Roundworm Repository Contributes to Agricultural
By Jan Suszkiw
January 4, 2010
Agricultural Research Service (ARS)
scientists in Beltsville, Md., manage a most unusual sort of insurance: 43,000
slides and vials containing all manner of wormlike organisms called nematodes,
from the costliest pest of soybeans, Heterodera glycines, to
bacteria-feeding species with potential use in biological insect control.
The collection, known as the
Collection, is among the largest repositories of its kind, according to
Chitwood, who leads the
Nematology Laboratory in Beltsville. There, six scientists and support
staff maintain the collection for systematic studies, taxonomic classifications
and training purposes. They also provide expert species identification for
regulatory agencies tasked with helping safeguard U.S. agriculture, such as
USDAs Animal and Plant Health
Inspection Service (APHIS).
Nematode identification requests come often. In 2008, ARS microbiologist
Handoo identified nearly 700 samples, including nearly 300 sent by APHIS
personnel at ports of entry or from domestic surveys.
One of the more high-profile cases occurred in 2000, when laboratory
researchers met with a visiting Brazilian delegation in response to a ban
Brazil had imposed on U.S. wheat exports for fear of introducing the seed gall
nematode, Anguina tritici.
A turning point came when the researchers discovered a single slide of a
specimen that a port inspector had submitted in 1953. A database search of
information on the collection revealed the genus (Anguina), and the host
plant from which the specimen had been isolated (reedgrass). The search also
revealed that the country of origin was actually Brazil, which subsequently
lifted its ban, reopening a $50-200 million annual market for U.S. wheat.
According to Chitwood, the market could have remained closed had it not been
for that one slide, illustrating the collections importance to U.S.
agriculture and trade.
Distinguishing one nematode species from another is no easy feat,
considering many have similar-looking mouthparts, tail tips and other
more about the research in the January 2010 issue of Agricultural
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture. The research
supports the USDA priority of promoting international food security.