title: Phylogenetic relationships of Xylella fastidiosa strains based on 16S-23S rDNA sequences.
abstract: In spite of the lack of resolution of Xylella fastidiosa phylogenetic relationships, parsimony analysis of the 16S-23S rDNA sequence from a wide range of hosts has been evaluated in this research. In order to establish an easier method for sequencing the spacer region completely, a new primer pair was designed. The sequences obtained revealed a higher level of variation than that found in 16S gene sequences, with similarity values ranging from 0.80 to 1.00. The cladogram constructed allowed the clustering of two major clades. From these results it has been possible to recognize the monophyletic grouping of some strains belonging to the same host, possibly representing only one infection process. However, for other hosts there is paraphyletic and polyphyletic grouping. This methodology followed from promising results regarding strain-host clustering. With the parsimony approach, hypothetical genealogical relationship among Xylella strains may be inferred.
authors.affiliation: Cell and Molecular Biology Laboratory, Agriculture Nuclear Energy Center (CENA/USP), Piracicaba, São Paulo, Brazil. jumarti@cena.usp.br
authors.forename: Juliana Camargo
authors.initials: JC
authors.lastname: Martinati
authors.forename: Flávia Tereza Hansen
authors.initials: FT
authors.lastname: Pacheco
authors.forename: Vitor Fernandes Oliveira
authors.initials: VF
authors.lastname: de Miranda
authors.forename: Siu Mui
authors.initials: SM
authors.lastname: Tsai
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis* / Q000235:genetics; D020563:Gammaproteobacteria / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S