DNA Markers for Detection and Genotyping of .

is a bacterial species encompassing both pathogenic and non-pathogenic strains and is frequently found colonizing the same host plants as . This presents the need to develop a detection and genotyping assay able to track these bacteria in microbial consortia with other xanthomonads. Eight -specific DNA markers (XEA1-XEA8) were selected by comparative genomics and validated in silico regarding their specificity and consistency using BLASTn, synteny analysis, CG content, codon usage (CAI/eCAI values) and genomic proximity to plasticity determinants.

Comparative Genomics of and pv. Strains Isolated from a Single Walnut Host Tree.

The recent report of distinct lineages of pv. and within the same walnut tree revealed that this consortium of walnut-associated includes both pathogenic and nonpathogenic strains. As the implications of this co-colonization are still poorly understood, in order to unveil niche-specific adaptations, the genomes of three strains (CPBF 367, CPBF 424, and CPBF 426) and of an pv.

Complete Genome Sequences of Walnut-Associated Strains CPBF 367 and CPBF 426 Obtained by Illumina/Nanopore Hybrid Assembly.

We present the complete genome sequences of two strains isolated from buds of a walnut tree. The whole-genome sequences of strains CPBF 367 and CPBF 426 consist of two circular chromosomes of 4,923,218 bp and 4,883,254 bp and two putative plasmids of 45,241 bp and 17,394 bp, respectively. These data may contribute to the understanding of species-specific adaptations to walnut.

sp. nov., a new xanthomonad species including pathogenic and non-pathogenic strains of walnut.

We describe a novel species isolated from walnut () which comprises non-pathogenic and pathogenic strains on walnut. The isolates, obtained from a single ornamental walnut tree showing disease symptoms, grew on yeast extract-dextrose-carbonate agar as mucoid yellow colonies characteristic of species. Pathogenicity assays showed that while strain CPBF 424 causes disease in walnut, strain CPBF 367 was non-pathogenic on walnut leaves.

Assessment of pv. Bacterial Load in Infected Walnut Fruits by Quantitative PCR.

pv. is the etiologic agent of important walnut ( L.) diseases, causing severe fruit drop and high economic losses in walnut production regions.