The Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA.
New Phytol. 2013 Mar;197(4):1311-1320. doi: 10.1111/nph.12110. Epub 2013 Jan 11.
Although adaptive plant population divergence across contrasting soil conditions is often driven by abiotic soil factors, natural enemies may also contribute. Cryptic matching to the native soil color is a form of defensive camouflage that seeds can use to avoid detection by seed predators. The legume Acmispon wrangelianus occurs across a variety of gray-green serpentine soils and brown nonserpentine soils. Quantitative digital image analysis of seed and soil colors was used to test whether genetically based seed color is a closer match to the color of the native soil than to the color of other nearby soils. Lineages bear seeds that more closely match the color of their native serpentine or nonserpentine soil type than the opposing soil type. Further, even within a soil type, lineages bear seeds with a closer color match to the soil at their native site than to other sites. The striking concordance between seed and native soil color suggests that natural selection for locally camouflaged seed color morphs, probably driven by seed predators, may maintain adaptive divergence in pigmentation, despite the opportunity for migration between soil environments.
尽管适应不同土壤条件的植物种群的分化通常是由非生物土壤因素驱动的，但自然天敌也可能起到一定的作用。与原生土壤颜色的隐性匹配是种子可以用来避免被种子捕食者发现的一种防御性伪装形式。豆科植物 Acmispon wrangelianus 广泛分布于各种灰绿色蛇纹石土壤和棕色非蛇纹石土壤中。利用种子和土壤颜色的定量数字图像分析来测试基于遗传的种子颜色是否比其他附近土壤更接近原生土壤的颜色。谱系种子更接近其原生蛇纹石或非蛇纹石土壤类型的颜色，而不是相反的土壤类型。此外，即使在同一土壤类型内，谱系种子的颜色与原生栖息地的土壤更匹配，而与其他栖息地的土壤不匹配。种子与原生土壤颜色之间惊人的一致性表明，自然选择可能会驱动具有局部伪装的种子颜色形态，以适应种子捕食者，这可能会维持色素沉着的适应性分化，尽管有机会在土壤环境之间迁移。
