四川都江堰亚热带针阔混交林中主要晚生型外生菌根真菌类群的空间分布

晚生型外生菌根真菌通常出现在森林演替的后期,是成熟林中的优势外生菌根真菌类群.对四川都江堰一片亚热带针阔混交林中的菌根真菌地上群落进行调查,并应用二元逻辑回归分析对晚生型外生菌根真菌的主要类群,即鹅膏菌科、牛肝菌科和红菇科,与周围(5 m×5 m样方)树种组成的关系进行研究.还应用次级变量分析方法对主要外生菌根真菌类群的空间格局进行了分析.结果表明,非外生菌根树种及某些外生菌根树种对特定类群菌根真菌子实体的出现有抑制作用,而不同类群外生菌根真菌在克隆生长上的差异并不是子实体空间分布的决定因素.我们认为,当研究自然林中外生菌根子实体的空间分布时,除了宿主植物的分布,也应考虑非宿主植物的分布以及菌根真菌相互作用的影响.     

Amanita xenokommosis (Agaricales,Basidiomycota), a striking new species from sand dune forest of northeastern Brazil,with a key for phenetically similar species*

Abstract

Amanita is a well established genus corresponding one to the major groups of Agaricales having with a rich systematic story. Several species belonging to this genus were recently reported from Brazil. Recent studies changed drastically its infrageneric classification, recognizing the subgenera Amanita, Amanitina and Lepidella. Within the subg. Amanitina, the ectomycorrhizal species with amyloid basidiospores, appendiculate pileus and stipe base with more globose to subglobose bulb belong to sect. Roanokenses. Amanita xenokommosis belongs to this section and is described here a new species from the Brazilian Coastal Sand Dune. It is characterized by elongate to cylindrical amyloid basidiospores, brown pileus with sharp floccose appendiculate remnants and bulb covered by a large limbate/saccate universal veil. Amanita caojizong, A. manginiana, A. modesta, A. pseudomanginiana and A. pseudoporphyria are similar species, but differ in many aspects, such as basidiospores size, shape of bulb and characteristics of the universal veil.     

四川都江堰亚热带针阔混交林中主要晚生型外生菌根真菌类群的空间分布

晚生型外生菌根真菌通常出现在森林演替的后期,是成熟林中的优势外生菌根真菌类群。对四川都江堰一片亚热带针阔混交林中的菌根真菌地上群落进行调查,并应用二元逻辑回归分析对晚生型外生菌根真菌的主要类群,即鹅膏菌科、牛肝菌科和红菇科,与周围(5m×5m样方)树种组成的关系进行研究。还应用次级变量分析方法对主要外生菌根真菌类群的空间格局进行了分析。结果表明,非外生菌根树种及某些外生菌根树种对特定类群菌根真菌子实体的出现有抑制作用,而不同类群外生菌根真菌在克隆生长上的差异并不是子实体空间分布的决定因素。我们认为,当研究自然林中外生菌根子实体的空间分布时,除了宿主植物的分布,也应考虑非宿主植物的分布以及菌根真菌相互作用的影响。     

DNA-based fungal diversity in Madagascar and arrival of the ectomycorrhizal fungi to the island

Madagascar is known for its high diversity and endemism of fauna and flora. Fungi, however, have been largely overlooked in diversity and evolution studies on the island, and whether fungi exhibit the same patterns as animals and plants has yet to be further examined. We collected fungal sporocarps and ectomycorrhizal (EcM) roots during three opportunistic surveys in five forests in Madagascar and generated a dataset of fungal Internal Transcribed Spacer (ITS) DNA sequences. We analyzed them together with all publicly available fungal ITS DNA sequences and identified 620 Operational Taxonomic Units (OTUs) from Madagascar, 10% of which contained only sequences from our surveys. Two hundred and ninety-two OTUs belonged to EcM species with /russula-lactarius, /boletus, /tomentella-telephora, /cortinarius, and /amanita being the most abundant EcM lineages. Overall, 60% of all fungi and 81% of the EcM species from Madagascar appear to be endemic. We conducted a phylogenetic analysis using all the OTUs in Amanitaceae, Boletaceae, and Russulaceae families to elucidate their relative timing of arrival in Madagascar. We found that most EcM species from Madagascar in the three families diverged less than 22 million years ago (mya), long after the separation of India and Madagascar (88 mya), which is consistent with a dispersal mediated process of arrival to the island. Our study provides the first comprehensive view of the overall DNA-based fungal diversity in Madagascar and the current state of knowledge of EcM fungi based on DNA sequences, useful for further ecological and evolutionary studies. Abstract in Malagasy is available with online material.