Geographic distribution of mating type and female fertile isolates inrnMagnaporthe grisea of China

摘要

@@Population studies of Magnaporthe grisea have brought new insight on old controversies. This species include pathogens of rice, causing the rice blast, and of other grass hosts. It has been demonstrated that isolates collected from rice are pathogenic to rice and to a limited number of grass hosts. The genetic structure of the M. Grisea populations showed that a sexual reproduction was predominant in most rice growing areas. Being a hermaphroditic heterothallic ascomycete, sexual reproduction of M. Grisea required isolates of both mating types. Moreover, it also required the existence of female fertile isolates. Thus, the first step to find sexual reproduction in the field was to look for the presence of strains of both mating types and of female fertile ones. Female fertile isolates collected from rice was very rare. Thus, further investigation was made for testing the hypothesis of sexual reproduction by population genetics studies.