The workers in professor Jianxin Ma's lab have one primary goal. They are looking for new genes that could help modern soybeans either yield more, fend off diseases and insects more completely, or do all of these things. And they're looking for them in plants that are soybeans, but not the kind grown commercially in Indiana. They are wild soybean relatives.
"One of the biggest differences between corn and soybeans is that the genetics are much more diverse in corn," Ma says. "The soybean germplasm in this country is not very diverse. A very small number of lines and varieties make up a large share of the commercial market.
What it means is that it's tougher to develop a pool of new genes that might be sources for nematode resistance or disease resistance, he notes. That's critical since the event that confers nematode resistance in most varieties today is showing signs of vulnerability and weakness.
Ma and his co-workers are searching for new germplasm in wild soybeans. Some of these plants grow almost flat on the ground. The idea isn't to try to release them for growing in the field. Instead, it's to see if they have genes not found in modern soybean varieties that could have value, and could help breeders develop modern varieties that perform better in some fashion.
Why there isn't as much diversity is not fully understood, notes Shaun Casteeel, Purdue University Extension agronomist and soybean specialist. It's possible that the fact that soybeans self-pollinate while corn often cross-pollinates to other plants may be part of the explanation. It's also true that industry has concentrated on the best genetics, and the same or similar genetics are grown on a large number of acres across the Midwest each year.
Once Ma and his crew find possible genes that could have value, Purdue's newest plant breeder, Katherine Rainey, will help incorporate them into plants and further study if putting genes from wild plants into modern varieties is a feasible practice.