Time filter

Source Type

Roosevelt, NJ, United States

Tullossi R.E.,P. O. Box 57 | Lialling R.E.,New York Botanical Garden | Mueller G.M.,Chicago Botanic Garden
Mycotaxon | Year: 2011

Amanita conara, A. costaricensis, and A. garabitoana are proposed as new species. These taxa are added to twelve previously described species known from, or reported here for the first time from, the region of study: A. advena, A. arocheae, A. brunneolocularis, A. colombiana, A. ebumea, A. farinosa, A. flavoconia var. inquinata, A. fuligineodisca, A. muscaria subsp. flavivolvata, A. polypyramis, A. sororcula, and A. xylinivolva. Amanita flavoconia var. sinapicolor is proposed to be a taxonomic synonym of A. flavoconia var. inquinata. An unusual species of Amanita subsection Vittadiniae is given the code Amanita sp. HONI and treated only in a key to regional species of Amanita section Lepidella. A gazetteer is provided for Costa Rican sites at which Amanita species have been collected. © 2011 Publishing Technology. Source

Sanchez-Ramirez S.,Royal Ontario Museum | Sanchez-Ramirez S.,University of Toronto | Tulloss R.E.,P. O. Box 57 | Tulloss R.E.,New York Botanical Garden | And 3 more authors.
Journal of Biogeography | Year: 2015

Aim: The geographical distributions of most fungal species are still poorly known; consequently, their origins and historical distributions remain largely understudied. High levels of cryptic diversity, scarce fossil records and poorly sampled regions can explain some of these shortcomings. We extensively sampled an iconic group of edible ectomycorrhizal (EM) fungi, Amanita caesarea and its allies, in order to infer evolutionary patterns on a global scale. Location: Worldwide. Methods: DNA sequences from three nuclear genes were derived for 120 collections. Divergence times were estimated using fossil calibrations within the Agaricomycetes, followed by more inclusive (A. sect. Caesareae + outgroup) root-recalibrated estimations. Ultrametric trees from beast were used in ancestral-area reconstructions and to infer geodispersal models. They were further used in diversification-rate analyses using maximum-likelihood and Bayesian methods. Results: Molecular dating and ancestral-area reconstruction indicated a Palaeotropical origin of A. sect. Caesareae between the Palaeocene and Eocene. Dispersal events to temperate regions in Mediterranean Europe, eastern Australia and North and Central America, occurred mostly during the late Miocene and Pliocene. A boreotropical model was supported as the most likely mode of geodispersal. Diversification rates were significantly higher in the New World than in the Old World. Main conclusions: We present evidence that this group of edible EM mushrooms was ancestrally Palaeotropical from around the Eocene to the late Miocene, reaching temperate insular and continental areas during the late Miocene and Pliocene. The mode of dispersal is largely consistent with Wolfe's boreotropical hypothesis. We also found that the overall diversification rate has been rather constant, but has increased relatively recently in the New World, possibly as a result of the well-documented Plio-Pleistocene climatic fluctuations. © 2015 John Wiley & Sons Ltd. Source

Chen S.,CAS Kunming Institute of Botany | Chen S.,Yunnan University | Chen S.,Honghe University | Chen S.,University of Chinese Academy of Sciences | And 5 more authors.
World Journal of Microbiology and Biotechnology | Year: 2012

Lateral gene transfer (LGT) plays an important role in the molecular evolution of haloarchaea. Polyethylene glycol-mediated LGT in haloarchaea has been demonstrated in the laboratory, yet few explanations have been put forward for the apparently common, natural occurrence of plentiful plasmids within haloarchaeal cells. In this study, LGT was induced in two genera of haloarchaea, Haloferax and Halorubrum, by modification of salt concentration of media-a factor that may vary naturally in native haloarchaeal habitat. Minimal growth salt concentrations (MGSCs) of four strains of haloarchaea from these two genera were established, and transformations using two circular double-stranded DNAs (dsDNAs), pSY1 and pWL102, were then produced in media at strain-appropriate MGSCs. The four strains of haloarchaea were transformed successfully by both kinds of dsDNAs with an efficiency of 102-103 transformants per microgram dsDNA. The transformation under reduced salt concentration may be an imitation of natural LGT of dsDNA into haloarchaea when salinity in normally hypersaline environments is altered by sudden introduction of fresh water-for example, by rainfall, snow-melt, or flooding-providing a reasonable interpretation for haloarchaea being naturally richer in plasmids than any other known organisms. © 2012 Springer Science+Business Media B.V. Source

Sanchez-Ramirez S.,Royal Ontario Museum | Sanchez-Ramirez S.,University of Toronto | Tulloss R.E.,P. O. Box 57 | Tulloss R.E.,New York Botanical Garden | And 10 more authors.
Molecular Ecology | Year: 2015

Some of the effects of past climate dynamics on plant and animal diversity make-up have been relatively well studied, but to less extent in fungi. Pleistocene refugia are thought to harbour high biological diversity (i.e. phylogenetic lineages and genetic diversity), mainly as a product of increased reproductive isolation and allele conservation. In addition, high extinction rates and genetic erosion are expected in previously glaciated regions. Some of the consequences of past climate dynamics might involve changes in range and population size that can result in divergence and incipient or cryptic speciation. Many of these dynamic processes and patterns can be inferred through phylogenetic and coalescent methods. In this study, we first delimit species within a group of closely related edible ectomycorrhizal Amanita from North America (the American Caesar's mushrooms species complex) using multilocus coalescent-based approaches; and then address questions related to effects of Pleistocene climate change on the diversity and genetics of the group. Our study includes extensive geographical sampling throughout the distribution range, and DNA sequences from three nuclear protein-coding genes. Results reveal cryptic diversity and high speciation rates in refugia. Population sizes and expansions seem to be larger at midrange latitudes (Mexican highlands and SE USA). Range shifts are proportional to population size expansions, which were overall more common during the Pleistocene. This study documents responses to past climate change in fungi and also highlights the applicability of the multispecies coalescent in comparative phylogeographical analyses and diversity assessments that include ancestral species. © 2015 John Wiley & Sons Ltd. Source

Discover hidden collaborations