaV.

The team learned that BRDaV hitches a ride on the raspberry aphid Amphorophora agathonica. In fact, spread rates appear to be directly related to aphid numbers. This suggests that controlling the aphid population could slow the disease's proliferation.

The Corvallis researchers also learned that BRDaV can infect other commercial and native Rubus berry plants—such as blackberry and raspberry—without triggering symptoms, making isolation from other commercial berry plantings an important part of any disease-control strategy.

Read more about the research in the June 2006 issue of Agricultural Research magazine.

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