Xanthomonas translucens from Small Grains: Diversity and Phytopathological Relevance

Abstract

Sixty-eight presumptive Xanthomonas translucens strains isolated from 15 small grains or grass species were studied by pathogenicity tests on barley, bread wheat, oat, and bromegrass species, and also by AFLP, analysis of fatty acid methyl esters (FAME), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of protein extracts. The X. translucens strains were divided into three pathogenicity types based on differences observed on barley and bread wheat. Two unspeciated strains producing atypical symptoms formed a fourth pathogenicity type. Pathogenicity on oat and bromegrass species varied within these types. Clusterings observed by AFLP analysis and, to a lesser extent, by FAME analysis were consistent with these pathogenicity groupings. The current results, as well as those of previous restriction fragment length polymorphism analyses of the same strains, support the recent reclassification of X. translucens pv. translucens and X. translucens pv. hordei as true synonyms. X. translucens pv. cerealis, X. translucens pv. translucens, and X. translucens pv. undulosa cluster in different groups by AFLP and FAME analyses. Even though distinction by simple biochemical tests is not clear-cut, the data indicate that the pathovars cerealis, translucens, and undulosa correspond to true biological entities.

Evaluation of Xylella fastidiosa genetic diversity by fAFPL markers

“…The advantages of this technique in characterizing microbial populations is the extensive coverage of the genome under study and that the complexity of the AFLP fingerprinting can be advantageously managed by adding selective bases to the primers during PCR amplifications (Vos et al 1995). For the bacterial genome, the AFLP method has been evaluated in microbial taxonomy (Vaneechoutte, 1996), in diversity studies of human pathogenic bacteria (Purcell & Hopkins 1996), and in characterizing plant pathogenic bacteria at the pathovar level (Bragard et al 1997, Janssen et al, 1996.…”

Comparison of AFLP and rep-PCR genomic fingerprinting with DNA-DNA homology studies: Xanthomonas as a model system.

“…However, the power of rDNA-based protocols resides at a low phylogenetic or taxonomic level of resolution, which is valuable for classifying bacteria from the genus to even the kingdom level but which is insufficient to classify bacteria at the (sub)species level (Woese, 1987 ;Fox et al, 1992 ;Stackebrandt & Goebel, 1994 ;Hauben et al, 1997). Therefore, we postulated that rapid molecular genomic fingerprinting methods would be valuable, high-resolution alternative approaches to the classification of bacteria, especially on the species-, subspecies-or strain-specific level (Louws et al, 1994(Louws et al, , 1995Lin et al, 1996 ;Rademaker et al, , 1998Bragard et al, 1997).…”

Evaluation of a fluorescent amplified fragment length polymorphism (FAFLP) methodology for the genotypic discrimination of Aeromonas taxa

“…Originally developed for plant breeding purposes, this technique essentially interweaves the speci¢city of whole-genome restriction fragment analysis and the selectivity of high-stringency PCR ampli¢cation without prior knowledge of primer target sequences [12]. The AFLP method is currently used in various ¢elds of microbiology including taxonomy [13,14], epidemiology [15,16], population ecology [17,18], and molecular evolution [19]. In the genus Aeromonas, it has been demonstrated that AFLP clustering and HG delineation are usually highly concordant and that AFLP data can be used for the construction of a reliable taxonomic framework in nomenclatural rearrangements [20] and new species descriptions [21].…”