Inhaltszusammenfassung

Most species of Sebacinales (Basidiomycota) form symbiotic relationships with land plants including endophytic interactions and a broad range of mycorrhizae. Phylogenetic studies based on rDNA sequences of fungi associated with plant roots have revealed high genetic diversity in the Sebacinales. However, the identification, diversity and community structure of these mutualistic fungi are largely unknown. Using a combined analysis of DNA sequences and environmental factors, the following quest...Most species of Sebacinales (Basidiomycota) form symbiotic relationships with land plants including endophytic interactions and a broad range of mycorrhizae. Phylogenetic studies based on rDNA sequences of fungi associated with plant roots have revealed high genetic diversity in the Sebacinales. However, the identification, diversity and community structure of these mutualistic fungi are largely unknown. Using a combined analysis of DNA sequences and environmental factors, the following questions were addressed: (i) Which genetic factors drive intraspecific phylogenetic diversity in two model species, Sebacina epigaea and S. incrustans? (ii) Do environmental factors influence the structure of Sebacinales communities along an altitudinal gradient? (iii) Do the diversity and composition of endophytic Sebacinales change along a land use gradient in agricultural and grassland ecosystems? In summary, the main findings were: (i) Recombination and negative selection played a significant role in generating genetic diversity within the two morphospecies, Sebacina epigaea and S. incrustans. (ii) Land use, pH and humus content were important drivers of the diversity and structure of plant root-associated Sebacinales communities, whereas the type of plant community and elevation had no relevance in these study sites. (iii) Sebacinales communities in agricultural and grassland habitats were dominated by a single species, which is described here as Sebacina herbamans. In this study a large amount of cryptic diversity was discovered in the Sebacinales. This highlights the importance of genetic and environmental factors to the diversity and structure of mutualistic Sebacinales communities.» weiterlesen» einklappen

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DDC Sachgruppe:
Biowissenschaften, Biologie