Ames, Iowa
July 22, 2008
Researchers at
Iowa State University have
been flying balloons this summer in the name of biosecurity
science.
A team of plant pathologists and engineering researchers led by
Forrest Nutter, plant pathology professor, are using weather
balloons to carry a first-of-its-kind device developed to
measure the spore clouds escaping from a diseased field of
wheat. The researchers infected the field near campus with wheat
rust, a fungal disease, to see if they could measure the density
of spores above the crop. The spores are the microscopic
infectious structures the fungus uses to spread.
The work is an offshoot of Nutter's work using satellite images
to find diseased fields of soybeans in Brazil and South Africa.
The research developed a method to detect soybean rust using the
difference in the light reflected from the diseased plants
compared with healthy soybeans and the characteristic way the
disease moves through a field.
This is the final year of a U.S. Department of Agriculture grant
funded through the National Research Initiative's Plant
Biosecurity Program. Nutter recently won a $1.13 million grant
from the Department of Homeland Security to fund research on the
early detection of plant diseases in other countries using
satellite technology.
Successfully gathering spores with balloons gives plant
pathologists another way to target the identification of plant
diseases, either natural in origin or deliberately infected.
"If a field viewed from satellites has suspicious areas, we
could provide the GPS coordinates to go look at them. This makes
our warning system more accurate," Nutter said.
The spore collector carried by the balloon includes six samplers
that can be turned on remotely, allowing researchers to measure
spore densities at different altitudes and calculate the size
and density of the spore cloud. The sampler is returned to the
lab to identify and count the spores.
Analyzing the spores genetically would also give investigators
information on their origin, Nutter said. If the biotype of the
disease is new to the region, then scientists might investigate
if it was introduced deliberately. After locating a suspicious
field, investigators could look for tell-tale substances that
would indicate an act of bioterrorism, he said. |
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