Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Proceedings
Publication Acceptance Date: 12/5/2003
Publication Date: 5/1/2004
Citation: Larsen, R.C., Eastwell, K.C. 2004. A pcr based assay for differentiation of clover yellow vein virus and bean yellow mosaic virus in common bean. Bean Improvement Cooperative Annual Report. 47:123-124. Interpretive Summary: Clover yellow vein virus (CYVV) and Bean yellow mosaic virus (BYMV) can seriously affect snap and dry bean, clover, and other legume crops. The two viruses have typically been difficult to differentiate in the field and in the laboratory because they are very closely related. Standard tests using ELISA and scarce antibodies made against the viruses are generally not specific enough to differentiate between them. Using amino acid sequence comparisons of the coat proteins of each virus, we were able to locate a small area of sequence unique to CYVV and BYMV, respectively, which allowed us to develop DNA primers for use in polymerase chain reaction (RT-PCR) that could unambiguously differentiate between them in single and mixed infections in bean. This technology has enabled us to identify CYVV as a major pathogen associated with the 'chocolate pod' disease in snap bean in the Great Lakes region of the US, a disease that has caused severe losses to growers during the 2000-2003 growing seasons. Previously, the disease was believed to have been caused exclusively by Cucumber mosaic and Alfalfa mosaic viruses. A significant advantage of this work is that the diagnostic assays can be easily conducted in a single day.
Technical Abstract: Clover yellow vein virus (CYVV) and Bean yellow mosaic virus (BYMV) (Family: Potyviridae) are important viruses of snap and dry bean. Serological differentiation of the two viruses has typically been difficult because of the close relationship between their respective coat proteins. An RT-PCR assay has been developed that can unambiguously distinguish between CYVV and BYMV in single and mixed infections of bean.