Canola heat tolerance in the spotlight

Researchers investigate canola lines to better handle heat stress


Oilseeds
Aa

World search unveils genetics to help breed canola that can beat the heat.

Aa
Research is continuing into genetics that will help canola crops better handle heat and drought stress in western and southern regions. PHOTO: GRDC

Research is continuing into genetics that will help canola crops better handle heat and drought stress in western and southern regions. PHOTO: GRDC

Western Australian research has identified and delivered 14 canola lines able to cope with heat and/or drought stress.

The research was undertaken at The University of Western Australia (UWA) as part of the projects 'Expanding the Brassica Germplasm Base through Collaboration with China and India' and the 'National Brassica Germplasm Improvement Program'. Both have GRDC investment.

As well as identifying canola lines that can be used as parental lines in canola breeding programs, the research has made recommendations for canola breeding protocols.

UWA Institute of Agriculture researcher Sheng Chen told the AusCanola 2018 conference, in September, that drought and heat stress was impacting significantly on Australias $1.7 billion canola industry, and high temperatures could halve the yield potential of some varieties currently grown.

Dr Chen says canola lines that had been identified by UWA researchers included those with good tolerance to drought, moderate tolerance to both drought and heat and those with the ability to recover well from drought or heat.

I expect this germplasm, which includes material from China and India, will be very useful for Australian canola breeders, he says.

The overseas material was sourced from the project, led by the University of Melbourne, that collaborated with China and India to expand the canola germplasm base and incorporate desirable traits, also including disease resistance and shatter tolerance, into Australian canola breeding programs.

I expect this germplasm, which includes material from China and India, will be very useful for Australian canola breeders - The University of Western Australia Institute of Agriculture researcher Dr Sheng Chen

Another recent achievement of the canola heat tolerance research is the finding that the stigma (female part) of the canola flower is more sensitive to heat stress than the pollen (a male part) of the flower.

This finding is useful to canola breeders who are making F1 hybrids because it means they should use a heat-tolerant female canola line to make F1 hybrid seed, and this will produce a heat-tolerant hybrid offspring, Dr Chen says.

The research also confirms the most heat-sensitive stage for canola is seven days before and seven days after the plant produces its first open flower.

Average reductions of 85 per cent occurred in F1 hybrid seed production on female plants when subjected to daily maximum temperatures of 32C for seven days following their first flower in a controlled environment, Dr Chen said.

In field trials, the most heat susceptible varieties suffered yield losses of up to 50 per cent when exposed to these temperatures they could not recover after the heat stress.

Aa