Virus Diseases

Abstract

Numerous viruses have been reported as infecting red clover. Thirty-four different viruses have been listed and doubtless the list could be extended with further inoculations (Edwardson and Christie, 1986). However, only seven viruses are of widespread major importance: Bean yellow mosaic potyvirus (BYMV), peanut stunt cucumovirus (PSV), red clover vein mosaic carlovirus (RCVMV), pea streak carlovirus (PStrV), alfalfa mosaic ilarvirus (AMV), white clover mosaic potyvirus (WCMV), and clover yellow vein potyvirus (CYVV) (Barnett and Diachun, 1985). They are mostly nonpersistent aphid transmitted viruses (Table 7.1). BYMV was the most prevalent virus infecting red clover in southeastern United States (McLaughlin and Boykin, 1988) and probably is the most important worldwide (Smrtz et al., 1983). Strain 204–1 of BYMV probably is the most prevalent strain, at least in the United States. Recently a new strain RC was found in Kentucky but it is not nearly as important as 204–1 (Doupnik et al., 1981). PSV is probably the second most prevalent virus of red clover at least in Kentucky (Naidu et al., 1995). The physical aspects of clover viruses have been described in detail by Barnett and Diachun (1986) and will not be dealt with here.