Developing Molecular Diagnostic Techniques to Detect Oak Wilt

Christine Engelbrecht, P&S, Plant Pathology


Every year, the Plant Disease Clinic receives many samples to test for oak wilt, a serious fungal disease of oak trees in Iowa.  Testing for this disease requires culturing samples for several weeks on Petri plates.  Testing is thought to result in many false negatives due to contaminants on the Petri plates and low concentrations of the fungus in the sample.  A faster, more accurate diagnostic technique would better serve the Plant Disease Clinic clientele.

To develop a fast, accurate, molecular (DNA-based) diagnostic test to test oak samples for oak wilt.  After this test is developed, tests for other difficult-to-diagnose plant diseases will follow.

We are still currently perfecting a method to extract DNA from a woody plant sample for use in a polymerase chain reaction (PCR) test that is specific for the oak wilt fungus.  The PCR test accurately detects the oak wilt fungus when a pure culture is used but we are still working on perfecting the reaction so it works with DNA extracted from an infected plant sample.

This project is still in progress.  We anticipate that when our test is successful with infected plant samples we will be able to cut response time on such samples from several weeks to two days, with greater accuracy, to better serve homeowners and county extension offices in Iowa.
146 -- Consumer Horticulture and Forestry

Page last updated: July 9, 2006
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