In the context of ongoing climate change, expected temperature rise may significantly limit plant growth and productivity of crop species. In this study, we investigated the effects of a sub-optimal temperature on buckwheat, a pseudocereal known for its nutraceutical advantages. Two buckwheat species differing by their reproduction method, namely Fagopyrum esculentum and Fagopyrum tataricum were grown at 21 °C and 27 °C in growth chambers. High temperature increased leaf production mainly in F. tataricum but decreased leaf area in both species. Water and photosynthesis-related parameters were affected by high temperature but our results suggested that although transpiration rate was increased, adaptive mechanisms were developed to limit the negative impact on photosynthesis. High temperature mainly affected the reproductive stage. It delayed flowering time but boosted inflorescence and flower production. Nevertheless, flower and seed abortions were observed in both species at 27 °C. Regarding flower fertility, heat affected more the female stage than the male stage and reduced the stigma receptivity. Pollen production increased with temperature in F. esculentum while it decreased in F. tataricum. Such discrepancy could be related to the self-incompatibility of F. esculentum. Both species increased their antioxidant production under high temperature to limit oxidative stress and antioxidant capacity was higher in the inflorescences than in the leaves. Total flavonoid content was particularly increased in the leaves of F. esculentum and in the inflorescences of F. tataricum. Altogether, our results showed that even if high temperature may negatively affect reproduction in buckwheat, it improves its antioxidant content.

中文翻译：

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两种荞麦品种 Fagopyrum esculentum 和 Fagopyrum tataricum 的耐高温性比较

在持续的气候变化背景下，预期的温度上升可能会显着限制植物生长和作物物种的生产力。在这项研究中，我们研究了次优温度对荞麦的影响，荞麦是一种以其营养优势而闻名的假谷物。两种荞麦的繁殖方法不同，即 Fagopyrum esculentum 和 Fagopyrum tataricum 在 21 °C 和 27 °C 的生长室中生长。高温主要增加了 F. tataricum 的叶子产量，但减少了两个物种的叶子面积。水和光合作用相关参数受高温影响，但我们的研究结果表明，虽然蒸腾速率增加，但适应性机制已被开发以限制对光合作用的负面影响。高温主要影响生殖阶段。它延迟了开花时间，但促进了花序和花卉产量。然而，在 27 °C 时，在这两个物种中都观察到了花和种子的败育。关于花的生育能力，热对雌性阶段的影响大于雄性阶段，并降低了柱头的可受性。F. esculentum 的花粉产量随着温度的升高而增加，而 F. tataricum 的花粉产量则下降。这种差异可能与 F. esculentum 的自交不亲和有关。两种物种在高温下都增加了抗氧化剂的产生以限制氧化应激，并且花序中的抗氧化能力高于叶子。F. esculentum 的叶子和 F. tataricum 的花序中的总黄酮含量特别增加。共，