Pathogen Testing

The Corvallis germplasm repository seeks to preserve and distribute plant material free of harmful virus diseases. Plants are tested for viruses by inoculating sensitive "indicator plants" and by an immunological technique called "Enzyme Linked Immunosorbent Assay" or ELISA.

The yellow wells in an ELISA plate indicate that virus-infected plants have been detected. Bioassays include sap-inoculation of herbaceous plants to detect viruses with a wide host-range, and graft-inoculation of closely related perennial plants to detect viruses with a narrow host-range. Plants found to be infected with viruses are subjected to "heat therapy" where they are grown for several weeks at temperatures around 38C. Meristems less than 1mm in length are dissected from new shoots that grow during the heat therapy. These meristems are grown in vitro, eventually regenerated into plants, and retested to determine whether the virus was successfully eliminated.

Collections of temperate fruit germplasm-borne pathogens have been assembled in support of the repository's virus testing program, and also to preserve these important microbial genetic resources. To request samples, or more information about these collections, please use the "mail-to" link at the bottom of this page.


Other Temperate Fruit Pathology Resources

The American Phytopathological Society (APS) publishes lists of preferred common names for plant diseases. Select below to retrieve lists of Plant Diseases for several NCGR crops: 

For more information please contact Joseph Postman
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A germplasm collection is like a "pharmacy filled with miracle drugs without labels. Somewhere within the collections there exists one or more 'cures' for nearly every disease, but without the labels, we are forced to search randomly for the right one."

Steven Witt. 1985. Biotechnology and Genetic Diversity