South Australia
April 23, 2008
Discovery supports multi-billion
dollar industry
Brief
Gene function scientists at
SARDI are helping to take the guesswork out of developing an
exciting new line of pastures (non-GM), discovering a
crucial gene known to bolster medic legume growth by as much
as 50%. The discovery of the gene, which turns off the
sensitivity of legume pasture to traces of commonly used SU
herbicides, often left-over from cropping, is a step up for
Australia’s pastoral industries, now worth more than $14
billion. Now plant breeders have the means to detect the
presence of the valuable gene in days, rather than months
and to drastically accelerate legume improvement in the
ongoing challenge to maintain feed supplies for Australia’s
livestock industries.
Precision accelatates pasture
development
Gene function scientists at SARDI (SA Research and Development
Institute) are helping to take the guesswork out of breeding an
exciting new line of non-GM pastures.
In 2007, SARDI and University of Adelaide scientists released
Angel, the world’s first medic pasture able to regenerate
strongly after cropping because it can tolerate residues from
widely-used sulfonylurea herbicides.
Now SARDI’s Gene Function scientists have taken the innovation
one step further, by pinpointing the critical gene responsible
for this valuable trait.
This development offers plant breeders the opportunity to
drastically accelerate their improvement programs, which
contribute to Australia’s pastoral industries worth more than
$14 billion.
Sulfonylurea herbicides (SU) are used across millions of
hectares during the cropping phase but when soils carryover
minute traces, sensitive legume varieties can suffer. Trials
show SU-tolerant pasture offers farmers the ability to quickly
boost livestock feed by as much as 50% after cropping.
Productive pasture stands are also better at fixing nitrogen
from the atmosphere and raising organic matter to enrich soil.
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SARDI’s Pasture scientists David Peck (left) and Dr Ram
Nair (right) combined efforts with Gene function
researcher Dr Klaus Oldach to identify an economically
important gene to advance pasture development. |
SARDI’s Gene Function scientist Dr
Klaus Oldach has led the team responsible for identifying the
gene form.
“Pastures are a valuable asset underlying Australia’s pastoral
industries worth billions, so as a scientist, it is highly
rewarding to link an economically important trait to its genetic
basis,” Klaus said.
“Our research has identified the gene form that enables medics
to regenerate strongly in the presence of SU herbicides
residues, its activity, where this gene form resides within the
genome (chromosome), and the molecular markers, or genetic
signposts to identify its presence or absence in breeding
material.
“For plant breeders it’s the difference in knowing in days
rather than weeks or months, whether plants they have selected
are carrying the advantageous gene. The capacity to incredibly
accelerate breeding for this trait, means scientists can focus
their energies on developing other favourable traits.
“With these diagnostic tools breeders can be 100% confident they
are selecting plants that carry the SU tolerance trait. DNA does
not give an ambiguous answer, in contrast to visually assessing
plants in the field, where environmental factors can ‘tamper’
with the results to mislead researchers.”
SARDI’s Gene function and pasture breeding scientists combined a
suite of techniques to verify the gene discovery. They applied
traditional genetic population approaches, sourced bioformatics
information available within the public domain, and finally,
undertook gene function analysis.
Importantly research has shown that existing SU tolerant
varieties can be readily controlled so they don’t become a weed
when paddocks return to cereal cropping.
The first SU tolerant variety Angel was developed with support
from GRDC and further agronomic research into its benefits
continues with the SA Grains Industry Trust Fund. |
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