Australia
January 30, 2008
Source:
GRDC's The Crop Doctor
Necrotrophic fungal pathogens –
fungi obtaining nutrients from dead or dying plant cells – such
as root rot, black spot and Fusarium wilt, cost growers millions
of dollars a year.
According to Professor Richard Oliver, Director of the Grains
Research and Development Corporation (GRDC) supported Australian
Research Centre for Necrotrophic Fungal Pathogens (ACNFP) at
WA’s Murdoch University, fungal necrotrophic diseases are the
greatest constraint to the long term viability of Australian
grain legume production.
Recorded crop losses from these pathogens, at around 25 per
cent, erode grower confidence and reduce income.
Phytophthora medicaginis, which causes root rot in chickpeas,
costs up to $3.5 million in crop loss and control measures in
Australia.
Expanding and maintaining legume cropping area is therefore
directly linked to providing robust crop protection solutions.
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With GRDC support,
Dr Judith Lichtenzveig has identified three
genomic regions coding for M. truncatula
resistance to Fusarium wilt, which affects many
crops, including faba bean, pea, lentil and
chickpea |
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Professor Oliver’s ACFNP team has
identified strong resistance to key fungal diseases of grain
legumes, including Ascochyta species, Phoma medicaginis and
Fusarium oxysporum in the legume Barrel Medic or Medicago
truncatula.
According to Professor Oliver, legume crops have been regarded
as too small to justify the expense of developing a set of
markers, traits and maps for effective-marker assisted breeding
and legume breeding is therefore hampered by a lack of molecular
tools.
However, M. truncatula and other legume species show synteny, or
co-linearity of the gene order and Barrel medic can be used as a
model legume to map genes coding for disease resistance in other
legume species.
With GRDC support, Dr Judith
Lichtenzveig (photo) has identified three genomic regions coding
for M. truncatula resistance to Fusarium wilt, which affects
many crops, including faba bean, pea, lentil and chickpea.
Dr Simon Ellwood has mapped genes for resistance to Phoma, a
close relative of the pea black spot pathogen.
According to Dr Lichtenzveig, conserving gene structure and
function among related legume species will enable scientists to
understand the relationship between genotype and resistance in
the less examined crops such as chickpea and lupin.
The close genetic relationship between the model species and
other legumes will help in molecular marker and accelerated crop
development.
Molecular markers are being used to develop maps for genes
conferring resistance to necrotrophic fungal pathogens in lupin,
chickpea, lentil, lucerne and faba bean.
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The Crop Doctor is
GRDC Managing Director,
Peter Reading |
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