PREMISE A key question in plant dispersal via animal vectors is where and why fruit colors vary between species and how color relates to other fruit traits. To better understand the factors shaping the evolution of fruit color diversity, we tested for the existence of syndromes of traits (color, morphology, and nutrition) in the fruits of Viburnum. We placed these results in a larger phylogenetic context and reconstructed ancestral states to assess how Viburnum fruit traits have evolved across the clade. RESULTS We find that blue Viburnum fruits are not very juicy, and have high lipid content and large, round endocarps surrounded by a small quantity of pulp. Red fruits display the opposite suite of traits: they are very juicy with low lipid content and smaller, flatter endocarps. The ancestral Viburnum fruit may have gone through a sequence of color changes before maturation (green to yellow to red to black), though our reconstructions are equivocal. In one major clade of Viburnum (Nectarotinus), fruits mature synchronously with reduced intermediate color stages. Most transitions between fruit colors occurred in this synchronously fruiting clade. CONCLUSIONS It is widely accepted that fruit trait diversity has primarily been driven by the differing perceptual abilities of bird versus mammal frugivores. Yet within a clade of largely bird-dispersed fruits, we find clear correlations between color, morphology, and nutrition. These correlations are likely driven by a shift from sequential to synchronous development, followed by diversification in color, nutrition, and morphology. A deeper understanding of fruit evolution within clades will elucidate the degree to which such syndromes structure extant fruit diversity.

中文翻译：

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荚莲属植物的果实综合症：鸟类传播的肉质果实的颜色、营养成分和形态的相关进化。


前提 植物通过动物媒介传播的一个关键问题是果实颜色在不同物种之间的位置和原因以及颜色与其他果实性状的关系。为了更好地了解影响果实颜色多样性进化的因素，我们测试了荚莲属植物果实中是否存在性状（颜色、形态和营养）综合症。我们将这些结果置于更大的系统发育背景中，并重建祖先状态，以评估荚莲属植物果实性状如何在整个进化枝中进化。结果我们发现蓝色荚蒾果实多汁，脂质含量高，内果皮大而圆形，周围有少量果肉。红色水果则表现出相反的特征：它们非常多汁，脂质含量低，内果皮更小、更平坦。古老的荚莲属植物的果实在成熟之前可能经历了一系列颜色变化（绿色到黄色到红色到黑色），尽管我们的重建是模棱两可的。在荚莲属植物（Nectarotinus）的一个主要分支中，果实同步成熟，中间颜色阶段减少。大多数果实颜色之间的转变发生在这个同步结果的进化枝中。结论 人们普遍认为，水果性状多样性主要是由鸟类与哺乳动物食果动物不同的感知能力驱动的。然而，在主要由鸟类传播的水果的进化枝中，我们发现颜色、形态和营养之间存在明显的相关性。这些相关性可能是由顺序发育向同步发育的转变以及随后颜色、营养和形态的多样化驱动的。对进化枝内水果进化的更深入了解将阐明此类综合症在多大程度上构成了现有的水果多样性。