Indirect Evidence Based on Mating-Type Ratios for the Role of Sexual Reproduction in European and Chinese Populations of (Blackleg of Oilseed Rape).

Blackleg (Phoma) disease, caused by the ascomycete fungi and , threatens oilseed rape (OSR; ) crops internationally. In many parts of the world, both species co-occur, but in China only has so far been reported. reproduces asexually (pycnidiospores), but also sexually (pseudothecia-yielding ascospores), via a heterothallic mating system requiring and genotypes.