Adapting wheat to stressful environments: Identifying key transpiration efficiency components reducing day-time water loss and heat stress linked to yield

该伙伴关系的总体目标是为育种者提供更具体的选择标准，以便更快地发布能够更好地抵御多种胁迫（干旱和热胁迫）并具有更高产量稳定性的新品种。这直接支持了我们的两个现金资助合作伙伴，Sask小麦和阿尔伯塔小麦和大麦委员会（AWC）。SaskWheat旨在减少对环境的影响，提高小麦生产商的盈利能力，而AWC旨在提高正常和非生物胁迫情况下的粮食产量。在草原地区，预计气候将继续变得更加炎热和干燥，并伴有极端天气事件。在田间，干旱胁迫通常伴随着热胁迫，干旱和热胁迫的结合比单独的胁迫更常见，成本是每种胁迫的六倍（Lamaoui et al. 2018; Mittler 2006）。然而，很少有研究将田间干旱和热胁迫对任何作物的影响结合起来。该项目将建立一个独特的高隧道现场设施，以因子组合（3级干旱应力× 3级热应力）检测干旱和热应力。蒸腾效率（TE）的关键植物响应被广泛定义为每单位水分蒸腾产生的生物量，基本上整合了Casadebaig等人（2016）在小麦中确定的90个集体性状。我们的综合研究将包括：1)茎/叶/轴结构/超微结构特征；2)水通道蛋白和3)角质层蜡质在花前10天至灌浆结束期间控制TE。所研究的参数将主要针对那些被证明具有高遗传指数和/或与粮食产量有关的表型和生理反应。高光谱成像也将被纳入推进与关键性状相关的高通量分析（见Hein et al. 2021的综述）。最后，通过这种生理育种方法，将夜间和白天的TE参数整合起来，以确定在胁迫下显著增加TE的常见白天和夜间因素，并将其与高温和干旱胁迫下的产量恢复能力联系起来。

The overall goal of the partnership is to provide breeders with more specific selection criteria to more quickly release new cultivars which can better withstand multiple stresses (drought and heat stress) and which have greater yield stability. This directly supports our two cash funding partners, Sask Wheat and the Alberta Wheat & Barley Commission (AWC). SaskWheat aims to reduce environmental impact to enhance wheat producers' profitability, and AWC seeks to improve grain yield in normal and abiotic stress situations. In the prairies, climate is expected to continue to be more hot and dry with extreme weather events. In the field, drought stress is normally accompanied by heat stress and the combination of drought and heat stress is more common and six times more costly than each stress alone (Lamaoui et al. 2018; Mittler 2006). However, few if any studies have combined both drought and heat stress in the field on any crops. This project will establish a unique high tunnel field facility examining both drought and heat stress in a factorial combination (3 levels of drought stress × 3 levels of heat stress). The key plant response of Transpiration Efficiency (TE) is broadly defined as biomass produced per unit water transpired and essentially integrates the 90 collective traits identified by Casadebaig et al. (2016) in wheat. Our comprehensive study will examine: 1) shoot/leaf/rachis architecture/ultrastructural characteristics, 2) aquaporins and 3) cuticular waxes controlling TE at 10 days pre-anthesis through to the end of grain filling. The parameters investigated will primarily target those phenotypic and physiologic responses demonstrated to have a high heritability index and/or have been linked to grain yield. Hyperspectral imaging will also be incorporated to advance high throughput analysis linked to key traits (see Hein et al. 2021 for a review). Finally, both Night-Time and Day-Time TE parameters will be integrated to identify those common Day and Night Time factors which significantly increase TE under stress and are linked to yield resilience to both heat and drought stress through this physiological breeding approach.