Phylogeny and classification of Pinus
Phylogeny and classification of Pinus
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作者：
Gernandt, DS;López, GG;Liston, A
我们使用matK和rbcL的叶绿体DNA序列来推断大约111种松属（松科）中的101种的亲缘关系。在亚组及以上的水平上，cpDNA树与基于核DNA的同源性一致，但有一个值得注意的例外：来自亚组的cpDNA序列。北美硬松是所有其他北美硬松的姐妹，而不是在同一分支中占据更衍生的位置。我们使用cpDNA树加上核核糖体DNA和形态学的证据，提出了一个新的分类属。在该属的最深分支处，分子的同源性是对称的，允许划分两个亚属，每个亚属有两个部分形成姐妹群。在部分，分支略有不对称，有时含糊不清地解决。为了适应一些相互关系的模糊性，避免创建新的等级，并保留传统的名称，我们承认每个部分最多有三个单系子部分。松亚属（diploxylon，或硬松）分为主要的欧亚和地中海松组，由松亚组和Pinaster组成，以及严格的北美Trifoliae组，由亚组Australales，Ponderosae和Contortae组成。松松亚属（学名：Strobus）分为严格的北美Parrya组（由Cembroides亚组、Nelsoniae亚组和Balfourifiridae亚组组成）和欧亚和北美Quinquefoliae组（由Gerardidae亚组、Krempfiridae亚组和Strobus亚组组成）。10个形态和分布特征的映射表明，两个是诊断的亚属分类群：每叶维管束数区分松亚属与松亚科，和一个终端定位的脐上的排卵锥规模是诊断的亚组。斯特罗布斯
We used chloroplast DNA sequences from matK and rbcL to infer the phylogeny for 101 of the approximately 111 species of Pinus (Pinaceae). At the level of subsection and above, the cpDNA tree is congruent with phylogenies based on nuclear DNA with one notable exception: cpDNA sequences from subsect. Contortae are sister to all other North American hard pines rather than occupying a more derived position in the same clade. We used the cpDNA tree plus evidence from nuclear ribosomal DNA and morphology to propose a new classification for the genus. The molecular phylogenies are symmetrical at the deepest branches of the genus, allowing for the delineation of two subgenera, each with two sections that form sister groups. Within sections, clades were slightly asymmetric and sometimes ambiguously resolved. To accomodate ambiguity in some interrelationships, avoid the creation of new ranks, and retain traditional names, we recognised up to three monophyletic subsections per section. Subgenus Pinus (the diploxylon, or hard pines) is divided into the predominantly Eurasian and Mediterranean section Pinus, composed of subsections Pinus and Pinaster, and the strictly North American section Trifoliae, composed of subsections Australes, Ponderosae, and Contortae. Subgenus Strobus (the haploxylon, or soft pines) is divided into the strictly North American section Parrya, composed of subsections Cembroides, Nelsoniae, and Balfourianae, and the Eurasian and North American section Quinquefoliae, composed of subsections Gerardianae, Krempfianae, and Strobus. Mapping of ten morphological and distributional characters indicates that two were diagnostic for infrageneric taxa: the number of vascular bundles per leaf distinguishes subgenus Pinus from subgenus Strobus, and a terminal-positioned umbo on the ovulate cone scale is diagnostic of subsect. Strobus.