Seed ImagingNew Tool in Germplasm
The Slant Growth Robotic System is designed to monitor seed
germination and root growth. Images are recorded hourly using a digital camera
and then sent to a microcomputer for analysis, data summary, and image
Digital technology is now helping scientists and engineers protect our
genetic resources by recording and storing valuable information about seeds in
an electronic form that computers can use.
"We're using digital imaging equipment to help identify seed that is in
danger of dying in storage," says ARS agronomist Phillip C. Stanwood.
"This will give us time to regrow seed and thus save genetic material that
someday may be a source of insect or disease resistance for commercial
All seeds lose some vigor, or ability to survive, during extended storage
and must be regrown periodically to produce a new generation.
Root length is one test for vigor. But measuring it is an expensive and
time-consuming process. So ARS researchers at the National Seed Storage
Laboratory in Fort Collins, Colorado, developed a digital system that
automatically records when seed germinates, how fast it sends out roots, and
the root length.
Digital imaging, whether by television cameras in a laboratory or by data
collectors aboard orbiting satellites, breaks a picture up into small dots, or
pixels, with average values of light intensity assigned for each pixel. This
digital information is analyzed immediately by a computer or saved to disk for
later analysis. Encoded information can be decoded back into images humans can
Scientists place test seeds on a carousel of 50 moist, blotter paper-covered
boards that rotates inside a germination chamber. The chamber can maintain
specific temperature and humidity requirements for each plant species being
testedlettuce and sorghum so far. A digital camera records images every
hour as the boards make their circuit in front of the camera.
"Results we're getting from the new equipment are very close to those
obtained by technicians actually measuring each seed," says Stanwood. He
developed the equipment with engineer M. Scott Howarth at the lab.
"Although all seeds that germinated had the same germination100
percentwe're learning more about each seed sample with much less
work," says Stanwood. "Plant breeders could also use the system to
select plants with the highest vigor and fastest growing roots."
The Colorado scientists are also using the digital equipment to build an
image database on chickpeas, better known to salad bar patrons as garbanzo
Information on 505 important accessionsout of almost 6,000 so far
identifiedwill eventually be available. Each entry will include text
explaining the seed's origin and botanic description. Pictures will show seed
size, shape, and color; how the plant looks in the fieldtall or short
stature, for example; and how diseases and insects affect flowers and leaves.
Scientists are assisting others who are assembling digital databases of
other key plant collections stored around the country. By Dennis
Seed Storage Laboratory, 1111 S. Mason St., Fort Collins, CO 80521-4500;
phone (970) 495-3226, fax (970) 221-1427.