ABSTRACT

Serendipita is one of the main fungal genera that form mutualistic associations with species of orchids (Orchidaceae). Here, seven new Serendipita species associated with various Australian orchid genera are described. These Serendipita species were originally characterized by multilocus DNA sequence species delimitation analyses (three mtDNA and four nuclear genes) and confirmed as distinct with addition of further isolates and reanalysis of nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and nuc 28S rDNA (28S). Culture morphology and microscopic features are presented for each species, three of which are binucleate and four multinucleate. For the ITS region, the seven species have within-species sequence divergence between 1.07% and 4.31%, and all but one of the species pairs is separated by interspecific divergence of at least 4.35%. The newly described Serendipita species, S. australiana, S. communis, S. occidentalis, S. rarihospitum, S. secunda, S. talbotii, and S. warcupii, are shown to be separate species from S. vermifera on the basis of comparison against a sequence from the type. Isolates originally identified by Warcup as Sebacina “vermifera” from Caladenia orchids are revised and shown to belong to three of the species newly described here. Some non-Caladenia isolates identified by Warcup as S. “vermifera” are also shown to be non-conspecific with the type of S. vermifera. On the basis of ITS sequences, 346 isolates from 26 other studies, previously identified under provisional designations, are accommodated under the novel species. The species of Serendipta described here associate with the Australian orchid genera Caladenia, Cyanicula, Elythranthera, Ericksonella, Eriochilus, Glossodia, and Pheladenia. Most of the novel Serendipita species occur widely across Australia, often with widely distributed hosts, but one species, Serendipita rarihospitum, associates with narrowly distributed orchid species.

摘要

Serendipita是主要的真菌属之一，与兰花（兰花科）物种形成互惠关系。在这里，描述了与各种澳大利亚兰花属相关的七个新的Serendipita物种。这些Serendipita物种最初通过多位点 DNA 序列物种定界分析（三个 mtDNA 和四个核基因）进行表征，并通过添加进一步的分离物和对 nuc rDNA 内部转录间隔区 ITS1-5.8S-ITS2 (ITS) 和 nuc 28S rDNA 的重新分析确认为不同的(28 秒)。每个物种都有培养形态和微观特征，其中三个是双核的，四个是多核的。对于 ITS 区域，这七个物种的种内序列差异在 1.07% 和 4.31% 之间，除了一个物种对之外，所有物种之间的种间差异至少为 4.35%。新描述的Serendipita物种，S. australiana、S.communis、S. occidentalis、S. rarihospitum、S. secunda、S. talbotii和S. warcupii,根据与该类型的序列进行比较，显示为与S. vermifera不同的物种。最初由 Warcup 鉴定为来自Caladenia兰花的Sebacina “ vermifera ”的分离株经过修订并显示属于这里新描述的三个物种。一些非Caladenia分离株被 Warcup 鉴定为S。“ vermifera ”也被证明与S. vermifera的类型不同。根据 ITS 序列，来自 26 项其他研究的 346 株分离物（以前以临时名称确定）被归入新物种。Serendipta的种类这里描述的与澳大利亚兰花属Caladenia、Cyanicula、Elythranthera、Ericksonella、Eriochilus、Glossodia和Pheladenia 相关。大多数新的Serendipita物种广泛分布在澳大利亚各地，通常寄主分布广泛，但有一个物种Serendipita rarihospitum与分布狭窄的兰花物种相关联。