Consistency and uniformity have always been Canada's assurance of quality. Our variety registration and visual grading systems make this possible. Each class of wheat has its own unique kernel appearance that enables grain handlers to segregate one class from another. This is called kernel visual distinguishability (KVD). Varieties of wheat within each class conform to certain end-use quality characteristics. Only those varieties that meet the requirements for kernel appearance and end-use quality are registered. Thus, wheat classes are kept intact and separate from each other, and quality is assured by class and grade.
But things are changing. Within the next few years, DNA fingerprinting, used in medicine and forensics, will revolutionize Canada's grain handling and quality assurance systems and enhance our ability to meet customers' quality requirements.
For more than six decades, the eyes of skilled grain inspectors alone assessed the quality of wheat and barley shipments by class and grade. In the 1970s, researchers began using a technique called protein fingerprinting to discern varieties of wheat and barley that couldn't be distinguished by the naked eye. Today, protein fingerprinting is routinely used to support the visual grading system. However a new technology is on the horizon: DNA fingerprinting.
Research in DNA fingerprinting is part of highly specialized work underway at the Canadian Grain Commission (CGC) to develop and use biochemical methods for identifying grain varieties. DNA fingerprinting methods developed by the CGC will provide Canada with rapid, automated, portable and cost-effective technology to certify wheat and barley shipments as being the varieties desired by the customer.
"If you can identify the variety genetically, you know almost everything about it," says Bill Scowcroft, director of the CGC's Grain Research Laboratory. "The goal is to use DNA fingerprinting as an alternative to protein fingerprinting and to complement the visual grading system."
The CGC has led the grain industry in developing innovative technologies for testing grain. For example, the CGC routinely certifies barley shipments up to 95 per cent purity by using two techniques for protein fingerprinting: polyacrylamide gel electrophoresis or PAGE and high performance liquid chromatography or HPLC. Barley is no longer bred to meet KVD requirements so this technology is essential when identifying barley varieties that look virtually identical.
But DNA fingerprinting has even greater advantages. Regions of plant DNA are analyzed to identify differences in DNA coding sequences that uniquely distinguish one variety from another. These sequences can then serve as probes to identify the DNA of varieties commingled in grain shipments. In medical and forensic research, detection platforms called microarrays, or gene chips, are being developed. With this technology, hundreds if not thousands of samples can be DNA-fingerprinted automatically on a chip the size of a postage stamp.
"This is the leading edge of genetic fingerprinting, and Canada will be using it as part of its grain quality assurance system," says Scowcroft.
By using instruments instead of the naked eye, the CGC is answering new and challenging quality assurance needs. Using PAGE and HPLC protein fingerprinting, the CGC certifies barley shipments for purity of variety. And with automated, portable tests using DNA fingerprinting, the CGC will be able to support Identity Preservation (IP) systems. Shipments will be able to be certified for a certain desired variety, for the GMO status of grain, or for a variety with a new, valuable trait.
DNA tests are now in the research and development stage. Supported by a partnership of government, industry, producer groups, and universities, this work will ensure that the CGC continues to meet the quality requirements of our grain customers.
Published in, Grains from Western Canada, 2000-2001, Canadian Wheat Board and Canadian Grain Commission.
More information
Variety Identification. Grain Research Laboratory.
Last updated: 2003-04-23