Currently available improved peanut varieties continue to beat all expectations in terms of yield and pest resistance, but the best may be yet to come, according to presenters at the recent Georgia Peanut Farm Show held in Tifton.
The University of Georgia Peanut Breeding Program headed by Bill Branch continues to release new and improved peanut varieties with an eye towards combining high-yielding traits with high-oleic chemistry, which is being demanded by the industry for longer shelf life and enhanced flavor.
Also, the National Peanut Research Laboratory in Dawson, Ga., in cooperation with Auburn University is working to develop cultivars with desirable, improved traits adapted to all peanut-producing regions.
“We’re working to develop genome-wide molecular marker approaches to determine the genetic variability of important pathogens, such as those causing early and late leaf spot,” says Marshall Lamb, research director for the laboratory. “Our scientists are using marker selection and transformation technologies.”
Research team members include Charles Chen, Phat Dang and Renee Arias De Ares.
Trials are being conducted in four locations, he says, including one in Mississippi, two in Alabama – Fairhope and Headland, and one in Dawson, Ga. “All of our lines are comparable to the standard, which is Georgia-06G. These are mainly medium maturity, smaller outturn and smaller seed size. Two of them are high-oleic varieties. We’ve transitioned our breeding lines to looking at all high-oleic as we go forward into the future,” he says.
The researchers are looking at the genetic diversity of leaf spot pathogens, says Lamb. “Leaf spot is a big problem among growers who spray for it every 10 to 14 days. In addition to looking at the genetic diversity, we have developed some leaf spot-resistant lines through our biotechnology program, and they are showing extremely good resistance to both early and late leaf spot.
“We have handed those off to Auburn University, and they’ll be looking at them to test their levels of resistance. We’re hoping that they will have high-enough levels of resistance that we won’t have to spray or that we won’t have to spray nearly as much as we do now for leaf spot.
We’re also looking at the genetic diversity of peanut rust. It’s not really a problem for a lot of growers, but it is a problem in Florida and southwest Alabama,” he says.
One of the most exciting projects, says Lamb, is research into detoxification genes from aspergillus. “This research is showing a lot of promise. We’re also looking at resistance to tomato spotted wilt virus.”
Industry asking for higher folate
At the request of industry, researchers are looking at increasing folate values in peanuts, according to Lamb.
“Folates are important for expectant mothers early in their pregnancies because it is actually related to birth defects. Some lines showed from a three to four-fold increase in folates, and if we could get peanuts up to these levels, we could make the claim that it would help expectant mothers reduce birth defects. We’ve still got a long way to go with this project, but we’re very excited about the possibilities.”
Researchers also are looking at RNAi technology and applying it to identify genes that can be used to prevent aflatoxin in peanuts, says Lamb. RNAi is used in the medical field to fight macular degeneration and to reduce tumor size in cancer patients.
“There are a tremendous number of applications in the medical field, and we’ve developed a system in our lab to introduce this into peanuts to reduce aflatoxin. We’re basically trying to interrupt the pathway. They have been successful in transforming plants that had the gene transfer we were looking for. We had an 80 to 95-percent reduction in aflatoxin in these plants. If we reduce the risk of aflatoxin in peanuts, it’ll really open some doors for us.”
Much of this work won’t be emerging for several years, says Lamb, but real progress is being made.