Molecular Detection and Characterization of Chinese Yam Mild Mosaic Virus Isolates

摘要

An improved RT-PCR was developed and validated for the detection of Yam mild mosaic virus (YMMV). Sequences of the coat protein core region of 19 Chinese isolates were obtained, and analysis indicated the presence of different genetic variants. Phylogenetic analyses showed that the Chinese isolates were divided into two distinct clusters. Complete genomic sequences of two distinct Chinese variants were determined to be 9527 and 9529 nucleotides long, excluding the 3 poly (A) tail. Their genomic structure and organization were virtually identical to that of a Brazilian isolate. The two variants shared identity of 87.3% to one another and 83.9-84.6% to the Brazilian variant at the genomic sequence level. Phylogenetic analyses supported that they represented two distinct YMMV lineages.