Will the right soybean please stand up?
Thomas Carter celebrated his 56th birthday this year. Twenty-eight years ago, half his lifetime to this point, he began a long-range project to find a soybean with drought resistance. Now he’s on the edge of his work coming to fruition. Carter has designed five drought-hardy soybean varieties that appear to have the right kind of drought hardiness. He will release the first of them this winter.
• Geneticist Thomas Carter will soon release a new drought-resistant soybean.
• Carter has designed five promising drought-hardy soybeans over 28 years.
• Transgenic modification is being tried by companies in search of the same trait.
Carter is a research geneticist with the Agricultural Research Service, the research arm of USDA, working out of the USDA ARS Soybean and Nitrogen Fixation Research Laboratory in Raleigh, N.C. For years he’s been combing through the USDA Soybean Germplasm Collection housed in Urbana, Ill. This is a collection of over 20,000 different types of soybeans gathered by USDA “plant explorers,” whose job from the late 1800s to about 1920 was to travel all over the world gathering examples of plants. Some of these farmer-developed varieties, or landraces, were thousands of years old. The plant explorers collected them and brought them to the United States.
Carter began his work with the hypothesis that somewhere in that tremendous bank of soybean germplasms there would be at least a few examples that had developed drought hardiness.
“When I started on this back in the early 1980s, there really wasn’t any work ongoing in that area,” Carter says. “We really didn’t even know if drought tolerance existed in soybeans, or if it did, what kind of limitations it would pose for us. A lot of breeders said that if there was such a thing as drought tolerance, if you bred for higher yield under drought, that this would just limit the variety’s yield under good conditions. They didn’t think you could have a high-yielding variety that was also drought-tolerant.”
Something for everyone
The Urbana soybean collection is a “treasure trove of genetic diversity,” Carter says. After locating the desired traits, his goal is to fold all those good traits and genes into varieties “that farmers can grow here in North Carolina and elsewhere in the United States.” His team cross-pollinates the soybeans, grows them out and tags them.
Between six and 10 team members start with tweezers and glasses, spreading tiny deposits of pollen around as they sit on little stools out in the fields at the Central Crops Station in Clayton, N.C. They grow the varieties in the moisture-robbing sandy soil of the Sandhills Research Station in Jackson Springs.
“When we find a good drought-tolerant type — it might be from Asia or elsewhere — we will pick out a very adapted Southern variety and cross those two together,” Carter says. “We develop progeny, a number of brothers and sisters from that cross. Then we select from among those to find which have not only the drought-tolerance trait, but also all the good yield ability of the adapted types.”
Another way of working
At the same time that Carter is researching traits using traditional geneticist methods, commercial companies are also seeking drought hardiness traits using primarily transgenic modifications. One type of research doesn’t compete with the other, says Carter. Instead, it would be smart for those using the various techniques to work cooperatively.
“Anything we do will be available to industry,” he says. “That is our whole mission as public servants, to get things out there that will make it to the farmer, to the consumer and to society.”
In some instances it is also his hope. Most soybean varieties that are used are Roundup Ready, but in the USDA program they don’t use Roundup Ready. “So we hand off our material to the industry, and they actually do the last job of putting the finished product into varieties in the field for the farmers, at least the farmers that want Roundup Ready,” he says. Drought-resistant traits can also be stacked, he notes, increasing the benefit.
“Down the road it may be that some of the transgenic research could use genes in drought-resistant beans by placing them into other crops like corn,” Carter says. That might have seemed far-fetched 28 years ago — but, with gene modification, not today.
DRY TAKE ON IT: The sandy soil at Jackson Springs, N.C., Sandhills Research Station is a good medium in which to study drought resistance. Plants growing in this soil may begin to wilt after just two dry weeks in the summer. Photos courtesy of Thomas Carter, USDA ARS.
MAKING INTRODUCTIONS: ARS geneticist Tommy Carter is on the verge of bringing decades of variety work to the public as drought-resistant soybeans.
This article published in the January, 2010 edition of CAROLINA-VIRGINIA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2010.