IRTG Seminar Series - “Breeding ‘Systems Resilience’ and Not ‘Crop Resistance’ for Reliable Crop Production in Future Climates”

Abstract

Climate change is forecast to significantly drive crop productivity and reliability to affect global food security in the future. To address this challenge, efforts are underway to guide future breeding efforts to adapt crop varieties to the environments and systems in which they will be grown. However, successful breeding relies on a: (1) strong and systematic signal to permit selection for important adaptation alleles; and, (2) an established value proposition for environmental constraints poorly understood in terms of frequency and intensity. Together, these challenges risk significant cost in time and effort targeting alleles for ‘resistance’ to individual environmental constraints (ie frost, heat and drought) and ignoring the potential for crop damage through combinations of these. Evidence to date has seen substantial variability in these climate extremes and their interactions (e.g. temperature × VPD) from one season to the next with southern NSW experiencing every rainfall decile in the past decade alone. One approach to develop adapted crop varieties is to target traits that support opportunistic management in the cropping system to ‘play the season’, effectively reducing business risk in current and future climates. Such traits can complement ongoing, longer-term and more challenging breeding efforts to identify novel traits and new genetics that can resist specific climatic extremes. I will report on studies targeting constitutively expressed ideotypes (e.g. high biomass, shorter-duration wheats for later sowing, increased rates of spike and grain-filling and increased coleoptile length) to establish their value to increase profitability of wheat systems in current and future environments. The genetics for these traits are understood, and are available now, and there are no expected costs to grain yield or quality in cooler, wetter seasons. I will also discuss the potential to mitigate risk by breeding traits that allow other economic uses of crops unavoidably and inevitably damaged by heat, frost or drought such as awnless, milling wheat varieties suitable for domestic and export hay.