Molecular phylogeny and radiation time of Erysiphales inferred from the nuclear ribosomal DNA sequences
Molecular phylogeny and radiation time of Erysiphales inferred from the nuclear ribosomal DNA sequences
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从核核糖体 DNA 序列推断白粉菌的分子系统发育和辐射时间
DOI：
10.1007/bf02461662
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发表时间：
2000
期刊：
影响因子：
1.4
通讯作者：
S. Takamatsu
中科院分区：
文献类型：
--
作者：
Y. Mori;Yukio Sato;S. Takamatsu
根据新测定的10个丹毒类群的18S rDNA序列和28S rDNA的部分序列（包括D1和D2区），推测了子囊菌门内丹毒类群的系统发育关系。系统发育分析表明，丹毒门在子囊真菌中形成了一个独特的分支，表明丹毒门从一个单一的祖先分类单元分化而来。Onygenales的粘毛科与其他onygenale科有远亲关系，是Erysiphales calde的姐妹群，并与之结合形成一个分支。Erysiphales/Myxotrichaceae分支还与一些不合生真菌（Leotiales， Cyttariales和theelebolaceae）密切相关，包括形成闭囊性ascomata的分类群。目前的分子分析和先前报道的形态学观察表明，可能存在一种从闭锁囊性失调真菌到丹毒科和粘菌科的新进化途径。然而，由于除了丹毒菌外，这些真菌大多对粪便和/或植物材料腐生，因此像丹毒菌这样的专性生物营养物质如何以及为什么从腐生真菌中辐射出来的问题仍有待解决。我们还使用18S rDNA序列和先前报道的两个分子钟估计了丹参的辐射时间。计算结果表明，丹毒属植物是在190 ~ 127亿年前从黏液科植物中分离出来的。即使考虑到分子钟的不确定性，由于丹毒属植物的辐射时间也不超过230毫微里，因此有可能认为丹毒属植物是在被子植物的辐射之后进化的。我们的计算结果还表明，Erysiphales内部的第一次辐射（138-92 myr前）与被子植物主要多样化（130-90 myr前）的日期相吻合。这些结果可能支持我们早期的假设，即丹毒的辐射与被子植物的进化是一致的。
Phylogenetic relationships of Erysiphales within Ascomycota were inferred from the newly determined sequences of the 18S rDNA and partial sequences of the 28S rDNA including the D1 and D2 regions of 10 Erysiphales taxa. Phylogenetic analyses revealed that the Erysiphales form a distinct clade among ascomycetous fungi suggesting that the Erysiphales diverged from a single ancestral taxon. The Myxotrichaceae of the Onygenales was distantly related to the other onygenalean families and was the sister group to the Erysiphales calde, with which it combined to form a clade. The Erysiphales/Myxotrichaceae clade was also closely related to some discomycetous fungi (Leotiales, Cyttariales and Thelebolaceae) including taxa that form cleistothecial ascomata. The present molecular analyses as well as previously reported morphological observations suggest the possible existence of a novel evolutionary pathway from cleistothecial discomycetous fungi to Erysiphales and Myxotrichaceae. However, since most of these fungi, except for the Erysiphales, are saprophytic on dung and/or plant materials, the questions of how and why an obligate biotroph like the Erysiphales radiated from the saprophytic fungi remain to be addressed. We also estimated the radiation time of the Erysiphales using the 18S rDNA sequences and the two molecular clockes that have been previously reported. The calculation showed that the Erysiphales split from the Myxotrichaceae 190–127 myr ago. Since the radiation time of the Erysiphales does not exceed 230 myr ago, even when allowance is made for the uncertainty of the molecular clocks, it is possible to consider that the Erysiphales evolved after the radiation of angiosperms. The results of our calculation also showed that the first radiation within the Erysiphales (138–92 myr ago) coincided with the date of a major diversification of angiosperms (130–90 myr ago). These results may support our early assumption that the radiation of the Erysiphales coincided with the evolution of angiosperm plants.