Oidiodendron: A survey of the named species and related anamorphs of Myxotrichum

AbstractSynoptic and dichotomous keys to 23 species of Oidiodendron and similar arthroconidial anamorphs of Myxotrichum were developed using morphological and physiological characters. Illustrations and brief descriptions based on living isolates and published descriptions are provided for all species treated. Included are the unnamed Oidiodendron states of Myxotrichum arcticum, M. cancellatum, M. emodense, M. setosum, and M. striatosporum, as well as the anamorphic species O. ambiguum, O. cerealis, O. chlamydosporicum (inclusive of O. scytaloides as a synonym), O. echinulatum, O. fimicola, O. flavum, O. fuscum, O. griseum, O. hughesii (inclusive of O. reticulatum as a synonym), O. maius (inclusive of O. maius var. citrinum and O. maius var. maius), O. muniellense, O. myxotrichoides, O. periconioides, O. pilicola, O. rhodogenum, O. setiferum (inclusive of O. ramosum as a synonym), O. tenuissimum, and O. truncatum. Oidiodendron fuscum, the original type species, is recognized as distinct. Oidiodendron robustum is excluded because of its large conidia and conidiophores and because the original drawings do not convincingly portray arthroconidia. Oidiodendron terrestre is excluded because its large, two-celled conidia, rapid growth, and hyaline conidiophores are inconsistent with the generic diagnosis and because the mode of its conidiogenesis is unclear from the original descriptions and illustrations.Taxonomic novelties: Oidiodendron maius var. citrinum (Barron) Rice & Currah stat. nov

Multilocus species identification and fungal DNA barcoding: insights from blue stain fungal symbionts of the mountain pine beetle.Mol

Abstract There is strong community-wide interest in applying molecular techniques to fungal species delimitation and identification, but selection of a standardized region or regions of the genome has not been finalized. A single marker, the ribosomal DNA internal transcribed spacer region, has frequently been suggested as the standard for fungi. We used a group of closely related blue stain fungi associated with the mountain pine beetle (Dendroctonus ponderosae Hopkins) to examine the success of such single-locus species identification, comparing the internal transcribed spacer with four other nuclear markers. We demonstrate that single loci varied in their utility for identifying the six fungal species examined, while use of multiple loci was consistently successful. In a literature survey of 21 similar studies, individual loci were also highly variable in their ability to provide consistent species identifications and were less successful than multilocus diagnostics. Accurate species identification is the essence of any molecular diagnostic system, and this consideration should be central to locus selection. Moreover, our study and the literature survey demonstrate the value of using closely related species as the proving ground for developing a molecular identification system. We advocate use of a multilocus barcode approach that is similar to the practice employed by the plant barcode community, rather than reliance on a single locus

Data from: Comparative phylogeography, genetic differentiation, and contrasting reproductive modes in three fungal symbionts of a multipartite bark beetle symbiosis

No description availabl

Data from: Polygamy and an absence of fine-scale structure in Dendroctonus ponderosae (Hopk.) (Coleoptera: Curcilionidae) confirmed using molecular markers

An understanding of mating systems and fine-scale spatial genetic structure is required to effectively manage forest pest species such as Dendroctonus ponderosae (mountain pine beetle). Here we used genome-wide single-nucleotide polymorphisms to assess the fine-scale genetic structure and mating system of D. ponderosae collected from a single stand in Alberta, Canada. Fine-scale spatial genetic structure was absent within the stand and the majority of genetic variation was best explained at the individual level. Relatedness estimates support previous reports of pre-emergence mating. Parentage assignment tests indicate that a polygamous mating system better explains the relationships among individuals within a gallery than the previously reported female monogamous/male polygynous system. Furthermore, there is some evidence to suggest that females may exploit the galleries of other females, at least under epidemic conditions. Our results suggest that current management models are likely to be effective across large geographic areas based on the absence of fine-scale genetic structure

Data from: Population structure of mountain pine beetle symbiont Leptographium longiclavatum and the implication on the multipartite beetle-fungi relationships

Over 18 million ha of forests have been destroyed in the past decade in Canada by the mountain pine beetle (MPB) and its fungal symbionts. Understanding their population dynamics is critical to improving modeling of beetle epidemics and providing potential clues to predict population expansion. Leptographium longiclavatum and Grosmannia clavigera are fungal symbionts of MPB that aid the beetle to colonize and kill their pine hosts. We investigated the genetic structure and demographic expansion of L. longiclavatum in populations established within the historic distribution range and in the newly colonized regions. We identified three genetic clusters/populations that coincide with independent geographic locations. The genetic profiles of the recently established populations in northern British Columbia (BC) and Alberta suggest that they originated from central and southern BC. Approximate Bayesian Computation supports the scenario that this recent expansion represents an admixture of individuals originating from BC and the Rocky Mountains. Highly significant correlations were found among genetic distance matrices of L. longiclavatum, G. clavigera, and MPB. This highlights the concordance of demographic processes in these interacting organisms sharing a highly specialized niche and supports the hypothesis of long-term multipartite beetle-fungus co-evolutionary history and mutualistic relationships

Data from: Population structure of mountain pine beetle symbiont Leptographium longiclavatum and the implication on the multipartite beetle-fungi relationships

Over 18 million ha of forests have been destroyed in the past decade in Canada by the mountain pine beetle (MPB) and its fungal symbionts. Understanding their population dynamics is critical to improving modeling of beetle epidemics and providing potential clues to predict population expansion. Leptographium longiclavatum and Grosmannia clavigera are fungal symbionts of MPB that aid the beetle to colonize and kill their pine hosts. We investigated the genetic structure and demographic expansion of L. longiclavatum in populations established within the historic distribution range and in the newly colonized regions. We identified three genetic clusters/populations that coincide with independent geographic locations. The genetic profiles of the recently established populations in northern British Columbia (BC) and Alberta suggest that they originated from central and southern BC. Approximate Bayesian Computation supports the scenario that this recent expansion represents an admixture of individuals originating from BC and the Rocky Mountains. Highly significant correlations were found among genetic distance matrices of L. longiclavatum, G. clavigera, and MPB. This highlights the concordance of demographic processes in these interacting organisms sharing a highly specialized niche and supports the hypothesis of long-term multipartite beetle-fungus co-evolutionary history and mutualistic relationships