Molecular evolution of <Emphasis Type="Italic">Agaricus</Emphasis> species based on ITS and LSU rDNA sequences

Phylogenetic analyses of 62 isolates of 42 Agaricus and related secotioid species (A. inapertus, Gyrophragmium dunalii and Longula texensis) were conducted based on sequence data of the internal transcribed spacers (ITS) and partial large subunit (LSU) of ribosomal DNA. Bayesian, maximum likelihood and maximum parsimony analyses were used to reveal evolutionary groups within the genus Agaricus, while molecular clock analyses were carried out to obtain more information about the divergence times during the evolution of Agaricus within the Basidiomycota. Six major distinct clades were found within the genus with varying levels of support. These monophyletic groups suggested interspecific relationships both confirming and challenging previous morphological sections in several cases. Our results show that most morphological features likely have evolved in apparently similar ways multiple times independently during evolution, and that the secotioid A. inapertus, Gyrophragmium dunalii and Longula texensis evolved from Agaricus species in Clade I. A new name Agaricus aridicola, and a new combination Agaricus texensis are suggested to replace the names Gyrophragmium dunalii and Longula texensis, respectively. Molecular clock estimates for minimal age of separation of the genus Agaricus from its closest relatives were 32.63 ± 8.06 and 15.45 ± 3.82 Ma, respectively, using calibrations based on other molecular clock studies on fungi and fossil data. However, Agaricus likely diverged much earlier (73.30 ± 18.12 Ma), as suggested by the estimate based on the most robust calibration.     

Phylogeny and taxonomy of Macrolepiota (Agaricaceae)

The position and composition of Macrolepiota within the Agaricaceae and its phylogenetic relationships with other members of the family were investigated, using both molecular (ITS and LSU rDNA sequences) and morphological characters. The molecular data separate the genus into two clades. The first clade comprises M. procera, M. mastoidea, M. clelandii and allies and is a sister group of Leucoagaricus and Leucocoprinus. The second, more diverse, clade, with M. rachodes and allies, M. globosa, Chlorophyllum molybdites, Leucoagaricus hortensis and Endoptychum agaricoides, is a sister group of Agaricus. The separation of the two clades is supported by morphological characters, such as the structure of the pileus covering, the stipitipellis and the shape of the germ pore and the spore apex. The two clades are regarded as genera for which the names Macrolepiota and Chlorophyllum are proposed. Macrolepiota nympharum does not belong to either clade but is assigned to the genus Leucoagaricus, close to L. leucothites. Endoptychum depressum is transferred to the genus Agaricus as A. inapertus.     

双孢蘑菇及大肥菇的种内及种间多态性RAPD分析

应用RAPD方法分析双孢蘑菇（Agaricusbisporus）及大肥菇（Agaricusbitorquis）的种内及种间多态性,进一步证实由于双孢蘑菇的遗传保守性,多数孢子为自体可育的异核孢子,从而导致种内相似性很高;而依赖天然杂交具四孢特性的大肥菇种内相似程度较低。研究还分析评价了蘑菇属中的这两个不同种之间的亲缘关系,为种间杂交选材提供了理论依据。     

双孢蘑菇及大肥菇的种内及种间多态性RAPD分析*

应用RAPD方法分析双孢蘑菇（Agaricusbisporus）及大肥菇（Agaricusbitorquis）的种内及种间多态性,进一步证实由于双孢蘑菇的遗传保守性,多数孢子为自体可育的异核孢子,从而导致种内相似性很高;而依赖天然杂交具四孢特性的大肥菇种内相似程度较低。研究还分析评价了蘑菇属中的这两个不同种之间的亲缘关系,为种间杂交选材提供了理论依据。     

The family Agaricaceae: phylogenies and two new white-spored genera

A well resolved phylogeny of the Agaricaceae based on partial rpb2 sequences is presented from a wide geographic and systematic sampling of the family and compared to phylogenies based on nrLSU and tef1 sequences. A smaller dataset of the family focusing on the Agaricus clade of nrITS sequences and a combined dataset were used to determine the position of several white-spored taxa from northern Thailand. Two new genera are described from Thailand. Coniolepiota accommodates Lepiota spongodes, a gray-lilac-purple floccose white-spored species with a wide distribution in tropical Asia; Eriocybe has a white wooly felt-like covering of pileus and stipe, white spores and is described with one new species E. chionea, so far known only from northern Thailand. These new genera are closely related to three genera with colored spores (viz. Agaricus, Heinemannomyces and Clarkeinda) and not to other white-spored taxa.     

Two new species of sequestrate Agaricus (section Minores) from Australia

The novel species Agaricus lamelliperditus and A. colpeteii are described and illustrated, and affinities to other taxa determined by analysis of ITS sequence data. Both taxa resemble several other recently described Australian sequestrate Agaricus species, in particular A. pachydermus, A. wariatodes and A. chartaceus, which all have a powdery hymenophore from very early stages of basidiome formation. Both novel species have affinities to section Minores.     

Widespread distribution of low-copy-number variants of mitochondrial plasmid pEM in the genus Agaricus

The incidence of the linear mitochondrial plasmid pEM in Agaricus spp. was believed to be rare, based on visualization by gel electrophoresis and Southern hybridization. However, we report in this study PCR amplification of pEM-like sequences from all but one species of Agaricus examined. Regions amplified included (1) the pEM RNA polymerase gene and (2) adjoining carboxy-termini of the DNA and RNA polymerase genes. Sequence data from the RNA polymerase-like products support a plasmid, rather than mitochondrial, origin for these sequences. Sequence variation was low, and most differences were silent or conservative at the amino acid level. Stop codons were found in two of seven sequence types suggesting that functional constraints are low. A parsimony-derived phylogeny for these sequences did not match expected phylogenies for the host species. Recent acquisition of the plasmid is presented as the most likely hypothesis explaining these observations.     

A phylogenetic and morphological overview of sections Bohusia, Sanguinolenti, and allied sections within Agaricus subg. Pseudochitonia with three new species from France,Iran, and Portugal

The genus Agaricus was recently rearranged to accommodate numerous tropical taxa. Accordingly, the genus was split into six subgenera and 22 sections of which 12 are included in A. subg. Pseudochitonia. Preliminary data indicated that three putative new species belong to this subgenus. Our objectives were to describe these species, to determine to which sections they belong, and to experience the interest of some traditional traits in this new context. We morphologically described Agaricus coniferarum from France and Portugal, Agaricus iranicus from Iran, and Agaricus lusitanicus from Portugal. Multi-gene phylogenetic analyses based on ITS, LSU, and tef1 sequence data of representatives of the 12 sections clearly indicated that A. coniferarum and A. lusitanicus are placed in Agaricus sect. Bohusia, while A. iranicus is in A. sect. Sanguinolenti. Incidentally, we replaced the illegitimate name Agaricus magnivelaris by Agaricus fiardianus. In a phylogenetic tree, based on all available ITS sequence data and focussing on six related sections, we examined the phylogenetic distribution of various characters. The intensity of red discolouration when the sporocarp is rubbed or cut appeared as a phylogenetically weak informative trait. We propose a determination key leading to a group of three hardly distinguishable sections (Bohusia, Nigrobrunnescentes, and Sanguinolenti).     

Differential effect of Agaricus host species on the population development of Megaselia halterata (Diptera: Phoridae)

Twelve isolates from the genus Agaricus (Fungi, Basidiomycota) were investigated for their ability to support development of the phorid fly, Megaselia halterata (Wood), which is an important pest of the commercial white button mushroom Agaricus bisporus. Combined effects of oviposition of adult female M. halterata and larval development in mushroom compost inoculated with Agaricus mycelium were determined using bioassays. The numbers of M. halterata offspring that developed were affected by the Agaricus isolate used, and there was a significant separation between resistant and susceptible isolates. In a bioassay where the female phorids had a choice of all 12 isolates for oviposition, three isolates produced >200 adults per 100 g compost pot while the remaining nine isolates had <20 adults per pot. Where there was no choice of Agaricus isolate for oviposition, five isolates resulted in >100 adults per 100 g compost pot while the remainder resulted in <4 adults per pot. With the susceptible isolates, there was a positive correlation between increasing concentration of mycelium in the substrate and phorid development until the concentration exceeded 40% after which numbers of emerging phorids declined. Genetic identity of Agaricus isolates was determined using ITS sequencing and phylogenetic methods, which revealed two major cluster groups. Isolates supporting the development of large populations of M. halterata were located in one of these clusters (group I), and were either Agaricus bisporus or other species from the same Agaricus section Duploannulatae. Isolates that did not support the development of M. halterata populations were located in a different cluster (group II) and were more genetically distant from A. bisporus, e.g. Agaricus sections Arvenses, Minores and Xanthodermatei. Species of Agaricus with resistance to M. halterata could have significant potential for the breeding and cultivation of phorid-free mushrooms.     

邮票中的蘑菇属种类及其分布

截至2010年,通过对全世界范围蘑菇邮票的收集和统计得知,世界上76个国家和地区共发行了蘑菇属24个种计126枚邮票,从中大致了解世界范围上蘑菇属真菌的资源分布和栽培状况。     

五种食用菌氨基酸含量的测定及营养评价

研究测定了五种食用菌中氨基酸的含量,并利用五种非生物学指标对蛋白质的营养价值进行评价。五种食用菌氨基酸种类齐全,必需氨基酸占氨基酸总量的百分比分别达到45.94%、37.62%、42.45%、41.54%、35.98%。茶树菇和姬松茸的限制性氨基酸为半胱氨酸和甲硫氨酸,鸡腿菇、香菇和黑木耳的限制性氨基酸是缬氨酸。不同的评价指标对蛋白质进行营养评价,评价结果会有所差异。     

我国食药用菌驯化栽培物种名录

为了解我国食药用菌资源的开发利用情况,需要对我国食药用菌栽培驯化情况进行统计分析。通过公共数据库关键词搜索,统计栽培驯化食药用菌种类,经过拉丁名以及中文名称的核实,本名录收录了192种驯化栽培的食药用菌,隶属于2门15目48科89属,包括子囊菌门(Ascomycota) 26个种,担子菌门(Basidiomycota)166个种,其中在科水平上,多孔菌科(Polyporaceae)、蘑菇科(Agaricaceae)、侧耳科(Pleurotaceae)以及泡头菌科(Physalacriaceae)种类最多;在属水平,侧耳属(Pleurotus)、蘑菇属(Agaricus)、木耳属(Auricularia)、灵芝属(Ganoderma)等栽培驯化种类较多。通过本名录发现,我国已经完成栽培驯化的食用菌种类繁多,还有大量食药用菌有开发利用前景。     

Agaricus section Xanthodermatei: a phylogenetic reconstruction with commentary on taxa

Agaricus section Xanthodermatei comprises a group of species allied to A. xanthodermus and generally characterized by basidiomata having phenolic odors, transiently yellowing discolorations in some parts of the basidiome, Schaeffer's reaction negative, and mild to substantial toxicity. The section has a global distribution, while most included species have distributions restricted to regions of single continents. Using specimens and cultures from Europe, North America, and Hawaii, we analyzed DNA sequences from the ITS1+2 region of the nuclear rDNA to identify and characterize phylogenetically distinct entities and to construct a hypothesis of relationships, both among members of the section and with representative taxa from other sections of the genus. 61 sequences from affiliated taxa, plus 20 from six (or seven) other sections of Agaricus, and one Micropsalliota sequence, were evaluated under distance, maximum parsimony and maximum likelihood methods. We recognized 21 discrete entities in Xanthodermatei, including 14 established species and 7 new ones, three of which are described elsewhere. Four species from California, New Mexico, and France deserve further study before they are described. Type studies of American taxa are particularly emphasized, and a lectotype is designated for A. californicus. Section Xanthodermatei formed a single clade in most analyses, indicating that the traditional sectional characters noted above are good unifying characters that appear to have arisen only once within Agaricus. Deep divisions within the sequence-derived structure of the section could be interpreted as subsections in Xanthodermatei; however, various considerations led us to refrain from proposing new supraspecific taxa. The nearest neighbors of section Xanthodermatei are putatively in section Duploannulati.     

Crosses among Homokaryons from Commercial and Wild-Collected Strains of the Mushroom Agaricus brunnescens (= A. bisporus)

A new technique for the production of hybrid strains of the cultivated mushroom Agaricus brunnescens is described. Homokaryons were recovered from regenerated protoplasts obtained from several heterokaryotic strains. A total of 16 novel hybrids were produced in 63 attempted crosses between paired homokaryons. Recovery of both homokaryons and hybrids was verified by analysis of restriction fragment length polymorphisms. Three of four hybrids fruited in small-scale tests, further confirming that the isolates were true hybrids. Colony morphology alone was found to be a poor indicator of hybrid status. In two instances, three homokaryons crossed successfully in all combinations, suggesting that there are at least three alleles at the putative mating-type locus. Crosses between homokaryons from commercial and wild-collected isolates indicated that these strains belong to the same biological species.     

Fleshy fungi of grass fields HI. Reaction to different fertilizers and to age of grass turf. Periodicity of fruiting

The fungus flora of an experimental grass field was studied over a ten years period. 48 squares were fertilized with combinations of NPK fertilizers. The nitrogen source was varied over the years. Calcium nitrate was applied in four seasons, ammonium sulphate and calcium ammonium nitrate were each applied in three seasons. Two series of squares had grass turf of different age, in the period ranging from one year to 12 years of age. The 55 species of fungi recorded were clearly divided in a nitrophilous group and a nitrophobous group. In the three first seasons, when an ongoing nitrate programme was continued, the species frequencies in the +N parcels were much higher than in the—N parcels. Most species in the nitrophilous group showed preference for nitrate, and application of ammonium had an almost poisonous effect on a large number of nitrophilous species, including most of the fairy ring formers. Agaricus campestris and two other nitrophilous species reacted positively to potassium. Most of the nitrophobous species were ± attached to moss and to grass debris. A few species had preference for grass turf 1–2 years old while the vaste majority of the fungi were established after 3–5 years.
The fruiting periods of the more common species were found to have a range of several months.     

A phylogenetic reconstruction and emendation of Agaricus section Duploannulatae

Agaricus section Duploannulatae comprises the group of species allied with A. bisporus and A. bitorquis. Disagreement exists in the literature regarding the composition of this group. We used DNA sequence data from the ITS segments of the nuclear ribosomal DNA region, in a sample of European and North American isolates, to identify characters shared by this group, to further delimit species-level taxa within the section, and to develop a phylogenetic hypothesis. Shared polymorphisms that suggest a natural limit for section Duploannulatae were found. ITS1 data were assessed using parsimony, distance and maximum likelihood methods of phylogeny. The section Duploannulatae comprised six robust clades. Five clades corresponded to well characterized species from the temperate Northern Hemisphere (A. bisporus, A. subfloccosus, A. bitorquis, A. vaporarius, A. cupressicola). The sixth clade encompassed an A. devoniensis complex. Species concepts, nomenclature, and relationships are discussed and compared with prior reports.