Pringle Herbarium, Department of Plant Biology, University of Vermont, 111 Jeffords Hall, 63 Carrigan Drive, Burlington, Vermont 05405.
Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803.
Mycologia. 2019 Nov-Dec;111(6):1041-1055. doi: 10.1080/00275514.2019.1668905. Epub 2019 Oct 24.
is a poorly known genus of epibiotic and saprophytic species with a subcosmopolitan distribution. Here, we investigate the intriguing relationship between and its host plants in the fern family Polypodiaceae, where it occurs upon approximately 45 neotropical species. We conducted phylogenetic analyses using an eight-marker comprehensive ascomycete data set comprising 719 species representing all major lineages along with 23 new specimens sampled from ferns. We ask whether fern-dwelling are monophyletic, whether epibiotic have evolved independently from saprophytic ancestors, and identify anamorphic phases by incorporating sequences for all suspected taxa. Our results corroborate the placement of Acrospermales within the Dothideomycetes with strong support. However, the order remains incertae sedis due to weak support along the branches subtending the clade that includes the Acrospermales plus Dyfrolomycetales. Our results show a strong phylogenetic pattern in lifestyles but do not clearly identify an ancestral life history state. The first divergence in Acrospermaceae splits fungicolous taxa from taxa that inhabit plants; saprophytes and anamorphic phases found on angiosperms occur in both clades. Fungicolous species are monophyletic, whereas species with an epibiotic or necrotic life history upon plants are nonmonophyletic due to the position of the saprophyte . Previously, all collected from ferns were identified as . Our results indicate that this is not monophyletic due to the inclusion of . Two species are described herein as , sp. nov., and , sp. nov. We find no instances of co-cladogenesis; however, our ability to detect this is limited by the lack of resolution in the clade. Rather, we see that that the distribution of epibiotic is explained by the overlap between the ecological niche of the species and its host.
是一个鲜为人知的外生和腐生种属，分布范围广泛。在这里，我们研究了它与蕨类植物Polypodiaceae 科的宿主植物之间有趣的关系，在那里它发生在大约 45 种新热带物种上。我们使用包含 719 个物种的全面子囊菌数据集进行了系统发育分析，这些物种代表了所有主要谱系，以及从蕨类植物中采样的 23 个新的 标本。我们询问了蕨类植物栖息的 是否是单系的，外生 的是否是从腐生祖先独立进化而来的，以及通过整合所有可疑分类单元的序列来识别无性阶段。我们的结果证实了 Acrospermales 在 Dothideomycetes 中的位置，支持度很强。然而，由于包括 Acrospermales 加 Dyfrolomycetales 在内的分支的支持较弱，该目仍然属于未定类群。我们的结果显示了生活方式的强烈系统发育模式，但没有清楚地确定祖先的生活史状态。Acrospermaceae 中的第一次分歧将真菌类群与栖息在植物上的类群分开；在被子植物上发现的腐生和无性阶段出现在两个分支中。真菌类群是单系的，而在植物上具有外生或坏死生活史的物种由于腐生 的位置是非单系的。以前，所有从蕨类植物中收集到的 都被鉴定为 。我们的结果表明，由于包括 在内，这不是单系的。本文描述了两个物种，即 ，sp. nov. 和 ，sp. nov. 我们没有发现共进化的实例；然而，由于 分支的分辨率有限，我们检测到这种情况的能力受到限制。相反，我们看到外生 的分布是由 物种的生态位与其宿主的重叠来解释的。
