Department of Agricultural Economics, Mississippi State University, Mississippi State, MS, 39762, USA.
Department of Agricultural Economics, Kansas State University, Manhattan, KS, 66506, USA.
Glob Chang Biol. 2016 Aug;22(8):2904-12. doi: 10.1111/gcb.13163. Epub 2016 May 10.
The impact of climate change on crop yields has become widely measured; however, the linkages for winter wheat are less studied due to dramatic weather changes during the long growing season that are difficult to model. Recent research suggests significant reductions under warming. A potential adaptation strategy involves the development of heat resistant varieties by breeders, combined with alternative variety selection by producers. However, the impact of heat on specific wheat varieties remains relatively unstudied due to limited data and the complex genetic basis of heat tolerance. Here, we provide a novel econometric approach that combines field-trial data with a genetic cluster mapping to group wheat varieties and estimate a separate extreme heat impact (temperatures over 34 °C) across 24 clusters spanning 197 varieties. We find a wide range of heterogeneous heat resistance and a trade-off between average yield and resistance. Results suggest that recently released varieties are less heat resistant than older varieties, a pattern that also holds for on-farm varieties. Currently released - but not yet adopted - varieties do not offer improved resistance relative to varieties currently grown on farm. Our findings suggest that warming impacts could be significantly reduced through advances in wheat breeding and/or adoption decisions by producers. However, current adaptation-through-adoption potential is limited under a 1 °C warming scenario as increased heat resistance cannot be achieved without a reduction in average yields.
气候变化对作物产量的影响已经得到广泛研究；然而，由于冬季小麦漫长的生长季节中天气变化剧烈，难以建模，因此对其的关联研究较少。最近的研究表明，在变暖的情况下，产量会显著减少。一种潜在的适应策略是由育种者开发耐热品种，并结合生产者的替代品种选择。然而，由于数据有限且耐热性的遗传基础复杂，热量对特定小麦品种的影响仍然相对没有得到充分研究。在这里，我们提供了一种新的计量经济学方法，该方法将田间试验数据与遗传聚类图谱相结合，对小麦品种进行分组，并估计跨越 197 个品种的 24 个品种组的单独极端高温影响（温度超过 34°C）。我们发现了广泛的异质耐热性和平均产量与耐热性之间的权衡。结果表明，最近发布的品种比旧品种的耐热性差，这种模式也适用于农场品种。目前发布的（但尚未采用）品种与目前在农场种植的品种相比，并没有提供更好的抗性。我们的研究结果表明，通过小麦育种的进步和/或生产者的采用决策，可以显著减少变暖的影响。然而，在 1°C 的变暖情景下，当前的适应-通过采用的潜力是有限的，因为如果不降低平均产量，就无法提高耐热性。
