Book of Abstracts (PDF) - International Mycological Association

IMC7 Tuesday August 13th Lectures
interphase as a site where plants, insects and pathogens will
interact to determine fungal efficacy, cycling and survival.
However, the rhizospheric effect was less marked for
GPMa, and overall it showed reduced persistence in soils
compared to GMa.
186 - Entomophthorales host-pathogen relationships:
ecology, pathobiology and molecular characterization
J. Eilenberg * , A.B. Jensen, C. Nielsen & L. Thomsen
Department of Ecology, The Royal Veterinary and
Agricultural University, Thorvaldsensvej 40, DK 1871 Frb.
C., Denmark. - E-mail: Jei@kvl.dk
Fungi from the order Entomophthorales are pathogenic to
arthropods, especially insects. They are highly specialized
and provide us with valuable insight in the development of
host-pathogen relationships and are also potential
biological control agents. Attention will be given to three
host-pathogen systems, which recently were studied with
respect to ecology, pathobiology and molecular
characterization. 1) Entomophthora muscae complex and
hosts from Diptera. Morphological and pathobiological
characters allow us to discriminate between the limited
number of recognized species, but the inclusion of
molecular data strongly suggest that each host-pathogen
system is independent. Each fly species thus harbors its
own selection of genotypes 2) Strongwellsea spp. and hosts
from Diptera. This genus disperses conidia from abdominal
holes in the still living hosts. We have found infections in
many dipteran families, including in the arctic.
Morphological and pathobiological characters indicate a
high diversity and specialization. 3) Pandora neoaphidis,
Neozygites fresenii and Entomophthora planchoniana and
hosts from Aphididae. These fungi are adapted to the
holocyclic life-cycle of many host aphids. Further, a recent
study has revealed that two clonal populations of an
anholocyclic aphid host each harbored only one of these
pathogens.
187 - The occurrence and stability of the entomogenous
hyphomycete fungi Metarhizium anisopliae and
Beauveria bassiana
T.M. Butt * , C.S. Wang & N. Patel
School of Biological Sciences, University of Wales
Swansea, Singleton Park, SA2 8PP, U.K. - E-mail:
t.butt@swansea.ac.uk
There is considerable interest in the development of
entomogenous, hyphomycete fungi, such as Metarhizium
anisopliae and Beauveria bassiana, for the control of
arthropod pests. The successful deployment of these
biocontrol agents will depend on a thorough understanding
of their ecology and population dynamics. Biochemical and
molecular markers have been developed to study: (1) the
occurrence of indigenous strains, (2) the efficacy and fate
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Book of Abstracts
of released (exotic) strains, (3) impact of fungi on nontarget
organisms, and (4) fungal stability. The latter has
received considerable attention because it influences
sporulation, virulence, host specificity and ecological
fitness which, in turn, influences production costs and
efficacy. In vitro studies show that some strains of
entomogenous fungi are more stable than others. Some of
the changes observed may be due to parasexual
recombination, gene silencing or gene deletion.
Recombinants were recovered from insects co-infected
with two strains of either M. anisopliae or B. bassiana.
188 - Biodiversity of thermophilic fungi
J. Mouchacca
Laboratoire de Cryptogamie, M.N.H.N., 12, rue Buffon,
75005 PARIS, France. - E-mail: mouch@mnhn.fr
Critical knowledge on the biodiversity of thermophilic
fungi has been hindered by the proposal of several
unwarranted nomenclatural and taxonomic decisions which
have led to a misunderstanding of the taxonomic concepts
of some thermophiles. The situation has been further
aggravated by the current chaotic state in binomial citations
of common members of the group. The systematics of
thermophilic fungi has been recently re-appraised in a
series of contributions which have appeared almost 30
years after the last major monograph on their taxonomy,
biology and economic importance (Cooney and Emerson,
1964). To date, about 50 new names have been introduced
at both species and varietal levels; a total almost equal to
earlier names reported for the group. However, some of
these introductions proved not to be justified. Indeed, some
name changes do not appear to be supported by sound
taxonomic arguments. Thermophilic fungi now acceptable
as valid from a nomenclatural point of view comprise about
40 taxa. Thus some Mucorales, several Ascomycetes and
hyphomycetes and a single agonomycete could appear to
be true thermophiles. However, from a taxonomic point of
view, the status of some species still requires further study.
Once these basic studies have been completed, they will
guarantee that a sound database exists for thermophilic
fungi. Such taxonomic stability will also ensure that any
new discoveries of interest have the potential for eventual
industrial application.
189 - Heat and the physiology of thermophilic fungi
B. Jensen
Department of General MicrobiologyUniversity of
Copenhagen, Sølvgade 83H DK-1307 Copenhagen,
Denmark. - E-mail: boj@mermaid.molbio.ku.dk
The thermophilic fungi compose a small ecological group
defined solely on temperature requirement for growth,
ranging from 20 °C to at or above 50 °C. There are only
about 40 known species of thermophilic fungi and for only