Diversity of Backusella (Mucoromycotina) in south-eastern Australia revealed through polyphasic taxonomy

Here we explore the diversity of one morphologically distinguishable genus in the Mucoromycotina, Backusella, in south-eastern Australia. We isolated more than 200 strains from locations across the states of Victoria and Tasmania. Characterization of these strains using a combination of approaches including morphology, sucrose utilization and whole genome sequencing for 13 strains, revealed 10 new species. The genetic basis for interspecies variation in sucrose utilization was found to be the presence of a gene encoding an invertase enzyme. The genus Backusella is revised and a new key for species identification produced. Given that we have more than doubled the number of species in this genus, this work demonstrates that there may be considerable undiscovered species diversity in the early diverging fungal lineages.