The occurrence of viral pathogens of the genus Potyvirus on maize (Zea mays L.) in the Czech Republic

In 1997-1999, the occurrence of viruses belonging to the genus Potyvirus - Sugarcane mosaic virus (SCMV) and Maize dwarf mosaic virus (MDMV) - was stu died in the Czech Republic. In these years, a total number of 304 samples o f maize plants with different symptoms of virus infection were collected at nine localities and 227 virus isolates were derived. According to the resp onse to the differentiation sorghum cultivar 'Atlas' and ELISA tests, 224 i solates (98,7 %) were identified as SCMV and three isolates (1,3 %) were id entified as MDIMV. Some of the SCMV and MDMV isolates derived were characte rized on the differentiation species and cultivars of Sorghum spp. Two MDMV isolates and seven SCMV isolates from the Czech Republic were tested for p athogenicity to 10 maize lines of different origin. All the lines rested we re infected with the isolates of SCMV and MDMV bur they differed in the tim e taken to produce symptoms.