Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Proc Biol Sci. 2017 Oct 11;284(1864). doi: 10.1098/rspb.2017.1654.
The efficacy of camouflage through background matching is highly environment-dependent, often resulting in intraspecific colour divergence in animals to optimize crypsis in different visual environments. This phenomenon is largely unexplored in plants, although several lines of evidence suggest they do use crypsis to avoid damage by herbivores. Using an alpine plant with cryptic leaf colour, we quantified background matching between leaves and surrounding rocks in five populations based on an approximate model of their butterfly enemy's colour perception. We also investigated the pigment basis of leaf colour variation and the association between feeding risk and camouflage efficacy. We show that plants exhibit remarkable colour divergence between populations, consistent with differences in rock appearances. Leaf colour varies because of a different quantitative combination of two basic pigments-chlorophyll and anthocyanin-plus different air spaces. As expected, leaf colours are better matched against their native backgrounds than against foreign ones in the eyes of the butterfly. Furthermore, improved crypsis tends to be associated with a higher level of feeding risk. These results suggest that divergent cryptic leaf colour may have evolved to optimize local camouflage in various visual environments, extending our understanding of colour evolution and intraspecific phenotype diversity in plants.
背景匹配的伪装效果高度依赖于环境，这往往导致动物的种内颜色分化，以优化在不同视觉环境中的隐身效果。尽管有几条证据表明植物确实利用隐身来避免被草食动物破坏，但这种现象在植物中还没有得到广泛的探索。我们使用一种具有隐蔽叶色的高山植物，根据蝴蝶天敌的颜色感知近似模型，在五个种群中量化了叶片与周围岩石之间的背景匹配。我们还研究了叶片颜色变化的色素基础以及觅食风险与伪装效果之间的关系。我们表明，植物在种群之间表现出显著的颜色分化，与岩石外观的差异一致。叶片颜色的变化是由于两种基本色素——叶绿素和花青素的不同定量组合，加上不同的气隙。正如预期的那样，在蝴蝶眼中，叶片颜色与本地背景的匹配度要好于与外来背景的匹配度。此外，伪装效果的改善往往与更高的觅食风险相关。这些结果表明，不同的隐蔽叶色可能是为了在各种视觉环境中优化局部伪装而进化的，这扩展了我们对植物中颜色进化和种内表型多样性的理解。
