This year marks the 10-year anniversary of scientists' ability to identify plant gene functions and track them through the breeding process.  The technology has already delivered dramatic improvements for farmers using genes native to the crops.

Marker-assisted selection (MAS), a leading technology for more efficiently advancing desirable soybean traits, is celebrating a decade of progress.

"MAS has made a remarkable difference in ensuring the products we release have the attributes our growers expect," says John Soper, director of soybean research, Pioneer Hi-Bred International, Inc.  "It allows us to more quickly zero in on sought-after traits and bring the best possible lines to market."

MAS is the process of using genetic markers to identify the presence of a specific gene that carries a given trait.  For example, MAS allows researchers to identify a marker associated with a positive trait, such as soybean cyst
nematode (SCN) resistance, then track the presence of the marker -- and the particular trait it represents -- in each new variety.

"Pioneer has led the development of patented processes for using MAS in soybeans," says Soper.  "The technology has allowed researchers to see things that were not possible to see and capitalize on a decade ago.  Before MAS, breeders were limited to using visual observations and yield data to evaluate varieties and make selections.  With MAS, Pioneer scientists now are able to understand the genetic basis for what they are seeing and use this knowledge to design and select better varieties.

"For growers, this means access to varieties that deliver the most profit, most often," he adds.

Specifically, MAS has had significant influence on developing varieties with enhanced disease and pest resistance/tolerance, including SCN, brown stem rot (BSR) and Phytophthora.

In addition to the progress made toward combating specific agronomic challenges, Pioneer has dramatically expanded the overall capacity of MAS by combining automation, computer robotics and extensive information management systems with the biotechnology.

"When we first began using MAS, we were pleased to analyze 10,000 plants per year.  Today, we analyze more than 1 million plants annually," says Soper. "Additionally, since we have largely addressed the key problems of SCN and BSR resistance, we now can focus on other areas of progress."

Yield: The Next Frontier in MAS Technology

Yield improvement is the next developmental milestone for MAS. "We have come a long way in using MAS to couple high-yielding varieties with strong defensive packages," says Soper.

For instance, a decade ago SCN-resistant varieties were at the lower end of Pioneer research trials for yield performance.  Today, they are competitive for yield compared to varieties lacking SCN resistance, he says.

"MAS has allowed Pioneer scientists to double the rate of genetic improvement for yield among Pioneer's SCN-resistant varieties," says Soper.

Continuing to enhance yield improvement is a constant goal.

"During the past 20 years, U.S. soybean breeders have averaged yield improvements of approximately one-half bushel/acre/year improvement," says Soper.  "Our goal is to double that rate of yield improvement, achieving a
full bushel/acre/year gain.  MAS is one of the tools that will allow this goal to become a reality.  These yield advancements will translate into breakthrough performance for growers," he adds.

Expanding the Vision of MAS

"While significant progress has been made, we must remember MAS is a relatively new technology and far greater advances lie ahead," says Soper.

"The research conducted to support MAS technology will provide us with a deeper understanding -- in a way we cannot fathom right now -- of how genes work together."

For instance, marker-assisted backcrossing is gaining in use and will continue to deliver on the promise of MAS.  Marker-assisted backcrossing is a process that allows researchers to select one highly desirable gene from an
otherwise undesirable line and add that particular gene to an elite variety. Backcrossing technology then allows the specific, highly sought-after trait to express while selecting against all other traits of the less desirable line.

Likewise, looking ahead from a defensive trait standpoint, Pioneer intends to expand its use of MAS to address tolerance and/or resistance to additional diseases, pests and environmental stresses including sudden death syndrome, white mold, frogeye leaf spot, Chinese soybean aphid, Asian soybean rust and iron deficiency chlorosis, says Soper.

"We have seen only the tip of the iceberg when it comes to the benefits MAS will provide," says Soper.  "To be sure, Pioneer is investing heavily in the use of MAS technologies to help growers improve their productivity and
performance.  We look forward to continuing to do so and delivering on the benefits of MAS in the next 10 years and beyond."

Pioneer Hi-Bred International, Inc., a subsidiary of DuPont, is the world's leading source of customized solutions for farmers, livestock producers and grain and oilseed processors.  With headquarters in Des Moines, Iowa, Pioneer provides access to advanced plant genetics, crop protection solutions and quality crop systems to customers in nearly 70 countries. DuPont is a science company.  Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture, nutrition, electronics, communications, safety and protection, home and construction, transportation and apparel.