The LSU AgCenter wheat and oat breeding programs are making more variety crosses and evaluating more breeding lines per year than ever before.
Improved breeding techniques, such as the use of molecular markers and genomic selection, have helped breeders work more efficiently, said LSU AgCenter wheat and oat breeder Steve Harrison.
A big focus of the program is breeding for resistance to the disease Fusarium head blight, or scab.
“The most important thing that we’ve done breeding wise in the last year is we’ve made a lot of progress on Fusarium head blight,” Harrison said. “That disease has discouraged growers from planting wheat because of the damage it does and potential yield losses.”
Through molecular markers they screen for FHB1, a major gene for resistance to the disease. Harrison said they rate families of breeding lines for the disease and place them in one of three categories: those that either have two copies of the resistance genes, lines that had one copy of the resistant gene and one copy of the susceptible gene, or lines that did not have the resistance gene.
“When you rank them by Fusarium-damaged kernels, it is a very clean picture,” he said
Trey Price, AgCenter plant pathologist, conducts research on managing foliar diseases in wheat through fungicide efficacy trials.
“Fungicides are a tool, but resistant varieties make more sense economically,” Price said. “Additionally, the best scab control you can achieve with a fungicide application is 50%. We are working towards using resistant varieties in conjunction with fungicides to manage scab in Louisiana wheat.”
Price also said through his research he has determined that fungicide seed treatments do not increase wheat yields.
“We look for ways farmers can cut their input costs, and this is one that we’ve identified,” he said.
Pathologist and wheat specialist Boyd Padgett also is working on disease management in wheat.
“Prior to breeding for resistance, we had bad scab about four out of five years in a row,” Padgett said, adding that he did not see a lot of disease on wheat this year.
The breeders are working to combine the Fusarium-resistance genes with genes for high yield. Using double haploid production allows them to speed up the breeding process. Harrison said they can get a pure line in two years instead of six or eight.
Harrison said this year was a rough year for the breeding program. Severe rainstorms damaged breeding material during planting and at harvest. In years like this, he can rely on other SunGrains breeders, a consortium of Southeastern universities’ wheat and oat research programs, to get good data from field trials across the region. He also said technology can help.
“With our genomic selection program, you can make up for a lot of lost field data because you have predictions that are based on thousands of molecular markers, and that has been the really big addition to the program,” Harrison said.
Genomics can help with predictions for test weight, yield and disease reaction, among other traits.
Niranjan Baisakh, a molecular biologist with the AgCenter, has made significant progress in the wheat and oat breeding program using molecular markers.
“On the marker development aspect, we are focusing on narrowing the genomic regions controlling the traits of interest so we can use those genes and identify the markers linked to the genes that we can use in our breeding program for screening,” Baisakh said.
With a new piece of equipment in his lab, Baisakh is screening markers for known genes on the breeding materials in house. The results of this screening will be significant in the genomic predictions of the breeding materials. In previous years they would send the materials to the LSU AgCenter H. Rouse Caffey Rice Research Station. The tests can determine which lines have the desired genes, which don’t, and which are heterozygous, which means they have one copy of the desired gene.
The program didn’t release any new varieties this year because of a lack of large-scale seed increases, but Harrison said there are two or three wheat lines and two or three oat lines that are being considered for release next summer.
A small plot combine harvests wheat at the Macon Ridge Research Center. Photo provided by Steve Harrison