Ectomycorrhizal fungi with edible fruiting bodies 2.Boletus edulis

Boletus edulis sensu lato (penny bun mushroom, cep, cèpe de Bordeaux, porcino, Steinpilz) is a complex of at least five species (or sub-species) of mycorrhizal fungi which grow primarily with hosts in Fagaceae, Pinaceae, and Betulaceae. They occur in a wide variety of habitats throughout the Northern Hemisphere and have been accidentally introduced into South Africa and New Zealand. The fruiting bodies have a very strong flavor and are widely used both commercially and domestically, particularly in Europe and North America. The vegetation, climate, and soils where B. edulis grows and methods that have been used in unsuccessful attempts to cultivate it are described.     

ITS primers for the identification of marketable Boletus

Boletus species belonging to the section Boletus are the most frequently eaten fungi among those harvested in natural conditions in Europe. This section groups 10 taxa which are hardly distinguishable on the basis of their morphology. Some of them have been shown to induce allergic IgE-mediated symptoms either through inhalation, ingestion or contact. Since questions relating to the presence of allergens in any of the species most in demand (B. edulis, B. aereus, B. pinophilus, B. aestivalis, all classified as B. edulis s.l.) remain open, together with the absence of tools which distinguish the species, we sequenced the ITS region of 28 Boletus samples and then we designed specific primers. These allowed the effective separation of the taxa. In addition, the phylogenetic tree obtained from the sequences alignment revealed that B. violaceofuscus, a spectacular Chinese fungus considered belonging to the section Boletus and often sold intermixed with B. edulis s.l. specimens, clusters outside the section Boletus.     

Soil fungal communities in a Castanea sativa (chestnut) forest producing large quantities of Boletus edulis sensu lato (porcini): where is the mycelium of porcini?

A study was conducted in a Castanea sativa forest that produces large quantities of the edible mushroom porcini (Boletus edulis sensu lato). The primary aim was to study porcini mycelia in the soil, and to determine if there were any possible ecological and functional interactions with other dominant soil fungi. Three different approaches were used: collection and morphological identification of fruiting bodies, morphological and molecular identification of ectomycorrhizae by rDNA-ITS sequence analyses and molecular identification of the soil mycelia by ITS clone libraries. Soil samples were taken directly under basidiomes of Boletus edulis, Boletus aestivalis, Boletus aereus and Boletus pinophilus. Thirty-nine ectomycorrhizal fungi were identified on root tips whereas 40 fungal species were found in the soil using the cloning technique. The overlap between above- and below-ground fungal communities was very low. Boletus mycelia, compared with other soil fungi, were rare and with scattered distribution, whereas their fruiting bodies dominated the above-ground fungal community. Only B. aestivalis ectomycorrhizae were relatively abundant and detected as mycelia in the soil. No specific fungus-fungus association was found. Factors triggering formation of mycorrhizae and fructification of porcini appear to be too complex to be simply explained on the basis of the amount of fungal mycelia in the soil.     

辽东栎幼苗的外生菌根合成

 在温室花盆中播种辽东栎（Quercus liaotungensis）种子获得辽东栎幼苗,并对幼苗接种外生菌根真菌进行菌根合成试验。所用的外生菌根真菌有：铆钉菇（Gomphidius viscidus）、臭红菇（Russula foetens）、厚环乳牛肝菌（Suillus grevillei）、褐环乳牛肝菌（S. luteus）、彩色豆马勃（Pisolithus tinctorius）、美味牛肝菌（Boletus edulis）、赭丝膜菌（Cortinarius russus）、土生空团菌（Cenococ     

舜皇山自然保护区的大型真菌资源

通过考察、采集到舜皇山自然保护区大型真菌资源标本600余份,共计31科,78属,200种.其中有国内新记录种1种,湖南省内新记录种72种.这些真菌中,食用菌57种,药用菌38种,外生菌根菌25种,木材致腐菌66种.     

中国大型高等真菌生物多样性的关键类群

由于生物多样性的关键类群在科学研究、社会经济及生态系统中所处的重要地位,有必要对其进行筛选和确定。在多年的野外考察和有关文献资料分析的基础上,参照植物和动物关键类群的划分原理及方法,结合高等真菌的特点将大型高等真菌划分为3种类型：濒危类群、重大科学价值类群和重要经济类群。其中,濒危类群指在近年的考察和报告中发现的数量急剧减少或由于过度的采集资源明显受到威胁的种类,其中有虫草属(Cordyceps)的中华虫草(C．siaensis)、块菌属(Tuber)的中华块菌(T．sinense)、假下陷块菌(T．pseu—doexcawatum)、喜马拉雅块菌(T.himalayense)、革菌属(Thelephora)的干巴菌(T．ganbajun)、口蘑属的松茸(Tricholoma matsuatke)及其近缘种和蒙古口蘑(T．mongolicum);重大科学价值类群指在真菌系统演化或与动、植物和其它真菌协同进化中的一些重要类群,或在应用研究领域具重要价值的类群,如鸡Zong菌属(Termitomyces)、鹅膏属(Amanita)、腹菌与伞菌的过渡类型如地红菇属(Macowanites)、粉褶包属(Richoniella)、轴腹菌属(Hydnangium)、腹牛肝菌属(Gastroboletus)等、牛肝菌类中的一些特殊单种属和寡种属如圆花孢牛肝菌属(Heimiel-la)、圆孔牛肝菌属(Gyroporus)等;重要经济类群指广为利用的食用菌、药用菌和外生菌根菌,其中主要有虫草属的中华虫草、块菌属的中华块菌、鸡Zong菌属盾尖鸡Zong菌(T．dypeatus)、鸡Zong菌(T.ewrhizus)、球形鸡Zong菌(T．gtoulus)、口蘑属的松茸群及蒙古口蘑、牛肝菌属(Bolaus)的美味牛肝菌(B．edulis)、小美牛肝菌(R．speciosus)、茶褐牛肝菌(B．brunneissimus)等,乳菇的红汁乳菇(L,hatsudake)、松乳菇(L．deliciosus)、多汁乳菇(L．volemus）、红菇属的变绿红菇(R．vir-escens)、蓝黄红菇(R．cyanoxantha)、鹅膏属的红黄鹅膏(A．hemibapha)、隐花青鹅膏(A．mang-iniana)、灵芝属(Ganoderma)的灵芝(G,lucidum)及紫芝(G,sinense)、竹荪属(Dictyophora)、豆马勃属(Pisdithus)的一些种。这些种由于具有重要的经济价值而受到过度的采集,故往往与濒危的种类一致。关键类群的筛选与提出为大型高等真菌的研究、应用和保护提供参考。     

过量钠盐胁迫对3种外生菌根真菌生长和钠元素积累的影响*

通过测定3种外生菌根真菌-美味牛肝菌(Boletus edulis)、红绒盖牛肝(Xerocomus chtysenterort)和铆钉菇(Gomphidius viscidus)在Na2SO4和NaCl处理下的菌斑增长特性、生物量积累和菌丝中钠元素积累量显示,2种盐都没有影响菌丝的生长模式。但在0．1mol／L浓度下,NaCl显抑制了X．chrysertterort和G．viscidus的干重增长;在Na2SO4处理下,X．chrysenteron生物增长量比对照显增加,G．viscidus则降低,而2种盐处理对B．edtdis的生物量积累没有显影响。3供试菌种在2种盐处理下,其对钠元素的吸收和积累量差异显。NaCl处理下,X．chtysenteron菌丝积累的钠量最多,而在Na2SO4条件下,B．edulis菌丝中钠积累量显高于其他2菌种。     

DNA sequence analyses reveal abundant diversity, endemism and evidence for Asian origin of the porcini mushrooms

The wild gourmet mushroom Boletus edulis and its close allies are of significant ecological and economic importance. They are found throughout the Northern Hemisphere, but despite their ubiquity there are still many unresolved issues with regard to the taxonomy, systematics and biogeography of this group of mushrooms. Most phylogenetic studies of Boletus so far have characterized samples from North America and Europe and little information is available on samples from other areas, including the ecologically and geographically diverse regions of China. Here we analyzed DNA sequence variation in three gene markers from samples of these mushrooms from across China and compared our findings with those from other representative regions. Our results revealed fifteen novel phylogenetic species (about one-third of the known species) and a newly identified lineage represented by Boletus sp. HKAS71346 from tropical Asia. The phylogenetic analyses support eastern Asia as the center of diversity for the porcini sensu stricto clade. Within this clade, B. edulis is the only known holarctic species. The majority of the other phylogenetic species are geographically restricted in their distributions. Furthermore, molecular dating and geological evidence suggest that this group of mushrooms originated during the Eocene in eastern Asia, followed by dispersal to and subsequent speciation in other parts of Asia, Europe, and the Americas from the middle Miocene through the early Pliocene. In contrast to the ancient dispersal of porcini in the strict sense in the Northern Hemisphere, the occurrence of B. reticulatus and B. edulis sensu lato in the Southern Hemisphere was probably due to recent human-mediated introductions.     

Widespread occurrence of Neotyphodium-like endophyte in populations of Bromus tomentellus Boiss. in Iran

Neotyphodium species occur as endophytic fungi in cool-season grasses around the world. The beneficial aspects of grass-Neotyphodium associations have provoked researchers to look for a novel association in plant species where this symbiotum has not been reported. We surveyed Russian bromegrass (Bromus tomentellus Boiss.) accessions from a germplasm collection for the presence of Neotyphodium spp. fungi and determined levels of endophyte infection in B. tomentellus populations in native rangelands of Iran. Among 50 collected accessions, symbiotic fungi were detected in 45 accessions without any symptoms of choke disease on host plants. In culture medium, fast-growing endophytes appeared from seeds after 7-14 days. Plants grown from seed collections were 80-100% infected. Based on morphological characteristics and PCR analysis, we concluded that this fungus is a member of the Neotyphodium group of endophytic fungi. Lack of apparent toxicity to grazing animals suggests a place for endophyte-infected B. tomentellus in rangeland renovation, providing this infected grass exhibits increased tolerance to abiotic stresses.     

七株外生菌根真菌与三种松苗菌根的形成能力

松树外生菌根菌资源丰富,但实际应用的种类不多。为筛选出与松苗形成菌根能力较强的菌种,采用播种接菌和芽苗截根移栽接菌两种方法,对7株外生菌根真菌与马尾松、湿地松和黑松3种松苗的菌根合成进行了研究。结果表明：形成的菌根以二叉分枝状为主,棒状菌根相对较少,多叉状菌根以马尾松较多。PC2形成的菌根表面菌丝厚且紧密,504、EG、Pt,形成的菌根表面菌丝紧密程度中等,而505、ZJ和HX形成的菌根其表面菌丝则比较稀疏;Pt1、Pt2、EG形成的菌根外延菌丝较长,而505、HX形成的菌根外延菌丝极短。截根接菌时的感染率和感染指数要高于播种接菌。504形成菌根的能力最强,在3种松苗上的菌根感染率都达100％,感染指数最高可达90,最低也达70;Pt2和EG与马尾松和黑松形成菌根的能力较强;而505和HX仅与马尾松形成菌根的能力较强;Pt1形成菌根的能力较差,在3种松苗上菌根感染率和感染指数都较低。在3种松苗中,马尾松的菌根化状况最好,其次为黑松,湿地松的菌根化状况较差。     

Neighboring trees affect ectomycorrhizal fungal community composition in a woodland-forest ecotone

Ectomycorrhizal fungi (EMF) are frequently species rich and functionally diverse; yet, our knowledge of the environmental factors that influence local EMF diversity and species composition remains poor. In particular, little is known about the influence of neighboring plants on EMF community structure. We tested the hypothesis that the EMF of plants with heterospecific neighbors would differ in species richness and community composition from the EMF of plants with conspecific neighbors. We conducted our study at the ecotone between pinyon (Pinus edulis)-juniper (Juniperus monosperma) woodland and ponderosa pine (Pinus ponderosa) forest in northern Arizona, USA where the dominant trees formed associations with either EMF (P. edulis and P. ponderosa) or arbuscular mycorrhizal fungi (AMF; J. monosperma). We also compared the EMF communities of pinyon and ponderosa pines where their rhizospheres overlapped. The EMF community composition, but not species richness of pinyon pines was significantly influenced by neighboring AM juniper, but not by neighboring EM ponderosa pine. Ponderosa pine EMF communities were different in species composition when growing in association with pinyon pine than when growing in association with a conspecific. The EMF communities of pinyon and ponderosa pines were similar where their rhizospheres overlapped consisting of primarily the same species in similar relative abundance. Our findings suggest that neighboring tree species identity shaped EMF community structure, but that these effects were specific to host-neighbor combinations. The overlap in community composition between pinyon pine and ponderosa pine suggests that these tree species may serve as reservoirs of EMF inoculum for one another.     

Characterization of 27 microsatellite loci in the European flat oyster Ostrea edulis

The flat oyster Ostrea edulis is native to Europe and populations have been severely depleted by the parasite Bonamia ostreae since the 1980s. Additional genetic markers are required to improve population genetics study and linkage map development for selection for B. ostrea-resistance in this species. Here, we characterized 27 novel microsatellite loci for O. edulis. Number of alleles per locus ranged from 6 to 25 and observed heterozygosity between 0.375 and 1. Null alleles were suggested at a few loci but most loci were in Hardy-Weinberg agreement enabling their reliable use in further population and mapping genetics approaches.     

Temporal and spatial patterns in recruitment and succession of a temperate marine fouling assemblage: a comparison of static panels and boat hulls during the boating season

Protection against biofouling is essential for efficient operation of boats and ships. Restrictions on the use of traditional, toxic antifouling coatings call for new less toxic methods. Future antifouling strategies will likely be based on more specific action against dominant foulers and will require more detailed information about spatial and temporal differences in fouling communities on artificial substrates. In this study, the recruitment and succession of fouling organisms was examined on artificial (PMMA) panels exposed to natural flow speeds on the Skagerrak coast (Sweden). The recruitment of foulers on static panels was then compared to fouling allowed to develop on boat hulls in surveys of new nontoxic coatings. The temporal and spatial variation in recruitment was examined on a monthly interval within the boating season, from May-September. Furthermore, the succession of the fouling community was examined during the same interval. A total of 12 sessile invertebrate species was recorded on the static panels with dominant foulers being the barnacle Balanus improvisus (July-September) and the mussel Mytilus edulis (June-August). The mean abundance during peak settlement on panels after 1 month's deployment was 370 +/- 134 individuals dm-2 for B. improvisus and 340 +/- 415 individuals dm-2 for M. edulis. The succession of foulers on the panels led to a dominance of M. edulis (maximum of 7470 +/- 2830 individuals dm-2) over B. improvisus (maximum of 2295 +/- 680 individuals dm-2). This was in contrast to the fouling development on boat hulls, examined after 4 months exposure in 3 successive years, where B. improvisus was the dominant species (mean abundance 222 +/- 104 and maximum 713 +/- 527 individuals dm-2). Some boats were covered to an extent of almost 100% by B. improvisus with only a few M. edulis (mean abundance 20 +/- 16). The biomass of fouling on boat hulls varied from average dry weights of 1.3 +/- 1 to 13 +/- 5 g dm-2. These results show that extrapolation from static panels (common in evaluation of antifouling performance) to fouling on boat hulls may be problematic.     

Genetic differentiation of Euterpe edulis Mart. populations estimated by AFLP analysis

Heart-of-palm (Euterpe edulis Mart.) is a wild palm with a wide distribution throughout the Atlantic Rainforest. Populations of E. edulis represent important renewable natural resources but are currently under threat from predatory exploitation. Furthermore, because the species is indigenous to the Atlantic Rainforest, which is located in the most economically developed and populated region of Brazil, social and economic pressures have devastated heart-of-palm forests. In order to estimate the partitioning of genetic variation of endangered E. edulis populations, 429 AFLP markers were used to analyse 150 plants representing 11 populations of the species distribution range. Analysis of the genetic structure of populations carried out using analysis of molecular variance (AMOVA) revealed moderate genetic variation within populations (57. 4%). Genetic differentiation between populations (FST = 0.426) was positively correlated with geographical distance. These results could be explained by the historical fragmentation of the Atlantic coastal region, together with the life cycle and mating system. The data obtained in this work should have important implications for conservation and future breeding programmes of E. edulis.     

Molecular phylogeny of asexual entomopathogenic fungi with special reference to Beauveria bassiana and Nomuraea rileyi

The phylogenetic lineage, taxonomic affiliation and interrelationships of important asexual entomopathogenic fungal genera were studied using the sequences of partial regions of β-tubulin and rRNA genes. The species structures of Beauveria bassiana and Nomuraea rileyi were also investigated. A total of 147 fungal entries covering 94 species were analysed. Phylogenetic analysis placed all the asexual entomopathogenic fungal species analysed, in the family Clavicipitaceae of the order Hypocreales of Ascomycota. Deep phylogenetic lineages were observed in B. bassiana iterating the complex nature of this species. Some of the isolates assigned to this species separated out more distinctly than morphologically distinguishable genera. Cryptic speciation was also evident in N. rileyi. It is concluded that the asexual fungi with entomopathogenic habit arose from a single lineage in sexual Clavicipitaceae.     

Genetic connections between some species of Mytilidae (Mollusca: Bivalvia) from the northern part of the Pacific Ocean

In 1978 and 1999, seven and eight species of Mytilidae (Mollusca: Bivalvia) were analyzed using gel electrophoresis. Mean heterozygosity per individual (Hobs and Hexp) and genetic distances (Rogers' DR, Nei's DN, and others) were estimated for 21 and 24 allozyme loci. Mytilus modiolus had the highest variation among the species examined. Genetic distances were lowest for the M. trossulus-M. galloprovincialis species pair: DR = 0.147, DN = 0.078. Overall, five species of the genera Mytilus and Crenomytilus were genetically closer to each other (DR = 0.147, DN = 0.078) than to the remaining three species of this group (DR = 0.807, DN = 2.243). The relationships among the species were examined using cluster analysis and parsimony methods. The densest clusters in the dendrograms consisted of (1) M. trossulus and M. galloprovincialis and (2) M. coruscus, M. californianus, and M. grayanus. These two clusters form a larger cluster (3), which comprises all representatives of the nominal genus Mutilus and C. grayanus. The Mytilus-Crenomytilus cluster is consecutively joined by Adula falcatoides, Mytilus modiolus, and Septifer keenae. According to Nei's genetic distances DN, the time of divergence between M. trossulus and M. galloprovincialis is 0.8-1.6 Myr; between M. californianus and C. grayanus, it is approximately 9 Myr; and between M. coruscus and the latter pair, it is 13 Myr before present. Two representatives of the Mytilus ex gr. edulis complex diverged from the Mytilus-Crenomytilus group of large-size Pacific species about 20 Myr ago. These results are in good agreement with paleontological data and indicate a relatively recent origin of the Mytilus ex gr. edulis complex. The results obtained can be used in systematics and phylogeny of modern Mytilidae.     

竹子扩张对阔叶林物种多样性的影响:两竹种的叠加效应

研究了不同扩张强度下毛竹和肿节少穗竹对江西武夷山常绿阔叶林群落结构和物种多样性的影响.结果表明: 毛竹、肿节少穗竹扩张都会不同程度地改变阔叶林群落结构与物种组成,两者同时高强度扩张时(毛竹30～50 ind·100 m^-2,肿节少穗竹300～500 ind·100 m^-2),群落的乔∶灌(密度比)由2∶8变成1∶9,竹∶木(密度比)由0∶10变成9∶1.毛竹、肿节少穗竹扩张对阔叶林物种多样性影响的主效应显著,毛竹主要影响乔木层,肿节少穗竹主要影响灌木层,但两种竹子的交互作用不显著.两种竹子同时扩张对群落生物多样性的影响存在叠加效应,尤其是高强度扩张使群落Shannon指数下降91.3%.毛竹与肿节少穗竹同时低强度扩张时,两者相互影响不大,但当达到一定密度后两者会相互竞争排斥.这表明,当常绿阔叶林同时遭受毛竹、肿节少穗竹扩张时,虽然二者交互作用不明显,但会通过叠加效应影响木本植物,导致阔叶林群落简单化.     

分子时代的白僵菌研究

白僵菌属是全球分布的最常见的虫生真菌。自上世纪90年代以来,有关白僵菌的研究进入分子时代,各方面的研究都有快速甚至是突破性的进展。作为复合种的球孢白僵菌和布氏白僵菌已被分割,而且还有其他新种被陆续命名,有多种有性型被发现;在查明一些致病基因及其作用机制后,通过转基因改良菌株工作取得突破性进展;分子生态学的研究解决了与白僵菌在农林生态系中的流行有关的一些难题。文中就白僵菌的分类学与系统演化、生物学、分子致病机制与基因工程,以及生态学与流行病学等方面的研究进展进行了综述。     

Evaluation of the antioxidant activity of four edible mushrooms from the Central Anatolia, Eskisehir - Turkey: Lactarius deterrimus, Suillus collitinus, Boletus edulis, Xerocomus chrysenteron

The methanolic extracts of Lactarius deterrimus, Suillus collitinus, Boletus edulis, Xerocomus chrysenteron were analyzed for their antioxidant activities in different test systems namely beta-carotene/linoleic acid, DPPH free radical scavenging, reducing power and metal chelating activities in addition to their total phenolic and flavonoid contents. In beta-carotene/linoleic acid and DPPH systems, L. deterrimus and B. edulis showed the strongest activity patterns. Their activities were as strong as the positive controls. The reducing power of the species was excellent. Chelating capacity of the extracts was increased with the increasing concentration. On the other hand, B. edulis found to have the highest phenolic content. Total flavonoid content of S. collitinus found the superior to the other mushrooms.     

Radionuclide accumulation in fruit bodies of macromycetes

Coefficients of 137Cs accumulation and 90Sr were determined in macromycetes of different trophic groups (137Cs in 43 species and 90Sr in 19 species) in the conditions of droughty year (1992). Their variability in forest formations was determined in the period from 1992 to 1998. In the year with increased atmospheric humidity (1998), two-fold rise of 137Cs accumulation in fruit bodies was registered on average. The pollution of Boletus edulis correlates with photosynthetically active part of Betula pendula and Pinus silvestris closer than with soil pollution. This shows the possibility to indicate the pollution of short-living fruit bodies of fungi by the pollution of plants-symbiotrophs.