ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.toxicity is due to the diatom culture conditions in the laboratory or that cases of toxicity are exceptions, owing to the species or strains maintained in laboratory cultures being unrepresentative of natural field populations.However, any explanation for the discrepancy between the laboratory and field results does not affect our conclusion. The range of areas and copepod and diatom species considered in this study provide strong evidence that, under natural environmental conditions, there is no negative effect of diatoms on copepod hatching success. We conclude that there is no need to revise existing conceptual models of energy transfer from phytoplankton, through copepods, to fish in diatom-dominated systems.A Methods Hatching successEggs for the hatching success measurements were obtained from females incubated in filtered or natural sea water (depending on the species, some copepods stop spawning in filtered sea water) during the first 12-24 h after capture 18 . The intention was to minimise the effect of the incubation conditions to obtain hatching rates representative of the field values. From the egg production experiments 30-100 eggs were selected randomly and gently transferred to 60-ml tubes filled with filtered sea water. The samples were incubated, at sea surface temperature, for periods ranging from 48 to 96 h (depending on the temperature). After the incubation period, the samples were examined microscopically to determine the number of nauplii and unhatched eggs. Microplankton identification and biomassWater samples for identification of microplankton (.2 mm, nanoplankton plus microplankton) species and carbon estimation were collected generally at the chlorophyll maximum depth and preserved with 1% final concentration of Lugol's iodine solution 19 . Subsamples (100 ml) were settled (Utermöhl technique) and counted with an inverted microscope. Phytoplankton carbon biomass was estimated from cell volume 20 and using a factor of 0.21 pg C mm 23 (ref. 21) for ciliates. Heterotrophic dinoflagellates were separated from autotrophic forms according to taxonomic considerations 22 .

Truffles have evolved from epigeous (aboveground) ancestors in nearly every major lineage of fleshy fungi. Because accelerated rates of morphological evolution accompany the transition to the truffle form, closely related epigeous ancestors remain unknown for most truffle lineages. This is the case for the quintessential truffle genus Tuber, which includes species with socio-economic importance and esteemed culinary attributes. Ecologically, Tuber spp. form obligate mycorrhizal symbioses with diverse species of plant hosts including pines, oaks, poplars, orchids, and commercially important trees such as hazelnut and pecan. Unfortunately, limited geographic sampling and inconclusive phylogenetic relationships have obscured our understanding of their origin, biogeography, and diversification. To address this problem, we present a global sampling of Tuberaceae based on DNA sequence data from four loci for phylogenetic inference and molecular dating. Our well-resolved Tuberaceae phylogeny shows high levels of regional and continental endemism. We also identify a previously unknown epigeous member of the Tuberaceae – the South American cup-fungus Nothojafnea thaxteri (E.K. Cash) Gamundí. Phylogenetic resolution was further improved through the inclusion of a previously unrecognized Southern hemisphere sister group of the Tuberaceae. This morphologically diverse assemblage of species includes truffle (e.g. Gymnohydnotrya spp.) and non-truffle forms that are endemic to Australia and South America. Southern hemisphere taxa appear to have diverged more recently than the Northern hemisphere lineages. Our analysis of the Tuberaceae suggests that Tuber evolved from an epigeous ancestor. Molecular dating estimates Tuberaceae divergence in the late Jurassic (∼156 million years ago), with subsequent radiations in the Cretaceous and Paleogene. Intra-continental diversification, limited long-distance dispersal, and ecological adaptations help to explain patterns of truffle evolution and biodiversity.

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Molecular phylogenetic analyses for the gomphoid-phalloid fungi were conducted based on the five gene dataset with extensive taxon sampling. The monophyly of the gomphoid-phalloid clade was strongly supported, and four well supported major subclades were recognized. Three of the four subclades were represented entirely by gastroid taxa, and only Gomphales contained both gastroid and nongastroid taxa. While the gastroid morphology is derived from epigeous, nongastroid taxa in Gomphales, the topology of Phallales indicated that truffle-like form is an ancestral morphology of the stinkhorn fruiting bodies. Although basidiospore maturation occurs within the enclosed fruiting bodies of the stinkhorn, the elevation of the mature sporeproducing tissue represents an independent origin of the stipe among Basidiomycota. Comparisons are made between previous and new classification schemes, which are based on the results of phylogenetic analyses. Based on the results of these analyses, a new subclass Phallomycetidae, and two new orders, Hysterangiales and Geastrales, are proposed.

Summary1. Dominant plant functional types (PFTs) are expected to be primary determinants of communities of other above-and below-ground organisms. Here, we report the effects of the experimental removal of different PFTs on arbuscular mycorrhizal fungi (AMF) communities in a shrubland ecosystem in central Argentina. 2. On the basis of the biomass-ratio hypothesis and plant resource use strategy theory, we expected the effect of removal of PFTs on AMF colonization and spores to be proportional to the biomass removed and to be stronger when more conservative PFTs were removed. The treatments applied were: undisturbed control (no plant removed), disturbed control (mechanical disturbance), no shrub (removal of deciduous shrubs), no perennial forb (removal of perennial forbs), no graminoid (removal of graminoids) and no annual forb (removal of annual forbs). AMF colonization was assessed after 5, 17 and 29 months. Total density of AMF spores, richness and evenness of morphotaxa, and AMF functional groups were quantified after 5, 17, 29, 36 and 39 months. 3. Five months after the initial removal we found a significant reduction in total AMF colonization in all plots subjected to PFT removals and in the disturbed control plots, as compared with the undisturbed controls. This effect disappeared afterwards and no subsequent effect on total colonization and colonization by arbuscules was observed. In contrast, a significant increase in colonization by vesicles was observed in months 17 and 29, mainly in no graminoid plots. In general, treatments did not significantly affect AMF spores in the soil. On the other hand, no annual forb promoted transient (12-18 months) higher ammonia availability, and no shrub promoted lower nitrate availability in the longer term (24-28 months). 4. Synthesis. Our experiment, the first to investigate the effects of the removal of different PFTs on AMF communities in natural ecosystems, indicates that AMF communities are resilient to changes in the soil and in the functional composition of vegetation. Furthermore, it does not provide consistent evidence in support of the biomass-ratio hypothesis or differential trait-based direct or indirect effects of different PFTs on AMF in this particular system.

Twenty-three polypore species were found in Polylepis Ruiz & Pav. (Rosacecae) woodlands from Argentina. Six species occur exclusively in the neotropics and four are host-specific to Polylepis ( Phellinus tabaquilio , Phellinus uncisetus , Phellinus daedaliformis , and Datronia orcomanta ), of which the first two are facultative parasites or occur during the early stages of wood decay. Host specificity and patterns of distribution vary among species. Datronia orcomanta Robledo & Rajchenb. is described as a new endemic taxon and Inonotus serranus is reduced to synonymy with Inonotus venezuelicus .

Summary• Arachnitis uniflora , a myco-heterotrophic plant species, has fleshy tuberous roots colonized by the arbuscular mycorrhizal fungal genus Glomus (Phylum Glomeromycota). These roots produce apical and lateral propagules, both reported here for the first time. The objective of the study was to characterize the ontogeny and structure of the propagules, and to determine their function.• Scanning electron microscopy, laser scanning confocal microscopy and light microscopy were used to study the ontogeny and structure of the propagules.• Propagules developed either from cortical parenchyma cells or from cells immediately beneath the root cap; they developed a shoot meristem and cells in the basal region which were colonized by various fungal structures including hyphae and vesicles.• These propagules may detach from the roots, establishing new plants.

Field studies in Argentina's Yunga District revealed Alpova austroalnicola sp. nov., a hypogeous fungus associated with Alnus acuminata ssp. acuminata. Morphological and molecular studies based on amplification and sequencing of the nuclear LSU rDNA gene showed its unique identity within Alpova. Related genera included in the analyses were Boletus edulis, Rhizopogon spp., Suillus luteus and Truncocolumella citrina. Additional observations of animal diggings around the sites and microscopic examination of fecal pellets of the nine-banded armadillo (Dasypus novemcinctus novemcinctus) indicate A. austroalnicola is consumed and its spores dispersed by animals.