Monilochaetes and allied genera of the Glomerellales, and a reconsideration of families in the Microascales

We examined the phylogenetic relationships of two species that mimic Chaetosphaeria in teleomorph and anamorph morphologies, Chaetosphaeria tulasneorum with a Cylindrotrichum anamorph and Australiasca queenslandica with a Dischloridium anamorph. Four data sets were analysed: a) the internal transcribed spacer region including ITS1, 5.8S rDNA and ITS2 (ITS), b) nc28S (ncLSU) rDNA, c) nc18S (ncSSU) rDNA, and d) a combined data set of ncLSU-ncSSU-RPB2 (ribosomal polymerase B2). The traditional placement of Ch. tulasneorum in the Microascales based on ncLSU sequences is unsupported and Australiasca does not belong to the Chaetosphaeriaceae. Both holomorph species are nested within the Glomerellales. A new genus, Reticulascus, is introduced for Ch. tulasneorum with associated Cylindrotrichum anamorph; another species of Reticulascus and its anamorph in Cylindrotrichum are described as new. The taxonomic structure of the Glomerellales is clarified and the name is validly published. As delimited here, it includes three families, the Glomerellaceae and the newly described Australiascaceae and Reticulascaceae. Based on ITS and ncLSU rDNA sequence analyses, we confirm the synonymy of the anamorph genera Dischloridium with Monilochaetes. Consequently Dischloridium laeënse, type species of the genus, and three related species are transferred to the older genus Monilochaetes. The teleomorph of D. laeënse is described in Australiasca as a new species. The Plectosphaerellaceae, to which the anamorph genus Stachylidium is added, is basal to the Glomerellales in the three-gene phylogeny. Stilbella annulata also belongs to this family and is newly combined in Acrostalagmus. Phylogenetic analyses based on ncLSU, ncSSU, and combined ncLSU-ncSSU-RPB2 sequences clarify family relationships within the Microascales. The family Ceratocystidaceae is validated as a strongly supported monophyletic group consisting of Ceratocystis, Cornuvesica, Thielaviopsis, and the type species of Ambrosiella. The new family Gondwanamycetaceae, a strongly supported sister clade to the Ceratocystidaceae, is introduced for the teleomorph genus Gondwanamyces and its Custingophora anamorphs. Four families are accepted in the Microascales, namely the Ceratocystidaceae, Gondwanamycetaceae, Halosphaeriaceae, and Microascaceae. Because of a suggested affinity of a Faurelina indica isolate to the Microascales, the phylogenetic position of the Chadefaudiellaceae is reevaluated. Based on the results from a separate ncLSU analysis of the Dothideomycetes, Faurelina is excluded from the Microascales and placed in the Pleosporales

The Botryosphaeriaceae: genera and species known from culture

In this paper we give an account of the genera and species in the Botryosphaeriaceae. We consider morphological characters alone as inadequate to define genera or identify species, given the confusion it has repeatedly introduced in the past, their variation during development, and inevitable overlap as representation grows. Thus it seems likely that all of the older taxa linked to the Botryosphaeriaceae, and for which cultures or DNA sequence data are not available, cannot be linked to the species in this family that are known from culture. Such older taxa will have to be disregarded for future use unless they are epitypified. We therefore focus this paper on the 17 genera that can now be recognised phylogenetically, which concentrates on the species that are presently known from culture. Included is a historical overview of the family, the morphological features that define the genera and species and detailed descriptions of the 17 genera and 110 species. Keys to the genera and species are also provided. Phylogenetic relationships of the genera are given in a multi-locus tree based on combined SSU, ITS, LSU, EF1-α and β-tubulin sequences. The morphological descriptions are supplemented by phylogenetic trees (ITS alone or ITS + EF1-α) for the species in each genus.We would like to thank the curators of the numerous fungaria and Biological Resource Centres cited in this paper, for making specimens and cultures available for examination over the past 15 yr, without which this study would not have been possible. Part of this work was supported by Fundação para a Ciência e a Tecnologia (Portugal) through grant PEst-OE/BIA/UI0457/2011. Artur Alves and Alan Phillips were supported by the programme Ciência 2008, co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007–2013) and the European Social Fund (EU).publishe

The ontogeny of perithecia in Guignardia bidwellii

International audienceThe ontogeny of perithecia in Guignardia bidwellii was studied with contaminated berries and under in vitro conditions. The first developmental stage consists of a stromatic envelope surrounding a carpocentrum in which an ascogonial apparatus (composed of ascogonial cells and trichogynes) differentiates at the second stage. Stage 3 is marked by the incipient formation of the ascal locule and development of pseudoparaphyses. At the subadult stage ( = stage 4) these filaments intermingle with asci and they are progressively stretched owing to ascus expansion. The mature ascocarp (stage 5) contains numerous eight-spored asci and opens through an apical ostiole. The developmental features of Guignardia bidwellii indicate a pseudoparaphysate ascolocular type of development. Consequently, the fungus is more correctly placed in the Botryosphaeriaceae than in the Mycosphaerellaceae

Particularités des ascocarpes et de l’hyménium des truffes (Ascomycètes) I. Développement et structure des ascocarpes

Les caractères particuliers de l’organogenèse de l’ascocarpe chez Tuber melanosporum Vitt. sont rappelés : la formation du primordium, sa transformation en une cupule (ébauche apothécioïde, dont les paraphyses produisent le réseau arachnoïde), la réalisation d’une ébauche globuleuse close, comprenant un péridium écailleux et une volumineuse glèbe, la présence dans l’ascocarpe adulte d’un hyménium « dissocié ». D’autres espèces de Tuber et diverses autres truffes sont comparées. La diversité morphologique et structurale de l’ensemble de ces ascocarpes ne permet toutefois pas de les présenter selon un enchaînement cohérent.The ascocarp development is recorded in Tuber melanosporum Vitt. The chief characteristic points are: the primordium formation, the cup-like apothecioid “ébauche” (with arachnoid network growing from paraphyses) which gradually becomes globular and closed, comprising a scaly peridium and a voluminous gleba, the “dissociated” hymenium in mature ascocarps. Comparative data are provided concerning other Tuber species and other genera of truffles. Morphological and structural features of ascocarps are so diverse that it is impossible to arrange the group in order of growing complexity.</p

Les périthèces et les asques du

La paroi ascale du Leptosphaeria senegalensis se rattache nettement au type bituniqué ; elle comporte, au stade final, un exoascus et un endoascus séparés par un espace clair ; l’endoascus contient des fibrilles, réparties en trois sous-couches, et dont les plus internes sont plissées en accordéon. Les ascospores ont une paroi complexe comportant, de l’intérieur vers l’extérieur : une endospore, une épispore, plus épaisse autour de la moitié antérieure du corps sporal, une périspore et une ectospore, épaissie en une cupule coiffant l’extrémité postérieure. La comparaison des ascospores de deux Leptosphaeria « vrais » (L. acuta et L. maculans) avec celle du L. senegalensis montre que le rattachement de cette dernière espèce au genre Leptosphaeria n’est pas justifié

Les périthèces et les asques du

Les périthèces du Leptosphaeria senegalensis naissent à partir de primordiums de type stromato-glomérulaire. Dans les ébauches, des cellules carpocentrales privilégiées donnent naissance à une ou plusieurs cellules femelles (= ascogones) surmontées chacune d’un court trichogyne unicellulaire ; les ascogones se transforment directement en cellules à dicaryon, sans qu’intervienne une fécondation par trichogamie et sans l’intermédiaire de vésicules pro-sporophytiques. Le développement des parties stériles du périthèce est celui d’un Pyrénomycète ascoloculaire à carpocentre de type Pleospora avec formation d’une garniture périloculaire (ménisque sous-hyménial fugace et cloche sus-hyméniale génératrice de pseudo-paraphyses, mais non de périphyses)