Breeding for the future – avoiding climate extremes and maximising yield of spring wheat in water-limited environments
Scott C. Chapman1, Bangyou Zheng1, Karine Chenu2 and Matthieu Bogard3
1CSIRO Plant Industry, 306 Carmody Rd, St.
Lucia 4067 QLD, Australia
Extreme climate (frost, heat and drought) can severely reduce yield. Adaptation to maximise seasonal utilisation of solar radiation and rainfall is achievable through combinations of management and genotype, which may need to change in future environments. As global warming has already increased mean temperature and the occurrence of extreme temperatures (and potential risk of drought) in Australia, it has become urgent to accelerate the 5–20 year process of breeding for new wheat varieties, to adapt to future climate. We analyzed the patterns of frost and heat events from 50 years (1960–2009) for 2864 weather stations (Zheng et al 2012). For a subset of locations, flowering dates and drought patterns for contrasting-maturity varieties were simulated for a wide range of sowing dates for ‘current’ climate and eight future scenarios (high and low CO2 emission, dry and wet precipitation scenarios, in 2030 and 2050). The results highlighted the substantial spatial variability of frost, heat and drought events across the Australian wheatbelt in current and future climates and the opportunities to adapt via maturity and sowing time.
We further examined this adaptation by incorporating simulation parameters as affected by specific combinations of spring and winter alleles of VRN and PPD genes and their interaction with ‘earliness-per-se’ effects (Zheng et al 2013). Presently, we are extending the model to include SNP effects on these simulation parameters (unpublished data). While drought and heat events are less frequent in Nordic environments where spring wheat is grown, the crop yields (3 to 5 t/ha) are not so different to Australian environments. However, environmental limits are largely associated with a short season that is bounded by extreme low temperatures (and precipitation events), as well as cool temperature limitations to growth rate and development. For potentially warmer and longer seasons in the future, it may become important to consider whether there is sufficient genetic variability to extend the crop season.
Zheng et al Global Change Biology 2012. Breeding for the future: what are the potential impacts of future frost and heat events on sowing and flowering time requirements for Australian bread wheat (Triticum aestivium) varieties?
Zheng et al J Exp Bot 2013. Quantification of the effects of VRN1 and Ppd-D1 to predict spring wheat (Triticum aestivum) heading time across diverse environments