Heat stress significantly limits yield in many wheat‐growing areas globally including north‐western NSW. While various traits linked to high‐temperature tolerance have been identified, the combination of traits that optimize the heat tolerance of wheat has not been established in most environments. A total of 554 genotypes were evaluated in the field at different times of sowing in north‐western NSW for three consecutive years to develop a heat‐tolerant wheat ideotype for this environment. The later sown experiments were exposed to higher temperatures at the critical reproductive and grain‐filling stages of development. The impact of high temperature was greatest at anthesis, and eventual grain yield was reduced by between 4% and 7% with every 1°C rise in average maximum temperature above the optimum of 25°C. High temperature reduced yield, plant height, grain weight and days to anthesis and maturity, and increased the percentage of screenings and grain protein content. Genotypes that produced higher yield under heat stress had shorter days to flowering and maturity, higher NDVI during grain filling, greater chlorophyll content at the milk stage of grain fill, taller plants, greater grain weight and number, and lower screenings compared with the benchmark cultivar Suntop. The genotype closest to the predicted heat‐tolerant wheat ideotype identified from trait ranges had 79.6% similarity.

中文翻译：

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耐热小麦的表型发展策略

热应激严重限制了包括新南威尔士州西北部在内的全球许多小麦种植区的单产。虽然已经确定了与高温耐受性相关的各种性状，但在大多数环境中尚未建立优化小麦耐热性的性状组合。连续三年在新南威尔士州西北部不同播种时间对田间共评估了554个基因型，以开发出适合该环境的小麦耐热型。后期播种的实验在发育的关键生殖和籽粒充实阶段处于较高的温度下。在花期，高温的影响最大，最终平均最高温度每升高25°C，温度每升高1°C，谷物的最终产量就会降低4％至7％。高温降低产量 株高，粒重和到花期和成熟的天数，并增加了筛选的百分比和籽粒蛋白质含量。在热胁迫下产生更高产量的基因型与开花和成熟期相比，具有较短的开花，成熟期的NDVI，在籽粒灌浆的奶阶段叶绿素含量更高，植物更高，籽粒重量和数量更高以及与基准品种相比筛查较低的基因型Suntop。从性状范围确定的最接近预测的耐热小麦基因型的基因型具有79.6％的相似性。与基准品种Suntop相比，在籽粒灌浆的牛奶阶段叶绿素含量更高，植物更高，谷粒重量和数量更大，筛分更低。从性状范围确定的最接近预测的耐热小麦基因型的基因型具有79.6％的相似性。与基准品种Suntop相比，在籽粒灌浆的牛奶阶段叶绿素含量更高，植物更高，谷粒重量和数量更大，筛分更低。从性状范围确定的最接近预测的耐热小麦基因型的基因型具有79.6％的相似性。