Revisión del género Tuber (Tuberaceae: Pezizales) de México

ResumenLas especies del género Tuber han recibido escasa atención taxonómica en México, a pesar de su gran importancia ecológica y económica. A la fecha, 10 especies han sido descritas para el país. En este estudio se describen por primera vez para la micobiota Mexicana a Tuber canaliculatum, T. gibbosum y T. malacodermum. Las especies fueron determinadas por una combinación de características principalmente morfológicas y ecológicas. Así mismo, se presenta una clave dicotómica de las especies conocidas y descritas para México.AbstractSpecies in the genus Tuber have received little taxonomic attention in Mexico, despite its great ecological and economic importance. Only 10 species have been described for Mexico. In this study, Tuber canaliculatum, T. gibbosum, and T. malacodermum are described for the first time for the Mexican mycobiota. These species are distinguished by a combination of morphological and ecological characteristics. Illustarations and a dichotomic key are presented for the known described species from Mexico

Mycorrhizal inoculation of pecan seedlings with some marketable truffles

Pecan is the common name of Carya illinoinensis (Wangenh.) K. Koch, an ectomycorrhizal tree native to North America, also frequently known as hickory. Mycorrhizal inoculations of pecan seedlings with: Tuber aestivum Vittad., T. borchii Vittad., T. indicum Cooke & Massee, and T. lyonii Butters are described and discussed

Calongea, un nuevo género de trufas en las Pezizaceae (Pezizales)

Phylogenetic analysis of the ITS and LSU rDNA of Pachyphloeus species from Europe and North America revealed a new truffle genus. These molecular analyses plus sequences downloaded from a BLAST search in GenBank indicated that Pachyphloeus prieguensis is within the Pezizaceae but well outside of the genus Pachyphloeus. Morphological differences in the peridial and glebal hyphae and spores distinguish this genus from Pachyphloeus. We here propose the monotypic new genus Calongea, with the type species C. prieguensis comb. nov., in honor of Prof. Francisco de Diego Calonge, who has long studied the truffle fungi of Spain and participated in describing the type species of Calongea.El análisis filogenético del ITS y LSU rDNA de especies europeas y norteamericanas de Pachyphloeus revelan un género nuevo de trufa. Los datos moleculares de este estudio, además de las secuencias obtenidas de una búsqueda BLAST en GenBank, indican que Pachyphloeus prieguensis es un miembro de la familia Pezizaceae pero no está relacionado con ninguna otra especie hipogea o epigea de dicha familia. Encontramos diferencias morfológicas en las hifas del peridio y gleba así como en las esporas que morfológicamente distinguen éste de Pachyphloeus. Proponemos el nuevo género monotípico Calongea, con C. prieguensis comb. nov. como la especie tipo, en honor a uno de los descubridores originales, Prof. Francisco de Diego Calonge

Fungal Endophytes of Populus trichocarpa Alter Host Phenotype, Gene Expression, and Rhizobiome Composition.

Mortierella and Ilyonectria genera include common species of soil fungi that are frequently detected as root endophytes in many plants, including Populus spp. However, the ecological roles of these and other endophytic fungi with respect to plant growth and function are still not well understood. The functional ecology of two key taxa from the P. trichocarpa rhizobiome, M. elongata PMI93 and I. europaea PMI82, was studied by coupling forest soil bioassays with environmental metatranscriptomics. Using soil bioassay experiments amended with fungal inoculants, M. elongata was observed to promote the growth of P. trichocarpa. This response was cultivar independent. In contrast, I. europaea had no visible effect on P. trichocarpa growth. Metatranscriptomic studies revealed that these fungi impacted rhizophytic and endophytic activities in P. trichocarpa and induced shifts in soil and root microbial communities. Differential expression of core genes in P. trichocarpa roots was observed in response to both fungal species. Expression of P. trichocarpa genes for lipid signaling and nutrient uptake were upregulated, and expression of genes associated with gibberellin signaling were altered in plants inoculated with M. elongata, but not I. europaea. Upregulation of genes for growth promotion, downregulation of genes for several leucine-rich repeat receptor kinases, and alteration of expression of genes associated with plant defense responses (e.g., jasmonic acid, salicylic acid, and ethylene signal pathways) also suggest that M. elongata manipulates plant defenses while promoting plant growth

Tidying up international nucleotide sequence databases

Sequence analysis of the ribosomal RNA operon, particularly the internal transcribed spacer (ITS) region, provides a powerful tool for identification of mycorrhizal fungi. The sequence data deposited in the International Nucleotide Sequence Databases (INSD) are, however, unfiltered for quality and are often poorly annotated with metadata. To detect chimeric and low-quality sequences and assign the ectomycorrhizal fungi to phylogenetic lineages, fungal ITS sequences were downloaded from INSD, aligned within family-level groups, and examined through phylogenetic analyses and BLAST searches. By combining the fungal sequence database UNITE and the annotation and search tool PlutoF, we also added metadata from the literature to these accessions. Altogether 35,632 sequences belonged to mycorrhizal fungi or originated from ericoid and orchid mycorrhizal roots. Of these sequences, 677 were considered chimeric and 2,174 of low read quality. Information detailing country of collection, geographical coordinates, interacting taxon and isolation source were supplemented to cover 78.0%, 33.0%, 41.7% and 96.4% of the sequences, respectively. These annotated sequences are publicly available via UNITE (http://unite.ut.ee/) for downstream biogeographic, ecological and taxonomic analyses. In European Nucleotide Archive (ENA; http://www.ebi.ac.uk/ena/), the annotated sequences have a special link-out to UNITE. We intend to expand the data annotation to additional genes and all taxonomic groups and functional guilds of fungi

Kalapuya brunnea gen. & sp. nov. and its relationship to the other sequestrate genera in Morchellaceae

Kalapuya is described as a new, monotypic truffle genus in the Morchellaceae known only from the Pacific northwestern United States. Its relationship to other hypogeous genera within Morchellaceae is explored by phylogenetic analysis of the ribosomal LSU and EF1α protein coding region. The type species, K. brunnea, occurs in Douglas-fir forests up to about 50 y old on the west slope of the Cascade Range in Oregon and in the Coastal Ranges of Oregon and northern California. It has a roughened, warty, reddish brown to brown peridium, a solid whitish gleba that develops grayish brown mottling as the spores mature, and produces a cheesy-garlicky odor at maturity. Its smooth, ellipsoid spores resemble those of Morchella spp. but are much larger. The four hypogeous genera known in the Morchellaceae, Kalapuya, Fischerula, Imaia and Leucangium, are distinct from the epigeous genera Morchella and Verpa, but it is uncertain whether they resulted from a single transition to a hypogeous fruiting habit or from multiple independent transitions. Kalapuya, locally known as the Oregon brown truffle, has been commercially harvested for culinary use.Keywords: LSU rDNA, taxonomy, Pezizales, EF1α, Douglas-fir, Ascomycota, Fischerula, Morchellaceae, Leucangium, hypogeous fungus, truffl

Mycorrhizal inoculation of pecan seedlings with some marketable truffles

Pecan is the common name of Carya illinoinensis (Wangenh.) K. Koch, an ectomycorrhizal tree native to North America, also frequently known as hickory. Mycorrhizal inoculations of pecan seedlings with: Tuber aestivum Vittad., T. borchii Vittad., T. indicum Cooke & Massee, and T. lyonii Butters are described and discussed

Fungal-Bacterial Networks in the Populus Rhizobiome Are Impacted by Soil Properties and Host Genotype

Plant root-associated microbial symbionts comprise the plant rhizobiome. These microbes function in provisioning nutrients and water to their hosts, impacting plant health and disease. The plant microbiome is shaped by plant species, plant genotype, soil and environmental conditions, but the contributions of these variables are hard to disentangle from each other in natural systems. We used bioassay common garden experiments to decouple plant genotype and soil property impacts on fungal and bacterial community structure in the Populus rhizobiome. High throughput amplification and sequencing of 16S, ITS, 28S and 18S rDNA was accomplished through 454 pyrosequencing. Co-association patterns of fungal and bacterial taxa were assessed with 16S and ITS datasets. Community bipartite fungal-bacterial networks and PERMANOVA results attribute significant difference in fungal or bacterial communities to soil origin, soil chemical properties and plant genotype. Indicator species analysis identified a common set of root bacteria as well as endophytic and ectomycorrhizal fungi associated with Populus in different soils. However, no single taxon, or consortium of microbes, was indicative of a particular Populus genotype. Fungal-bacterial networks were over-represented in arbuscular mycorrhizal, endophytic, and ectomycorrhizal fungi, as well as bacteria belonging to the orders Rhizobiales, Chitinophagales, Cytophagales, and Burkholderiales. These results demonstrate the importance of soil and plant genotype on fungal-bacterial networks in the belowground plant microbiome

Optimising in vitro culture conditions for the truffle Tuber brumale

The vegetative propagation of ectomycorrhizal truffle fungi is limited by their slow mycelial growth. Many factors including media, isolate genotypes and environmental conditions can alter fungal mycelial growth rates. This study aimed to improve the in vitro growth rate of Tuber brumale by determining the optimal carbohydrate and nitrogen sources, temperature and pH. After 8 weeks, the highest level of growth and densest hyphal branching were recorded in the medium containing glucose as the main carbohydrate. For nitrogen, glutamine (200 mg N l-1) provided the greatest hyphal growth and density compared to the other amino acid treatments. Regarding temperature, 16°C proved to be optimal for T. brumale growth and branching. Media of pH 6 and pH 7 were most favourable for the growth of T. brumale. The results from this research provide baseline data on the vegetative nutrition of T. brumale and have implications for the in vitro culture of winter truffle hyphae