title: Population structure of Citrus tristeza virus from field Argentinean isolates.
abstract: We studied the genetic variability of three genomic regions (p23, p25 and p27 genes) from 11 field Citrus tristeza virus isolates from the two main citrus growing areas of Argentina, a country where the most efficient vector of the virus, Toxoptera citricida, is present for decades. The pathogenicity of the isolates was determinated by biological indexing, single-strand conformation polymorphism analysis showed that most isolates contained high intra-isolate variability. Divergent sequence variants were detected in some isolates, suggesting re-infections of the field plants. Phylogenetic analysis of the predominant sequence variants of each isolate revealed similar grouping of isolates for genes p25 and p27. The analysis of p23 showed two groups contained the severe isolates. Our results showed a high intra-isolate sequence variability suggesting that re-infections could contribute to the observed variability and that the host can play an important role in the selection of the sequence variants present in these isolates.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña N0 352, Bernal, Buenos Aires B1876BXD, Argentina.
authors.forename: Néstor G
authors.initials: NG
authors.lastname: Iglesias
authors.forename: Selma P
authors.initials: SP
authors.lastname: Gago-Zachert
authors.forename: Germán
authors.initials: G
authors.lastname: Robledo
authors.forename: Norma
authors.initials: N
authors.lastname: Costa
authors.forename: María Inés
authors.initials: MI
authors.lastname: Plata
authors.forename: Osmar
authors.initials: O
authors.lastname: Vera
authors.forename: Oscar
authors.initials: O
authors.lastname: Grau
authors.forename: Liliana C
authors.initials: LC
authors.lastname: Semorile
mesh_terms: D000595:Amino Acid Sequence; D001118:Argentina; D001483:Base Sequence; D002957:Citrus / Q000821:virology*; D003001:Cloning, Molecular; D017790:Closterovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014644:Genetic Variation; D006239:Haplotypes; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology; D018807:Polymorphism, Single-Stranded Conformational; D016415:Sequence Alignment