Nachdem eine pilzfloristische Untersuchung des Odenwaldes vorlaeufig abgeschlossen worden war, konnten deren Ergebnisse mit einzelnen weit verstreuten frueheren Befunden verglichen und dabei gezeigt werden, dass eine groessere Zahl selbst von auffaelligen Arten im Lauf der letzten Jahrzehnte als offenbar im Gebiet ausgestorben gelten muss. Andere z.T. nicht haeufige Arten haben sich jedoch seit rund 50 Jahren an oft eng begrenzten Wuchsorten mit erstaunlicher Ortstreue gehalten, einige wenige Arten scheinen heute sogar wesentlich haeufiger zu sein als seinerzeit. Die pilzfloristischen Befunde gehen zum grossen Teil in die von der Deutschen Mykologischen Gesellschaft getragene Kartierung der mitteleuropaeischen Grosspilze (= groessere Fruchtkoerper bildende Art) mit ein. - Neu in Angriff genommen wurden mykologische bzw. mykofloristische Arbeiten in der Rheinebene, und zwar mit Untersuchungen ueber holzzersetzende 'niedere' (='aphyllophorale') Basidiomyceten, eine Artengruppe, die fuer das Oekosystem Wald eine entscheidende Rolle im Rahmen seiner Stoffumsaetze spielt. Die Rheinebene stellt besonders mit ihren Auenwaeldern hinsichtlich der Aphyllophoralen ein noch weitgehend unerforschtes Gebiet dar.
This project is aimed at the characterization of the systemic reprogramming in barley, which modulates the compatible interaction with the biotrophic leaf pathogen Blumeria graminis f.sp. hordei upon root infestation with the mutualistic endophyte Piriformospora indica. We have recently shown that the basidiomycete P. indica - upon successful establishment in the roots - reprograms barley to salt stress tolerance, resistance to root diseases and higher yield (Waller et al., 2005). Successful powdery mildew infections in barley leaves are also disturbed by the mutualistic fungus. These processes are associated with a strong change in plant metabolism, especially with a drastic alteration of leaf and root antioxidants. On the basis of these findings we will perform an in-depth analysis of the barley metabolome (B6) and transcriptome (B7) with two specific foci: First, to elucidate the process of establishment of the mutualistic fungus within the barley roots; second, to characterize elements of the systemic response in leaves leading to an interruption or failure of compatibility processes required for successful establishment of biotrophic leaf pathogens like Blumeria. New gene candidates will be pre-selected systematically for their regulatory role in compatibility by means of transiently transformed barley leaves upon Blumeria inoculation. Stable transgenic barley and maize lines (B3) generated with verified gene candidates and genes identified by other projects (A1, A2, B5, B6) will be tested with Blumeria and P. indica. By comparing candidate genes in the different plant - microbe systems, we will identify common regulatory processes, metabolites and metabolic networks implicated in compatibility including those required for successful interactions with mutualistic fungi.
The basidiomycete Armillaria mellea s.l. is one of the most important root rot pathogens of forest trees and comprises several species. The aim of the project is to identify the taxa occurring inSwitzerland and to understand their ecological behaviour. Root, butt and stem rots caused by different fungi are important tree diseases responsible for significant economic losses. Armillaria spp. occur world-wide and are important components of many natural and managed forest ecosystems. Armillaria spp. are known saprothrophs as well as primary and secondary pathogens causing root and butt rot on a large number of woody plants, including forest and orchard trees as well as grape vine and ornamentals. The identification of several Armillaria species in Europe warrants research in the biology and ecology of the different species. We propose to study A. cepistipes for the following reasons. First, A. cepistipes is dominating the rhizomorph populations in most forest types in Switzerland. This widespread occurrence contrasts with the current knowledge about A. cepistipes, which is very limited. Second, because the pathogenicity of A. cepistipes is considered low this fungus has the potential for using as an antagonist to control stump colonising pathogenic fungi, such as A. ostoyae and Heterobasidion annosum. This project aims to provide a better understanding of the ecology of A. cepistipes in mountainous Norway spruce (Picea abies) forests. Special emphasis will be given to interactions of A. cepistipes with A. ostoyae, which is a very common facultative pathogen and which often co-occurs with A. cepistipes. The populations of A. cepistipes and A. ostoyae will be investigated in mountainous spruce forests were both species coexist. The fungi will be sampled from the soil, from stumps and dead wood, and from the root system of infected trees to determine the main niches occupied by the two species. Somatic incompatibility will be used to characterise the populations of each species. The knowledge of the spatial distribution of individual genets will allow us to gain insights into the mode of competition and the mode of spreading. Inoculation experiments will be used to determine the variation in virulence expression of A. cepistipes towards Norway spruce and to investigate its interactions with A. ostoyae.