Institute of Ecology and Earth Sciences, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
Fungal Biol. 2013 May;117(5):348-67. doi: 10.1016/j.funbio.2013.03.005. Epub 2013 Apr 11.
Temperate species of Hypomyces and Cladobotryum that produce the red pigment aurofusarin are common on agaricoid and polyporoid basidiomata of species from five orders of Agaricomycetes. Several cause cobweb disease of commercially cultivated mushrooms resulting in serious losses. We sequenced rpb1, rpb2, tef1, and FG1093 regions in 90 wild strains and 30 strains from mushroom farms, isolated from Europe, North America, Africa, Asia, Australia, and New Zealand. Multigene analyses support the distinctness of five species but reveal Hypomyces rosellus to be paraphyletic, comprising several cryptic lineages. Hypomyces rosellus s. str. is characterised by wide dispersal and gene flow across Eurasia but does not occur in North America. Instead, the lineages from the West and the East Coast appear distinct, having given rise to species inhabiting the Southern Hemisphere. Our results reveal wide misuse of the name H. rosellus, especially for cobweb isolates. The majority of these belong to Hypomyces odoratus, including a weakly supported group of fungicide-resistant strains from Europe and North America sharing identical sequence data. New collections are presented for Cladobotryum rubrobrunnescens and Cladobotryum tenue as well as Cladobotryum multiseptatum and Hypomyces dactylarioides, all previously known only from their type material. The former species pair occurs in Europe and the latter in Australia and New Zealand. Separate lineages appear to be maintained by geographic isolation in North America and temperate Australasia but by host specialisation in the species occurring sympatrically in Europe and Asia. Both specialist and generalist host use strategies have evolved in the group. Although teleomorphs are known in most of the species and unnamed lineages, analyses of the five-gene regions suggest the prevalence of clonal reproduction in H. odoratus. This can be the reason for its success in mushroom farms, also facilitating the spread of fungicide resistance. While tef1 and rpb2 can be recommended for species delimitation, low variation, not exceeding 1 % in the whole ingroup, impeaches the use of ITS as a barcoding gene region in this group of fungi.
温带的 Hypomyces 和 Cladobotryum 物种产生红色色素金灰菌素，常见于担子菌纲 Agaricomycetes 的五个目琼脂和多孔菌的担子果上。一些物种会导致商业种植蘑菇的蛛网病，造成严重损失。我们对来自欧洲、北美、非洲、亚洲、澳大利亚和新西兰的 90 个野生菌株和 30 个蘑菇场分离株进行了 rpb1、rpb2、tef1 和 FG1093 区域的测序。多基因分析支持 5 个物种的独特性，但表明 Hypomyces rosellus 是并系的，包含几个隐生谱系。Hypomyces rosellus s. str. 分布广泛，在欧亚大陆具有基因流，但不在北美洲出现。相反，来自西海岸和东海岸的谱系似乎是不同的，它们产生了栖息在南半球的物种。我们的结果表明，Hypomyces rosellus 的名称被广泛滥用，特别是用于蛛网分离株。这些分离株中的大多数属于 Hypomyces odoratus，包括一个来自欧洲和北美的抗真菌剂抗性菌株的弱支持组，它们共享相同的序列数据。本文还介绍了 Cladobotryum rubrobrunnescens 和 Cladobotryum tenue 以及 Cladobotryum multiseptatum 和 Hypomyces dactylarioides 的新采集物，这些物种之前仅在其模式标本中被发现。前一对物种存在于欧洲，后一对存在于澳大利亚和新西兰。在北美洲和温带的澳大拉西亚，地理隔离似乎维持了不同的谱系，但在欧洲和亚洲的同域物种中，通过宿主专化维持了不同的谱系。该组已经进化出了专门和通用的宿主使用策略。尽管大多数物种和未命名的谱系都有有性型，但 5 个基因区域的分析表明，Hypomyces odoratus 中存在克隆繁殖。这可能是它在蘑菇场中成功的原因，也促进了抗真菌剂抗性的传播。虽然 tef1 和 rpb2 可用于物种界定，但整个内群的变异率低，不超过 1%，这使得 ITS 不适用于该真菌组的条形码基因区域。
