Molecular characterization of cucumber mosaic virus isolates infecting Sugar beet (Beta vulgaris) and other crops in three governorates of Egypt

S UGAR beet ( Beta vulgaris ) is one of the principal sources for sugar production in Egypt. Viral infections could seriously impact its cultivation and development. This study was performed to investigate genetic diversity of cucumber mosaic virus (CMV) isolates infecting sugar beet and other crops growing nearby such as pepper, cowpea, common bean and sweet potato. A total of nine CMV isolates were characterized at the molecular level, according to capsid protein gene sequence analysis (6 isolates from sugar beet and other three isolates from other crops). Four isolates showed highest identity to CMV subgroup IA. The other five isolates showed the highest levels of nucleotide identity to CMV group II. While group IA and 1B were known to occur in Egypt, to our knowledge, this is the first report of CMV group II from sugar beet and sweet potato in Egypt indicating recent introduction of new CMV genotypes.