Cloning and Sequence Analysis of Partial ci Gene and cp Gene of Panax Virus Y

Partial ci and cp genes of different Panax virus Y (PnVY) isolates from Wenshan in Yunnan Province were amplified, cloned and sequenced. The partial ci gene obtained in this study consists of 657 nt, encoding 219 amino acid, while the partial cp gene consists of 834 nt, encoding 278 amino acid. The results showed that the nucleotide (nt) and amino acid (aa) sequences of ci gene of 11 PnVY Yunnan isolates shared 80.8%~99.8% and 91.3%~100% identity with each other, and shared 80.8%~98.8% and 92.7%~99.5% identity with the recorded PnVY isolates. The nt and aa sequences of cp gene of 18 PnVY Yunnan isolates shared 91.8%~ 99.9% and 93.9%~100% identity with each other, and shared 92.0%~100% and 95.7%~100% identity with the PnVY isolates deposited in GenBank. The available PnVY isolates could be divided into two groups according to the phylogenetic tree based on the nucleotide sequences of partial ci gene, and the isolates in groupⅡshowed more diversity compared with those in groupⅠ. While the PnVY isolates could be divided into three groups base on the cp nt sequence, and the isolates of group Ⅲ showed the highest diversity. The results indicated that high genetic diversity exists among different PnVY populations, but whether the molecular variations on PnVY genome related to the different symptoms of the disease is still unknown.