The complete nucleotide sequence of a Pakistani isolate of Watermelon mosaic virus provides further insights into the taxonomic status in the Bean common mosaic virus subgroup.
Watermelon mosaic virus (WMV) is a potyvirus with a worldwide distribution, but is mostly found in temperate and Mediterranean regions. The complete nucleotide (nt) sequence of a Pakistani isolate of WMV (WMV-Pk) was determined and compared with French isolate (WMV-Fr) and other closely related potyviruses. WMV-Pk showed overall identities of 94.4% (nt) and 96% (amino acid; aa) with the WMV-Fr. However, variability was observed in the 5' UTR and P1 region. Although sequence identities over most of the genome were well above 90% at both the nt and aa levels, reaching 99.6% (aa) in the CP and 100% (aa) in the 6K1 and 6K2, thereby suggesting that WMV-Pk and WMV-Fr are identical strains, but the sequence identities in the P1 region were only 80.6% (aa) and 82.8% (nt), while that in the 5' UTR was 82%. These differences may be due to different mutation phenomena of a common ancestor virus or mutations caused by different selection pressures in two different agro-ecological zones. The sequence of WMV-Pk is very close to that of Soybean mosaic virus (SMV) over most of the genome, except for the N-terminal region, which is subject to recombination between SMV and Peanut stripe virus (PSV)/Bean common mosaic virus (BCMV), as revealed by Simplot and phylogenetic analyses of N- and C-terminal P1, HC-Pro, and 5' UTR regions of the genome.
Ali
Asad
A
Faculty of Agriculture, Utsunomiya University, 321-8505, Utsunomiyas, Japan.
Natsuaki
Tomohide
T
Okuda
Seiichi
S
D001483:Base Sequence; D029773:Citrullus / Q000821:virology*; D007887:Fabaceae / Q000821:virology*; D005602:France; D016679:Genome, Viral; D008969:Molecular Sequence Data; D010154:Pakistan; D010802:Phylogeny; D017800:Potyvirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA