Premise Difficulties in comparing extremely divergent features in fully mycoheterotrophic plants with those in closely related chlorophyllous plants have complicated attempts to reveal the evolutionary patterns and processes of fully mycoheterotrophic plants. Albino mutants of partially mycoheterotrophic plants, generally observed in Orchidaceae, have provided an ideal model for investigating the evolution of mycoheterotrophy within similar genetic backgrounds. In 2018, we found a putative albino population of Pyrola (Ericaceae). Here we aimed to reveal the identity of the albino pyroloid and confirm its fully mycoheterotrophic status. Methods To reveal the putative albino pyroloid's identity, we examined its morphology and sequenced its chloroplast DNA. In addition, we assessed the trophic status of the putative albino pyroloid by analyzing chlorophyll fluorescence, chlorophyll concentration, and natural 13C and 15N abundances. Results We identified albino individuals as P. japonica—otherwise a partially mycoheterotrophic species. We confirmed their albino status by their considerably lower chlorophyll fluorescence and concentrations than those of sympatrically occurring chlorophyllous plants. 13C abundance in the albino individuals was significantly higher than in the green individuals of P. japonica. Conclusions This first report of albino mutants from partially mycoheterotrophic species in angiosperms other than orchids will play a valuable role in further studies focused on mycoheterotrophy. For instance, their δ 13C and δ 15N values represent a reference for fully mycoheterotrophic plants in Pyrola. Our findings also indicate the strong dependence of some leafy Pyrola species on fungal C during their entire life cycle.

中文翻译：

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鹿蹄草中新发现的白化突变体的证据：对鹿蹄草属营养模式的影响


前提 将完全霉菌异养植物与密切相关的叶绿素植物的极其不同的特征进行比较的困难使得揭示完全霉菌异养植物的进化模式和过程的尝试变得复杂。通常在兰科植物中观察到的部分霉菌异养植物的白化突变体为研究相似遗传背景下霉菌异养进化提供了理想的模型。 2018 年，我们发现了鹿蹄草（杜鹃花科）的推定白化种群。在这里，我们的目的是揭示白化焦样蛋白的身份并确认其完全霉菌异养状态。方法 为了揭示假定的白化热解体的身份，我们检查了其形态并对其叶绿体 DNA 进行了测序。此外，我们通过分析叶绿素荧光、叶绿素浓度以及天然 13C 和 15N 丰度，评估了假定的白化热解体的营养状况。结果我们将白化个体鉴定为P. japonica——否则是部分霉菌异养物种。我们通过其叶绿素荧光和浓度比同域存在的叶绿素植物低得多来证实它们的白化状态。粳稻白化个体的 13C 丰度显着高于绿化个体。结论 除兰花外，首次报道了来自被子植物中部分霉菌异养物种的白化突变体，这将在进一步的霉菌异养研究中发挥重要作用。例如，它们的 δ 13C 和 δ 15N 值代表了鹿蹄草中完全霉菌异养植物的参考。我们的研究结果还表明，一些多叶鹿蹄草物种在其整个生命周期中对真菌 C 具有很强的依赖性。