The International Maize and Wheat Improvement Center develops and annually distributes elite wheat lines to public and private breeders worldwide. Trials have been created in multiple sites over many years to assess the lines’ performance for use in breeding and release as varieties, and to provide iterative feedback on refining breeding strategies¹. The collaborator test sites are experiencing climate change, with new implications for how wheat genotypes are bred and selected². Using a standard quantitative genetic model to analyse four International Maize and Wheat Improvement Center global spring wheat trial datasets, we examine how genotype–environment interactions have changed over recent decades. Notably, crossover interactions—a critical indicator of changes in the ranking of cultivar performance in different environments—have increased over time. Climatic factors explained over 70% of the year-to-year variability in crossover interactions for yield. Yield responses of all lines in trial environments from 1980 to 2018 revealed that climate change has increased the ranking change in breeding targeted to favourable environments by ~15%, while it has maintained or reduced the ranking change in breeding targeted to heat and drought stress by up to 13%. Genetic improvement has generally increased crossover interactions, particularly for wheat targeted to high-yielding environments. However, the latest wheat germplasm developed under heat stress was better adapted and more stable, partly offsetting the increase in ranking changes under the warmer climate.

国际玉米和小麦改良中心开发并每年向全球公共和私人育种者分发优质小麦品系。多年来，已在多个地点进行试验，以评估品系在育种和作为品种发布时的性能，并提供改进育种策略的迭代反馈¹。合作者试验点正在经历气候变化，对小麦基因型的培育和选择方式产生新的影响². 使用标准的定量遗传模型分析四个国际玉米和小麦改良中心全球春小麦试验数据集，我们研究了近几十年来基因型-环境相互作用的变化。值得注意的是，交叉相互作用——不同环境中品种性能排名变化的关键指标——随着时间的推移而增加。气候因素解释了产量交叉相互作用中超过 70% 的年度变化。1980 年至 2018 年试验环境中所有品系的产量反应表明，气候变化使针对有利环境的育种排名变化增加了约 15%，同时维持或减少了针对高温和干旱胁迫的育种排名变化高达 13%。遗传改良通常增加了交叉相互作用，特别是针对高产环境的小麦。然而，在热胁迫下开发的最新小麦种质具有更好的适应性和稳定性，部分抵消了气候变暖下排名变化的增加。