Sanders, Ian R.*. The dogma of asexuality in symbiotic arbuscular mycorrhizal fungi. In: International Meeting on "Population and Evolutionary Biology of Fungal Symbionts", Ascona, Switzerland, 2007. AB-16.

Given the importance of arbuscular mycorrhizal (AM) fungi for the growth and ecology of plants, we know remarkably little about their basic genetics and genome organization. Furthermore, AM fungi form the phylum Glomeromycota that diverged from other fungi a long time ago (400-1000 million years ago), allowing many possibilities for the evolution of a different genome organization and different mating system to that seen in other fungi. AMF are thought to be entirely asexual and not exchange DNA with other AMF individuals but remarkably this is backed up by little or no real experimental data. Our recent studies on genome organization in AM fungi, coupled with studies of AM fungal population genetics, vegetative compatibility / incompatibility and genetic exchange provide us with a completely different picture of the genetics of AM fungi. I will present how a population genetic approach can help us to understand genetic exchange processes among genetically different AMF individuals and how our recent findings on genetic exchange among AMF, and its consequences on the AMF phenotype, lays a foundation for experimentally studying AM fungal genetics. Finally, I will address whether genetic exchange among AM fungi has any consequences for the fitness of plants that form symbioses with these important fungi.

Keywords: genetic exchange, symbiosis, AMF

*Institution: University of Lausanne
Email: ian.sanders@unil.ch