Des Moines, Iowa
February 14,  2001

Pioneer Hi-Bred International, Inc., has received a patent for the marker-assisted selection (MAS)
process that uses molecular markers to select soybean varieties resistant to soybean cyst nematodes (SCN). This marker technology helps company researchers identify high-yielding, SCN-resistant varieties and bring them to market as much as two years faster than in the past.

"MAS is a critical tool for streamlining the development of soybean varieties that combine SCN-resistance with superior performance," notes John Soper, director of soybean research for Pioneer. "Soybean cyst nematodes cost growers across North America more than $1 billion in lost yields each year. MAS enhances the precision and efficiency of identifying resistant varieties, which helps us speed product development and ultimately provides growers with more choices in combating these costly pests."

In addition to the new patent for SCN selection, Pioneer received a similar patent in 1999 for the MAS process used to select soybean varieties with brown stem rot (BSR) resistance. Molecular markers act as genetic road signs, indicating where scientists can look on a segment of DNA for genes related to a specific trait. Once molecular markers are identified, researchers can use DNA analysis early in product development to screen for the presence of these traits. This reduces extensive trait-specific field-testing, which can be very time-intensive and is far less precise. 

"Field characterization and identification of a complex trait can be tricky," Soper notes. "The ideal conditions – the combination of pathogen, environment and plant genes – to determine whether or
not the trait is present, do not always exist. This can extend the testing process and delay commercialization of products with valuable characteristics."

Screening varieties for SCN- and BSR-resistance prior to yield testing is more efficient and saves valuable time. "If we know the gene with resistance is in the variety before we yield test, we have a greater probability of identifying higher-performing, resistant varieties in our field plots," Soper says.

"We’re now able to move our experimental lines into the field with complete confidence that they contain the traits we want," he adds. "This allows us to focus our field-testing efforts on what we really need to do – test for yield and performance across a broad range of growing environments and conditions.

Since 1996, every first-year experimental soybean variety has been tested using MAS. More than one-half-million soybean plant samples are screened annually and those showing resistance are passed along to field-testing. Four new SCN-resistant varieties and one new BSR-resistant variety in the 2001 Pioneer soybean lineup can be directly attributed to the company’s use of this patented molecular marker technology.

In addition to screening for SCN- and BSR-resistance, marker-assisted selection is also being used today to screen many experimental soybean varieties for Phytophthora-resistance and will be key to the development of markers for other valuable traits in the future.

Pioneer Hi-Bred International, Inc., a DuPont business, is the world’s leading developer and supplier of advanced plant genetics to farmers worldwide. With headquarters in Des Moines, Iowa, Pioneer develops, produces and markets a full line of top-quality seeds and forage and grain additives and provides services to customers in nearly 70 countries. DuPont is a science company, delivering science-based solutions that make a difference in people’s lives in food and nutrition, health care, apparel, home and construction, electronics and transportation.

Company news release
N3351