中国北方拟蜡伞属一个可食用的新种

拟蜡伞属Hygrophoropsis是牛肝菌目中的一个小属,现归属于独立的科——拟蜡伞科.本研究从形态学特征、分子生物学证据、生态学和地理分布等方面描述了一种可食用的新种——芦苇拟蜡伞.该新种的特征为菌盖表面乳白色至淡赭色;菌褶白到奶油色;担孢子长圆形至椭圆形,厚壁,具轻微糊精反应,大小为6-10×4-5.5 μm,生...     

Phylogenetic placement of Diplocystis wrightii in the Sclerodermatineae (Boletales) based on nuclear ribosomal large subunit DNA sequences

Diplocystis wrightii is an enigmatic gasteroid basidiomycete from the Caribbean. It has taxonomic affiliations with Lycoperdaceae, Broomeiaceae, and Sclerodermataceae. This study sampled ITS and 28S ribosomal genes from three D. wrightii specimens to determine the phylogenetic placement and the closest relatives of this species. Results of database searches and phylogenetic analysis indicate this species to be a member of the Sclerodermatineae and most closely related to the genera Astraeus and Tremellogaster.     

Patterns of vegetative growth and gene flow in Rhizopogon vinicolor and R. vesiculosus (Boletales, Basidiomycota)

We have collected sporocarps and tuberculate ectomycorrhizae of both Rhizopogon vinicolor and Rhizopogon vesiculosus from three 50 x 100 m plots located at Mary's Peak in the Oregon Coast Range (USA); linear map distances between plots ranged from c. 1 km to c. 5.5 km. Six and seven previously developed microsatellite markers were used to map the approximate size and distribution of R. vinicolor and R. vesiculosus genets, respectively. Genetic structure within plots was analysed using spatial autocorrelation analyses. No significant clustering of similar genotypes was detected in either species when redundant samples from the same genets were culled from the data sets. In contrast, strong clustering was detected in R. vesiculosus when all samples were analysed, but not in R. vinicolor. These results demonstrate that isolation by distance does not occur in either species at the intraplot sampling scale and that clonal propagation (vegetative growth) is significantly more prevalent in R. vesiculosus than in R. vinicolor. Significant genetic differentiation was detected between some of the plots and appeared greater in the more clonal species R. vesiculosus with Phi(ST) values ranging from 0.010 to 0.078*** than in R. vinicolor with Phi(ST) values ranging from -0.002 to 0.022** (*P < 0.05, **P < 0.01, ***P < 0.001). When tested against the null hypothesis of no relationship between individuals, parentage analysis detected seven likely parent/offspring pairs in R. vinicolor and four in R. vesiculosus (alpha = 0.001). Of these 11 possible parent/offspring pairs, only two R. vinicolor pairs were still supported as parent/offspring when tested against the alternative hypothesis of being full siblings (alpha = 0.05). In the latter two cases, parent and offspring were located at approximately 45 m and 28 m from each other. Challenges to parentage analysis in ectomycorrhizal fungi are discussed.     

Comparative phylogenies and host specialization in the alder ectomycorrhizal fungi Alnicola, Alpova and Lactarius (Basidiomycota) in Europe

Background  

Mycorrhizal fungi form intimate associations with their host plants that constitute their carbon resource and habitat. Alnus spp. (Betulaceae) are known to host an exceptional species-poor and specialized ectomycorrhizal (ECM) fungal community compared to other tree species, but the host-specificity pattern and its significance in terms of fungal diversification and speciation remain poorly documented. The degree of parallel speciation, host switching, and patterns of biogeography were explored in the historical associations between alders and three ECM taxa of Basidiomycetes: Alnicola (Agaricales), Alpova (Boletales), and Lactarius (Russulales). The aim was to develop an evolutionary framework on host specificity and diversification of Basidiomycetes in this highly specialized plant-fungus symbiosis.     

Phylogeny of the ectomycorrhizal mushroom genus Alnicola (Basidiomycota, Cortinariaceae) based on rDNA sequences with special emphasis on host specificity and morphological characters

Alnicola (=Naucoria, pro parte) is a mushroom genus of strictly temperate, obligately ectomycorrhizal species, traditionally included in the family Cortinariaceae. Most Alnicola spp. are primarily host specific on Alnus, although a few are mycobionts of Salix or other hosts. The different species of Alnicola exhibit unique morphological (cystidia, pileipellis) and cytological (dikaryotic or monokaryotic hyphae) characters. This makes the genus Alnicola of particular interest for studying the evolution of host specificity and morphological characters in ectomycorrhizal basidiomycetes. We used a combination of classical morphological and phylogenetic methods (rDNA ITS and LSU sequences) to address the following questions: (i) Is Alnicola monophyletic? And (ii) Are characters like host specificity or microscopical structures synapomorphic for certain clades? The study included nearly all currently known European Alnicola sp. Our results demonstrated that, on one hand, the genus Alnicola is polyphyletic, with sistergroup relationships to Hebeloma, Anamika or the clades /Hymenogaster I and /Hymenogaster II. On the other hand, Alnicola splits into three well-supported clades corresponding to the sections Alnicola, Submelinoides, and Salicicolae. The strict host-specificity to Alnus is a derived character and has occurred at least twice. The following morphological characters are synapomorphic for defined clades: the spindle-shaped hymenial cystidia for sect. Alnicola, the hymeniform pileipellis for sect. Submelinoides, and monocaryotic/clampless hyphae for sect. Salicicolae and its sistergroup /Hymenogaster II. As a taxonomical consequence, polyphyly of Alnicola implies that the sects. Submelinoides and Salicicolae need to be segregated from Alnicola.     

Phylogeny and character evolution in the jelly fungi (Tremellomycetes, Basidiomycota, Fungi)

The Tremellomycetes (Agaricomycotina, Basidiomycota, Fungi) are a nutritionally heterogeneous group comprising saprotrophs, animal parasites, and fungicolous species (fungal-inhabiting, including lichen-inhabiting). The relationships of many species, particularly those with a lichenicolous habit, have never been investigated by molecular methods. We present a phylogeny of the Tremellomycetes based on three nuclear DNA ribosomal markers (nSSU, 5.8S and nLSU), representing all main taxonomic groups and life forms, including lichenicolous taxa. The Cystofilobasidiales, Filobasidiales, Holtermanniales, and Tremellales (including the Trichosporonales) are recovered as monophyletic, but this is not the case for the Tremellomycetes. We suggest, however, that the Cystofilobasidiales tentatively continue to be included in the Tremellomycetes. As currently circumscribed, the Filobasidiaceae, Sirobasidiaceae, Syzygosporaceae and Tremellaceae are non-monophyletic. Cuniculitremaceae, Sirobasidiaceae and Tetragoniomycetaceae are nested within Tremellaceae. The lichenicolous species currently included within the Tremellomycetes belong in this group, distributed across the Filobasidiales and Tremellales. Lichen-inhabiting taxa do not form a monophyletic group; they are distributed in several clades and sometimes intermixed with taxa of other nutritional habits. Character state reconstruction indicates that two morphological traits claimed to characterize groups in the Tremellomycetes (the basidium habit and basidium septation) are highly homoplastic. Comparative phylogenetic methods suggest that the transitions between single and catenulate basidia in the Tremellales are consistent with a punctuational model of evolution whereas basidium septation is likely to have evolved under a graduational model in the clade comprising the Holtermanniales, Filobasidiales, and Tremellales.     

Phylogeny of the Pluteaceae (Agaricales, Basidiomycota): taxonomy and character evolution

The phylogeny of the genera traditionally classified in the family Pluteaceae (Agaricales, Basidiomycota) was investigated using molecular data from nuclear ribosomal genes (nSSU, ITS, nLSU) and consequences for taxonomy and character evolution were evaluated. The genus Volvariella is polyphyletic, as most of its representatives fall outside the Pluteoid clade and shows affinities to some hygrophoroid genera (Camarophyllus, Cantharocybe). Volvariella gloiocephala and allies are placed in a different clade, which represents the sister group of Pluteus, and a new generic name, Volvopluteus, is proposed to accommodate these taxa. Characters such as basidiospore size and pileipellis structure can be used to separate Pluteus, Volvariella and Volvopluteus. The genus Pluteus is monophyletic and includes species with partial veil traditionally classified in the genus Chamaeota. The evolution of morphological features used in the infrageneric taxonomy of the genus, such as metuloid cystidia and pileipellis structure, was analyzed. Agreement between the molecular phylogeny and morphological subdivision of Pluteus is, generally speaking, good, though some rearrangements are necessary: (i) species with non-metuloid pleurocystidia and pileipellis as a cutis are placed either in sect. Celluloderma, together with the species characterized by a hymenidermal pipeipellis, or in sect. Pluteus, with the metuloid bearing species; (ii) subdivision of sect. Celluloderma according to the presence/absence of cystidioid elements in the pileipellis is not supported by molecular data.     

Phylogeny and classification, origins, and evolution of host associations of lice

Lice are highly successful ectoparasites. Most species of mammals and birds are infested by at least 1 but up to 6 species of lice. Current opinion is that lice evolved from free-living Psocoptera (booklice, barklice and psocids). It is generally agreed that there are 4 main groups of lice: Anoplura, Amblycera, Ischnocera and Rhyncophthirina. In contrast, there is no agreement on the phylogenetic relationships of these groups and their classification. In particular, there is much debate over the validity of the taxon Mallophaga, which is almost certainly paraphyletic. For many years the sister-group of the Boopiidae, which almost exclusively infest Australasian marsupials, was thought to be a group of lice that now infest marsupials in South America. This, however, is almost certainly incorrect; the sister-group of the Boopiidae probably contains bird-infesting lice from the Menoponidae (Amblycera). Thus, menoponid lice transferred from birds to mammals and from these arose the Boopiidae. Transfers of lice between mammals and birds have occurred on other occasions during the evolution of the lice; 2 of the 4 main groups of lice, the Ischnocera and Amblycera, contain families that infest birds and families that infest mammals. Strict cospeciation and coevolution was thought to predominate among the lice; however, detailed studies indicate this to be incorrect. Consequently, the axiom that lice and their hosts invariably coevolve should be abandoned. Ironically, biologists may learn more about the evolutionary biology of hosts when host-switching has occurred. Some evidence exists for competition between species of lice; this interaction may determine whether or not the transfer of a species of louse to an atypical hose (a potential host-switch) is successful. Thus, the extincion of populations of lice (that result in uninfested hosts) may facilitate host-switching and perhaps the evolution of new taxa of lice. In contrast, extinction of hosts unfortunately often leads to the extinction of species of lice.     

Cryptic species and host specificity in the ectomycorrhizal genus Strobilomyces (Strobilomycetaceae)

Taxonomical classification of higher fungi remains an important challenge and can benefit from the application of molecular analysis. We propose that the ectomycorrhizal (EM) fungal taxa might include a number of cryptic species because there are few morphological characteristics useful for distinguishing among these fungi. Previously, host specificity in most EM fungi was thought to be low, but we suspect that confusion of cryptic species has led to an underestimate of fungal host specificity. We analyzed both nuclear and mitochondrial DNA sequences from Strobilomyces fungi and obtained evidence that what were previously described as four species can be grouped into 14 distinct lineages, suggesting that these lineages might be distinct biological species. Moreover, we identified host plants for Strobilomyces via nucleotide sequencing of both fungal and plant DNA from EM samples. Most lineages of Strobilomyces tested in this study were associated only with Fagaceae trees, even though Strobilomyces species were previously thought to be generalists with regard to hosts. Thus, we present an approach useful for identifying cryptic species and detecting the true host range of a set of EM fungi in natural conditions.     

Molecular phylogenetics and the evolution of host plant associations in the nematode genus Fergusobia (Tylenchida: Fergusobiinae)

Fergusobia nematodes (Tylenchida: Fergusobiinae) and Fergusonina flies (Diptera: Fergusoninidae) are putative mutualists that develop together in galls formed in meristematic tissues of many species of the plant family Myrtaceae in Australasia. Fergusobia nematodes were sampled from a variety of myrtaceous hosts and gall types from Australia and one location in New Zealand between 1999 and 2006. Evolutionary relationships of these isolates were inferred from phylogenetic analyses of the DNA sequences of the nuclear ribosomal DNA near-full length small subunit (up to 1689bp for 21 isolates), partial large subunit D2/D3 domain (up to 889bp for 87 isolates), partial mitochondrial cytochrome oxidase subunit I (618 bp for 82 isolates), and combined D2/D3 and mtCOI (up to 1497bp for 66 isolates). The SSU data supported a monophyletic Fergusobia genus within a paraphyletic Howardula. A clade of Drosophila-associated Howardula, including Howardula aoronymphium, was the closest sequenced sister group. Phylogenetic analysis of sequences from D2/D3 and mtCOI, separately and combined, revealed many monophyletic clades within Fergusobia. The relationships inferred by D2/D3 and mtCOI were congruent with some exceptions. Well-supported clades were generally consistent with host plant species and gall type. However, phylogenetic analysis suggested host switching or putative hybridization events in many groups, except the lineage of shoot bud gallers on the broad-leaved Melaleuca species complex.     

Genetic Diversity and Evolution of Chinese Traditional Medicinal Fungus Polyporus umbellatus (Polyporales,Basidiomycota)

Background

Polyporus umbellatus is an important medicinal fungus distributed throughout most area of China. Its wide distribution may have resulted in substantial intraspecific genetic diversity for the fungus, potentially creating variation in its medical value. To date, we know little about the intraspecific genetic diversity of P. umbellatus.

Methodology/Principal Findings

The objective of this research was to assess genetic differences of P. umbellatus from geographically diverse regions of China based on nrDNA ITS and 28S rRNA (LSU, large subunit) sequences. Significant sequence variations in the ITS and LSU sequences were detected. All sclerotial samples were clustered into four clades based on phylogenetic analysis of ITS, LSU and a combined data set of both regions. Heterogeneity of ITS and LSU sequences was detected in 5 and 7 samples respectively. All clone sequences clustered into the same clade except for one LSU clone sequences (from Henan province) which clustered into two clades (Clade I and Clade II). Significant genetic divergence in P. umbellatus was observed and the genetic diversification was greater among sclerotial samples from Shaanxi, Henan and Gansu provinces than among other provinces. Polymorphism of ITS and LSU sequences indicated that in China, P. umbellatus may spread from a center (Shaanxi, Henan and Gansu province) to other regions.

Conclusions/Significance

We found sclerotial samples of P. umbellatus contained levels of intraspecific genetic diversity. These findings suggested that P. umbellatus populations in Shaanxi, Henan and Gansu are important resources of genetic diversity and should be conserved accordingly.     

Diversity and host associations of parasitoids attacking mycophagous drosophilids (Diptera: Drosophilidae) in northern and central Japan

The diversity and host associations of parasitoids attacking mycophagous drosophilids were studied in Tokyo (a warm‐temperate region) and Sapporo (a cool‐temperate region) in Japan. Field collections were carried out using traps baited with mushrooms in May, June, September and October 2009 in Tokyo and in July and August 2010 in Sapporo. The major drosophilid species that emerged from mushroom baits was Drosophila bizonata in Tokyo and D. orientacea in Sapporo. In total, 13 parasitoid species emerged from drosophilids occurring in mushroom baits, and 11 of them were larval parasitoids belonging to Braconidae and Figitidae. Among the 11 larval parasitoids, 10 were collected in Tokyo, while only two were collected in Sapporo. It is not known why their diversity differed so much between these two regions. Four of the 11 larval parasitoids have also been recorded from drosophilid larvae occurring in fruit (banana). The use of these two habitats (mushrooms and fruit) by these four species seems to reflect the occurrence (i.e. resource use) of their suitable hosts. On the other hand, most larval parasitoids from Tokyo attacked D. bizonata, and two larval parasitoids from Sapporo attacked D. orientacea, suggesting that the abundance of potential hosts is one of the important factors affecting their host use.     

Relative importance of the endomycorrhizal and (or) ectomycorrhizal associations in Allocasuarina and Casuarina genera

This work was carried out to determine the relative importance of the endomycorrhizal and (or) ectomycorrhizal association in species of Casuarina and Allocasuarina. Under axenic conditions, Pisolithus and Scleroderma isolates formed ectomycorrhizas with a mantle and a Hartig net on Allocasuarina verticillata but failed to form a Hartig net on Casuarina glauca. In a controlled soil system, C. glauca was inoculated with the endomycorrhizal fungus Glomus intraradices Schenck & Smith, and A. verticillata was inoculated with Pisolithus albus IR100 Bougher & Smith and (or) G. intraradices. Both symbionts significantly stimulated growth in both plant species. For A. verticillata, its growth response to ectomycorrhizal inoculation was higher than to endomycorrhizal inoculation. When both symbionts were inoculated, antagonism among the fungal isolates was observed with a higher ectomycorrhizal colonization. These results showed that A. verticillata was ectomycorrhizal dependent, whereas C. glauca was endomycorrhizal dependent. From a practical point of view, this study shows the importance of selecting compatible mycorrhizal fungi for developing successful inoculation programmes. In addition, it would help to further research and determine the effect of ecto- and endo-mycorrhizal symbiosis on the formation and function of N2-fixing actinorhizal nodules.     

Phylogenetic species delimitation in ectomycorrhizal fungi and implications for barcoding: the case of the Tricholoma scalpturatum complex (Basidiomycota)

Population studies have revealed that the fungal ectomycorrhizal morphospecies Tricholoma scalpturatum consists of at least two genetically distinct groups that occur sympatrically in several geographical areas. This discovery prompted us to examine species boundaries and relationships between members formerly assigned to T. scalpturatum and allied taxa using phylogenetic analyses. Sequence data were obtained from three nuclear DNA regions [internal transcribed spacer (ITS), gpd and tef], from 101 carpophores collected over a large geographical range in Western Europe, and some reference sequences from public databases. The ITS was also tested for its applicability as DNA barcode for species delimitation. Four highly supported phylogenetic clades were detected. The two previously detected genetic groups of T. scalpturatum were assigned to the phylospecies Tricholoma argyraceum and T. scalpturatum. The two remaining clades were referred to as Tricholoma cingulatum and Tricholoma inocybeoides. Unexpectedly, T. cingulatum showed an accelerated rate of evolution that we attributed to narrow host specialization. This study also reveals recombinant ITS sequences in T. inocybeoides, suggesting a hybrid origin. The ITS was a useful tool for the determination of species boundaries: the mean value of intraspecific genetic distances in the entire ITS region (including 5.8S rDNA) was <0.2%, whereas interspecific divergence estimates ranged from 1.78% to 4.22%. Apart from giving insights into the evolution of the T. scalpturatum complex, this study contributes to the establishment of a library of taxonomically verified voucher specimens, an a posteriori correlation between phenotype and genotype, and DNA barcoding of ectomycorrhizal fungi.     

中国小木层孔菌属研究

小木层孔菌属的种类在我国共有7种,其中芳香小木层孔菌Phellinidium fragrans为中国首次报道,该种发现于吉林省长白山自然保护区,与同属其它种的区别是子实体多年生、平伏、具有芳香气味,其担孢子在同属的种类中最小,菌肉中具有形状不规则的厚垣孢子。根据中国的材料对这个种进行了详细描述和显微结构绘图。给出了该属种类的检索表,并将每种孢子统计数据列在检索表中。     

中国的软齿菌属的研究

详细描述了软齿菌属在中国的种类,其中稀软齿菌[Dentipellis separans(Peck)Donk]为中国新记录种,并根据中国的材料对3个种进行了详细描述和绘图。     

中国蜡革菌属的研究

介绍了蜡革菌属Ceraceomyces及该属在中国的种类,其中北方蜡革菌Ceraceomyces borealis是中国新记录种,根据中国的材料对其进行了详细的描述和显微结构绘图,同时给出了中国蜡革菌属5个种的检索表。     

Anamorphs of the Bolbitiaceae (Basidiomycota, Agaricales)

We describe and illustrate thallic conidiogenesis in 14 species of the Bolbitiaceae sensu Singer studied in culture. Conidiogenesis of 12 species is shown for the first time. Bolbitius vitellinus and the investigated species of Conocybe (C. albipes, C. appendiculata, C. magnicapitata, C. semiglobata, C. subovalis, C. subpubescens, C. sulcatipes and C. teneroides) possessed a similar mode of conidiogenesis. Species of both genera formed mostly coiled conidiogenous hyphae arising sympodially from differentiated conidiophores. The anamorphs of the Agrocybe species were not uniform and predominantly differed from those of Conocybe and Bolbitius. The conidia of Agrocybe dura, A. firma and A. praecox developed by the simple fragmentation of normally branched hyphae. Sympodially proliferating conidiophores occurred in Agrocybe arvalis and A. aegerita. Secretory cells of different size and shape were found in Agrocybe and in Conocybe. Our results corroborate a close phylogenetic relationship between Bolbitius and Conocybe as well as the polyphyly of the Bolbitiaceae as currently treated, which is consistent with recent molecular phylogenetic studies. Consequently we emend the family concept based on anamorphic characters.