Increasing temperatures associated with climate change will be the next challenge for crop improvement, especially for turfgrass species that are often grown in urban green spaces. Previous research on turfgrass heat stress tolerance has been limited to a small number of species and cultivars with different heat stress conditions between studies; therefore, we assessed heat stress tolerance of 34 turfgrasses representing 14 species. Four replicates of each entry were established for at least 12 wk and then subjected to 49 d of heat stress (35/25 °C day/night) followed by a 4 wk recovery period (25/15 °C day/night). Turfgrass entries were assessed using the normalized difference vegetative index, the percentage of green obtained with digital image analysis, and membrane stability estimated by electrolyte leakage. Buffalograss [Bouteloua dactyloides (Nutt.) J.T. Columbus], Kentucky bluegrass (Poa pratensis L.), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort], and slender creeping red fescue (Festuca rubra ssp. littoralis) were more tolerant of heat stress than the other species. The Canada bluegrass (Poa compressa L.), blue grama [Bouteloua gracilis (Willd. ex Kunth.) Lag. ex Griffiths], and smooth brome (Bromus inermis Leyss.) cultivars were all tolerant of heat stress; however, only one cultivar for these three species was tested, making species‐wide generalizations difficult. In some cases, the cultivars and/or selections within a given species differed in heat stress response. Almost all entries were able to recover from the heat stress by the end of the recovery period. Altogether, we were able to identify turfgrasses that should perform adequately in high‐temperature urban environments.

中文翻译：

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在受控环境中长时间热应激和恢复期间多种草皮草种的性能

与气候变化相关的温度升高将是作物改良的下一个挑战，特别是对于通常在城市绿地中生长的草皮树种而言。先前关于草皮草热胁迫耐受性的研究仅限于少数研究之间具有不同热胁迫条件的物种和品种。因此，我们评估了代表14种植物的34种草皮草的热胁迫耐受性。建立每个条目的四个重复样本至少12周，然后经受49 d的热应激（35/25°C日/夜），然后恢复4周（25/15°C昼/夜）。使用归一化的差异营养指数，通过数字图像分析获得的绿色百分比以及通过电解质泄漏估算的膜稳定性来评估草皮草条目。Buffalograss [野牛草（纳特。）JT哥伦布]，草地早熟禾（早熟禾L.），高羊茅[ Schedonorus茅（茅）Dumort]和细长匍匐紫羊茅（紫羊茅SSP。沙参）为热应力的更宽容比其他物种。加拿大早熟禾（Poa compressa L.），早熟禾（Bouteloua gracilis（Willd。ex Kunth。））滞后。ex Griffiths）和光滑的布罗姆斯（Bromus inermisLeyss。）品种都耐高温。但是，仅对这三个物种的一个品种进行了测试，这使物种范围的概括变得困难。在某些情况下，给定物种内的品种和/或选择在热胁迫响应方面有所不同。到恢复期结束时，几乎所有条目都能够从热应力中恢复。总体而言，我们能够确定在高温城市环境中应能充分发挥作用的草皮草。