Zusammenfassungen der Arbeitskreisbeiträge - Die DPG

investigation. To avoid further adaptation of P. pachyrhizi against fungicides, FRAC
recommendations should be followed.
EFFICACY OF FUNGICIDES AGAINST EARLY BLIGHT OF TOMATO
Jasmin Verena Philippi 1 , Gerd Stammler 1
1
BASF SE, Agrarzentrum, Speyerer Strasse 2, 67117 Limburgerhof, Deutschland
Contact: gerd.stammler@basf.com
Early blight of potato and tomato is caused by Alternaria solani and the involvement of
Alternaria alternata in this disease is under discussion. Therefore greenhouse studies of
tomatoes were performed to check differences in pathogenicity. A comparison of the
pathogenicity of eight A. solani and eight A. alternata isolates under different
conditions indicated a higher pathogenicity of A. solani on tomato in the greenhouse.
Early blight is mainly controlled by fungicide treatments, e.g. QoIs. Resistance to QoIs is
mediated by mutations in their target gene, the cytochrome b. Because of the genetic structure
of cytochrome b in Alternaria solani, the most important mutation, the G143A, did not occur
so far. However, another mutation, the F129L has been reported. Sensitivity of A. solani
isolates carrying the mutation F129L were compared with wild type isolates in microtiter
tests. Pyraclostrobin provided good control of F129L mutated isolates with slightly increased
ED50 values.
THE POSSIBLE ROLE OF HYPHAL ANASTOMOSIS IN FUNGICIDE
RESISTANCE DEVELOPMENT IN POPULATIONS OF BOTRYTIS CINEREA
John B. Speakman, Katja Stunz
BASF SE, Speyerer Strasse 2, 67117 Limbugerhof
Contact: john-bryan.speakman@basf.com
In vitro crosses with Botrytis cinerea isolates which carried different fungicide resistance
markers gave, as progeny, isolates with the resistant makers of both parents. Conidial and
hyphal anastomoses could be microscopically identified. The possible role of this observation
in the development of resistant populations in the field will be discussed.
COMPARATIVE ANALYSIS OF HAUSTORIAL SECRETOMES FROM
DIFFERENT RUST FUNGI
Kohlndorfer, Matthias 1 ; Ralf T. Voegele 1
1 Universität Hohenheim, FG Phytopathologie, Institut für Phytomedizin, Fakultät
Agrarwissenschaften, Otto-Sander-Str. 5, 70599 Stuttgart
Contact: matthias.kohlndorfer@uni-hohenheim.de
The interaction of obligate biotrophic fungi with their respective host plants is a fascinating
field which has drawn the interest of researchers for decades. A hallmark of obligate
biotrophic growth is the formation of specialized hyphae, so called haustoria. These structures
are the interface of interaction between obligate biotrophic parasites and their hosts and fulfill
a variety of different functions like the uptake of nutrients, or the production of specialized
proteins, so-called effector proteins. These proteins may be secreted into the extrahaustorial
matrix, or may even be transferred into the infected plant cell. Especially the latter class of
effectors is expected to interact with plant proteins and therefore might play an important role
in the suppression of plant defense mechanisms. Our research is aimed at the detection and
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