• Leaf reflectance spectroscopy is emerging as an effective tool for assessing plant diversity and function. However, the ability of leaf spectra to detect fine-scale plant evolutionary diversity in complicated biological scenarios is not well understood.
• We test if reflectance spectra (400–2400 nm) can distinguish species and detect fine-scale population structure and phylogenetic divergence – estimated from genomic data – in two co-occurring, hybridizing, ecotypically differentiated species of Dryas. We also analyze the correlation among taxonomically diagnostic leaf traits to understand the challenges hybrids pose to classification models based on leaf spectra.
• Classification models based on leaf spectra identified two species of Dryas with 99.7% overall accuracy and genetic populations with 98.9% overall accuracy. All regions of the spectrum carried significant phylogenetic signal. Hybrids were classified with an average overall accuracy of 80%, and our morphological analysis revealed weak trait correlations within hybrids compared to parent species.
• Reflectance spectra captured genetic variation and accurately distinguished fine-scale population structure and hybrids of morphologically similar, closely related species growing in their home environment. Our findings suggest that fine-scale evolutionary diversity is captured by reflectance spectra and should be considered as spectrally-based biodiversity assessments become more prevalent.

中文翻译：

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阅读灯：叶子光谱捕获密切相关的杂交北极灌木的精细多样性

• 叶反射光谱正在成为评估植物多样性和功能的有效工具。然而，叶子光谱在复杂的生物场景中检测精细植物进化多样性的能力尚不清楚。
• 我们测试反射光谱（400-2400 nm）是否可以区分物种并检测精细规模的种群结构和系统发育分歧——根据基因组数据估计——在两个同时发生的、杂交的、生态分化的仙人掌物种中。我们还分析了分类学诊断叶片性状之间的相关性，以了解杂交种对基于叶片光谱的分类模型构成的挑战。
• 基于叶片光谱的分类模型以 99.7% 的总体准确率和 98.9% 的总体准确率确定了两种仙人掌。光谱的所有区域都带有显着的系统发育信号。杂种被分类的平均总体准确率为 80%，我们的形态分析显示，与亲本相比，杂种内部的性状相关性较弱。
• 反射光谱捕获了遗传变异，并准确区分了在其家庭环境中生长的形态相似、密切相关的物种的精细种群结构和杂种。我们的研究结果表明，精细尺度的进化多样性是由反射光谱捕获的，并且应该被视为基于光谱的生物多样性评估变得更加普遍。