Mr Muhammad Yahya1, Dr Najeeb Ullah1, A/Prof. Daniel Cozzolino1, Dr Jack Christopher1, Dr Estelle Kuhn2, A/Prof. Karine Chenu1
1The University of Queensland, Gatton, Australia, 2INRAE, Paris, France
Biography:
A/Prof. Karine Chenu is a senior ecophysiologist and crop modeller at the University of Queensland. She leads a group that works on crop modelling, plant design and breeding strategies in winter cereals. Karine’s research mainly concerns understanding trait physiology and genetics, developing gene-to-phenotype crop modelling and exploring novel combinations of genotypes, environments and management practices to assist productivity improvement in changing environments. Karine has published over 60 papers in high-ranking international journals, and over 60 book chapters and refereed conference papers, including some breakthrough papers on crop modelling, plant response to heat and drought, and genetics.
Abstract:
Wheat is highly susceptible to heatwaves, especially during reproductive and grain-filling periods. Multi-environment trials were conducted over three years at three locations with different sowing dates to investigate the impact of heatwaves on individual grain weight, and grain protein content in 22 wheat genotypes. Genotypes were grown using a novel photoperiod-extension method (PEM) where single stems of synchronised phenology were tagged and hand-harvested at maturity. Adjacent to PEM trials, genotypes were cultivated in conventional yield plots and machine-harvested at maturity. Significant effects of sowing times and genotypes were observed for individual grain weight and protein content (p<0.001). Individual grain weight and grain protein content were also strongly correlated with the number of post-flowering hot days. The clear trade-off observed between grain weight and grain protein content underscored that adverse heat-stress effects resulting in reduced grain size were associated with increased protein content. The findings from this study will assist in improvement of heat response in crop models, and selection of genotypes with better adaptation to warmer environments.