Location: Crop Improvement and Protection Research
2013 Annual Report
Bacterial leaf spot of lettuce caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) results in significant losses throughout California the US. Genetic diversity of over 100 strains collected world-wide was described. Pathogen genotypes present in California elicited a hypersensitive response within 24 hours on host cultivars previously identified as resistant. In contrast, other genotypes of the pathogen from other geographic regions did not. Disease progress was significantly reduced in resistant cultivars compared to disease progress in susceptible cultivars inoculated with the California strains. The relationships between virulence and genotype are being further explored. In order to find sequences useful for the specific detection and quantification of the pathogen, whole genomes of ten strains of the pathogen and related organisms were sequenced.