Calico mosaic of soybean is caused by the alfalfa mosaic virus (AMV) (Almeida et al., 1981). Soybean plants infected with AMV were first reported in the USA by Allington et al. (1969), in soybean fields close to alfalfa fields. The presence of AMV in Brazil was reported by Costa et al. (1980), who demonstrated in their study that soybean was a good differential host for the virus.
Almeida, A. M. R.; Kiihl, Romeu A. S.; and Almeida, Leones A.
"Research Notes : Calico mosaic of soybeans: Sources of resistance and inheritance of reaction,"
Soybean Genetics Newsletter: Vol. 9
, Article 8.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol9/iss1/8