Molecular Analysis of Six Beet yellows virus (BYV) Isolates from West Azarbayjan, Kermanshah and Hamedan Provinces of Iran Based on ORF CP

Beet yellows virus (BYV) belongs to the genus Closterovirus, Closteroviridae family, is one the most important viruses of sugar beet worldwide. In order to identify and characterize some molecular aspects of the BYV, a total of 75 symptomatic leaf samples of sugar beet were collected from sugar beet field of West Azarbayjan, Hamedan and Kermanshah provinces, Iran. Leaves showing general yellowing, vein clearing and thickness were collected. The primary detection of BYV performed by DAS-ELISA, using specific antibodies raised against coat protein of the virus, resulted in positive reaction of six out of 75 samples. The coat protein ORF of BYV isolates was amplified by RT-PCR, using BYV-F/BYV-R primer pair. Amplified fragments in expected size of 615 bp were directly sequenced. All sequence data were multiple aligned with other BYV isolates (from NCBI) using DNAMAN 7 software. An Ukrainian isolate (X73476) showed the highest nucleotide (99.19%) and amino acid (97.55%) identity with our isolates in this study. Phylogenetic analyses were conducted by MEGA 5.2. The results of phylogenetic analysis showed that BYV Iranian isolates and BYV Ukrainian isolate are clustered together.