Frances Gould | 11/16/2011 10:21:23 AM
It takes about a decade to develop a new wheat variety, and the diligence of LSU AgCenter wheat breeder Dr. Stephen Harrison is paying off. Next year, the LSU AgCenter’s wheat breeding program will release LA01110D-150.
"We anticipated releasing this breeding line as a variety this summer but had problems with an increase of 20 acres of seed in Georgia last winter," Harrison said. "We will grow a large increase this winter and release it next July."
In trials, this new variety had the highest yields in 2011. Its mean yields over the past two and three years also were highest.
Along with this release come other exciting developments in wheat breeding. Harrison and his team recently started using molecular markers to identify and select for important disease- and insect-resistant genes. This work is done in collaboration with the U.S. Department of Agriculture’s Eastern Wheat Genotyping Lab in Raleigh, N.C.
"With this technology we can, for example, stack several different genes for resistance to stripe rust into the same breeding lines, making it less likely that a new race of rust will overcome the resistance," Harrison explained.
The LSU AgCenter wheat program also has a cooperative seed increase agreement with the University of Georgia to use its foundation seed program to increase potential wheat releases.
SUNGRAINS, an LSU AgCenter-coordinated consortium of six southern universities that collaborate on wheat and oat research and variety development, also renewed its cooperative agreement for another five years and continues to develop varieties for southeastern growers.
A new off-season summer wheat nursery in Idaho will speed up the process of getting varieties to growers. The first generation from a cross can be grown at this nursery to save a year in the breeding cycle. A change in the methodology in the final stage of selection can save an additional year.
Developing a new variety starts with crossing two wheat lines in hope of identifying progeny that are better than either of the parents.
"This process is repeated about 350 times each year for wheat," Harrison said. "The first three or four years are spent advancing the generations and purifying the lines."
This job is a challenge because of the southern region’s warm, moist climate and myriad of disease and insect pests. Harrison said every cross made is based on information about the traits and genes in the parents that are crossed.
"The most important trait is economic yield for the grower," Harrison said. "But that is really a complex of many traits."
Harrison must address a number of disease and pest problems that could plague wheat including leaf, stripe or stem rust; Fusarium headblight; aphids and Hessian flies.
"I’m fortunate to have several good plant pathologists and entomologists to assist with evaluating these pests," he said.
The LSU AgCenter had an inoculated nursery of about 2,000 wheat lines in Baton Rouge last year to screen for resistance to stem rust and three nurseries screening for the wheat scab Fusarium headblight. LSU AgCenter wheat material also is sent to Kenya for screening for resistance to Ug99 stem rust, a disease that threatens worldwide wheat production.
Harrison coordinates wheat variety trials. He said 50 to 75 varieties are tested each year at seven locations across the state. LSU AgCenter agronomists, entomologists and plant pathologists cooperate to plant the trials and rate the varieties.
The majority of the wheat vari-eties grown in the region have been developed by the LSU AgCenter and its SUNGRAINS partners, which also include the universities of Florida, Georgia, North Carolina and Arkansas and Texas A&M.
"The wonderful thing about SUNGRAINS is the complete and open sharing of unique breeding material, data, ideas, testing sites, grad students and many other essential resources," Harrison said.
According to Harrison, the SUNGRAIN members communicate regularly and meet for spring nursery tours and fall planning meetings.
With several SUNGRAINS nurseries, LSU AgCenter breeding lines can be tested each year across the region rather than just in Louisiana. SUNGRAIN breeders released 15 wheat varieties between 2005 and 2010, several of which were developed or co-developed by the LSU AgCenter. –Tobie Blanchard