Section for Genetics and Evolutionary Biology, University of Oslo, Blindernveien 31, 0316, Oslo, Norway.
Norwegian Institute for Nature Research, Gaustadalléen 21, 0349, Oslo, Norway.
ISME J. 2021 May;15(5):1445-1457. doi: 10.1038/s41396-020-00862-1. Epub 2021 Jan 11.
Sporocarps (fruit bodies) are the sexual reproductive stage in the life cycle of many fungi. They are highly nutritious and consequently vulnerable to grazing by birds and small mammals, and invertebrates, and can be infected by microbial and fungal parasites and pathogens. The complexity of communities thriving inside sporocarps is largely unknown. In this study, we revealed the diversity, taxonomic composition and host preference of fungicolous fungi (i.e., fungi that feed on other fungi) in sporocarps. We carried out DNA metabarcoding of the ITS2 region from 176 sporocarps of 11 wood-decay fungal host species, all collected within a forest in northeast Finland. We assessed the influence of sporocarp traits, such as lifespan, morphology and size, on the fungicolous fungal community. The level of colonisation by fungicolous fungi, measured as the proportion of non-host ITS2 reads, varied between 2.8-39.8% across the 11 host species and was largely dominated by Ascomycota. Host species was the major determinant of the community composition and diversity of fungicolous fungi, suggesting that host adaptation is important for many fungicolous fungi. Furthermore, the alpha diversity was consistently higher in short-lived and resupinate sporocarps compared to long-lived and pileate ones, perhaps due to a more hostile environment for fungal growth in the latter too. The fungicolous fungi represented numerous lineages in the fungal tree of life, among which a significant portion was poorly represented with reference sequences in databases.
子实体是许多真菌生命周期中的有性繁殖阶段。它们营养丰富，因此容易受到鸟类和小型哺乳动物以及无脊椎动物的捕食，也容易受到微生物和真菌寄生虫和病原体的感染。在子实体中茁壮成长的群落的复杂性在很大程度上是未知的。在这项研究中，我们揭示了子实体中真菌（即以其他真菌为食的真菌）的多样性、分类组成和宿主偏好。我们对来自 11 种木质腐朽真菌宿主物种的 176 个子实体的 ITS2 区进行了 DNA 宏条形码分析，这些子实体均在芬兰东北部的一片森林中采集。我们评估了子实体特征（如寿命、形态和大小）对子实体真菌群落的影响。以非宿主 ITS2 读数的比例衡量，子实体真菌的定殖水平在 11 个宿主物种之间变化范围为 2.8-39.8%，主要由子囊菌门主导。宿主物种是子实体真菌群落组成和多样性的主要决定因素，这表明宿主适应对于许多子实体真菌很重要。此外，与长寿命和叠生的子实体相比，短寿命和反卷的子实体的 alpha 多样性始终更高，这可能是由于后者的真菌生长环境更为恶劣。子实体真菌代表了生命之树中许多真菌谱系，其中相当一部分在数据库中的参考序列中代表性不足。
