Detection of a PCR-based mating type for native intraspecific Beauveria bassiana isolates

This study developed a PCR-based mating-type analysis of 30 intraspecific Beauveria bassiana isolates after ITS phylogenetic analysis. Out of 30 isolates, only 11 B. bassiana isolates, viz., Bb4, Bb5, Bb11, Bb18, Bb19, Bb20, Bb23, Bb25, Bb27, Bb28, and Bb29, exhibited amplification of the mating-type loci and were thought to be heterothallic. All of these isolates, with the exception of Bb20, had MAT1 mating-type amplification. All these 11 isolates were clustered together with the MAT1- and MAT2-specific reference strains of B. bassiana in the maximum likelihood phylogenetic analysis of mating-type genes (IFO 31953 and IFO 31676, respectively). Although the PCR products obtained by the mating-type assay were short, the phylogenetic trees of the mating-type genes gave better resolution than that of the ITS region. Understanding the mating type of fungi can clarify the biological species concept and the identification of sex-related genes in fungi without the presence of teleomorphs. So, combining phylogenetic, developmental, and mating research on each teleomorph specimen has the potential to clarify the systematics of Beauveria species.