Hub takes variety advances to a new level

Wheat variety development has been given an important boost through a new research hub that pairs three universities with three breeding companies to advance and potentially speed-up new trait discoveries. The hub pulls together advanced pre-breeding technology developed over the past decade and fosters its utilisation by commercial breeding programs.

Included is advanced technology that can rapidly screen a vast amount of biodiversity for traits that can potentially improve crop resilience, grain quality and yield.

First among the traits to be targeted by the hub is tolerance to the combined stress of heat and drought.

This work is underway at the ARC Industrial Transformation Research Hub for Wheat in a Hot and Dry Climate, a five-year program that is co-funded by the Australian Research Council and the GRDC. It is headed by Dr Delphine Fleury at the University of Adelaide’s Waite campus. Participant breeding companies LongReach, Australian Grain Technologies and InterGrain are running the field trials associated with typing and screening novel germplasm.

Pre-breeding expertise is provided by the University of Adelaide and University of Sydney, while the University of South Australia (Uni SA) is developing algorithms to process field trial images captured by drones.

Dr Fleury says the hub has made impressive progress closing gaps in the way pre-breeders and breeders seek out new traits – many of which are much more genetically complex than the targets of previous breeding efforts.

The hub aims to:

  • find new traits and genes for improving grain yield and quality in the Australian climate;
  • increase the genetic diversity of Australian wheat; and
  • develop new genomic and phenomic technologies to screen physiological and genetic plant characteristics with unprecedented efficiency and precision.

Advanced bioinformatics and statistical methods will allow the massive amounts of data generated to be analysed quickly.

Hub activities are structured around four programs: drone imaging technology; a new, highly diverse mapping population; screening for combined heat and drought tolerance; and investigations into fluctuations in grain protein levels in response to climatic conditions.

“We are seeing the most progress in the drone program,” Dr Fleury says. “This uses imaging technology to robotically screen plants and algorithms to convert plant growth data to physiological and genetic information. Collaboration between Uni SA, the Plant

Accelerator (at the Waite Campus) and breeders within the hub has vastly improved the image-processing algorithms, which expands the range of this technology and its capability.”

Screening is also getting underway with a new pool of 15,000 wheat lines, called the Nested Association Mapping (NAM) population.

This samples the biodiversity of 75 exotic wheats sourced from around the world. This material is crossed with two Australian varieties (Gladius and LongReach Scout) to create material that breeders can use directly to introduce new traits into Australian varieties.

The first 1000 yield plots of NAM lines were sown in 2017, with more material scheduled for planting during the 2018 season, including at sites that experience terminal heat and drought. A central aim of this early screening is to cull material that is agronomically irrelevant – for example, plants that are too tall.

“With breeding companies running the field trials, breeders also have the opportunity to observe the plants and pick material of
interest to them to progress further,” Dr Fleury says. “In the meantime, pre-breeding researchers can phenotype the material and
map genes of interest.”

To further advance heat and drought-tolerance research, 350 lines representing worldwide diversity of spring wheat are also being studied within a heat chamber, where it is possible to apply heat and drought stress at specific stages of the plant’s development.

Meanwhile, studies are attempting to understand why grain protein levels drop in wetter seasons. This involves contrasting the physiology and genetics of a wheat variety that maintains protein content in wet seasons (LongReach Spitfire) with a variety that does not (EGA Gregory).

“Genetic diversity is the key to making progress in variety development,” Dr Fleury says. “That is why the hub has focused on generating new, more diverse mapping populations and the technology to screen for complex traits.”

GRDC Research Code UA00160

More information:

Delphine Fleury,
delphine.fleury@adelaide.edu.au