title: Genomic variability and molecular evolution of Asian isolates of sugarcane streak mosaic virus.
abstract: Sugarcane streak mosaic virus (SCSMV), an economically important causal agent of mosaic disease of sugarcane, is a member of the newly created genus Poacevirus in the family Potyviridae. In this study, we report the molecular characterization of three new SCSMV isolates from China (YN-YZ211 and HN-YZ49) and Myanmar (MYA-Formosa) and their genetic variation and phylogenetic relationship to SCSMV isolates from Asia and the type members of the family Potyviridae. The complete genome of each of the three isolates was determined to be 9781 nucleotides (nt) in size, excluding the 3' poly(A) tail. Phylogenetic analysis of the complete polyprotein amino acid (aa) sequences (3130 aa) revealed that all SCSMV isolates clustered into a phylogroup specific to the genus Poacevirus and formed two distinct clades designated as group I and group II. Isolates YN-YZ211, HN-YZ49 and MYA-Formosa clustered into group I, sharing 96.8-99.5 % and 98.9-99.6 % nt (at the complete genomic level) and aa (at the polyprotein level) identity, respectively, among themselves and 81.2-98.8 % and 94.0-99.6 % nt (at the complete genomic level) and aa (at the polyprotein level) identity, respectively, with the corresponding sequences of seven Asian SCSMV isolates. Population genetic analysis revealed greater between-group (0.190 ± 0.004) than within-group (group I = 0.025 ± 0.001 and group II = 0.071 ± 0.003) evolutionary divergence values, further supporting the results of the phylogenetic analysis. Further analysis indicated that natural selection might have contributed to the evolution of isolates belonging to the two identified SCSMV clades, with infrequent genetic exchanges occurring between them over time. These findings provide a comprehensive analysis of the population genetic structure and driving forces for the evolution of SCSMV with implications for global exchange of sugarcane germplasm.
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.|College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Liang
authors.affiliation: Department of Plant Pathology and Microbiology, Texas A&M AgriLife Research and Extension Center, Weslaco, TX, 78596, USA.
authors.forename: Olufemi J
authors.initials: OJ
authors.lastname: Alabi
authors.affiliation: Department of Plant Pathology and Microbiology, Texas A&M AgriLife Research and Extension Center, Weslaco, TX, 78596, USA.
authors.forename: Mona B
authors.initials: MB
authors.lastname: Damaj
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Fu
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
authors.forename: Sheng-Ren
authors.initials: SR
authors.lastname: Sun
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
authors.forename: Hua-Ying
authors.initials: HY
authors.lastname: Fu
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
authors.forename: Ru-Kai
authors.initials: RK
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology and Microbiology, Texas A&M AgriLife Research and Extension Center, Weslaco, TX, 78596, USA.
authors.forename: T Erik
authors.initials: TE
authors.lastname: Mirkov
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China. gaosanji@yahoo.com.
authors.forename: San-Ji
authors.initials: SJ
authors.lastname: Gao
mesh_terms: D001208:Asia; D004279:DNA, Viral / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D016679:Genome, Viral; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology; D019176:Potyviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D011995:Recombination, Genetic; D031786:Saccharum / Q000821:virology*
chemical_list: D004279:DNA, Viral