Canola crops benefit from adding genes to combat heat stress

More growers could turn to Canola if research currently underway results in seed varieties better suited to hotter conditions

Canola is Australia’s third most economically important grain crop with up to 3.4 million tonnes expected for season 2020-21

Paddock have been planted down with experimental Canola in Western Australia and New South Wales, in trials that will help plant breeders decide what needs to be added to the current seed selection and give growers more resilient crops.

Many growers turned to Canola for much needed cash this winter season and have been rewarded with an expected 3.4 million tonnes haul, however weather conditions play a major role and in a season of less favourable conditions the harvest can easily drop by 30%.

To correct this disparity research is underway, the long-term objective over the five year course is expected to result in providing more heat-tolerant germplasm, genetic material for Canola seeds or tissues.

Identifying the genes that make canola heat-tolerant and better suited for a wider range of local growing conditions will be led by The University of Western Australia’s (UWA) Institute of Agriculture Research Fellow Sheng Chen.

Previous research at UWA identified temperatures of more than 30-deg Celsius during flowering reduced seed yield – Dr Sheng Chen is working to reduce losses – photo Evan Collis

Dr Sheng Chen said from this research plant breeders could create new commercial varieties, and help the industry maintain productivity as temperatures rose.

“Heat stress is globally identified as an issue of increasing concern, with average temperatures projected to rise in coming decades,” Dr Chen said.

“Canola is particularly sensitive to heat stress.

“Previous research undertaken at UWA identified that temperatures of more than 30 degrees Celsius during flowering reduced seed yield.

“In current canola varieties grown in Australia, losses could be as much as 300 kilograms per hectare for every one degree Celsius increase in the average daily temperature at flowering.”

Dr Chen said drought and high temperatures often occurred in combination, putting a dual stress on plants, which made it difficult to separate the combined influences in the field.

“However, the genes that influence a plant’s ability to withstand water stress are different to those that make them heat tolerant,” he said.

“This project looks specifically at the genetics of heat tolerance in canola, which is Australia’s third most economically important grain crop.

“It aims to separate the heat tolerance genes initially through the use of controlled-temperature experiments, which will screen 200 canola lines a year at UWA in a search for heat tolerant germplasm.”

Its back to the lab for a Canola plant breed that can withstand hotter growing conditions – photo Evan Collis

Selected germplasm from preliminary screening in controlled-environment rooms at UWA will be validated for heat tolerance in the field by the NSW Department of Primary Industries (NSW DPI), using portable heat chambers and in irrigated paddock trials in eastern states and in WA.

After starting in 2019, the first year of the project was spent developing research protocols and criteria to assess heat stress and building the facilities needed to conduct trials.

These included two new controlled-environment rooms adjacent to screen-houses at UWA’s Shenton Park Field Station, and eight portable heat chambers at the NSW DPI Wagga Wagga Agricultural Institute.

NSW DPI is a project partner, led by Rajneet Uppal, along with GRDC, UWA, the Western Australian Department of Primary Industries and Regional Development (DPIRD), and the western node of the Statistics for the Australian Grains Industry group (SAGI West). The five-year research project that commenced in 2020 is funded by the Grains Research and Development Corporation (GRDC).