Real-time PCR detection of Rhodococcus fascians and discovery of new plants associated with R. fascians in Pennsylvania.

摘要: Rhodococcus fascians is a gram-positive bacterium that causes bacterial fasciation on wide range of ornamental plants. To address the need for reliable, sensitive, and specific method detecting R. in infected plant materials, real-time (RT) PCR assay was developed. The target detection fas-1, plasmid-borne gene essential virulence. DNAs from all confirmed pathogenic strains consistently tested positive, with limit 30 fg DNA. In repeated experiments pure culture, as few 2.5 CFU were positive. Direct clinical samples Coreopsis successful, whereas Chrysanthemum, Pelargonium, Phlox, Veronica required enrichment modified D2 (mD2) medium. case geraniums, 10² CFU/100 mg tissues successfully detected after 72 h mD2. total, 115 strains, isolated 41 different kinds flowering crops Pennsylvania greenhouses during 1984-2010, to be by RT PCR. Geraniums speedwell most frequently submitted Department Agriculture. following are first report plants associated PA: Ajania pacifica, Anemone sp., Aruncus Baptisia Eutrochium maculatum, Helianthemum Lewisia Monarda Osteospermum ecklonis, Rudbeckia nitida, Saponaria ocymoides.