Acidovorax valerianellae sp. nov., a novel pathogen of lamb's lettuce [Valerianella locusta (L.) Laterr]. (1/1)
Bacterial spot disease of lamb's lettuce [Valerianella locusta (L.) Laterr.] was first observed in fields in 1991. This new bacterial disease is localized in western France in high-technology field production of lamb's lettuce for the preparation of ready-to-use salad. Nineteen strains isolated in 1992 and 1993 from typical black leaf spots of naturally infected lamb's lettuce were characterized and compared with reference strains of Acidovorax and Delftia. The pathogenicity of the 19 strains was confirmed by artificial inoculation. Biochemical and physiological tests, fatty acid profiles, DNA-DNA hybridization and other nucleic acid-based tests were performed. A numerical taxonomic analysis of the 19 lamb's lettuce strains showed a single homogeneous phenon closely related to previously described phytopathogenic taxa of the genus Acidovorax. DNA-DNA hybridization studies showed that the lamb's lettuce strains were 91-100% related to a representative strain, strain CFBP 4730(T), and constituted a discrete DNA hybridization group, indicating that they belong to the same novel species. Results from DNA-rRNA hybridization, 16S rRNA sequence analysis and fatty acid analysis studies confirmed that this novel species belongs to the beta-subclass of the Proteobacteria and, more specifically, to the family Comamonadaceae and the genus Acidovorax. The name Acidovorax valerianellae sp. nov. is proposed for this novel taxon of phytopathogenic bacteria. The type strain is strain CFBP 4730(T) (= NCPPB 4283(T)). (+info)Valerianella, also known as corn salad or lamb's lettuce, is a genus of plants in the family Caprifoliaceae, characterized by their small, rounded leaves and clusters of white or pink flowers, which are often used in salads and traditional medicine for their mildly sedative properties.
Valerianella is a genus of plants in the family Caprifoliaceae, also known as corn salads or lamb's lettuce. It is often used in herbal medicine for its mild sedative properties. The roots and sometimes the above-ground parts of certain species are used to make medicinal teas, tinctures, and capsules. Valerianella is native to Europe and Asia but has been naturalized in other parts of the world. It should not be confused with Valeriana officinalis, which is a different plant species also known as valerian and is used for its stronger sedative effects.