Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus (Potyviridae)

Abstract

Bean common mosaic virus and Bean common mosaic necrosis virus are species within the genus Potyvirus, family Potyviridae, that cause some of the most economically important diseases of legume crops worldwide. Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) both occur essentially wherever bean and cowpea (including Phaseolus, Vicia, Vigna), lupin (Lupinus), pea (Pisum), peanut (Arachis), and soybean (Glycine) are grown; they are transmitted by aphids in a non-persistent manner, and also seed-transmitted. Isolates of BCMV and BCMNV can be differentiated into eight pathotypes based on their reactions on differential bean cultivars. BCMV and BCMNV are typical potyviruses with non-enveloped flexuous virions, 12–15 nm wide, and 847–886 nm (BCMV) or 810–818 nm (BCMNV) long. Virions are composed of one single-stranded RNA of c. 9600 nt for BCMNV and c. 10,000 nt for BCMV, encapsulated in 1700–2000 subunits of a single coat protein (CP) species of c. 30 kDa for BCMNV and c. 33 kDa for BCMV. BCMV- and BCMNV-specific polyclonal antisera, monoclonal antibodies, and reverse transcription-polymerase chain reaction (RT-PCR) primers have been utilized to detect, differentiate, and characterize these viruses in infected plants. BCMV and BCMNV can be eradicated by eliminating susceptible genotypes and planting only resistant varieties; “virus-tested” certified seed can be used as an effective means to control these two viruses.