[ASC-media] The technology of grass

Niall Byrne niall at scienceinpublic.com.au
Mon Aug 7 00:14:09 CEST 2006

Fungi and grass work together to fight insects

Australian livestock farmers could soon be reaping the rewards of the
latest New Zealand research into "smart grasses" that fight back against
insects, and can even scare birds. 

Ag Research New Zealand researchers have been working for years on fungi
that co-exist with grass. Their main interest is breeding fungi that
improve grazing grasses. These endophytes can, for example, make the
grass insect and drought resistant. Along the way they've found a new
application - protecting airports from bird strike. 

Field trials are currently underway in Australia for their latest
ryegrass endophyte strain which has the potential to increase
productivity, offer better insect resistance and greater persistence.
The work is being presented in Melbourne today at the Agricultural
Biotechnology Industry Conference. 

The new endophyte strain, called AR37, has been discovered by scientists
at New Zealand's AgResearch, the country's largest crown research

Endophytes are a type of fungus that lives in the spaces between plant
cells. Over the past two decades, AgResearch scientists have been
studying these fungi which appear to offer plants insect resistance. But
as well as giving insect resistance, endophytes can be toxic to the
animals that graze on them causing illnesses such as ryegrass staggers,
as well as productivity loss.

In 1997, a team at AgResearch discovered an endophyte strain - called
AR1 - which, when embedded in ryegrass, offers protection against
numerous insects, such as black beetle and Argentine stem weevil,
without causing ryegrass staggers. AR1 ryegrasses now account for well
over 50 per cent of the proprietary ryegrasses sold in New Zealand.

But scientists at AgResearch believe they have found an endophyte which
can raise the bar higher. 
AR37, which was launched recently at New Zealand's national Field Days,
appears to protect against root aphid and porina caterpillar, while
standing up to black beetle better than AR1. 

Moreover, AR37 seems to be far less toxic to sheep and cattle than
endophyte commonly infecting traditional ryegrasses. Animal trials
indicate that under extreme conditions AR37 may cause mild staggers in
sheep but such conditions are unlikely to occur in farms and commercial
farm trials have as yet produced no reports of staggers.  AR37 grasses
also seem to develop deeper and more robust root systems than their
counterparts which means farmers will probably not have to replant so

This should all be good news for farmers in Victoria and New South Wales
where large areas are planted with ryegrass.

"This particular endophyte is very different to anything that is out
there at the moment," suggests John Stewart, R&D manager with PGG
Wrightson Seeds, which has collaborated with AgResearch, Grasslanz, and
Meat and Wool New Zealand in the development of AR37 ryegrass endophyte.

For one, scientists believe chemical compounds called epoxy janthitrems
are responsible for giving AR37 its insect fighting qualities. This is a
new group of compounds never seen before and different to the compounds
believed to be responsible for insect deterrent in other endophytes. 
AR37 will be sold from early 2007 in New Zealand and is expected to be
available in Australia in the near future. 

And the bird-scaring grasses - these are currently being trialled at
Christchurch Airport. If the insects can't eat the grass, and the seeds
taste bad to birds, then they hope the birds will stay away. 

For further information contact Niall Byrne, +61 417 131 977,
niall at scienceinpublic.com; Chris Boalch, Sector Director -
Biotechnology, New Zealand Trade and Enterprise, +64 27 2899581,
chris.boalch at nzte.govt.nz; Sophi Nauman, NZTE, +64 27 477 1987

For more information on New Zealand, please visit www.newzealand.com.


Niall Byrne

Science Communication Consultant
Science in Public
PO Box 199 Drysdale 3222 Australia
(185 Scotchmans Road Portarlington 3223) Ph +61 3 5253 1391, fax +61 3
9923 6008, mobile 0417 131 977 
niall at scienceinpublic.com or niallprivate at scienceinpublic.com for
personal matters

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