Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2005
Publication Date: 6/1/2005
Citation: Luo, G., Melcher, U., Bruton, B.D., Pair, S.D., Fletcher, J. 2005. Phytopathogenicity of Serratia marcescens strains in different plant host species [abstract]. Phytopathology. 95:S63.
Technical Abstract: Strains of Seriatia marcescens (Sm), cause of cucurbit yellow vine disease (CYVD), colonize many niches (water, soil, humans, animals, insects, plants). To assess whether phytopathogenicity is strain-specific, tobacco leaves were needle-inoculated with various Sm strains. A HR-like response was observed within 24 hr with all Sm strains at 10**9 cells/ml, but at 10**6 cells/ml CYVD strains caused necrosis within 48 hr, while non-CYVD strains did so only after 60 hr. the response to SM, needle-inoculated to squash and carrot stems, and to onion bulbs (the latter two are non-hosts of CYVD), differed. Squash seedlings were stunted, onions were water-soaked and softened, and carrot seedlings wilted and died. Rates of infection also differed; 17% of squash plants inoculated with CYVD strains, but 0% of those receiving non-CYVD strains, showed symptoms. Surprisingly, only 0-33% of carrots and onions inoculated with CYVD strains showed necrosis, while 70-100% of those receiving non-CYVD strains did so. When Sm inoculum was dropped onto the surface of peeled onion bulbs to assess whether Sm could enter plants naturally, only non-CYVD strains caused symptoms. Our results demonstrate that Sm strains from non-plant niches can cause symptoms in plants, but their interactions with the plant host differ from those of CYVD strains.