A strong east–west Mediterranean divergence supports a new phylogeographic history of the carob tree (Ceratonia siliqua, Leguminosae) and multiple domestications from native populations

Aim: Phylogeography of fruit trees is challenging due to the recurrent exchanges between domesticated and wild populations. Here we tested the eastern refugium hypothesis (ERH) for the carob tree, Ceratonia siliqua, which supports its natural and domestication origins in the Eastern Mediterranean and a feral origin in the West. Location: Mediterranean basin Taxon: Ceratonia siliqua L., Leguminosae Methods: Divergence time of the divergence between the carob tree and its sister species (C. oreothauma) was estimated based on two nuclear and one plastid sequences. Variation from four plastid regions and 17 nuclear microsatellite loci were used to decipher genetic structure in the carob tree and to test coalescent-based models by an Approximate Bayesian Computation (ABC) approach. We assessed our hypotheses by examining palaeobotanical records and hindcasting the past distribution of the carob tree at the Mid-Holocene, Last Glacial Maximum (LGM) and Last Interglacial (LIG) using species dis...

研究目的：果树系统地理学研究因驯化种群与野生种群间频繁的基因交流而颇具挑战性。本研究以角豆树（Ceratonia siliqua）为研究对象，检验东部避难所假说（Eastern Refugium Hypothesis, ERH）——该假说提出角豆树的自然起源与驯化起源均位于地中海东部，而其逸生种群起源于地中海西部。
研究区域：地中海盆地
研究类群：角豆树（Ceratonia siliqua L.），豆科（Leguminosae）
研究方法：基于2个核基因序列与1个质体基因序列，估算角豆树与其姊妹种（C. oreothauma）的分化时间。通过4个质体区域与17个核微卫星位点的遗传变异，解析角豆树的种群遗传结构，并采用近似贝叶斯计算（Approximate Bayesian Computation, ABC）方法检验基于溯祖理论的模型。本研究通过检视古植物学记录，并利用物种[原文截断为using species dis...]，回溯预测角豆树在中全新世、末次冰盛期（Last Glacial Maximum, LGM）以及末次间冰期（Last Interglacial, LIG）的历史分布范围，以验证所提出的研究假说。