Inoculum 63(3) - Mycological Society of America

ular soil horizons, the isotopic composition of macrofungal fruiting bodies might
be a useful tool for tracing lead origin. Our preliminary data from a case study in
Agaricus bernardii have supported this hypothesis. Furthermore, the isotopic
composition of lead in saprotrophic macrofungi (Agaricus campestris, A.
bernardii, A. xanthodermus and Leucoagaricus leucothites) of various origins has
reflected more or less the expected pollution sources.
Brewer, Marin T and Ashley N Turner. Department of Plant Pathology, University
of Georgia, Athens, GA 30602. Genetic diversity and reproductive isolation
in Didymella bryoniae, a fungal pathogen of cucurbits
We are interested in determining the center of diversity, as well as historical
and ongoing migration patterns in the cucurbit pathogen Didymella bryoniae.
This fungus causes gummy stem blight and black rot of cucurbits everywhere they
are grown, yet relatively little is known about how it is dispersed. Previous studies
with dominant markers have indicated that this species is diverse and contains
at least two distinct genetic groups. We sequenced four nuclear regions, including
calmodulin (CAL), beta-tubulin (TUB2), chitin synthase 1 (CHS-1), and the internal
transcribed spacer of the rDNA (ITS) of thirty-four isolates from diverse cucurbit
hosts across the United States (US). Isolates from both genetic groups were
represented in our sample. A total of 1415 bp were sequenced, resulting in 41
polymorphic sites and 13 unique haplotypes. A haplotype network constructed
with TCS demonstrated that there are two distinct genetic groups, which is consistent
with previous studies. However, a single isolate collected from a greenhouse
in California was quite distinct from both groups. There is no association
with genetic group and host species of origin, which is not surprising because earlier
studies indicated that host specialization is not evident with D. bryoniae. Geographic
associations were detected, however, as one of the groups was present
only in the northeastern US whereas the other group was found throughout the
US. There are no detectable morphological differences between the two genetic
groups indicating that these groups represent cryptic species that are reproductively
isolated. Studies on a worldwide collection of isolates are currently underway.
Coalescent analyses on this collection will be aimed at understanding migration
patterns, geographic origin, and approximate age of the divergence of the
genetic groups to elucidate the evolutionary processes contributing to the observed
patterns of diversity.
Broders, Kirk 1 , Andre Boraks 1 , Laura Barbison 2 , John Brown 2 , and Greg
Boland 2 . 1 Department of Biological Sciences, University of New Hampshire,
Durham, NH 03824, 2 School of Environmental Sciences, University of Guelph,
Guelph, ON N1G 2W1. Invasion biology of the butternut canker fungus
Ophiognomonia clavigignenti-juglandacearum
Butternut canker caused by the fungal pathogen Ophiognomonia
clavigignenti-juglandacearum (Oc-j) remains the primary cause for range-wide
mortality of butternut trees. The disease was first reported in Wisconsin in 1967,
however the fungus may have been present for several years prior. Several questions
still remain largely unanswered regarding the invasion by Oc-j. These questions
include; how many times was the fungus introduced; where was it introduced;
were more virulent strains introduced; and how was it able to spread so
rapidly within the native butternut population. Therefore, our objective was to
evaluate the invasion biology of this fungus including investigations into the ecology,
epidemiology, and population structure of Oc-j in North America. To complete
these objective flowers, developing seeds, and mature seeds of butternut,
heartnut and black walnut were assessed as potential vectors of Oc-j; Sixteen isolates
were evaluated for virulence on butternut, heartnut, and black walnut; and
100 isolates of Oc-j from across North America were used to analyze the population
structure of the fungus. Bayesian analyses based on 16 SNP markers revealed
that the Oc-j population in North American is composed of four genetically distinct
clonal lineages, suggesting multiple introductions of Oc-j, through successive
or simultaneous introductions of isolates having differentiated genetic backgrounds.
Isolates of Oc-j recovered from heartnut and black walnut caused larger
lesions on all three Juglans species compared to isolates originally recovered from
butternut. Four of the five isolates, which caused the largest lesions on butternut
belonged to a single genetic cluster. The pathogenicity data in combination with
geographic and population structure data indicate this fungus was introduced into
North America on multiple occasions, and a more virulent clonal lineage was recently
introduced into Minnesota and Wisconsin and subsequently spread
throughout the rest of the butternut canker population in North America.
Buchanan, Peter K and Peter R Johnston. Landcare Research, Private Bag
92170, Auckland 1142, New Zealand. Conservation of Fungi - threat status of
fungi in New Zealand and globally
Fungi have been included in threat status assessments of New Zealand’s
biota since 2002. Assessments have mainly addressed macrofungi, as well as obligate
species of fungi on threatened plants. The initial inclusion of fungi, and subsequent
need for reassessment of threat status, has generated new research initiatives
and raised awareness of fungal conservation. Aspects of fungal biology such
12 Inoculum 63(3), June 2012
as ephemeral reproductive stages add difficulty to threat status assessments. Examples
are presented of fungal species listed in the highest (Nationally Critical)
and other threat categories. Over 1,000 species of fungi are listed as Data Deficient
due to inadequate distribution data. Fungi have been included in a prioritization
exercise spanning all New Zealand’s threatened taxa that are in decline, to
evaluate methodology, feasibility, and cost of long-term recovery plans. Using
molecular techniques, new records of ectomycorrhizal fungi listed as Data Deficient
have been discovered by comparing environmental sampling of ectomycorrhizas
with DNA sourced from herbarium specimens. Responding to increasing
global awareness of the need for fungal conservation, the International Society for
Conservation of Fungi was formed in 2010, and five Fungal Specialist Groups
have been established under IUCN.
Burchhardt, Kathleen M and Marc A Cubeta. North Carolina State University,
Department of Plant Pathology, Raleigh, NC 27695. Population dynamics of
Monilinia vaccinii-corymbosi in blueberry fields throughout the United
States
Mummy berry disease of blueberry (Vaccinium spp.) is caused by the ascomycete
Monilinia vaccinii-corymbosi (Mvc). The fungus produces asexual and
sexual spores that infect blueberry shoots and fruit. While spore dispersal and sexual
reproduction can contribute to the spread and evolution of fungal populations,
little is known about the population dynamics of Mvc. The primary objective of
this study was to utilize microsatellite-based genetic markers to examine intraspecific
genetic diversity, population structure, and gene flow among populations
of Mvc throughout blueberry growing regions of the United States. In this
study, 438 isolates of Mvc sampled from 15 blueberry fields in New York, New
Jersey, Massachusetts, Georgia, Mississippi, Oregon, Washington, Michigan, and
North Carolina were screened with 10 polymorphic microsatellite markers. Results
based on analyzing a geographically diverse subsample of 55 isolates from
six fields indicate high intraspecific genetic diversity. Forty-eight private alleles
were detected across the 10 loci, providing evidence for population differentiation
and restricted gene flow among fields. Results from population genetic analyses
of a more comprehensive dataset of 438 isolates will be presented.
Burleigh, J Gordon 1 , Keith Crandall 2 , Karen Cranston 3 , Karl Gude 4 , David S
Hibbett 5 , Mark Holder 6 , Laura A Katz 7 , Richard H Ree 7 , Stephen A Smith 7 ,
Douglas E Soltis 7 , and Tiffani Williams 7 . 1 Department of Biology, University of
Florida, Gainesville, FL 32611, 2 Department of Biology, Brigham Young University,
Provo, UT 84602, 3 NESCENT, Durham, NC 27705, 4 College of Communication,
5
Arts and Sciences, Michigan State University, E. Lansing
6
MI 45622,
Biology Department, Clark University, Worcester MA 01610, Department of
Ecology
7
and Evolutionary Biology, University of Kansas, Lawrence KS 66045,
and elsewhere. Open Tree of Life: Community driven synthesis of the Tree
of Life
Reconstructing the phylogeny of all species has been a grand challenge
ever since Darwin. The scope of the problem is immense: current estimates of extant
biodiversity range from 1.8 million to 8.7 million species, a large fraction of
which are Fungi. Much progress has recently been made in resolving the tree, and
systematists continue to generate new phylogenetic knowledge at all depths of ancestry.
Nevertheless, despite 150 years of effort, 55 AToL projects, and numerous
other funded projects, we lack a comprehensive tree of life. Synthesis is currently
inhibited by limits of available data, analytical power, and informatics infrastructure.
Perhaps more importantly, it is also limited by a lack of compelling
means and incentives for community participation. A comprehensive synthesis
would yield great benefits across the life sciences, especially if it were self-sustaining,
community-driven, and continually updated. We describe a recently funded
project named “Open Tree of Life” that aims to establish a community-driven,
continually updated estimate of the entire tree, and develop new software tools
and new methods for merging and sharing data. Open Tree of Life will: 1) within
one year, compile the first comprehensive draft tree of life by synthesizing existing
phylogenetic and taxonomic knowledge; 2) enable the community to improve,
annotate, and expand this initial tree; 3) initiate a cultural transformation in
systematics towards pervasive and ingrained practices of data sharing; and 4) develop
novel methods for synthetic tree reconstruction. By engaging the systematics
community, including mycologists, our overarching goal is to cultivate ongoing
synthesis on a large scale, in a manner that will transform current cultural
norms in the field.
Bushley, Kathryn E and Joseph W Spatafora. Department of Botany and Plant
Pathology, Oregon State University, Corvallis, OR 97330. Convergent and divergent
evolution of nonribosomal peptide synthetases
Nonribosomal peptide synthetases (NRPSs) are large multimodular enzymes
which produce small bioactive peptides (NRPs) without the aid of ribosomes.
While the function of many NRPs remains unknown, it is becoming clear
Continued on following page