Phylogeography of sea oats (Uniola paniculata), a dune-building coastal grass in southeastern North America

We tested the hypothesis that Uniola paniculata populations are divided into eastern and western lineages, with the primary geographic break at the southern tip of Florida, as observed in codistributed animal taxa. We asked whether the geographic distribution of chloroplast DNA (cpDNA) variation in U. paniculata corresponds to 1) genetic structure in nuclear variation reported in previous studies, and 2) the geographic distribution of morphological adaptive traits reported in previous studies. We sampled 66 populations and performed phylogeographic analyses using sequence variations in maternally inherited cpDNA. We reconstructed the intraspecific phylogenetic network with TCS software and identified phylogeographic breaks in the species using Monmonier’s algorithm. Analyses identified 6 cpDNA haplotypes and 2 major lineages: eastern (Atlantic) and western (Gulf), with a phylogeographic break at the southern tip of Florida. The data suggest U. paniculata survived the last glacial maximu...本研究旨在验证如下假说：正如同域分布动物类群中所观察到的那样，海滩燕麦（Uniola paniculata）的种群可划分为东西两支谱系，其主要地理断点位于佛罗里达南端。本研究拟探究海滩燕麦的叶绿体DNA（chloroplast DNA, cpDNA）变异的地理分布是否契合：1）既往研究报道的核变异遗传结构；以及2）既往研究报道的形态适应性性状的地理分布。本研究共采集66个种群样本，利用母系遗传的cpDNA序列变异开展系统地理学分析。研究人员借助TCS软件重建了该物种的种内系统发育网络，并采用Monmonier算法鉴定了其系统地理断点。分析结果共鉴定出6个cpDNA单倍型以及2个主要谱系——东部（大西洋支）与西部（墨西哥湾支），系统地理断点位于佛罗里达南端。本研究数据表明，海滩燕麦（Uniola paniculata）在末次冰盛期得以存活……