Rešetnik Ivana, Frajman Božo, Schönswetter Peter
Faculty of Science, University of Zagreb, Marulićev trg 20/II, HR-10000 Zagreb, Croatia.
Institute of Botany, University of Innsbruck, Sternwartestraße 15, A-6020 Innsbruck, Austria.
Am J Bot. 2016 Jul;103(7):1300-13. doi: 10.3732/ajb.1500506. Epub 2016 Jul 17.
Knautia drymeia is a morphologically variable, diploid and tetraploid temperate forest understory species distributed in southeastern Europe and adjacent areas. The species is an excellent system to explore the influence of polypoidy on taxonomic delineations, the role of hybridization among genetically distant populations in polyploid evolution, and the impact of glacial refugia on the evolution of polyploids.
Amplified fragment length polymorphism fingerprinting and multivariate analyses of morphological characters were performed on 57 populations spanning the distribution area of K. drymeia. K-means clustering, comparison of in-silico tetraploids and observed tetraploids, and a phylogeographic analysis using relaxed random walks were used to explore the genetic structure within the diploids, to infer the origin of the tetraploids and to reconstruct range expansion through time. Further, we contrasted the morphology and genetic groups with current taxonomy and evaluated the status of the tetraploid Apennine endemic K. gussonei and the intraspecific taxa of K. drymeia.
The genetic structure was strongly geographically correlated and yielded four genetic groups; K. gussonei was inseparable from K. drymeia. Distributions of diploid lineages are suggestive of glacial refugia in the northwesternmost and southeastern Balkan Peninsula. Polyploids originated at least two times, as autopolyploids and probably additionally also as allopolyploids. Morphological divergence corresponded with neither genetic groups nor current taxonomy.
Genetic and morphometric data confirmed neither divergence of K. gussonei nor recognition of subspecies within K. drymeia. We therefore propose treating K. drymeia as a morphologically and genetically variable species without infraspecific taxa.
干花麻花头（Knautia drymeia）是一种形态多变的二倍体和四倍体温带森林林下物种，分布于欧洲东南部及邻近地区。该物种是探究多倍体对分类界定的影响、遗传距离较远的种群间杂交在多倍体进化中的作用以及冰期避难所对多倍体进化影响的绝佳系统。
对跨越干花麻花头分布区域的57个种群进行了扩增片段长度多态性指纹分析和形态特征的多变量分析。使用K均值聚类、虚拟四倍体与观察到的四倍体比较以及基于宽松随机游走的系统地理学分析，以探究二倍体中的遗传结构、推断四倍体的起源并重建随时间的范围扩张。此外，我们将形态和遗传群体与当前分类法进行对比，并评估四倍体亚平宁特有种古氏麻花头（K. gussonei）和干花麻花头的种内分类单元的地位。
遗传结构与地理因素密切相关，产生了四个遗传群体；古氏麻花头与干花麻花头无法区分。二倍体谱系的分布表明在巴尔干半岛最西北端和东南部存在冰期避难所。多倍体至少起源了两次，一次是同源多倍体，可能还另外有一次是异源多倍体。形态差异既不与遗传群体对应，也不与当前分类法相符。
遗传和形态测量数据既未证实古氏麻花头的分化，也未证实干花麻花头内存在亚种。因此，我们建议将干花麻花头视为一个形态和遗传上可变的物种，不设种下分类单元。
