title: Genetic variability among flavescence dorée phytoplasmas from different origins in Italy and France.
abstract: Flavescence dorée is a devastating disease of grapevine widespread in several countries in EU such as France, Italy and Spain. Genetic variability among 17 Italian and 3 French FD strains was investigated by RFLP analyses based on a fragment of the ribosomal protein operon and on the non-ribosomal DNA fragment FD9. RFLP analysis of the PCR amplified ribosomal protein fragment, coding for the 3' end of rpl22 and the entire rps3 genes, differentiated 4 rp-subgroups among the FD strains and 4 subgroups among the reference strains belonging to elm yellows group (16SrV). Sequencing and phylogenetic analysis of the same ribosomal protein DNA fragment validated the delineation of 4 distinct FD strain types derived by RFLP analyses. The results supported the differentiation based on analysis of the non-ribosomal DNA fragment FD9. The phylogenetic analysis further revealed relationships and a probable evolutionary trend among the FD strains and the other representatives of elm yellows group. All the FD strains together with the reference strains ALY, RuS and JWB formed a cluster very well distinct from the EY/ULW cluster. Moreover, ALY was shown to be more closely related to three FD strain types: the Lombardia/Piemonte, the French FD70, and the French FD88/Italian FD-D strain clusters.
authors.affiliation: DiSTA, Patologia Vegetale, University of Bologna, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Martini
authors.forename: S
authors.initials: S
authors.lastname: Botti
authors.forename: C
authors.initials: C
authors.lastname: Marcone
authors.forename: C
authors.initials: C
authors.lastname: Marzachì
authors.forename: P
authors.initials: P
authors.lastname: Casati
authors.forename: P A
authors.initials: PA
authors.lastname: Bianco
authors.forename: R
authors.initials: R
authors.lastname: Benedetti
authors.forename: A
authors.initials: A
authors.lastname: Bertaccini
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000235:genetics; D005602:France; D014644:Genetic Variation; D007558:Italy; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000145:classification / Q000235:genetics*; D009876:Operon; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D016415:Sequence Alignment; D027843:Vitis / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal