'IAPAR 57' released in 1992, was the first variety with high tolerance to golden mosaic virus disease released in Brazil. It yields under high virus disease pressure two and half times more than susceptible varieties. It originated from the cross of lines 'MD 632' x 'BAC 32'. The virus disease tolerance of MD 632 derived from its mutant parent 'TMD-1' which was used in various cross-breeding programmes [18,19]. Tolerance of TMD-1 to golden mosaic virus disease was induced by EMS seed treatment of 'Carioca' [17].