It's a whole new world for wheat breeding
By Jennifer M. Latzke
Since the wheat industry indicated support for a biotech wheat variety, the world of wheat breeding has changed.
In five years, wheat breeding has expanded beyond a handful of public breeding programs to now private and public partnerships that are all looking for the first commercially viable biotech wheat.
Brett Carver, professor of wheat genetics and breeding at Oklahoma State University, Stillwater, Okla., explained that public varieties are still holding their own, but they are working to be more competitive every year. Carver spoke at the 2014 Red River Crops Conference in Altus, Okla., Jan. 29.
He said in 2009 public programs held 25 trials, with 14 of those trials topped by public wheat varieties, for a 1.7 public to private ratio of varieties. By 2012, that ratio had risen to 2.0. This cooperative spirit between public and private breeders is good for growers as there has been an upward trend in wheat yields across the country by about a half a bushel per year since 1980.
Breeders know there are two ways to increase productivity, Carver said. One, raise the yield ceiling by increasing genetic potential; or two, reach the yield ceiling by capturing the genetic potential already present in the crop. Breeders today, he said, have to balance between reaching that Holy Grail of outstanding yields against selecting for pest and disease resistance that are yield robbers for farmers.
But farmers must also know their fields, know which factors they have that may impact their wheat yields, and manage their crop to limit those and control their influences, Carver said. The right variety is a start, but there’s more that goes into yield than just variety. Oklahomans know that when it rains the yield potential is brought out in their wheat varieties, he said. But farmers also need to optimize all the other factors so that if it doesn’t rain they still have an opportunity to capture that yield. Whether that’s applying fungicides, controlling for pests, optimizing nitrogen applications, or even using plant growth regulators, farmers have tools available to them to improve yields.
That’s not to say breeders aren’t trying. Traditional breeding methods take time. From the time of a first parent cross to a progeny cross, it can be six to 10 years. New doubled-haploid techniques can cut that interval in half . While breeders pass up the opportunity to mix genes and see what their interactions might bring, doubled haploid can work for small, elite parts of breeding programs. The goal is how to get more gain per breeding cycle. With more interest in wheat, Carver said the OSU program is almost three times bigger than it was in the 1990s.
Genetic modification is one breeding method that researchers are looking into. This is when genes are introduced from outside of the wheat, whether transgenic, from outside the species, or sysgenic, reintroducing genes from other wheat varieties in a targeted manner.
Beyond biotech means, though, there are other breeding methods that wheat breeders can use to find the next hot variety. Reverse Genetics, for example, looks at a mutation in the breeding that might impact yield or quality. Then, the researchers look for the targeted change in DNA that could affect that trait that is wanted.
“It creates variations, and yet it isn’t subject to regulation obstacles of genetically modified traits,” Carver said.
Some breeders are going “old school” and looking at distant wheat relatives in gene banks to see what parts of the genome can be used for modern breeding.
All of these methods will be needed to address serious concerns for wheat farmers and those around the world who rely on the crop, Carver said.
There’s wheat blast, which is an imminent threat, Carver said. Related to rice blast, it shares genetic similarities to an annual ryegrass pathogen. It prefers warm and wet conditions and is already found in South America. It’s even been noted in Kentucky in 2011, Carver said.
Another issue will be the need to find a wheat that uses phosphorous efficiently. Phosphorous rock reserves are nearly exhausted, Carver said, and five countries control 90 percent of the known supply. Wheat production uses 16 percent of phosphorous on the market, second only to fruit and vegetable production. If wheat growers are going to continue to raise the crop, resource efficiency must be included in future breeding programs, Carver said.
Ultimately, using all the tools in the toolbox, public and private breeders may one day find the answers to the challenges farmers face in bringing wheat to consumers.
Jennifer M. Latzke can be reached by phone at 620-227-1807 or by email at firstname.lastname@example.org.