The art of gene discovery
Have you ever been challenged to find a needle in a haystack? Plant breeders have that very task. They search through millions of plants, analyzing mountains of data, looking for the perfect trait—or at least one that will outperform others on the market.
Today’s technology makes that daunting task a little easier. Genome-wide selection (GWS) is the "new wave" of technology that plant breeders are riding. GWS allows breeders to select and aggregate complex combinations of native traits.
The use of molecular markers in gene selection goes back to the early 1990s, says John Soper, vice president of crop genetics research and development at DuPont Pioneer. It started in soybeans with brown stem rot resistance and soybean cyst nematode resistance. Through the years, marker use has extended beyond disease applications and now is applied to environmental stresses and key traits, such as yield stability, across different environments and seed quality.
The search is on. "GWS looks at the complete genetic makeup of a plant," Soper says. "Instead of looking for one gene we are looking at hundreds to find the right combination or package for improved performance."
Soper says it was fairly simple to control Phytophthora root rot. "You needed a single gene and had to identify the gene’s presence in the plant," he explains. "The complexity comes with yield, which is controlled by hundreds of genes. GWS allows breeders to look at combinations of genes that result in a higher yielding plant."
DuPont Pioneer’s latest market contribution is Optimum AquaMax corn hybrids, which are designed to help growers in water-limited areas. DuPont Pioneer identified native genes in corn plants, enabling plants to improve water use. The result is a line of non-transgenic hybrids with the ability to deliver a yield advantage under drought stress.
"At Syngenta, we use GWS to identify gene regions that house different types of desirable characteristics," explains Wayne Fithian, a technical trait lead in Omaha, Neb. "This enables us to broadly improve our genetic portfolio and accelerate our rate of gain for yield."
Specific targets. Both companies used GWS in bringing these new products to the marketplace. But it doesn’t stop there. Seed companies are also taking their methodologies a step further and targeting specific genes. DuPont Pioneer’s method is called Accelerated Yield Technology; Syngenta calls theirs Gene Blueprinting.
Using Gene Blueprinting, Syngenta designed Agrisure Artesian to maximize yield when it rains and increase yield when water is limited. Agrisure Artesian is comprised of 13 different genes and is not considered genetically modified.
"While the corn genome is mapped, we do not yet know what all the genes do, but we are learning very quickly," Fithian says. "This learning can be applied using both GWS and Gene Blueprinting."
Beck’s Hybrids recently completed their own lab in Atlanta, Ind., which became fully functional at the end of June. Now, they can apply GWS techniques to their research program, says Kevin Cavanaugh, research director. This new technology is very accurate and eliminates experimental error, he adds.
It’s not just the seed companies and plant breeders that benefit from this technology. Farmers benefit, too. Year after year, farmers can expect to see a faster rate of gain in plant performance, says Soper at DuPont Pioneer. The ability to select multiple native traits while simultaneously using markers enables faster performance enhancement. Unlike biotech traits, native trait improvements are not subjected to a regulatory process and can make their way into the hands of farmers faster—saving several years in the commercialization process.
What is a Native Trait?
It depends on who you ask. Everyone can agree that a native trait is obtained from the natural germplasm pool of a species, but disagreement can be found in the word "natural." Some researchers consider natural germplasm as what already exists in their research pools. Other researchers believe natural refers to ancestral strains of a species. Yet others set parameters around the word native or natural with a locale—for some it is within a watershed and others a specified radius. The important thing to remember is not to get hung up on the technicality of native or natural but to understand today’s technology can help plant breeders better mine
- Seed Guide 2013