Arrigo Nils, Guadagnuolo Roberto, Lappe Sylvain, Pasche Sophie, Parisod Christian, Felber François
Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel 11 rue Emile-Argand, 2000 Neuchâtel, Switzerland.
Evol Appl. 2011 Sep;4(5):685-95. doi: 10.1111/j.1752-4571.2011.00191.x. Epub 2011 May 25.
Gene flow between domesticated species and their wild relatives is receiving growing attention. This study addressed introgression between wheat and natural populations of its wild relatives (Aegilops species). The sampling included 472 individuals, collected from 32 Mediterranean populations of three widespread Aegilops species (Aegilops geniculata, Ae. neglecta and Ae. triuncialis) and compared wheat field borders to areas isolated from agriculture. Individuals were characterized with amplified fragment length polymorphism fingerprinting, analysed through two computational approaches (i.e. Bayesian estimations of admixture and fuzzy clustering), and sequences marking wheat-specific insertions of transposable elements. With this combined approach, we detected substantial gene flow between wheat and Aegilops species. Specifically, Ae. neglecta and Ae. triuncialis showed significantly more admixed individuals close to wheat fields than in locations isolated from agriculture. In contrast, little evidence of gene flow was found in Ae. geniculata. Our results indicated that reproductive barriers have been regularly bypassed during the long history of sympatry between wheat and Aegilops.
驯化物种与其野生近缘种之间的基因流动正受到越来越多的关注。本研究探讨了小麦与其野生近缘种（山羊草属物种）自然种群之间的基因渗入情况。采样包括从三种广泛分布的山羊草属物种（节节麦、疏忽山羊草和三芒山羊草）的32个地中海种群中收集的472个个体，并将麦田边界与远离农业的区域进行了比较。通过扩增片段长度多态性指纹图谱对个体进行特征分析，采用两种计算方法（即混合的贝叶斯估计和模糊聚类）进行分析，并对标记小麦特异性转座子插入的序列进行分析。通过这种综合方法，我们检测到小麦与山羊草属物种之间存在大量基因流动。具体而言，疏忽山羊草和三芒山羊草在靠近麦田的地方比在远离农业的地方表现出明显更多的混合个体。相比之下，在节节麦中几乎没有发现基因流动的证据。我们的结果表明，在小麦和山羊草长期同域共存的历史中，生殖障碍经常被突破。
