Takamatsu Susumu, Inagaki Mihoko, Niinomi Seiko, Khodaparast Seyed Akbar, Shin Hyeon-Dong, Grigaliunaite Banga, Havrylenko Maria
Department of Bioresources, Graduate School, Mie University, 1577 Kurima-Machiya, Tsu 514-8507, Japan.
Mycol Res. 2008 Mar;112(Pt 3):299-315. doi: 10.1016/j.mycres.2007.11.014. Epub 2007 Dec 14.
Phyllactinia is a unique genus within the Erysiphales (Ascomycota) having a partly endo-parasitic nature of the mycelium within the host plant tissues. We constructed phylogenetic trees for the genus Phyllactinia and its allied genera based on a total of 120 nucleotide sequences of the 28S rDNA and ITS regions to discuss their phylogenetic relationships with special references to host plants, biogeography, evolutionary dating, and taxonomy. The analysis of the Erysiphales confirmed the monophyly of the endo-parasitic genera, i.e. Leveillula, Phyllactinia, and Pleochaeta. Phyllactinia specimens used in this study were divided into six distinctive groups and three subgroups. Interestingly, Leveillula, an obligately endo-parasitic genus of the Erysiphales, grouped together with Phyllactinia, although this was not significantly supported by the Kishino-Hasegawa and Shimodaira-Hasegawa tests. This suggests that the evolution within this group of fungi occurred from partial endo-parasitism to obligate endo-parasitism. The host range of Phyllactinia is mostly confined to woody plants, especially deciduous trees. Betulaceae, Fagaceae, Ulmaceae, Moraceae, and Rosaceae may have close connections to the divergence of the groups and subgroups of Phyllactinia concerned. Most of these plant families are known as major members of the boreotropical flora of the Tertiary, which suggests an early Tertiary origin of this genus. A comparison of the phylogenies of hosts and parasites revealed that host range expansion at higher taxonomic levels (higher than family level) is independent of the phylogeny of plants. Conversely, host range expansions in lower taxonomic levels (infrafamilial or infrageneric) tend to occur within a single family or genus. An estimation of the evolutionary timing using a molecular clock approach suggested that Phyllactinia split from Pleochaeta about 60 M years ago (Ma) in the early Tertiary and divergence of the six major clades of Phyllactinia occurred between 5 and 40 Ma during the Oligocene and Miocene. Divergence within the major clades and within Leveillula occurred maybe from more than 5 Ma onwards during the Pliocene and Quaternary. This is the first comprehensive phylogenetic study of Phyllactinia and other endo-parasitic genera of the Erysiphales.
内丝白粉菌属是白粉菌目（子囊菌门）中的一个独特属，其菌丝体在寄主植物组织内具有部分内寄生的特性。我们基于28S rDNA和ITS区域的总共120个核苷酸序列，构建了内丝白粉菌属及其相关属的系统发育树，以探讨它们的系统发育关系，并特别参考寄主植物、生物地理学、进化年代测定和分类学。对白粉菌目的分析证实了内寄生属（即内丝白粉菌属、内丝白粉菌属和多叉白粉菌属）的单系性。本研究中使用的内丝白粉菌标本分为六个不同的组和三个亚组。有趣的是，白粉菌目中专性内寄生的内丝白粉菌属与内丝白粉菌属聚在一起，尽管这在木村-羽田检验和岛田-羽田检验中没有得到显著支持。这表明这组真菌的进化是从部分内寄生到专性内寄生。内丝白粉菌属的寄主范围大多局限于木本植物，尤其是落叶树。桦木科、壳斗科、榆科、桑科和蔷薇科可能与相关的内丝白粉菌属的组和亚组的分化有密切联系。这些植物科中的大多数被认为是第三纪北温带植物区系的主要成员，这表明该属起源于第三纪早期。寄主和寄生菌系统发育的比较表明，较高分类水平（高于科级）的寄主范围扩展与植物的系统发育无关。相反，较低分类水平（科级以下或属级以下）的寄主范围扩展往往发生在单个科或属内。使用分子钟方法估计进化时间表明，内丝白粉菌属在第三纪早期约6000万年前（Ma）从多叉白粉菌属分化出来，内丝白粉菌属的六个主要分支在渐新世和中新世期间的500万至4000万年前发生分化。主要分支内和内丝白粉菌属内的分化可能从上新世和第四纪期间500万年前开始。这是对内丝白粉菌属和白粉菌目其他内寄生属的首次全面系统发育研究。
