Soybean researcher hopes to borrow genes from wild lines to improve yield, composition and pest resistance in varieties that farmers grow
Lots of soybean researchers work with soybean genes to improve yield, composition and resistance to various pests. That includes U.S. Department of Agriculture Soybean Research Geneticist Tommy Carter, but he’s doing it a little differently.
Instead of working directly with genes from soybean varieties that farmers commonly plant, Carter is a collaborator on a multistate soy-checkoff-funded study of the genes from soybean lines that have been growing wild in China for thousands of years. He believes these wild lines hold valuable genetic diversity that can be tapped to improve current commercial varieties.
The breeding process that created today’s varieties left behind a large pool of beneficial genes, Carter says. In this interview, he discusses how this could improve soybean production for farmers.
Q: How genetically diverse are today’s farm-grown soybeans?
A: They’re not very diverse. There’s a real bottleneck in the way our commercial varieties are bred – if you look at our U.S. soybeans today, you can tell they’re all pretty closely related. The genetic base is fairly narrow in the United States, and that’s curtailing our ability to develop new higher-yielding products that are good for the farmer.
Q: What dangers could come from this lack of diversity?
A: Going back to when I was in graduate school, the corn blight in 1970 very nearly wiped out the corn crop. They had a new set of genetics in time for planting the next spring, and if they hadn’t done that, it could have wiped out the corn crop. That got everybody interested in genetic diversity like they had never been before. There’s a general fear that there’s not enough diversity in the soybean crop to protect against something like that if it were to come to soybeans.
Q: How can these wild soybean lines help?
A: Genetic studies have shown that when the soybean was first domesticated, only a few of the genes from the wild soybean were brought into the crop that we grow today. Since then, continuous breeder selection has improved our crop, but also led to the unintended consequence of losing even more of those original wild soybean genes along the way. So, what we left behind, and is still out there waiting for us, is a whole treasure trove of diversity in the wild bean The wild soybeans are actually much more variable than farmer varieties of the normal soybean.
Q: How are these genes different from what scientists have to work with now?
A: It’s easy to say that with all the technology we have today, we could probably just invent new beans. The truth is that we’re pretty far away from that. New technology is helping us as plant breeders, and it’s very important that we’re smart in using that. But we don’t want to ignore all those genes that Mother Nature has been storing up for hundreds of thousands of years. The genes from the wild soybeans are at our fingertips, so why won’t we go ahead and take advantage of that? These wild genes that are very unique and you’d never think to look for in the laboratory.
Q: What kinds of traits could this diversity help improve?
A: If you ask a farmer what are the three most important soybean traits, it’s yield, yield and yield, right? We are pretty sure there are yield genes in wild soybeans, and we have a way to extract them. It’s also a really high-protein-type of soybean, and they’re high in some of the amino acids, like methionine and cysteine. And there’s disease resistance in the wild soybean, such as resistance to soybean cyst nematode. So yield is number one, but all these other benefits are important, too.
Q: How will this help farmers?
A: This material will feed into commercial breeding, and, in fact, it already has. In our first round of breeding, we developed a whole series of lines from the wild soybeans that are very diverse and extremely exciting from the breeder’s standpoint. We’ve already transferred some of the materials to companies and they’re starting to cross with those in their programs.