Improving wheat tolerance to post-flowering heat using matched development stages and field-based reaction norms.

Post-flowering heatwaves reduce wheat grain weight by up to 30 mg and alter grain protein content, with tolerance levels varying widely among 25 genotypes.

• Why it matters: Understanding how heat impacts wheat development is crucial for breeding climate-resilient varieties, especially as global temperatures rise and heatwaves become more frequent.
• What they did: Researchers used a photoperiod-extension method to synchronize flowering across genotypes and measured responses in field trials across multiple locations and sowing dates, comparing with conventional plots.
• The result: High genotypic variability in heat tolerance was identified, enabling selection of more resilient wheat varieties and improving models for predicting crop performance under heat stress.