{"id":2550,"date":"2013-09-27T21:03:04","date_gmt":"2013-09-27T21:03:04","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=2550"},"modified":"2013-09-27T21:04:00","modified_gmt":"2013-09-27T21:04:00","slug":"phd-defense-a-coince","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=2550","title":{"rendered":"PhD Defense: A. Coince"},"content":{"rendered":"

The defense will be held the\u00a03th october 2013<\/strong>\u00a0at\u00a09H30<\/strong> in Amphitheater 7,<\/strong>\u00a0Facult\u00e9 des Sciences<\/strong>, Boulevard des Aiguillettes, Vandoeuvre<\/p>\n

 <\/p>\n

Diversity and composition of fungi and oomycete communities in beech forest in relation to climatic and edaphic variables: from the stand to the continent\u00a0<\/strong><\/p>\n

Forest soils are heterogeneous habitats full of microorganisms. In particular, the filamentous eukaryotes (fungi and oomycetes) exhibit a huge diversity and play essential functions in the dynamic and sustainable growth of the forest ecosystem. However, their diversity and their distribution are poorly known; thus, so are the structuring factors of these microbial communities. The main goals were: (i) use a high-throughput pyrosequencing to study soil microbial communities at a broad geographical scale, and particularly to validate its use for the study of soil forest Pythiaceae communities, (ii) study the diversity and structure of fungal and Pythiaceae communities at several spatial scales, (iii) identify possible climatic and edaphic variables structuring these communities and (iv) estimate the possible response of these microbial communities to climatic variation. A pilot study was undertaken at the stand scale. Then, two additional studies were carried out along environ! mental gradients at the regional and continental scales. The use of the pyrosequencing technique was found appropriate for the fungal communities, but difficulties arose in studying the Pythiaceae community. At the stand scale, results suggested the soil to be a valuable substitute for the roots to access the ectomycorrhizal richness and composition using pyrosequencing. The results along the broad scale gradients suggested that fungal richness may not be affected by climate warming but that the composition would be. Moreover, our work indicated that soil pH is a major factor explaining fungal community composition. The main conclusions are still to be confirmed and deeper knowledge of the response of different fungal phylum, or family, would be required. The detection and thus the diversity estimation of the Pythiaceae in forest soil remains a current challenge.<\/p>\n

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Diversit\u00e9 et composition des communaut\u00e9s de champignons et d’oomyc\u00e8tes de h\u00eatraies, en relation avec des facteurs climatiques et \u00e9daphiques : de la parcelle au continent\u00a0<\/strong><\/p>\n

Les sols forestiers sont des habitats h\u00e9t\u00e9rog\u00e8nes, v\u00e9ritables r\u00e9servoirs de microorganismes. Parmi ces microorganismes, les eucaryotes filamenteux (champignons et Pythiac\u00e9es) sont tr\u00e8s divers et jouent un r\u00f4le important dans le fonctionnement et la durabilit\u00e9 des \u00e9cosyst\u00e8mes forestiers. Leur diversit\u00e9 et leur r\u00e9partition spatiale \u00e0 diff\u00e9rentes \u00e9chelles sont encore peu connues et les facteurs qui sous-tendent cette dispersion sont encore peu \u00e9tudi\u00e9s. Aussi, les objectifs \u00e9taient (i) d\u2019exploiter le s\u00e9quen\u00e7age haut-d\u00e9bit pour des \u00e9tudes d\u2019\u00e9cologie microbienne \u00e0 large \u00e9chelle et valider son application aux communaut\u00e9s de Pythiac\u00e9es en milieu forestier, (ii) de d\u00e9crire ces communaut\u00e9s microbiennes, en termes de diversit\u00e9 et de structure, \u00e0 diff\u00e9rentes \u00e9chelles spatiales (locale, r\u00e9gionale et continentale), (iii) de caract\u00e9riser les variables biotiques et abiotiques structurant ces communaut\u00e9s et (iv) d\u2019\u00e9valuer la r\u00e9ponse \u00e9ventuelle de! s communaut\u00e9s aux variations climatiques.Une premi\u00e8re \u00e9tude pilote \u00e0 l\u2019\u00e9chelle de la parcelle a \u00e9t\u00e9 suivi de deux \u00e9tudes \u00e0 grande \u00e9chelle spatiale le long de gradients environnementaux. Des gradients d\u2019altitude et un gradient latitudinal, \u00e0 l\u2019\u00e9chelle continentale, ont \u00e9t\u00e9 utilis\u00e9s comme gradient climatique. L\u2019\u00e9tude pr\u00e9liminaire a donc valid\u00e9 l\u2019utilisation du pyros\u00e9quen\u00e7age pour les communaut\u00e9s fongiques, et en particulier pour les esp\u00e8ces ectomycorhiziennes, et apport\u00e9 des \u00e9l\u00e9ments pour \u00e9tablir une m\u00e9thodologie d\u2019\u00e9chantillonnage coupl\u00e9e \u00e0 cette technique. L\u2019application de ces outils mol\u00e9culaires \u00e0 l\u2019\u00e9tude des communaut\u00e9s de Pythiac\u00e9es reste \u00e0 optimiser. Les r\u00e9sultats obtenus sur les communaut\u00e9s fongiques telluriques sugg\u00e8rent que dans l\u2019hypoth\u00e8se d\u2019un r\u00e9chauffement climatique, la richesse fongique ne serait pas directement affect\u00e9e mais la composition des communaut\u00e9s le serait. La composition des communaut\u00e9s fo! ngiques est \u00e9galement fortement li\u00e9e au pH du sol. Ces r\u00e9sultats sont \u00e0 affiner en \u00e9tudiant plus en d\u00e9tail divers groupes taxonomiques et \u00e9cologiques en lien avec des variables climatiques plus pr\u00e9cises. Par ailleurs, de nombreuses perspectives sont envisageables pour am\u00e9liorer la d\u00e9tection des Pythiac\u00e9es dans les sols forestiers, qui reste un challenge en \u00e9cologie microbienne.<\/p>\n

Mots cl\u00e9s: champignons, mycorhizes, Pythophthora,\u00a0Fagus sylvatica<\/em>, gradient, temperature, pH, pyros\u00e9quen\u00e7age<\/p>\n","protected":false},"excerpt":{"rendered":"

The defense will be held the\u00a03th october 2013\u00a0at\u00a09H30 in Amphitheater 7,\u00a0Facult\u00e9 des Sciences, Boulevard des Aiguillettes, Vandoeuvre   Diversity and composition of fungi and oomycete communities in beech forest in relation to climatic and edaphic variables: from the stand to … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-2550","post","type-post","status-publish","format-standard","hentry","category-seminarmeeting"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/2550","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2550"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/2550\/revisions"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2550"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2550"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}