Mitotype (a) and chlorotype (b) composition of the 16 populations of <i>Pinus yunnanensis</i>.

<p>(a) Pie charts show the proportions of mitotypes in each population. Seven groups (I–VII) defined by mtDNA SAMOVA are shown. The current major rivers in Southwest China are illustrated in white, and the dashed red lines indicate the paleo-drainage routes before the major river reorganization (adapted from Clack et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067345#pone.0067345-Clark1" target="_blank">[22]</a>). In the mtDNA network, each link represents one mutation step. Circle size is proportional to the frequency of mitotypes over all populations. Mitotype nomenclature follows that in Wang et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067345#pone.0067345-Wang4" target="_blank">[39]</a>. M1–M10 occurred exclusively in <i>P. tabuliformis</i> and are used as an outgroup in this study. M17–M29 were detected in <i>P. yunnanensis</i> and are colored individually. (b) Pie charts show the proportions of chlorotypes in each population; singletons are grouped and shown in black. Relationships among 22 common chlorotypes are shown in the network, in which each link represents one mutation step. Circle size is proportional to the frequency of mitotypes over all populations. Chlorotype nomenclature follows that in Wang et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067345#pone.0067345-Wang4" target="_blank">[39]</a>. The five most common chlorotypes (frequency >5%; C26, C28, C30, C35 and C36) are indicated in bold, and colored green, brown, dark blue, red and light blue, respectively.