We characterized the diversity of cultivable fungal assemblages associated with the bryospheres of the bipolar mosses Polytrichastrum alpinum and Polytrichastrum juniperinum resident in King George Island, South Shetland Islands, Maritime Antarctica. From different parts of the mosses, 160 fungal isolates were obtained and identified using molecular biology methods as 43 taxa of 28 distinct genera. Antarctomyces psychrotrophicus, Mrakia gelida, Pseudogymnoascus sp., Melanodiplodia sp., and Vishniacozyma victoriae were the dominant taxa and displayed the highest values of frequency. Ecological diversity indices showed that the fungal assemblages were high but ranged among the mosses. Fungi of the bryospheres of both mosses showed different colonization patterns. Only A. psychrotrophicus, M. gelida, Pseudogymnoascus sp., and Leotiomycetidae sp. occurred as endophytes, epiphytes, and in the rhizoidosphere of P. alpinum. In contrast, the bryosphere of P. juniperinum did not show a single common fungus across its different portions. Our results show that the bryosphere of the bipolar Antarctic mosses seem to represent an interesting hostspot of fungal diversity dominated by cosmopolitan cold-adapted and endemic species recognized as symbionts and decomposer species. The high fungal diversity detected suggests that the Antarctic mosses may offer a protected microhabitat (bryosphere) favorable for the survival, dispersal, and colonization of symbionts and decomposer fungi in the different extreme environments of Antarctica.

中文翻译：

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与南极洲南设得兰群岛乔治王岛双极苔藓 Polytrichastrum alpinum 和 Polytrichum junipernum 苔藓圈相关的可培养真菌

我们描述了与居住在南极洲南设得兰群岛乔治王岛的双极苔藓 Polytrichastrum alpinum 和 Polytrichastrum juniperum 的苔藓圈相关的可培养真菌组合的多样性。从苔藓的不同部位，获得了 160 个真菌分离株，并使用分子生物学方法将其鉴定为 28 个不同属的 43 个分类群。Antarctomyces psychrotrophicus、Mrakia gelida、Pseudogymnoascus sp.、Melanodiplodia sp. 和 Vishniacozyma victoriae 是优势分类群，并显示出最高的频率值。生态多样性指数表明真菌群落较高，但分布在苔藓中。两种苔藓苔藓圈的真菌表现出不同的定植模式。只有 A. psychrotrophicus、M. gelida、Pseudogymnoascus sp. 和 Leotiomycetidae sp.。以内生菌、附生菌和 P. alpinum 的根际中的形式出现。相比之下，杜松的苔藓圈在其不同部分没有显示出单一的常见真菌。我们的研究结果表明，双极南极苔藓的苔藓圈似乎代表了一个有趣的真菌多样性宿主点，由被认为是共生体和分解者物种的世界性冷适应和特有物种主导。检测到的高真菌多样性表明，南极苔藓可能提供一个受保护的微生境（苔藓圈），有利于共生体和分解真菌在南极洲不同极端环境中的生存、扩散和定殖。杜松在其不同部分没有显示出单一的常见真菌。我们的研究结果表明，双极南极苔藓的苔藓圈似乎代表了一个有趣的真菌多样性宿主点，由被认为是共生体和分解者物种的世界性冷适应和特有物种主导。检测到的高真菌多样性表明，南极苔藓可能提供一个受保护的微生境（苔藓圈），有利于共生体和分解真菌在南极洲不同极端环境中的生存、扩散和定殖。杜松在其不同部分没有显示出单一的常见真菌。我们的研究结果表明，双极南极苔藓的苔藓圈似乎代表了一个有趣的真菌多样性宿主点，由被认为是共生体和分解者物种的世界性冷适应和特有物种主导。检测到的高真菌多样性表明，南极苔藓可能提供一个受保护的微生境（苔藓圈），有利于共生体和分解真菌在南极洲不同极端环境中的生存、扩散和定殖。