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.
|
|
Steven Witt. 1985. Biotechnology and Genetic Diversity