18 research outputs found
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 ÎČ-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 CiĂȘncia e a Tecnologia (Portugal) through grant PEst-OE/BIA/UI0457/2011. Artur Alves and Alan Phillips were supported by the programme CiĂȘncia 2008, co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007â2013) 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
Les périthÚces et les asques du
La paroi ascale du Leptosphaeria senegalensis se rattache nettement au type bituniquĂ© ; elle comporte, au stade final, un exoascus et un endoascus sĂ©parĂ©s par un espace clair ; lâendoascus contient des fibrilles, rĂ©parties en trois sous-couches, et dont les plus internes sont plissĂ©es en accordĂ©on.
Les ascospores ont une paroi complexe comportant, de lâintĂ©rieur vers lâextĂ©rieur : une endospore, une Ă©pispore, plus Ă©paisse autour de la moitiĂ© antĂ©rieure du corps sporal, une pĂ©rispore et une ectospore, Ă©paissie en une cupule coiffant lâextrĂ©mitĂ© postĂ©rieure.
La comparaison des ascospores de deux Leptosphaeria « vrais » (L. acuta et L. maculans) avec celle du L. senegalensis montre que le rattachement de cette derniĂšre espĂšce au genre Leptosphaeria nâest pas justifiĂ©
Les périthÚces et les asques du
Les pĂ©rithĂšces du Leptosphaeria senegalensis naissent Ă partir de primordiums de type stromato-glomĂ©rulaire. Dans les Ă©bauches, des cellules carpocentrales privilĂ©giĂ©es donnent naissance Ă une ou plusieurs cellules femelles (= ascogones) surmontĂ©es chacune dâun court trichogyne unicellulaire ; les ascogones se transforment directement en cellules Ă dicaryon, sans quâintervienne une fĂ©condation par trichogamie et sans lâintermĂ©diaire de vĂ©sicules pro-sporophytiques.
Le dĂ©veloppement des parties stĂ©riles du pĂ©rithĂšce est celui dâun PyrĂ©nomycĂšte ascoloculaire Ă carpocentre de type Pleospora avec formation dâune garniture pĂ©riloculaire (mĂ©nisque sous-hymĂ©nial fugace et cloche sus-hymĂ©niale gĂ©nĂ©ratrice de pseudo-paraphyses, mais non de pĂ©riphyses)