RESUMO
The genus Agaricus includes more than 500 species mostly containing the edible and cultivated species worldwide. As part of the ongoing studies on the biodiversity of genus Agaricus in Pakistan, our objective was to focus on A. sect. Minores which is the largest section of the genus. In the first phylogenetic analyses based on the ITS region of the nuclear ribosomal DNA, our sample included specimens of 97 named species, 27 unnamed species, and 31 specimens (29 newly generated sequences in this study) from subtropical climate zones of Pakistan that likely belong to this section based on their morphology. The 31 specimens grouped into five distinct, well-supported clades corresponding to five species: A. glabriusculus already known from Pakistan and India, A. robustulus first recorded from Pakistan and briefly described here but already known from Bénin, Malaysia, China, and Thailand, and three possibly endemic new species described in detail A. badiosquamulosus sp. nov., A. dunensis sp. nov., and A. violaceopunctatus sp. nov. The sixth species currently known in Pakistan, including A. latiumbonatus also found in Thailand, were included in a multigene tree based on ITS, LSU, and Tef-1α sequence data. They all belong to a large pantropical paraphyletic group while most temperate species belong to a distinct clade, which includes about half of the species of the section. The current study aims to propose three novel species of genus Agaricus based on comprehensive morphological as well as molecular phylogenetic evidences from Pakistan.
Assuntos
Agaricus , Filogenia , Paquistão , Agaricus/genética , Agaricus/classificação , Clima Tropical , DNA Fúngico/genéticaRESUMO
Agaricus is a genus with more than 500 species. Most of the new species reported since 2000 are tropical or subtropical. The study area, the Malakand region, located in the north of Pakistan, has a subtropical climate. In this study, nine species, including three new species, of Agaricus subgenus Pseudochitonia, are reported from this region. Description of the new species are based on morphological characteristics and phylogenetic analyses using three DNA regions: nuc ribosomal DNA internal transcribed spacers (ITS), fragments of the large subunit of nuc ribosomal DNA (28S), and the translation elongation factor 1-alpha gene (TEF1). One new species, Agaricus lanosus, with wooly squamules on its cap, forms a lineage within Agaricus sect. Bivelares and cannot be classified with certainty in one of the two subsections (Cupressorum and Hortenses) of this section. Agaricus rhizoideus with rhizoid-like structure at the base of the stipe forms a basal clade in Agaricus sect. Hondenses. Specimens of the third new species, Agaricus malakandensis, form a species-level clade within Agaricus sect. Catenulati and exhibits the morphological characteristics of this section. Due to their similar ITS sequences, two previously unnamed specimens from Thailand (A. sp. LD2012162 and CA799) are considered conspecific with A. malakandensis.
Assuntos
Agaricus , DNA Fúngico , DNA Espaçador Ribossômico , Filogenia , Paquistão , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Agaricus/genética , Agaricus/classificação , Análise de Sequência de DNA , RNA Ribossômico 28S/genética , DNA Ribossômico/genética , Fator 1 de Elongação de Peptídeos/genética , Dados de Sequência Molecular , Esporos Fúngicos/citologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genéticaRESUMO
Agaricus is a species-rich genus with more than 600 species around the world. In this work, three new species, Agaricus cacainus, A. baiyunensis, and A. praeclarefibrillosus are described from the specimens collected at Baiyun Mountain, Guangzhou, China, a subtropical area with a monsoon maritime climate, based on phylogenetic analyses and morphological examinations of internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), D1/D2 domains of the large subunit of ribosomal DNA (28S), and a part of translation elongation factor 1-alpha (TEF1). Agaricus cacainus in A. sect. Amoeni is characterized by a parabolic to applanate, slightly depressed pileus covered with chocolate brown, appressed, triangular squamules against white background, a white, furfuraceous stipe, an unchanging context when cut, a fragile and evanescent annulus, usually 4- or 2-spored basidia, and mostly pyriform cheilocystidia. Agaricus baiyunensis in A. sect. Minores has a pileus with a slightly truncate top covered with light brown, downy-wooly fibrillose scales and a light yellowish stipe with membranous annulus. Agaricus praeclarefibrillosus in A. sect. Brunneopicti is characterized by a pileus surface with brownish, triangular, recurved scales and longitudinally splitting lines toward margin, a cottony stipe with white, tiny, recurved fibrils, a single annulus, and variously shaped cheilocystidia, with sparsely ornamented basidiospores. The detailed comparison of their morphological characteristics with closely related species is provided.
Assuntos
Agaricus , DNA Fúngico , DNA Espaçador Ribossômico , Filogenia , China , Agaricus/classificação , Agaricus/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Análise de Sequência de DNA , Esporos Fúngicos/citologia , Esporos Fúngicos/classificação , RNA Ribossômico 28S/genética , Fator 1 de Elongação de Peptídeos/genética , Dados de Sequência MolecularRESUMO
Cultivation of Agaricus bisporus is a large horticultural industry for many countries worldwide, where a single variety is almost grown exclusively. Mushroom virus X (MVX), a complex of multiple positive-sense single stranded RNA (ss(+)RNA) viruses, is a major pathogen of typical A. bisporus crops. MVX can manifest a variety of symptoms in crops and is highly infective and difficult to eradicate once established in host mycelium. Currently our knowledge regarding the molecular response of A. bisporus fruit bodies to MVX infection is limited. In order to study the response of different A. bisporus strains with different susceptibilities to MVX, we designed a model system to evaluate the in-vitro transmission of viruses in A. bisporus hyphae over a time-course, at two crucial phases in the crop cycle. The symptom expression of MVX in these varieties and the transcriptomic and proteomic response of fruit bodies to MVX-infection were examined. Transmission studies revealed the high potential of MVX to spread to uninfected mycelium yet not into the fruit bodies of certain strains in a crop. MVX affected colour and quality of multiple fruit bodies. Gene expression is significantly altered in all strains and between times of inoculation in the crop. Genes related to stress responses displayed differential expression. Proteomic responses revealed restriction of cellular signalling and vesicle transport in infected fruit bodies. This in-depth analysis examining many factors relevant to MVX infection in different A. bisporus strains, will provide key insights into host responses for this commercially important food crop.
Assuntos
Agaricus , Proteoma , Transcriptoma , Fenômenos Fisiológicos Virais , Agaricus/classificação , Agaricus/genética , Agaricus/virologia , Regulação Fúngica da Expressão GênicaRESUMO
In a recent revision of the genus Agaricus, A. section Xanthodermatei was split into two sections A. sect. Hondenses and A. sect. Xanthodermatei. Our objectives were to investigate the species diversity of both sections in Pakistan and to give an overview of the major clades. Phylogenetic analyses based on the combined nucLSU, ITS and TEF1 dataset from 35 specimens of both sections revealed three major clades. Analyses based on ITS dataset and 106 specimens, including 33 from Pakistan, reveal eight new species and one new record species. These nine species are described in detail. It is noteworthy that intraspecific variability as well as interspecific variability between closely related species were very low in ITS sequences in many cases. In the case of the two new species A. xanthochromaticus and A. griseovariegatus, TEF1 sequence data were much more efficient than ITS to distinguish these species from each other. The other new species are A. atroumbonatus, A. fumidicolor, A. macropeplus, A. parviniveus, A. swaticus and A. bambusetorum. The latter is the only new species of A. sect. Hondenses in which it is morphologically atypical and also the unique (sub)tropical species. Agaricus gregariomyces is recorded for the first time in Pakistan. In addition, brief descriptions are provided not only for A. bisporiticus, A. endoxanthus and A. punjabensis, which are reported again in Pakistan, but also for A. californicus, which is reported for the first time in Spain and outside North America. In total 12 species of both sections were reported in Pakistan and half of them were from subtropical climatic areas, underlining the contribution of the climatic diversity to the high species richness in this country.
Assuntos
Agaricus/classificação , Agaricus/genética , Agaricus/citologia , Agaricus/isolamento & purificação , DNA Espaçador Ribossômico , Variação Genética , Paquistão , Fenótipo , Filogenia , Análise de Sequência de DNARESUMO
Agaricus subgenus Spissicaules is widely distributed in the world. In this study, 114 specimens were included in multigene phylogenetic analyses that allowed a better circumscription of the four sections in A. subg. Spissicaules. Three new species from China, A. brunneovariabilis, A. beijingensis, and A. planiceps, are described and placed in different sections. The invalidly described A. catenariocystidiosus is validated here as an additional new species. Comparisons between the sequences of the three closely related species A. thiersii, A. parasubrutilescens, and A. linzhiensis support the distinction between these three species despite the paraphyly of A. linzhiensis, which results from its high intraspecific variability with numerous heteromorphisms.
Assuntos
Agaricus/classificação , Agaricus/genética , DNA Fúngico/genética , Filogenia , China , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Análise de Sequência de DNA , Esporos Fúngicos/classificação , Esporos Fúngicos/genéticaRESUMO
Agaricus sect. Arvenses includes numerous species that are potential candidates for cultivation, and some have high nutritional and medicinal interests. Between 2012 and 2017, 147 specimens of A. sect. Arvenses were collected in China. For this study, nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and translation elongation factor 1-alpha (tef1) sequences were used to assess species boundaries of these samples from China. Combined with morphological examination, we recognize 22 species of A. sect. Arvenses from China, of which 12 are known species, one is new record for China, and nine are proposed as new.
Assuntos
Agaricus/classificação , Classificação , Agaricus/citologia , Agaricus/genética , China , DNA Espaçador Ribossômico/genética , Carpóforos/citologia , Genes Fúngicos/genética , Fator 1 de Elongação de Peptídeos/genética , Filogenia , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/genética , Esporos Fúngicos/citologiaRESUMO
Agaricus bisporus is an extensively cultivated edible mushroom. Demand for cultivation is continuously growing and difficulties associated with breeding programs now means strains are effectively considered monoculture. While commercial growing practices are highly efficient and tightly controlled, the over-use of a single strain has led to a variety of disease outbreaks from a range of pathogens including bacteria, fungi and viruses. To address this, the Agaricus Resource Program (ARP) was set up to collect wild isolates from diverse geographical locations through a bounty-driven scheme to create a repository of wild Agaricus germplasm. One of the strains collected, Agaricus bisporus var. bisporus ARP23, has been crossed extensively with white commercial varieties leading to the generation of a novel hybrid with a dark brown pileus commonly referred to as 'Heirloom'. Heirloom has been successfully implemented into commercial mushroom cultivation. In this study the whole genome of Agaricus bisporus var. bisporus ARP23 was sequenced and assembled with Illumina and PacBio sequencing technology. The final genome was found to be 33.49 Mb in length and have significant levels of synteny to other sequenced Agaricus bisporus strains. Overall, 13,030 putative protein coding genes were located and annotated. Relative to the other A. bisporus genomes that are currently available, Agaricus bisporus var. bisporus ARP23 is the largest A. bisporus strain in terms of gene number and genetic content sequenced to date. Comparative genomic analysis shows that the A. bisporus mating loci in unifactorial and unsurprisingly highly conserved between strains. The lignocellulolytic gene content of all A. bisporus strains compared is also very similar. Our results show that the pangenome structure of A. bisporus is quite diverse with between 60-70% of the total protein coding genes per strain considered as being orthologous and syntenically conserved. These analyses and the genome sequence described herein are the starting point for more detailed molecular analyses into the growth and phenotypical responses of Agaricus bisporus var. bisporus ARP23 when challenged with economically important mycoviruses.
Assuntos
Agaricales/classificação , Agaricales/genética , Agaricus/classificação , Agaricus/genética , Genoma Fúngico , Tipagem Molecular , Sequenciamento Completo do Genoma , Biologia Computacional/métodos , Anotação de Sequência Molecular , Filogenia , Locos de Características QuantitativasRESUMO
Agaricus bisporus consumes carbohydrates contained in wheat straw based compost used for commercial mushroom production. Double substituted arabinoxylan is part of the ~40% of the compost polysaccharides that are not degraded by A. bisporus during its growth and development. Genes encoding α-1,3-l-arabinofuranosidase (AXHd3) enzymes that act on xylosyl residues doubly substituted with arabinosyl residues are absent in this mushroom forming fungus. Here, the AXHd3 encoding hgh43 gene of Humicola insolens was expressed in A. bisporus with the aim to improve its substrate utilization and mushroom yield. Transformants secreted active AXHd3 in compost as shown by the degradation of double substituted arabinoxylan oligomers in an in vitro assay. However, carbohydrate composition and degree of arabinosyl substitution of arabinoxylans were not affected in compost possibly due to inaccessibility of the doubly substituted xylosyl residues.
Assuntos
Agaricus/enzimologia , Compostagem , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/metabolismo , Xilanos/metabolismo , Agaricus/classificação , Agaricus/genética , Agaricus/crescimento & desenvolvimento , Metabolismo dos Carboidratos , Proteínas Fúngicas/genética , Glicosídeo Hidrolases/genética , Organismos Geneticamente Modificados , Sordariales/enzimologia , Sordariales/genética , Transformação GenéticaRESUMO
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).
Assuntos
Agaricus/classificação , Filogenia , Agaricus/citologia , Agaricus/genética , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , França , Irã (Geográfico) , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , Fenótipo , Portugal , Especificidade da EspécieRESUMO
Agaricus section Minores contains the richest species diversity within the genus. Its Phylogeny is firstly presented by a Maximum Likelihood tree generated through DNA sequences from four gene regions of 91 species. Furthermore, a molecular dating analysis is conducted used those sequences, and it provided the divergence times of the clades within section Minores. Study showed section Minores has a tropical origin. Four main dispersal routes are proposed: (1) species from South Asia migrated through the Tibetan Plateau and reached Europe ca. 9-13 Ma; (2) species from out of South Asia dispersed to Europe in the earlier time of ca. 22 Ma; (3) species from South Asia dispersed through North Asia to Alaska, and reached West America around ca. 9 Ma; and (4) species from South Asia dispersed south and reached Oceania by at least three invading events about ca. 9, 12 and 16-18 Ma respectively. Those routes excepting the second route coincide with those of ectomycorrhizal mushrooms. To know whether the second route existed in the saprotrophic mushrooms requires further studies, and the fourth route may explain why the secotioid species occurring in Australia are morphologically similar but cluster in different phylogenetic clades. This study also demonstrates a great biodiversity of A. section Minores in China. Sixteen new species and three new records are introduced from China with morphological descriptions, illustrations, color photographs and phylogenetic analyses.
Assuntos
Agaricus/classificação , Análise de Sequência de DNA/métodos , Agaricus/genética , China , DNA Fúngico/genética , Evolução Molecular , FilogeniaRESUMO
Tricholoma matsutake, known widely as "matsutake," has great commercial and cultural significance in Japan. Because Japanese production is insufficient to meet the high domestic demand, morphologically similar mushrooms, thought by many to belong to T. magnivelare, are imported from western North America. However, molecular data produced since the early 2000s have indicated that more than one species of matsutake occur in North America and this raises the question of correct naming for the different species. To address this question, we assessed the phylogenetic diversity within North American matsutake based on nuc rDNA ITS1-5.8S-ITS2 (internal transcribed spacer [ITS] barcode) sequences, including newly obtained sequences from the type collections for Agaricus ponderosus and Armillaria arenicola, and morphological characters. Our results agree with earlier indications that three matsutake species occur in North America and allow us to clarify the correct application of names-T. magnivelare from the eastern USA and Canada, T. murrillianum from the western USA and Canada, and T. mesoamericanum from Mexico, newly described here. The existence of the three North American species is further supported by the results of evolutionary divergence analysis, geographical distributions, and morphological characters.
Assuntos
Variação Genética , Terminologia como Assunto , Tricholoma/classificação , Tricholoma/genética , Agaricus/classificação , Agaricus/genética , Agaricus/isolamento & purificação , Armillaria/classificação , Armillaria/genética , Armillaria/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , América do Norte , Filogenia , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Tricholoma/citologia , Tricholoma/isolamento & purificaçãoRESUMO
The internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene cluster is widely used in fungal taxonomy and phylogeographic studies. The medicinal and edible mushroom Agaricus subrufescens has a worldwide distribution with a high level of polymorphism in the ITS region. A previous analysis suggested notable ITS sequence heterogeneity within the wild French isolate CA487. The objective of this study was to investigate the pattern and potential mechanism of ITS sequence heterogeneity within this strain. Using PCR, cloning, and sequencing, we identified three types of ITS sequences, A, B, and C with a balanced distribution, which differed from each other at 13 polymorphic positions. The phylogenetic comparisons with samples from different continents revealed that the type C sequence was similar to those found in Oceanian and Asian specimens of A. subrufescens while types A and B sequences were close to those found in the Americas or in Europe. We further investigated the inheritance of these three ITS sequence types by analyzing their distribution among single-spore isolates from CA487. In this analysis, three co-dominant markers were used firstly to distinguish the homokaryotic offspring from the heterokaryotic offspring. The homokaryotic offspring were then analyzed for their ITS types. Our genetic analyses revealed that types A and B were two alleles segregating at one locus ITSI, while type C was not allelic with types A and B but was located at another unlinked locus ITSII. Furthermore, type C was present in only one of the two constitutive haploid nuclei (n) of the heterokaryotic (n+n) parent CA487. These data suggest that there was a relatively recent introduction of the type C sequence and a duplication of the ITS locus in this strain. Whether other genes were also transferred and duplicated and their impacts on genome structure and stability remain to be investigated.
Assuntos
Agaricus/classificação , Agaricus/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Amplificação de Genes , Testes Genéticos/métodos , Análise de Sequência de DNA/métodos , Agaricus/crescimento & desenvolvimento , Sequência de Bases , Genótipo , Heterozigoto , Filogenia , Homologia de Sequência do Ácido NucleicoRESUMO
Agaricus is a genus of saprobic basidiomycetes with more than 400 species recognized worldwide, with about 50 species known in China. Our objective was to investigate three new species of section Arvenses in highland subtropical Southwest China. Agaricus guizhouensis is a new species characterized by a white pileus with yellowish squamules, small ellipsoid spores and cheilocystidia with yellowish-brown pigments; another new species, Agaricus longistipes is recognized by its slender stipe, and its elongate-ellipsoid basidiospores; the third new one, Agaricus megalocarpus is remarkable by its large size and its pileus surface covered with fine brown squamules. It is firstly reported for Guizhou Province that Agaricus abruptibulbus, Agaricus flocculosipes, and Agaricus subrufescens are illustrated. Two probable new species require further studying. A phylogenetic analyses of rDNA-ITS sequence data belonging to section Arvenses showed that the section Arvenses is monophyletic and can be subdivided in five branches, the branch of A. subrufescens and four clades (A-D). The eight species from highland subtropical Southwest China were distributed in all five branches, indicating that this highland is at the climatic crossroads. The white pileus trait and the potential interest are discussed. These data suggest a potential species richness that remains to be discovered.
Assuntos
Agaricus/classificação , Agaricus/isolamento & purificação , Agaricus/genética , Agaricus/fisiologia , China , Clima , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Filogenia , Pigmentos Biológicos/metabolismo , Análise de Sequência de DNA , Esporos Fúngicos/citologiaRESUMO
Intraspecific mitochondrial variability was studied in ten strains of A. bisporus var. bisporus, in a strain representative of A. bisporus var. eurotetrasporus and in a strain of the closely related species Agaricus devoniensis. In A. bisporus, the cox1 gene is the richest in group I introns harboring homing endonuclease genes (heg). This study led to identify group I introns as the main source of cox1 gene polymorphism. Among the studied introns, two groups were distinguished according to the heg they contained. One group harbored heg maintained putatively functional. The other group was composed of eroded heg sequences that appeared to evolve toward their elimination. Low nucleotide substitution rates were found in both types of intronic sequences. This feature was also shared by all types of studied mitochondrial sequences, not only intronic but also genic and intergenic ones, when compared with nuclear sequences. Hence, the intraspecific evolution of A. bisporus mitochondrial genome appears characterized by both an important mobility (presence/absence) of large group I introns and by low nt substitution rates. This stringent conservation of mitochondrial sequences, when compared with their nuclear counterparts, appears irrespective of their apparent functionality and contrasts to what is widely accepted in fungal sequence evolution. This strengthens the usefulness of mtDNA sequences to get clues on intraspecific evolution.
Assuntos
Agaricus/genética , Genes Mitocondriais , Variação Genética , Íntrons , Agaricus/classificação , Sequência de Bases , Evolução Molecular , Ordem dos Genes , Dados de Sequência Molecular , Taxa de Mutação , Conformação de Ácido Nucleico , Filogenia , Polimorfismo de Nucleotídeo Único , Splicing de RNARESUMO
Agaricus subrufescens is a cultivated edible and medicinal mushroom. Its known geographical distribution encompasses the Americas, Europe, Oceania, and Asia. The objective of this study was to assess mating compatibility and interfertility of strains originating from Brazil, France, and Thailand. Progeny of each strain were analyed with codominant molecular markers. Multilocus genotype tests revealed that the three strains were amphithallic with percentages of heterokaryotic single spore progenies of 75% for the Thai strain and around 40% for the Brazilian and French strains. In mating tests A. subrufescens had a multiallelic unifactorial system of sexual incompatibility. The three parent strains were interfertile based on experimental pairings of single-spore isolates, the recovery of hybrid heterokaryons from compatible matings, and the ability of hybrids to produce mushrooms and fertile spores. This biological approach supports the inclusion of the European strains within the species and the extension of the geographical distribution range to Asia. Our data should help to develop breeding strategies and to better manage and exploit the diversity existing in A. subrufescens.
Assuntos
Agaricus/classificação , Hibridização Genética , Agaricus/genética , Agaricus/isolamento & purificação , Brasil , DNA Fúngico/genética , França , Loci Gênicos , Marcadores Genéticos , Técnicas de Genotipagem , Geografia , Filogeografia , TailândiaRESUMO
The genus Agaricus is known for its medicinal and edible species but also includes toxic species that belong to section Xanthodermatei. Previous phylogenetic reconstruction for temperate species, based on sequence data of nuc rRNA gene (rDNA) internal transcribed spacers (ITS), has revealed two major groups in this section and a possible third lineage for A. pseudopratensis. Recent research in Agaricus has shown that classifications need improving with the addition of tropical taxa. In this study we add new tropical collections to section Xanthodermatei. We describe three species from collections made in Pakistan and Thailand and include them in a larger analysis using all available ITS data for section Xanthodermatei. Agaricus bisporiticus sp. nov. and A. fuscopunctatus sp. nov. are introduced based on molecular and morphological studies, whereas A. microvolvatulus is recorded for the first time in Asia. Specimens from Thailand however have a much larger pileus than the type specimens from Congo. In maximum likelihood (ML) and maximum parsimony (MP) phylogenetic analyses these three species cluster with A. pseudopratensis from the Mediterranean area and A. murinocephalus recently described from Thailand. In Agaricus section Xanthodermatei this new group is monophyletic and receives low bootstrap support whereas the two previously known groups receive strong support. Within the new group, the most closely related species share some traits, but we did not find any unifying morphological character; however the five species of the group share a unique short nucleotide sequence. Two putatively toxic species of section Xanthodermatei are now recognized in Pakistan and six in Thailand.
Assuntos
Agaricus/classificação , Agaricus/citologia , Agaricus/genética , Agaricus/isolamento & purificação , Sequência de Bases , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Carpóforos , Dados de Sequência Molecular , Paquistão , Fenótipo , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , Esporos Fúngicos , TailândiaRESUMO
Antecedentes. Agaricus subrufescens Peck es un hongo cuyo cultivo ha despertado gran interés en todo el mundo en los últimos años, adquiriendo gran popularidad. Sus propiedades medicinales y culinarias hacen prever una rápida expansión del cultivo en todo el mundo. Objetivos. El trabajo plantea como objetivo la evaluación del efecto sobre los principales parámetros de producción de 3 cepas de Agaricus subrufescens que se han hecho fructificar sobre 5 capas de cobertura diferentes. Métodos. Se ha llevado a cabo un ciclo de cultivo de Agaricus subrufescens en condiciones controladas en el que se han evaluado los principales parámetros de producción. Resultados. Los mejores resultados han sido proporcionados por la cepa ABL 99/30. Las coberturas basadas en turba presentan mejor comportamiento que las basadas en suelo mineral. El mayor rendimiento (6,75 kg/m−2, eficiencia biológica 27,57 kg/dt) ha sido proporcionado por la combinación ABL 99/30-Euroveen. Conclusiones. Nuestros resultados evidencian que la combinación de la cepa ABL 99/30 utilizando una capa de cobertura basada en turba (Euroveen) ofrece un alto potencial para ser utilizada a escala comercial por el sector productor de hongos. La disponibilidad de alternativas a las especies de hongos comestibles cultivadas habitualmente puede suponer un mejor aprovechamiento de recursos y una mayor rentabilidad económica de la actividad (AU)
Background. Agaricus subrufescens Peck is a mushroom whose cultivation has aroused great interest worldwide in recent years, and is becoming increasingly popular. A rapid expansion of culture throughout the world is foreseen because of its medicinal and culinary properties. Aims. This work assesses the effect of 5 different casing layers on the production of 3 strains of Agaricus subrufescens. Methods. A growth cycle of Agaricus subrufescens under controlled conditions has been carried out. The main production parameters were evaluated. Results. The best results were provided by the ABL 99/30 strain. Peat-based casings have a better yield than those based on mineral soil. The highest yield (6.75 kg/m2, biological efficiency 27.57 kg/dt) was provided by the combination ABL 99/30-Euroveen. Conclusions. Our results suggest that the combination of the strain ABL 99/30 using a peat-based casing layer (Euroveen) offers a high potential for use on a commercial scale by the edible mushroom production sector. The availability of alternatives to the usually cultivated species can make better use of resources, and increase the profitability of this activity (AU)
Assuntos
Agaricus/isolamento & purificação , Agaricus/virologia , Plantas Medicinais/classificação , Plantas Medicinais/genética , Plantas Medicinais/metabolismo , Agaricales/classificação , Agaricales/isolamento & purificação , Agaricales/metabolismo , Agaricus/classificação , Agaricus , Plantas Medicinais/imunologia , Agaricales/crescimento & desenvolvimento , Agaricales/imunologiaRESUMO
Advanced button mushroom cultivars that are less sensitive to mechanical bruising are required by the mushroom industry, where automated harvesting still cannot be used for the fresh mushroom market. The genetic variation in bruising sensitivity (BS) of Agaricus bisporus was studied through an incomplete set of diallel crosses to get insight in the heritability of BS and the combining ability of the parental lines used and, in this way, to estimate their breeding value. To this end nineteen homokaryotic lines recovered from wild strains and cultivars were inter-crossed in a diallel scheme. Fifty-one successful hybrids were grown under controlled conditions, and the BS of these hybrids was assessed. BS was shown to be a trait with a very high heritability. The results also showed that brown hybrids were generally less sensitive to bruising than white hybrids. The diallel scheme allowed to estimate the general combining ability (GCA) for each homokaryotic parental line and to estimate the specific combining ability (SCA) of each hybrid. The line with the lowest GCA is seen as the most attractive donor for improving resistance to bruising. The line gave rise to hybrids sensitive to bruising having the highest GCA value. The highest negative SCA possibly indicates heterosis effects for resistance to bruising. This study provides a foundation for estimating breeding value of parental lines to further study the genetic factors underlying bruising sensitivity and other quality-related traits, and to select potential parental lines for further heterosis breeding. The approach of studying combining ability in a diallel scheme was used for the first time in button mushroom breeding.
Assuntos
Agaricus/genética , Variação Genética , Padrões de Herança/genética , Agaricus/classificação , Algoritmos , Cruzamentos Genéticos , Vigor Híbrido , Hibridização Genética , Modelos Genéticos , Especificidade da Espécie , Estresse MecânicoRESUMO
Antecedentes. Uno de los principales problemas para la preservación de los recursos genéticos de Agaricus subrufescens es mantener la viabilidad de sus cepas ya que el micelio es sensible al frío y, en consecuencia, envejece rápidamente. Objetivos. Evaluar la viabilidad de cepas de A. subrufescens y cepas de Agaricus bisporus en cultivos en semillas de sorgo a diferentes temperaturas. Métodos. Se estudiaron 18 cepas de A. subrufescens y 3 cepas de A. bisporus. Se evaluó la viabilidad de A. subrufescens en las condiciones siguientes: (1) control a 25°C (C), (2) enfriamiento hasta 4°C (E) y (3) congelación en nitrógeno líquido a −196°C (NL). Las muestras se recuperaron a las 4, 6, 8, 10, 12 y 24 semanas en C y E, mientras que en NL se recuperaron a las 4, 12 y 24 semanas. La viabilidad se evaluó en 50 semillas, por cepa y condición, en placas de Petri con medio de agar patata dextrosa (APD). También se evaluó el crecimiento de los micelios en APD tras obtención a los 14 días. Resultados. La mayoría de cepas mostraron un 100% de viabilidad, y en general, se obtuvieron en 24h. En la condición NL la viabilidad varió entre el 84 y el 100%, pero en algunos casos su obtención requirió > 10 días. El crecimiento de los micelios se redujo gradualmente con el tiempo y, aunque los resultados indicaron diferencias significativas entre los tratamientos C y E, este declive se asocia al envejecimiento del micelio más que al propio tratamiento. Conclusiones. El cultivo en semillas de sorgo y el almacenamiento a bajas temperaturas es un medio eficaz para preservar los recursos genéticos de A. subrufescens(AU)
Background. One of the main problems for the preservation of genetics resources of Agaricus subrufescens is to maintain the viability of the strains because the mycelium is very sensitive to cooling and therefore it ages rapidly. Aims. Evaluate the viability of A. subrufescens strains stored as cultures on sorghum grain (spawn) at different temperatures. Methods. Eighteen strains of A. subrufescens and three strains of Agaricus bisporus were studied. Spawn's viability was evaluated under the following conditions: (1) control at 25°C (C), (2) cooling to 4°C (R) and (3) freezing in liquid nitrogen at −196°C (LN). Samples were recovered from week 4 every 2 weeks until week 12 and week 24 in C and R, whereas in LN samples were recovered at 4, 12 and 24 weeks. Viability was evaluated in 50 seeds, by strain and condition, recovering the mycelium in Petri dishes with potato dextrose agar medium (PDA). Mycelium growth was also evaluated on PDA after 14 days of recovery. Results. Most strains showed 100% viability and they were recovered usually in 1 day. In LN the viability ranged between 84 and 100% depending on the strain, but in some cases recovery took more than 10 days. Mycelial growth decreased gradually over time and although the results show significant differences between treatments C and R, the decline is associated with ageing of the mycelium rather than the treatment itself. Conclusions. Culture on sorghum grain and storage at low temperature is an interesting way to preserve genetic resources of A. subrufescens(AU)