Xylaria species associated with fallen fruits and seeds

Twenty-five fructicolous and seminicolous species of Xylaria are classified into three groups by stromatal morphology: (i) the X. ianthinovelutina group; (ii) the X. carpophila group; and (iii) the X. heloidea group. Xylaria reevesiae, X. rossmanae, and X. vivantii are described as new species. Xylaria reevesiae belongs to the X. carpophila group, resembling X. euphorbiicola but differing from it mainly by having conspicuous perithecial mounds and growing on fallen fruits of a different host plant. Xylaria rossmanae and X. vivantii belong to the X. ianthinovelutina group. Xylaria rossmanae differs from the species of the group mainly by larger, paler, fusoid-inequilateral ascospores, and X. vivantii differs by larger ascospores with a slightly oblique germ slit. A dichotomous key is provided for identifying the 25 species. Doubtful names are also listed and annotated.

A New Postharvest Fruit Rot in Apple and Pear Caused by Phacidium lacerum

During surveys for postharvest diseases of apple and pear, an unknown postharvest fruit rot was observed in Washington State. The disease appeared to originate from infection of the stem and calyx tissue of the fruit or wounds on the fruit. An unknown pycnidial fungus was consistently isolated from the decayed fruit. Isolates from apple and pear were characterized and identified by molecular phylogenetic analysis and morphology. Pathogenicity of representative isolates on apple and pear fruit was tested under laboratory or field conditions. A BLAST search in GenBank showed that isolates differed from Phacidium lacerum and its synonym, Ceuthospora pinastri, by only 0 to 4 bp in sequences within part of the combined large ribosomal subunit + internal transcribed spacer + small ribosomal subunit regions. The phylogenetic analysis confirmed the taxonomic placement of the unknown fungus in the genus Phacidium, with the highest match being C. pinastri (formerly anamorphic P. lacerum) and with closely related taxa from GenBank forming congeneric clades. The fungus grew at 0 to 30°C and formed unilocular to multilocular pycnidial conidiomata on artificial media after approximately 5 to 7 days at room temperature. On potato dextrose agar incubated for a 12-h photoperiod, semi-immersed globose to subglobose pycnidial conidiomata were 250 to 1,000 μm in diameter (mean = 350), with 1 to 3 nonpapillate to slightly papillate ostioles and a buff conidial matrix. Conidia produced on phialides were 8 to 13 by 1.5 to 2.5 μm, hyaline, aseptate, cylindrical, with an abruptly tapered, typically slightly protuberant base, 2 to 3 guttules, and sometimes with a mucilaginous, flexuous, unbranched appendage which is attached to the apex of the conidium and disappears with age. Conidiogenous cells were flask shaped and 6 to 15 ×1.5 to 3 μm. Colony characteristics included felt-like aerial white mycelium, gray olivaceous at the center becoming greenish to colorless toward the margin, in concentric rings, with pycnidia forming in 5 to 7 days originating from the center of the plate. Morphological characteristics of the fungus had the greatest conformity with the description for C. pinastri. Based on molecular and morphological data, the fungus is identified as P. lacerum. 'Fuji' apple fruit and 'd'Anjou' pear fruit that were wounded, inoculated with representative isolates, and incubated at 0°C yielded the same symptoms as seen on decayed fruit collected from commercial fruit packinghouses. Stem-end rot, calyx-end rot, and wound-associated rot developed on fruit inoculated in the orchard after 3 months of cold storage. The fungus was reisolated from the diseased fruit. This is the first report of a fruit rot in apple and pear caused by P. lacerum. We propose Phacidium rot as the name of this disease.

Biology, ecology and ultrastructure of Ascobotryozyma and Botryozyma, unique commensal nematode-associated yeasts

Ascobotryozyma (anamorph Botryozyma) is an ascomycetous yeast genus characterized by its unusual morphology and ability to attach to free-living nematodes in the genus Panagrellus. Other than species descriptions for four taxa little is known about these yeasts. Investigations were carried out to determine the ecological relationship and specificity with nematodes in addition to examining basic cell structure, thallus development and sexual reproduction. Based on previous examinations of the yeast and nematode it was hypothesized the fungus did not parasitize the nematode but instead remained attached to nematodes for dispersal. Electron micrographs supported our hypotheses and revealed a specialized cell wall and mucilage that aid in attachment to the nematode cuticle. Tests to determine the ability of Ascobotryozyma and Botryozyma to attach to different nematode taxa revealed that attachment varies across taxonomic groups. Examinations of thallus cells, thallus growth, cell fusion and ascosporogenesis are presented. This study provides insight into an otherwise cryptic yeast genus.

Is there any chlorine monoxide in the stratosphere?

A ground-based search for stratospheric chlorine monoxide was carried out during May and October 1981 with an infrared heterodyne spectrometer in the solar absorption mode. Lines due to stratospheric nitric acid and tropospheric carbonyl sulfide were detected at about 0.2 percent absorptance levels, but the expected 0.1 percent lines of chlorine monoxide in this same region were not seen. Stratospheric chlorine monoxide is less abundant by at least a factor of 7 than is indicated by in situ measurements, and the upper limit for the integrated vertical column density of chlorine monoxide is 2.3 x 10(13) molecules per square centimeter at the 95 percent confidence level. These results imply that the release of chlorofluorocarbons may be significantly less important for the destruction of stratospheric ozone than is currently thought.

The Ascomycota tree of life: a phylum-wide phylogeny clarifies the origin and evolution of fundamental reproductive and ecological traits

We present a 6-gene, 420-species maximum-likelihood phylogeny of Ascomycota, the largest phylum of Fungi. This analysis is the most taxonomically complete to date with species sampled from all 15 currently circumscribed classes. A number of superclass-level nodes that have previously evaded resolution and were unnamed in classifications of the Fungi are resolved for the first time. Based on the 6-gene phylogeny we conducted a phylogenetic informativeness analysis of all 6 genes and a series of ancestral character state reconstructions that focused on morphology of sporocarps, ascus dehiscence, and evolution of nutritional modes and ecologies. A gene-by-gene assessment of phylogenetic informativeness yielded higher levels of informativeness for protein genes (RPB1, RPB2, and TEF1) as compared with the ribosomal genes, which have been the standard bearer in fungal systematics. Our reconstruction of sporocarp characters is consistent with 2 origins for multicellular sexual reproductive structures in Ascomycota, once in the common ancestor of Pezizomycotina and once in the common ancestor of Neolectomycetes. This first report of dual origins of ascomycete sporocarps highlights the complicated nature of assessing homology of morphological traits across Fungi. Furthermore, ancestral reconstruction supports an open sporocarp with an exposed hymenium (apothecium) as the primitive morphology for Pezizomycotina with multiple derivations of the partially (perithecia) or completely enclosed (cleistothecia) sporocarps. Ascus dehiscence is most informative at the class level within Pezizomycotina with most superclass nodes reconstructed equivocally. Character-state reconstructions support a terrestrial, saprobic ecology as ancestral. In contrast to previous studies, these analyses support multiple origins of lichenization events with the loss of lichenization as less frequent and limited to terminal, closely related species.

Methodological innovations in data gathering: newborn screening linkage with live births records, Michigan, 1/2007-3/2008

OBJECTIVE

To match Michigan birth and newborn screening records to identify and follow-up potentially unscreened infants, assess data quality, and demonstrate the utility of Link Plus linkage software for matching MCH related administrative datasets.

METHODS

Birth and newborn screening records maintained by the Michigan Department of Community Health from January 2007 through March 2008 were used in this study. Link Plus, a freely-available probabilistic record linkage software program developed at the Centers for Disease Control and Prevention, was used to match records. Linkage performance was assessed by the linkage success rate (percentage of valid matches). Follow-up of un-matched records was conducted by the Michigan Newborn Screening Follow-up Program.

RESULTS

Nearly all (99.2%) of the 142,178 birth records included in this study were successfully matched to newborn screening records. Following a transition to a web-based electronic birth certificate system and inclusion of a newborn screening card identification number on the birth record in 2008, the linkage success rate increased to 99.6% based on analysis of approximately 18,000 records. Of approximately 600 un-matched records, nearly half had received a newborn screen. Approximately 8% of un-matched records were due to parental refusal of newborn screening. Nine children received an initial screen as a result of this study; one was confirmed as having sickle cell trait.

CONCLUSIONS

We have demonstrated that a freely available record linkage software, Link Plus, can be used to successfully match records of MCH databases thereby providing an opportunity for further research and quality assurance investigations.

Didymella pisi sp. nov., the teleomorph of Ascochyta pisi

The anamorphic pycnidial fungus Ascochyta pisi is one member of a species complex that causes Ascochyta blight of pea, a potentially devastating disease. The teleomorphic state of this fungus was induced under laboratory conditions. Using morphological and molecular characters, we placed the teleomorph within the genus Didymella as D. pisi and describe a heterothallic mating system using a PCR-based mating type assay and in vitro crosses. We compare D. pisi with other Didymella spp. with which it might be confused.

Occurrence of Kluyveromyces marxianus var. marxianus Causing Onion Soft Rot in the Columbia Basin of Washington State

Kluyveromyces marxianus var. marxianus, a causal agent of onion (Allium cepa L.) soft rot, was originally isolated from Walla Walla sweet onion bulbs grown in Oregon and subsequently isolated from onion throughout the southeast Washington onion-growing area, but was not found to be infecting dry bulb storage onions grown in central Washington (1). During September of 2001, a yeast was isolated from dry storage onion bulbs (cv. Teton) grown under sprinkler irrigation in central Washington, exhibiting soft rot symptoms and identified to be K. marxianus var. marxianus (2). Koch's postulate was completed using cv. Teton bulbs surface disinfested with 0.5% NaOCl for 2 min. This isolate and four isolates of Kluyveromyces marxianus var. marxianus (1) were cultured on potato dextrose agar and resuspended to an OD₆₀₀ = 0.3 (approximately 10⁵ CFU/ml). One-half of a milliliter of each isolate was inoculated to onion using the cut bulb method with three replicates and incubated in a moist chamber at 25°C for 7 days. Onion slices inoculated with the new isolate exhibited soft rot symptoms similar to those caused by the known isolates while no symptoms were observed for the water control. The yeast reisolated from symptomatic tissue was confirmed to be K. marxianus var. marxianus (2). The identification of K. marxianus var. marxianus infecting dry bulb storage onions grown in the Columbia Basin is of interest because the disease can be confused with bacterial soft rot and could become a serious problem in this important storage onion-growing region. References: (1) D. A. Johnson et al. Plant Dis. 72:359, 1988. (2) N. J. W. Kreger-van Rig, ed. The Yeasts: A Taxonomic Study. Elsevier, Amsterdam, 1984.

An overview of the systematics of the Sordariomycetes based on a four-gene phylogeny

The Sordariomycetes is one of the largest classes in the Ascomycota, and the majority of its species are characterized by perithecial ascomata and inoperculate unitunicate asci. It includes more than 600 genera with over 3000 species and represents a wide range of ecologies including pathogens and endophytes of plants, animal pathogens and mycoparasites. To test and refine the classification of the Sordariomycetes sensu Eriksson (2006), the phylogenetic relationship among 106 taxa from 12 orders out of 16 in the Sordariomycetes was investigated based on four nuclear loci (nSSU and nLSU rDNA, TEF and RPB2), using three species of the Leotiomycetes as outgroups. Three subclasses (i.e. Hypocreomycetidae, Sordariomycetidae and Xylariomycetidae) currently recognized in the classification are well supported with the placement of the Lulworthiales in either a basal group of the Sordariomycetes or a sister group of the Hypocreomycetidae. Except for the Microascales, our results recognize most of the orders as monophyletic groups. Melanospora species form a clade outside of the Hypocreales and are recognized as a distinct order in the Hypocreomycetidae. Glomerellaceae is excluded from the Phyllachorales and placed in Hypocreomycetidae incertae sedis. In the Sordariomycetidae, the Sordariales is a strongly supported clade and occurs within a well supported clade containing the Boliniales and Chaetosphaeriales. Aspects of morphology, ecology and evolution are discussed.

A higher-level phylogenetic classification of the Fungi

A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community. The classification includes 195 taxa, down to the level of order, of which 16 are described or validated here: Dikarya subkingdom nov.; Chytridiomycota, Neocallimastigomycota phyla nov.; Monoblepharidomycetes, Neocallimastigomycetes class. nov.; Eurotiomycetidae, Lecanoromycetidae, Mycocaliciomycetidae subclass. nov.; Acarosporales, Corticiales, Baeomycetales, Candelariales, Gloeophyllales, Melanosporales, Trechisporales, Umbilicariales ords. nov. The clade containing Ascomycota and Basidiomycota is classified as subkingdom Dikarya, reflecting the putative synapomorphy of dikaryotic hyphae. The most dramatic shifts in the classification relative to previous works concern the groups that have traditionally been included in the Chytridiomycota and Zygomycota. The Chytridiomycota is retained in a restricted sense, with Blastocladiomycota and Neocallimastigomycota representing segregate phyla of flagellated Fungi. Taxa traditionally placed in Zygomycota are distributed among Glomeromycota and several subphyla incertae sedis, including Mucoromycotina, Entomophthoromycotina, Kickxellomycotina, and Zoopagomycotina. Microsporidia are included in the Fungi, but no further subdivision of the group is proposed. Several genera of 'basal' Fungi of uncertain position are not placed in any higher taxa, including Basidiobolus, Caulochytrium, Olpidium, and Rozella.