Publications by authors named "Robert E Marra"

Boxwood blight, a fungal disease of ornamental plants ( spp.), is caused by two sister species, () and (). Compared to , is documented to display reduced sensitivity to fungicides, including the azole class of antifungals, which block synthesis of a key fungal membrane component, ergosterol.

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Two isolates from Canada and the USA (UAMH 7122 and UAMH 7211, respectively) previously identified as were studied by morphology and six-locus phylogeny (, ITS, , , and ). UAMH 7122 and UAMH 7211 are morphologically related but phylogenetically distinct from (≡) and . Hence, UAMH 7122 and UAMH 7211 are described as a new species, sp.

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Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the community voiced near unanimous support for a concept of that represented a clade comprising all agriculturally and clinically important species, including the species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus into seven genera, including the FSSC described as members of the genus , with subsequent justification in 2018 based on claims that the 2013 concept of is polyphyletic.

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and . are two closely related fungal species responsible for boxwood blight disease of ornamental shrubs ( spp.) in the U.

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Functional toxicology has enabled the identification of genes involved in conferring tolerance and sensitivity to engineered nanomaterial (ENM) exposure in the model plant Arabidopsis thaliana (L.) Heynh. Several genes were found to be involved in metabolic functions, stress response, transport, protein synthesis, and DNA repair.

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Rapid and accurate molecular diagnostic tools are critical to efforts to minimize the impact and spread of emergent pathogens. The identification of diagnostic markers for novel pathogens presents several challenges, especially in the absence of information about population diversity and where genetic resources are limited. The objective of this study was to use comparative genomics datasets to find unique target regions suitable for the diagnosis of two fungal species causing a newly emergent blight disease of boxwood.

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The population structure of Armillaria gallica, an important pathogen of Quercus spp., was investigated from mixed oak forests in central Massachusetts, encompassing a sampling area over 500 km(2). From 16 plots at four sites a total of 153 isolates (34-40 isolates per site) was analyzed with amplified fragment length polymorphisms (AFLPs).

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Sudden vegetation dieback (SVD) is the loss of smooth cordgrass (Spartina alterniflora) along intertidal creeks in salt marshes of the Atlantic and Gulf states. The underlying cause of SVD remains unclear, but earlier work suggested a contributing role for Fusarium spp. in Louisiana.

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Neonectria ditissima is a fungal pathogen native to eastern North America that causes disfiguring cankers on numerous tree species, particularly birches (Betula spp.). In order to develop control strategies, fundamental knowledge of the pathogen's reproductive and dispersal dynamics is necessary.

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The study of quantitative traits provides a window on the interactions between multiple unlinked genetic loci. The interaction between hosts and pathogenic microbes, such as fungi, involves aspects of quantitative genetics for both partners in this dynamic equilibrium. One important pathogenic fungus is Cryptococcus neoformans, a basidiomycete yeast that can infect the human brain and whose mating system has two mating type alleles, a and alpha.

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Cryptococcus neoformans is a basidiomycetous yeast ubiquitous in the environment, a model for fungal pathogenesis, and an opportunistic human pathogen of global importance. We have sequenced its approximately 20-megabase genome, which contains approximately 6500 intron-rich gene structures and encodes a transcriptome abundant in alternatively spliced and antisense messages. The genome is rich in transposons, many of which cluster at candidate centromeric regions.

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To construct a genetic linkage map of the heterothallic yeast, Cryptococcus neoformans (Filobasidiella neoformans), we crossed two mating-compatible strains and analyzed 94 progeny for the segregation of 301 polymorphic markers, consisting of 228 restriction site polymorphisms, 63 microsatellites, two indels, and eight mating-type (MAT)-associated markers. All but six markers showed no significant (P < 0.05) segregation distortion.

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Selfing in the chestnut blight fungus, Cryphonectria parasitica, occurs by two different genetic mechanisms. Most self-fertile isolates of C. parasitica are heterokaryotic for mating type, and the progeny from selfing segregate for mating type.

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The most common cause of fungal meningitis in humans, Cryptococcus neoformans serotype A, is a basidiomycetous yeast with a bipolar mating system. However, the vast majority (>99.9%) of C.

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