Investment

The susceptibility of new wheat varieties to the Late Maturity alpha-Amylase (LMA) defect is a key concern for breeding programs developing high-quality milling grade wheat in Australia. A capacity to characterise and quantify actual LMA risk at field scale remains a crucial outstanding industry issue. The overarching aim of this project was to develop a LMA risk model from measured data collated for: field trials with four times of sowing, for 24 wheat lines, at 6 locations, for two seasons across the Australian wheat belt. The experimental data from this project was used to develop and calibrate a LMA expression model driven by environment.

Deploying this LMA incidence model for a low LMA susceptibility group showed trends of expressing at cooler ambient environments (~ 20 C), while genotypes with moderate LMA susceptibility showed trends to expressed at slightly warmer environments (~ 23 C). In addition, the simulated LMA risk for the lower LMA susceptible genotypes showed spatial and temporal changes towards lower trends in LMA risk as flowering dates increased from early August to early November, across 245 shires in the wheat-belt.

Results of these developments will allow better quantification of the actual risk of LMA incidence at field scale and generation of seasonal diagnostic data to identify likely LMA "hotspot" that should be avoided for a given sowing date and genotype across the wheat-belt. It will also enable better management of breeding systems to support genetic gain for yield while managing LMA risk.