THE incorporation of wild barley genetics into commercial varieties during trials conducted by University of Adelaide researchers could lead to new breeding lines with improved yields and drought tolerance.
Anh Pham, working in a project led by Department of Agricultural Science head Jason Able, is evaluating 108 experimental barley lines across three years to assess the performance of genomic regions from wild barley that could lead to improved yields, yield components and yield stability in future commercial varieties.
In a previous project funded by the GRDC, a population of barley was imported from Germany that had been developed by crossing 25 wild lines with commercial variety Barke.
Genomic regions from the wild barley, housing yield-lifting components, were identified and selected to cross with three leading commercial varieties grown in Australia - Compass, LaTrobe and GrangeR.
"I made crosses so the beneficial wild barley genomic regions were put into the background of the Australian varieties and they are being trialled in the field to see if the new genetic combinations will change yield components like grain number per ear or thousand grain weight," Dr Pham said.
She said they also identified genomic regions that improved barley biomass in water-limiting conditions in the green house.
They also wanted to investigate whether wild barley genetics could help improve drought tolerance and stabilise commercial yields across a range of growing conditions.
"In a lot of crops, not only barley, we are looking for genetic diversity and wild barley is an excellent reservoir of a range of genetic tools like disease resistance and components that may improve yield," she said.
"We want to evaluate that barley population from Germany in the Australian context - Australian environments, rainfalls, temperatures - and also test it out in the field under pressure from isolates like net form net blotch, spot form net blotch, scald, powdery mildew and leaf rust to see if there is anything from wild barley that is beneficial for disease resistance."
The first year of field trials were conducted last year at Roseworthy, Tarlee and Bordertown.
Among the traits measured were yield, yield components including tiller number, grain per ear and thousand grain weight, as well as agronomic traits like height, lodging and disease resistance.
Dr Pham said the field trials found 14 experimental lines that had yields that were 5 per cent higher than the yields of the commercial parent varieties used for crossing. The highest improvement in yield seen was 9pc over Compass and 16pc above GrangeR.
Dr Pham said the first year of results were environmentally-specific, with none of the 14 high-performing lines having higher yields at all three sites, though seven lines did cross the 5pc yield improvement threshold at two sites.
"A line, for example, would perform well in Tarlee and Roseworthy, but not in Bordertown," she said.
Promisingly, Dr Pham said they identified six experimental lines that had 5pc or better yields at Roseworthy - the trial site with the lowest rainfall among the three in 2020.
"This shows promise for improving yields in low rainfall environments," she said.
Lines with higher thousand grain weight (up to 10pc higher) and grain per ear (up to 15pc higher) than all of the commercial varieties were also identified, some of which were among the 14 lines with yield improvement.
"Two genomic regions from the exotic barley also exhibited a significant increase for grain number per ear and thousand grain weight in lines carrying the regions of interest, which validate the results obtained from the previous genetic study " Dr Pham said.
"These genomic regions are a potential new source of genetic diversity for breeders to improve yield components in barley."
Dr Pham says malting quality tests are also being conducted on the lines with equal and higher yield than the backcrossing parents, to provide breeders with a complete performance profile.
Research will continue, with the experimental lines to be further evaluated at nine sites in SA, WA and NSW.
"The goal is to provide breeders with adapted germplasm that has yield-improving traits from wild barley, but not their unfavourable traits," Dr Pham said.
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