Abstract Polyploidy can induce physiological novelties with adaptive potential, which may influence the range of environmental conditions that a neopolyploid tolerates. Dianthus broteri (Caryophyllaceae) is an autopolyploid complex that comprises four ploidy levels (2×, 4×, 6× and 12×) with separate distributions in the Iberian Peninsula, occupying different ecological niches along a gradient of temperature and aridity. We designed an experimental approach to disentangle the differential photochemical responses to temperature (from −3 °C to 53 °C) among D. broteri cytotypes by the measurement of leaf chlorophyll fluorescence. Our results showed higher energy fluxes, Fv/Fm and delayed fluorescence values along low and mild temperature levels in lower ploidies (2× and 4×) compared to higher ones (6× and 12×). This pattern would allow lower cytotypes to enhance their photosynthetic apparatus functionality in environmentally non-stressful habitats as those they inhabit. Contrarily, the 6× cytotype exhibited the overall lowest energy fluxes based on a reduced absorption while maximizing its flux ratios. Moreover, the 12× cytotype had notably high dissipation fluxes to ensure photoprotection, maintaining low but constant photochemical efficiency. These latter strategies would cause the reduction of photosynthetic capacities but help higher ploidies to tolerate the semi-arid Mediterranean environmental conditions with high temperatures under which they live.

中文翻译：

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地中海康乃馨复合体温度胁迫下多倍体介导的发散光捕获和光保护策略

摘要 多倍体可以诱导具有适应性潜力的生理新颖性，这可能会影响新多倍体耐受的环境条件范围。Dianthus broteri（石竹科）是一种同源多倍体复合体，包括四个倍性水平（2×、4×、6×和12×），在伊比利亚半岛有不同的分布，沿着温度和干旱的梯度占据不同的生态位。我们设计了一种实验方法，通过测量叶绿素荧光来解开 D. broteri 细胞型对温度（从 -3 °C 到 53 °C）的不同光化学反应。我们的结果显示，与较高倍性（6x 和 12x）相比，较低倍性（2x 和 4x）在低温和温和温度水平下具有更高的能量通量、Fv/Fm 和延迟荧光值。这种模式将允许较低的细胞类型在它们居住的环境无压力的栖息地中增强它们的光合装置功能。相反，基于减少的吸收同时最大化其通量比率，6x 细胞型表现出总体最低的能量通量。此外，12x 细胞型具有显着高的耗散通量以确保光保护，保持低但恒定的光化学效率。后一种策略会导致光合作用能力降低，但有助于更高倍性耐受半干旱的地中海环境条件，它们生活在高温下。基于减少的吸收同时最大化其通量比率，6x 细胞型表现出总体最低的能量通量。此外，12x 细胞型具有显着高的耗散通量以确保光保护，保持低但恒定的光化学效率。后一种策略会导致光合作用能力降低，但有助于更高倍性耐受半干旱的地中海环境条件，它们生活在高温下。基于减少的吸收同时最大化其通量比率，6x 细胞型表现出总体最低的能量通量。此外，12x 细胞型具有显着高的耗散通量以确保光保护，保持低但恒定的光化学效率。后一种策略会导致光合作用能力降低，但有助于更高倍性耐受半干旱的地中海环境条件，它们生活在高温下。