Collaborative effort breeds better understanding
GroundCover™ Issue: 90 | 11 Jan 2011
By Catriona Nicholls
As part of a four-year national project, researchers in Western Australia, South Australia and Queensland have been joining forces to better understand the vagaries of frost across the different environments in each state.
Research officer Dr Ben Biddulph, of the Department of Agriculture and Food, WA (DAFWA), has been managing the National Frost Characterisation site at Cuballing, WA.
“As a team we aim to better understand the complexities of frost in different environments, to determine whether there is genetic variation for frost tolerance in the field, to explore potential genetic and environmental interactions between regions, and to provide a focus on methods,” Dr Biddulph says.
“If there is variation – and preliminary results suggest that some genotypes may be more sensitive than others – we can assist breeding programs to develop varieties less sensitive to frost.”
While frost-tolerant crops are the ultimate goal, in order to get to that distant point we need a better understanding of how different frost events affect different cereals in different environments.
As every grower who has ever suffered the impacts of a frost-damaged crop already knows, yield losses can be devastating.
During 2005, WA growers lost 700,000 tonnes of wheat, worth $90 million, to frost and during 2008 frost damage cost the WA grains industry an estimated $109 million.
“What this collaborative project has allowed us to do is to bring together all the existing knowledge we have about frost and to standardise our approaches,” Dr Biddulph says
“This will allow us to get a handle on exactly what this phenomenon is, how it behaves and how various cereal species, and varieties within those species, are impacted by frost events.
“It’s not as simple as temperatures plummeting below zero at flowering causing crop sterilisation – it’s much more complex than that.
“We now have a standard set of weather stations at each site, specifically designed to monitor the conditions experienced at the canopy level during a frost, to help us better understand what is happening during each frost event and to compare the results from three sites.”
For the small, nationally coordinated trials, in the interest of a consistent approach, the Queensland and WA researchers have adopted the method used and developed by the University of Adelaide at the Loxton site in SA to screen for frost damage. In parallel, Queensland researchers are using locally developed methods, based on more than 30 years of research in Queensland and NSW, for more detailed screening and physiology studies.
“Using the standardised meteorological stations we know all the temperature measurements are comparable at each site, so even though frost events occur at different times and each event is different we can now collate the damage and provide a common frame of reference to compare the results.”
Results a mixed bag
According to Dr Biddulph, three years into the four-year project the results are somewhat of a mixed bag.
“There are some consistencies coming to light between SA and WA,” Dr Biddulph says. “Initial indications are that mid-winter conditions are more severe and are more often encountered at the Queensland test site.”
Further analysis of the data will be needed before these indications can be verified.
Seeking out the differences
According to Dr Biddulph, typical damage across varieties is hard to describe.
“Every event is different,” he says. “But when we get between 20 per cent and 70 per cent damage it highlights the differences between varieties.”
Dr Biddulph is quick to remind growers that the ‘silver bullet’ of a frost-tolerant wheat or barley variety is far from being ‘just around the corner’.
“We still need to confirm these varietal differences and there are still no confirmed genetic sources that are less susceptible than the best current cultivars,” he says.
“While identifying how and why some varieties are less frost susceptible than others may lead to solutions down the track, we now need to screen for and identify germplasm and develop processes to put enough varieties through to make it viable for breeding programs; we need to be able to screen thousands of varieties a year.”
Dr Biddulph recently received a scholarship from the GRDC to develop pre-screening techniques in collaboration with CSIRO Plant Industry to identify desirable tolerance traits.
He undertook laboratory experiments at CSIRO Plant Industry in Canberra with principal research scientist Dr Rudy Dolferus, who has worked on identifying heat and drought-tolerance traits during pollen development in wheat and rice. The research examined the chilling or cold tolerance of 10 popular and experimental wheat varieties.
“The aim was to see if we could find a correlation between cold tolerance under artificial conditions (1ËšC) and frost susceptibility in the field (0.0 to –3.0ËšC)”, Dr Biddulph says.
“The results showed that the most cold-sensitive variety in the laboratory was also sensitive in field frost events.
“We can now use this information to examine what impact frost and chilling events have on commercial germplasm at the critical plant development periods of pollen development and flowering.
“In the short term, by developing pre-screening methods to identify and characterise commercial germplasm, we can give growers more confidence in their existing varieties.
“In the longer term we hope to assist breeders in developing new varieties less sensitive to frost.”
The project is supported by the GRDC, DAFWA, the University of Adelaide and the Queensland Alliance for Agricultural and Food Innovation (QAAFI) – a joint initiative between the University of Queensland and the Queensland Department of Employment and Economic Development and Innovation (DEEDI).
GRDC Project Code DAW00162
Region North, South, West
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