Data from: The cacao pathogen Moniliophthora roreri (Marasmiaceae) possesses biallelic A and B mating loci but reproduces clonally

The cacao pathogen Moniliophthora roreri belongs to the mushroom-forming family Marasmiaceae but it has never been observed to produce such fruiting body, which questions its sexual reproduction capability. To address this, we identified potential A (HD1 and HD2) and B (pheromone precursors and pheromone receptors) mating genes in two available genomes of M. roreri. A PCR-based method was devised to determine the mating type for a set of 47 isolates from across its geographic range, followed by an eleven-marker microsatellite analysis to find hints of sexual reproduction through association and linkage disequilibrium (standardized index of association, IAs) analyses. We also performed an ancestral reconstruction analysis to show the ancestor of M. roreri is heterothallic tetrapolar, which together with sliding window analyses support A and B mating loci are likely unlinked and follow a tetrapolar organization within the genome. The A locus is composed of a pair of HD1 and HD2 genes, whereas the B locus of a pair of a pheromone precursor, Mr_Ph4, and a receptor, STE3_Mr4. Two A and B alleles but only two mating types were identified. Association analyses divided isolates into two well-defined genetically distinct groups that correlates with their mating type; IAs values show high linkage disequilibrium as true for clonal reproduction. Interestingly, both mating types were found in South American isolates but only one mating type was found in Central American isolates, supporting a prior hypothesis of clonal dissemination throughout Central America after a single or very few introductions of the fungus from South America.