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，以更快地推出新品种，这些品种可以更好地承受多重压力（干旱和高温压力），并具有更大的产量稳定性。 这直接支持了我们的两个现金资助合作伙伴，Sask Wheat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，以提高小麦生产商的盈利能力，AWC则旨在提高正常和非生物胁迫情况下的谷物产量。在大草原，气候预计将继续更加炎热和干燥，并出现极端天气事件。在田间，干旱胁迫通常伴随着热胁迫，干旱和热胁迫的组合更常见，成本是单独胁迫的六倍（Lamaoui et al. 2018; Mittler 2006）。然而，很少有研究将干旱和高温胁迫结合在任何作物上。该项目将建立一个独特的高隧道现场设施，以因子组合（3个干旱胁迫水平× 3个热胁迫水平）检查干旱和热胁迫。 蒸腾效率（TE）的关键植物反应被广泛定义为每单位水蒸腾产生的生物量，基本上整合了Casadebaig等人（2016）在小麦中确定的90个集体性状。我们的综合研究将检查：1）芽/叶/轴架构/超微结构特征，2）水通道蛋白和3）角质层蜡控制TE在开花前10天到籽粒灌浆结束。所研究的参数将主要针对那些表现型和生理反应，这些反应被证明具有高遗传力指数和/或与谷物产量相关。还将纳入高光谱成像，以推进与关键性状相关的高通量分析（参见Hein等人2021的综述）。 最后，夜间和白天的TE参数将被整合，以确定那些共同的白天和夜间的因素，显着增加TE压力下，并通过这种生理育种方法与产量恢复力的热和干旱胁迫。

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.