Water balance is crucial for the growth and flowering of plants. However, the mechanisms by which flowers maintain water balance are poorly understood across different angiosperm branches. Here, we investigated 29 floral hydraulic and economic traits in 24 species from ANA grade, magnoliids, monocots, and eudicots. Our main objective was to compare differences in flower water use strategies between basal angiosperms (ANA grade and magnoliids) and derived group (monocots and eudicots). We found that basal angiosperms had richer petal stomatal density, higher pedicel hydraulic diameter, and flower mass per area, but lower pedicel vessel wall reinforcement and epidermal cell thickness compared to monocots and eudicots. We also observed significant trade‐offs and coordination among different floral traits. Floral traits associated with reproduction, such as floral longevity and size, were strongly linked with physiological and anatomical traits. Our results systematically reveal the variation in flower economic and hydraulic traits from different angiosperm branches, deepening understanding of flower water use strategies among these plant taxa. We conclude that basal angiosperms maintain water balance with high water supply, whereas monocots and eudicots maintain a more conservative water balance.

中文翻译：

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单子叶植物和真双子叶植物比基部被子植物有更保守的花水利用策略

水平衡对于植物的生长和开花至关重要。然而，不同被子植物分支的花朵维持水平衡的机制却知之甚少。 在这里，我们研究了 24 个 ANA 级物种、木兰科植物、单子叶植物和真双子叶植物的 29 种花水力和经济性状。我们的主要目的是比较基础被子植物（ANA 级和木兰科）和衍生组（单子叶植物和真双子叶植物）之间花卉用水策略的差异。 我们发现，与单子叶植物和真双子叶植物相比，基部被子植物具有更丰富的花瓣气孔密度、更高的花梗水力直径和单位面积的花质量，但花梗导管壁加固和表皮细胞厚度较低。我们还观察到不同花卉性状之间存在显着的权衡和协调。与繁殖相关的花特征，例如花寿命和大小，​​与生理和解剖特征密切相关。 我们的研究结果系统地揭示了不同被子植物分支花卉经济和水力性状的变化，加深了对这些植物类群花卉水分利用策略的理解。我们得出的结论是，基础被子植物通过高供水量维持水平衡，而单子叶植物和真双子叶植物则维持更保守的水平衡。