GENEVA, N.Y. -- The device in Norm Weeden's laboratory at Cornell University's New York State Agricultural Experiment Station looks more like a high-tech waffle iron than something that could revolutionize the science of selective plant breeding. This so-called "matrix mill" is an example of emerging technology at Geneva that is in the process of being transferred to the private sector for commercial development.
In the past, plant breeders used lengthy analysis to identify plants that contained specific traits before they could improve particular varieties. With the matrix mill, what once took months can now be accomplished in a matter of days.
Weeden, Cornell professor of horticultural science at the experiment station, is one of the world's noted authorities on pea, apple, grape and bean genetics and breeding. He became interested in developing the device because of the sheer number of plants with which he worked to find the traits he desired.
"If we had to extract DNA from 2,000 plants using the usual procedure, it took about 10 weeks and cost about $8,000 for extraction only," says Weeden. The matrix mill reduces weeks to days, and the cost plummets to about $50.
The true power of the matrix mill comes into play with marker-assisted selection. A marker is a short fragment of DNA that identifies a particular region of the genome. If that region also contains a gene of interest -- for example, disease resistance or flavor -- then the marker can be used to identify plants that contain the desired trait.
"The matrix mill makes marker-assisted selection a viable alternative, especially for smaller breeding operations or crops where the profit margin is small," Weeden says.
The device reduces the time it takes to separate DNA from tissue. It works by breaking up 96 small tissue samples simultaneously in sodium hydroxide (NaOH), releasing the tissue's DNA and denaturing the protein. After the extraction there is one easy step: Neutralizing the sodium hydroxide and simultaneously diluting the DNA sample. The DNA then is ready for analysis. This process saves about 10 hours per 100 samples, reducing 10 hours of technician time to about five minutes for extraction.
Sue Gardiner, program leader for New Zealand's horticultural research apple-gene mapping program, and her colleagues used the matrix mill last spring to prepare DNA from apple-breeding populations that carry resistance to pests and diseases, as well as apple scab. They use molecular markers to select the seedlings from the populations that carry the gene combinations they require.
The New Zealand apple-gene mapping group works closely with Weeden, exchanging molecular markers for resistance genes as well as using Cornell's matrix mill. "Our new apple scab-resistant cultivars will have two resistances for scab pyramided into a single new cultivar of apple," Gardiner says. "Markers are necessary to identify the plants in our breeding populations that contain those two genes."
Thomas Bjšrkman, Cornell associate professor of horticultural sciences at the experiment station, plans to use the matrix mill to aid in marker-assisted selection to help identify broccoli plants that are heat resistant. He says: "Once we find a specific marker for heat resistance in broccoli, the matrix mill will allow us to identify broccoli plants that contain that marker in days instead of months."
Weeden developed the technology for creating the matrix mill in 1995. The prototype was built and tested over the following winter with co-inventors Joe Celeste, a former machinist at Rumsey Loomis, of Freeville, N.Y., and Dale Loomis, a designer and owner of Rumsey Loomis. In the 1980s, Celeste and Loomis worked with John Sanford, Cornell associate professor of horticulture at the Geneva experiment station, on the development of the "gene gun" -- a Cornell invention that so revolutionized the science of genetic engineering, its prototype is at the Smithsonian Institution.
There are six matrix mills in existence. One is in Weeden's lab. Five others are being field tested at sites that involve plant crops as well as animal tissue.
A standard matrix mill costs about $5,000. Cornell is looking for a partner to help commercially produce the device. Weeden and his co-inventors have applied for a patent with the help of the Cornell Research Foundation. Income generated by patents from technologies developed at the Geneva Experiment Station is returned to Cornell and the inventor.