Cloning and sequence analysis of HC-Pro genes of Turnip mosaic virus Eurasian isolates

Sixteen virus isolates of Turnip mosaic virus(TuMV)were collected from Austria,!Denmark,Germany,Hungary,Nepal and United Kingdom,respectively.The HC-Pro(Helper component proteinase)genes of these isolates were amplified by Immunocapture RT-PCR(IC-RT-PCR),cloned and determined.HC-Pro genes of the 16 isolates were all composed of 1 374 nucleotides encoding a polypeptide of 458 amino acids sharing 79.5% to 99.8% and 94.1% to 99.8% identities at the nucleotide and the amino acid level,respectively.The phylogenetic trees constructed based on nucleotide sequences of HC-Pro genes of the 16 TuMV isolates together with 14 previously reported TuMV isolates indicate that 15(all from Europe)of the 16 Eurasian isolates belong to world-B group,but isolate N23(only one from Asian)belongs to Asian-BR group.Among the 15 Eurasian isolates in world-B group,isolate H1 belongs to world-wide subgroup,while the other 14 Eurasian isolates belong to New World subgroup.