They don't use horses to explore their frontiers, but two scientists based at the University of Illinois are blazing trails in soybean genetics.
>From wild relatives to foreign ancestors, the tracks these researchers use to pursue primitive genes may offer new promise for domestic soybean production.
"Selection has reduced the genetic diversity of soybeans," says plant geneticist Theodore Hymowitz.
"Wild perennials are more genetically diverse because they evolved under different environmental conditions. We're finding these plants offer alternative sources of genetic material for soybean breeders."
For more than 20 years, discovering wild plants related to the annual soybean has been Hymowitz's passion. He has scouted remote regions of the world, from Australia to the Pacific Rim. Hymowitz has determined the relationship between the 16 species he's collected and uses the information to produce crosses between the wild perennials and domestic varieties.
So far, Hymowitz has found resistance to nine pathogens, including soybean cyst nematode, white mold and sudden-death syndrome. He believes resistance to other diseases, including stem canker and brown stem rot, also exists in the lines. However, identification of resistance and gene transfer take time.
"We can't expect immediate results. It could be 10 years before farmers see any of this in commercial varieties," he says. "My job is to look 30 to 40 years down the road. We can say at this point that the hybrids are interesting and the disease resistance easy to identify. But we don't know yet how yield is affected or whether we've changed the protein and oil content."
Hymowitz believes wild perennials may ultimately provide the best route to better beans.
"If we don't try something different to improve the diversity and the yield of soybeans, then soybean production in this country could be in trouble."
In another campus laboratory, USDA-ARS geneticist Randy Nelson is working with old soybean strains to unearth similar genetic diversity. Nelson is coordinating collection of several hundred soybean lines from China, the country where the modern soybean has its roots.
"Although we don't know all of the genetics yet, we have found disease resistance to white mold, sudden-death syndrome, phytophthora root rot and others," Nelson says. "Some of this material is moving into breeding programs now and could conservatively end up in commercial varieties within a decade."
Can the genetic trails scouted by Hymowitz, Nelson and their colleagues eventually produce a perfect soybean?
"We can't perfect soybeans because the factors that stress the crop are a moving target," Nelson answers. "For instance, diseases that weren't a problem 35 years ago are a problem now. But we do hope our efforts will improve yields. Yield is critical to meeting future demand, and the current gene pool is too limited to support that."