Powerful New Microscope Probes Sex Glands of Worm Pest

By Hank Becker
April 23, 2001

New information about the anatomy of a microscopic worm could help scientists identify weak links in this destructive pest's reproductive process.

Known as the lesion nematode, Pratylenchus penetrans is one of the most economically destructive parasites. It ranks among the worst parasites of crop plants, after its cousins--the soybean cyst and root-knot nematodes.

The lesion nematode consistently attacks and extensively damages just about every agricultural crop, including potatoes and corn, as well as most ornamental plants. By damaging the plants, the worm exposes them to many other destructive soilborne pathogens that can cause additional stress. Until now, it’s been difficult to identify this nematode.

Now, a powerful microscope used to study the P. penetrans anatomy has uncovered some new information on the structure of the pest’s reproductive systems. ARS nematologist Burton Y. Endo, an expert on nematode anatomy, working with Agricultural Research Service cytologist William P. Wergin at the agency’s Nematology Laboratory, Beltsville, Md., and Ulrich Zunke at the University of Hamberg-Germany, used a transmission electron microscope to magnify male and female nematodes. With up to 20,000-x magnification, they could study and map the structures of both reproductive systems for the first time.

According to Endo, the study was undertaken to use state-of-the-art technology to find weak links in the nematode’s reproductive systems. He believes these links may be manipulated and exploited to develop alternatives to chemical nematicides that may contaminate groundwater. Today, only a few chemicals are available, and they’re often inadequate, unsuitable or too costly. Findings could lead to more effective, environmentally safe, target-specific controls for lesion nematodes.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.

Scientific contact: Burton Y. Endo, ARS Nematology Laboratory, Beltsville, Md., phone (410) 721-7759, fax (301) 504-5589, endo26@juno.com.