Characterization of the mating-type locus (MAT) reveals a heterothallic mating system in Knightiella splachnirima

In the present study, we characterized the mating-type locus of Knightiella splachnirima (Icmadophilaceae) using degenerate and inverse PCR techniques. We screened for the presence of both mating-type locus idiomorphs in DNA extracts of minuscule samples of haploid thalline tissue. We found that only one of the two idiomorphs was present in each sample, and the mating-type ratio (MAT1-1:MAT1-2) was very balanced, being 8:10 and 13:14 at local and global scales, respectively. This indicates that the species is probably self-incompatible and requires the presence of compatible mating partners for sexual reproduction (heterothallic mating system). Furthermore, we provide a mating-type screening protocol with K. splachnirima specific mating-type locus primers, which could serve as an essential tool for the conservation management of this rare Australasian endemic.