Okane Izumi, Ono Yoshitaka, Ohmachi Katsura, Aime M Catherine, Yamaoka Yuichi
a Faculty of Life and Environmental Sciences, University of Tsukuba.
b College of Education, Ibaraki University.
Mycoscience. 2021 Nov 20;62(6):364-372. doi: 10.47371/mycosci.2021.06.006. eCollection 2021.
The rust fungi () that infect ferns, early diverging vascular plants, are neither "primitive" nor monophyletic, as once hypothesized. The neotropical fern pathogen, (), specializes on species of . is believed to have evolved in a period ca. 211 mya, which is after the evolution of the temperate fern rust fungi that parasitize later diverged ferns. is the only rust species in the genus known to infect ferns, the majority of which infect flowering plants. In this study we examined multiple new and herbarium specimens of and reconstructed its phylogenetic history with data generated from the 28S nuclear rDNA repeat. is the sister species to another neotropical fern rust, (), which also infects early diverged leptosporangiate fern species, and the new combination is made. Interestingly, and differ primarily in sorus structure, i.e., subepidermal in the former vs. suprastomatal in the latter fungus. Characters such as suprastomatal sori and probasidia that germinate without dormancy are now known to represent a suite of adaptations that have been derived multiple times within , most likely in response to tropical climates.
侵染蕨类植物（早期分化的维管植物）的锈菌并不像曾经假设的那样是“原始的”或单系的。新热带蕨类病原体，即[具体名称未给出]，专化于[具体寄主名称未给出]的物种。据信它大约在2.11亿年前演化而来，这是在寄生较晚分化蕨类的温带蕨类锈菌演化之后。[具体名称未给出]是已知的该属中唯一侵染蕨类的锈菌物种，该属的大多数锈菌侵染开花植物。在本研究中，我们检查了多个[具体名称未给出]的新标本和标本馆标本，并利用从28S核rDNA重复序列产生的数据重建了其系统发育历史。[具体名称未给出]是另一种新热带蕨类锈菌[具体名称未给出]的姐妹物种，后者也侵染早期分化的薄囊蕨类物种，并形成了新的组合。有趣的是，[具体名称未给出]和[具体名称未给出]主要在孢子堆结构上有所不同，即前者的孢子堆在表皮下，而后者的在气孔上。现在已知诸如气孔上的孢子堆和不经过休眠就萌发的原担子等特征代表了在[具体属名未给出]内多次衍生的一系列适应，很可能是对热带气候的响应。
