Genetic discovery to keep crops disease-free

Feb 10, 2014

Curtin University researchers have found a way to breed disease-resistant wheat with no downside, potentially bringing multi-million dollar savings to Australia's agricultural industry.

According to John Curtin Distinguished Professor Richard Oliver, Director of the Australian Centre for Necrotrophic Fungal Pathogens (ACNFP) at Curtin, farmers can lose more than 0.35 tonnes per hectare in wheat yields to Yellow Spot, even after applying fungicide.

For an average-sized farm of 4000 hectares, this could mean an almost $500,000 loss to disease per year – or about $212 million worth of damage to the wider Australian agricultural industry.

Funded by the Grains Research & Development Corporation, Professor Oliver and his team, in conjunction with independent research provider Kalyx Australia, have demonstrated that by taking away disease-sensitivity genes from the wheat germplasm, pathogens find it difficult to latch onto wheat and cause damage.

"Our finding will help breeders produce crops in which disease losses are 60 to 80 per cent lower, and would be a real win for farmers – they will often be able to avoid using foliar fungicides," Professor Oliver said.

"Before now, breeding for resistance to Yellow (Tan) Spot and Septoria Nodorum Blotch was very time-consuming – no molecular markers were in use. The key has been to supply breeders with specific proteins (we call them effectors) that the fungi use to cause disease.

"For the first time, our technology allows for a steady and sustained improvement in disease resistance without affecting the farmer's pocket.

"Furthermore, breeders are able to devote more time and resources to breeding for yield, as well as for rust and frost resistance."

Using large wheat variety trials provided by Kalyx Australia, the team looked at yield loss of different cultivars (plants chosen for breeding because of desirable characteristics) when subjected to natural disease and stress pressures in the WA wheatbelt.

They compared cultivars with disease-sensitivity genes to cultivars that lacked these particular genes, and were able to show that the cultivars lacking the gene showed no yield loss and in some instances increased yields in the presence of disease.

From this, the team were able to conclude if a sensitivity gene was eliminated, there would be minimal associated risks and it would be a safe and straightforward strategy for improving disease resistance.

Professor Oliver said this research had never been done before as direct mapping for disease resistance had not led to useful molecular markers.

"Previously geneticists would infect plants that were progeny of crosses between relatively resistant and relatively susceptible parents before doing the QTL (quantitative disease-resistance gene) mapping. But as is multifactorial due to the several effector reactions, the QTL mapping was always a bit fuzzy and was therefore never passed on," Professor Oliver said.

"Our research looks directly at the loci that recognise the pathogens, which can be readily identified using a process we developed earlier, thereby bypassing the need for QTL mapping."

Explore further: Climate-resilient wheat

More information: The paper, Absence of detectable yield penalty associated with insensitivity to Pleosporales necrotrophic effectors in wheat grown in the West Australian wheat belt, can be found at onlinelibrary.wiley.com/doi/10… 1/ppa.12191/abstract

add to favorites email to friend print save as pdf

Related Stories

Climate-resilient wheat

Jan 20, 2014

JIC scientists have discovered that changing temperatures can have a big effect on resistance to yellow rust, one of the most serious diseases of wheat.

Building disease-beating wheat

Dec 12, 2007

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 ...

Resistance gene found against Ug99 wheat stem rust pathogen

Jun 27, 2013

The world's food supply got a little more plentiful thanks to a scientific breakthrough. Eduard Akhunov, associate professor of plant pathology at Kansas State University, and his colleague, Jorge Dubcovsky from the University ...

New club wheat is tough on fungi

Feb 20, 2013

Pacific Northwest wheat growers now have added insurance against outbreaks of yield-robbing fungi, thanks to "Cara," a new, white winter club wheat cultivar developed by U.S. Department of Agriculture (USDA) ...

Recommended for you

'Most famous wheat gene' found

22 hours ago

Washington State University researchers have found "the most famous wheat gene," a reproductive traffic cop of sorts that can be used to transfer valuable genes from other plants to wheat.

Mosses survive climate catastrophes

Sep 15, 2014

Mosses have existed on Earth for more than 400 million years. During this period they survived many climate catastrophes that wiped out more robust organisms such as, for example, dinosaurs. Recently, British ...

Final pieces to the circadian clock puzzle found

Sep 14, 2014

Researchers at the UNC School of Medicine have discovered how two genes – Period and Cryptochrome – keep the circadian clocks in all human cells in time and in proper rhythm with the 24-hour day, as well ...

User comments : 0