Soybean Viruses

A view of virus particles taken with an electron microscope.

Most soybean viruses are spread by insect vectors, such as the soybean aphid. Photo credit: University of Wisconsin.

Viruses are submicroscopic particles of DNA or RNA that can cause disease in plants. They can grow and reproduce only inside a living plant cell. Unlike other soybean pathogens, soybean viruses are not spread by wind, water, soil or plant debris. Most plant viruses are spread from plant to plant by specific insect vectors.

Researchers in the North Central region are observing more virus-like symptoms in soybean. Bean pod mottle virus (BPMV), soybean mosaic virus (SMV), tobacco ringspot virus and alfalfa mosaic virus have been identified in symptomatic and nonsymptomatic plants, often in dual or multiple infections. The agronomic effects of dual or multiple infections are much greater than of either virus alone.

Insect-virus complex

Because viruses spread from plant to plant by insects, each type of virus is part of a unique plant-insect-virus relationship. Recognizing the virus as part of a complex is the key to effective management.

For example, the bean pod mosaic virus overwinters in bean leaf beetles, perennial weedy species, and infected seed. If bean leaf beetles are infected with the virus, or acquire BPMV from infected noncrop plants, they will transmit the virus when they move to soybean fields and feed on emerging seedlings.

Virus-infected seeds are considered to be the most important means by which the soybean mosaic virus is introduced into a soybean field. Once the virus is in the field, the soybean aphid and other aphids spread SMV from plant to plant.

Information on these pages is from the cooperative effort of researchers throughout the North Central states. Information from this site can be copied and distributed for educational use. Please credit the source with our name and URL: NCSRP Plant Health Initiative at www.planthealth.info. Please do not use copyrighted photos without permission.