Bushland, Texas
May 29, 2006
Source:
AGNMORE
(Agriculture and More) News from Texas Cooperative Extensionand
Texas
Maintaining competitiveness in the
world market requires scientists to lay out a new roadmap for
crops, according to a Texas
Agricultural Experiment Station leader.
Dr. Bill McCutchen, Experiment Station deputy associate director
from College Station spoke on "A Platform for Yield Gain through
Genetic Discovery in Wheat" at the Small Grains Field Day in
Bushland on May 25.
"We have to maintain our international competitiveness,
especially with our wheat program and our varieties," McCutchen
said. "That means we have to stay a couple steps ahead in the
area of technology."
One such technology is "marker assisted selection," which he
equated to building a map.
The Wheat Coordinated Agricultural Project, funded by the U.S.
Department of Agriculture's Cooperative State Research,
Education and Extension Service, uses DNA technology to reduce
the time needed to develop different varieties.
Dr. Jackie Rudd, Experiment Station state wheat breeder, is
leading the program in Texas with research in Amarillo, Vernon,
Dallas and other breeding locations.
Texas' scientists initial interests are greenbug and leaf rust
resistance, McCutchen said. However, the possibilities are not
limited to those two areas. It is possible to identify genes
controlling traits for disease and insect resistance, as well as
cold and drought tolerance.
In traditional breeding programs, a researcher may start with
200 crosses in year one and expand to 20,000 lines in the second
year in several locations looking for one variety with the
desired traits, he said. Most of these will be discarded until
one product is found up to six years later.
Researchers can combine this traditional breeding with molecular
breeding to more efficiently improve quality and yield of row
crops, McCutchen said.
"You have to intertwine the genetic and environmental factors,"
he said.
Traits important to growers are controlled by the genetic
make-up of each wheat cultivar. A genetic roadmap leads to the
identification of yield traits.
"Molecular breeding doesn't mean genetically engineered,"
McCutchen said. "But the use of molecular markers provides
breeders with a more detailed roadmap to improve row crops like
wheat in a more timely and precise manner."
These yield genes can be mapped much like historical markers on
a roadmap, marking the way to something significant along the
chromosome interstate, he said, whether that is rust or greenbug
resistance or some other trait.
Essentially, McCutchen said, this new technology will allow
breeders to take a variety with high yield potential but
insufficient rust resistance and streamline the process to
integrate a rust trait from another line to produce a superior
yielding wheat variety with rust resistance.
"We can expect to see the impact of this technology in the next
five years," he said. "It may take a little longer for wheat
producers to see the benefits, but you will see products from
this technology with corn and perhaps other crops within the
next few years." |