XVI International Botanical Congess

Ant species in the Neotropical tribe Attini are dependent on fungi for food, which they propagate in their nests and transmit from mother to daughter colonies as vegetative clones. These observations underly hypotheses that fungus gardening had a single origin, that ant and fungal lineages have co-diverged, and that fungal cultivars are ancient asexual lineages. I will present phylogenetic analyses, population genetic data and other evidence that test each of these assumptions. Additionally, I will present results of a community survey of fungal cultivars of leafcutter ants demonstrating that 1) local cultivar populations are comprised of relatively few genets, 2) individual leafcutter species cultivate multiple cultivar genotypes that are also cultivated by other leafcutter species, and 3) somatic incompatibility between cultivar genotypes indicates that leafcutter fungi are recombining.