Australia
December 12, 2007
Disease resistance genes from
three different grass species have been combined in the world’s
first ‘trigenomic’ chromosome, which can now be used to breed
disease resistant wheat varieties.
Pioneered by CSIRO
researchers, in collaboration with
the International Maize and
Wheat Improvement Center (CIMMYT) and
Sydney University, the
research illustrates the major genetic improvements possible
without genetic modification (GM) technology.
“Wheat breeders often use wild relatives of wheat as sources of
novel genes in breeding new disease-resistant wheats,” research
team leader Dr Phil Larkin says.
“The exciting part of the new research is that we have been able
to retain the useful genes but leave behind the associated
undesirable genes - most notably in this case those for yellow
flour colour, an important quality characteristic in wheat,”
Dr Larkin says.“Unfortunately genes from wild relatives usually
come in large blocks of hundreds of genes, and often include
undesirable genes. Furthermore, these blocks of genes tend to
stay together, even after many generations of breeding.
“The problem can be so difficult to overcome that plant breeders
sometimes give up on very valuable genes because they cannot
separate them from the problematic genes.”
A paper published this month in the respected international
journal Theoretical and
Applied Genetics details how the team ‘recombined’ two wild
blocks of genes from two different Thinopyrum grass species – a
wild relative of wheat – bringing together resistance genes for
leaf rust and Barley Yellow Dwarf Virus (BYDV), two of the
world’s most damaging wheat diseases. The recombined gene
‘package’ may also carry a resistance gene against a new stem
rust strain which is causing concern worldwide.
By developing new ‘DNA markers’ and by careful testing the team
has produced a number of the disease resistance ‘packages’ for
wheat breeders, making it faster and easier to include these
important disease resistance traits in future wheat varieties.
It is hoped other examples will follow and the genetic diversity
available in wild species can be recruited more extensively for
wheat improvement.
|
Fighting off the yellow dwarf |
Learn how the world’s first’ trigenomic’ chromosome
can be used to breed wheat varieties resistant to
diseases like Barley Yellow Dwarf Virus and leaf
rust.
http://www.csiro.au/multimedia/YellowDwarfVirus.html
The world’s
first trigenomic chromosome has been developed,
using the disease resistance genes from three
different grass species.
The chromosome was pioneered by CSIRO
researchers, in collaboration with the
International Maize and Wheat Improvement Center
(CIMMYT) and Sydney University.
A paper published this month in the respected
international journal Theoretical and Applied
Genetics details how the team ‘recombined’ two
wild blocks of genes from two different
Thinopyrum grass species – a wild relative of
wheat – bringing together resistance genes for
leaf rust and Barley Yellow Dwarf Virus (BYDV),
two of the world’s most damaging wheat diseases.
In this podcast, research team leader, Dr Philip
Larkin explains how the trigenomic chromosome
was created.
|
Other news
from CIMMYT
/
from Sydney University |
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