Genetic diversity loss and homogenization in urban trees: the case of Tilia × europaea in Belgium and the Netherlands

Urban trees form a vital component of sustainable cities but the use of a restricted range of species and genotypes may pose a risk to global biodiversity. Despite several studies investigating tree species diversity, intraspecific genetic diversity of urban trees remains largely unexplored. Here, we characterized the genetic diversity of Tilia × europaea, one of the most widely planted urban tree species in Northwest Europe. We compared the genotypic diversity of historical plantings of Tilia spp. from the 17th century with the genotypic diversity of currently available planting stock in Belgium and the Netherlands. In total, 129 trees were sampled and genotyped with 14 microsatellite loci and 150 polymorphic Amplified Fragment Length Polymorphism markers. In Northwest Europe, homogenization of urban T. × europaea plantings already started at the 17th century. Genetic diversity within contemporary commercial planting stocks was extremely narrow and consisted mainly of two clones, sold ...

城市树木是可持续城市的核心组成部分，但使用有限的树种与基因型（genotypes）可能对全球生物多样性构成威胁。尽管已有多项研究围绕树木物种多样性展开探讨，但城市树木的种内遗传多样性仍未得到充分探索。本研究针对西北欧种植规模最广的城市树种之一——欧洲椴（Tilia × europaea）的遗传多样性进行了表征分析。我们对比了17世纪留存的椴属（Tilia spp.）历史种植种群与当前比利时、荷兰市场在售商用种植材料的基因型多样性。本研究共采集129株树木样本，采用14个微卫星位点（microsatellite loci）与150个多态性扩增片段长度多态性（Amplified Fragment Length Polymorphism）标记完成基因分型。结果表明，西北欧地区的城市欧洲椴种植种群的遗传同质化现象早在17世纪便已初现。当前商业种植材料的遗传多样性极度匮乏，仅主要包含两个商用售卖的无性系……