Kim D-H, Heber D, Still D W
Department of Horticulture/Plant and Soil Science, California State Polytechnic University, Pomona, CA 91768, USA.
Genome. 2004 Feb;47(1):102-11. doi: 10.1139/g03-086.
The taxonomy of Echinacea is based on morphological characters and has varied depending on the monographer. The genus consists of either nine species and four varieties or four species and eight varieties. We have used amplified fragment length polymorphisms (AFLP) to assess genetic diversity and phenetic relationships among nine species and three varieties of Echinacea (sensu McGregor). A total of 1086 fragments, of which approximately 90% were polymorphic among Echinacea taxa, were generated from six primer combinations. Nei and Li's genetic distance coefficient and the neighbor-joining algorithm were employed to construct a phenetic tree. Genetic distance results indicate that all Echinacea species are closely related, and the average pairwise distance between populations was approximately three times the intrapopulation distances. The topology of the neighbor-joining tree strongly supports two major clades, one containing Echinacea purpurea, Echinacea sanguinea, and Echinacea simulata and the other containing the remainder of the Echinacea taxa (sensu McGregor). The species composition within the clades differs between our AFLP data and the morphometric treatment offered by Binns and colleagues. We also discuss the suitability of AFLP in determining phylogenetic relationships.
紫锥菊属的分类基于形态特征，且因专著作者的不同而有所差异。该属包含九个物种和四个变种，或者四个物种和八个变种。我们利用扩增片段长度多态性（AFLP）来评估紫锥菊属（按照麦格雷戈的定义）九个物种和三个变种之间的遗传多样性和表型关系。从六种引物组合中总共产生了1086个片段，其中大约90%在紫锥菊分类群中具有多态性。采用内氏和李氏遗传距离系数以及邻接法构建表型树。遗传距离结果表明，所有紫锥菊物种都密切相关，种群之间的平均成对距离约为种群内距离的三倍。邻接树的拓扑结构有力地支持了两个主要分支，一个包含紫松果菊、血松果菊和拟血松果菊，另一个包含紫锥菊属的其余分类群（按照麦格雷戈的定义）。分支内的物种组成在我们的AFLP数据和宾斯及其同事提供的形态测量处理结果之间存在差异。我们还讨论了AFLP在确定系统发育关系方面的适用性。
