The impact of heat stress coinciding with reproductive stages in winter canola was studied using walk-in controlled environment chambers and field-based tents. Six different cultivars (46W94, Edimax CL, Mercedes, Popular, DKW44-10 and DKW46-15) were used in both the experiments following a split-plot design. Under controlled environment chambers, all six cultivars were exposed to HDT (day/night; 34/15°C), HNT (23/20°C), HDNT (34/20°C) and control (23/15°C) conditions for 14 days coinciding with flowering. Under field conditions, custom built ‘heat tents’ were used to impose heat stress starting seven days after 50% of flowering till maturity. The results demonstrated that HDT and HDNT induced significant impact on floral morphology, extreme levels of floral sterility and complete yield loss with two weeks of stress exposure during flowering. However, biomass, seed weight and oil concentration at maturity were either significantly increased or unchanged which demonstrated significant post-stress phenotypic plasticity in canola to overcome damage caused by short episode of HDT and HDNT during flowering. The long duration heat stress under field conditions recorded significant decrease in yield parameters and oil concentration in the canola cultivars. Incorporating greater post-stress phenotypic plasticity will help develop canola as an ideal alternative crop under future climates associated with enhanced frequency of short heat stress episodes coinciding with critical reproductive stages.

中文翻译：

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热胁迫影响室内和田间种植的冬季双低油菜籽的花形，长角果定势和种子质量

使用步入式可控环境箱和野外帐篷研究了冬季油菜中热应激与生殖阶段的影响。按照分块图设计，在两个实验中使用了六个不同的品种（46W94，Edimax CL，Mercedes，Popular，DKW44-10和DKW46-15）。在可控环境箱中，所有六个品种均暴露于HDT（昼/夜； 34/15°C），HNT（23/20°C），HDNT（34/20°C）和对照（23/15°C） 14天的条件与开花相吻合。在田间条件下，使用定制的“热帐篷”在开花50％至成熟后7天开始施加热应力。结果表明，HDT和HDNT对花的形态，花的极高水平的不育性以及在开花过程中暴露了两周的应力导致完全的产量损失具有显着影响。然而，成熟期的生物量，种子重量和油浓度显着增加或保持不变，这表明油菜中有显着的胁迫后表型可塑性，以克服开花期间HDT和HDNT短暂发作所造成的损害。在田间条件下长期持续的热胁迫记录了油菜品种的产量参数和油浓度显着下降。结合更大的胁迫后表型可塑性，将有助于在未来气候下，与短期热胁迫发作频率增加和关键的生殖阶段相一致的双低油菜籽发展成为理想的替代作物。成熟期的种子重量和油浓度显着增加或保持不变，这表明油菜中有显着的胁迫后表型可塑性，以克服开花期间HDT和HDNT短暂发作所造成的损害。在田间条件下长期持续的热胁迫记录了油菜品种的产量参数和油浓度显着下降。结合更大的胁迫后表型可塑性，将有助于在未来气候下，与短期热胁迫发作频率增加和关键的生殖阶段相一致的双低油菜籽发展成为理想的替代作物。成熟期的种子重量和油浓度显着增加或保持不变，这表明油菜中有显着的胁迫后表型可塑性，以克服开花期间HDT和HDNT短暂发作所造成的损害。在田间条件下长期持续的热胁迫记录了油菜品种的产量参数和油浓度显着下降。结合更大的胁迫后表型可塑性，将有助于在未来气候下，与短期热胁迫发作频率增加和关键的生殖阶段相一致的双低油菜籽发展成为理想的替代作物。