Mating type characterization of Fusarium culmorum strains causing wheat crown rot in Iraq

Fusarium crown rot (CR) of wheat is one of the most important diseases known from regions of the world where cereal crops are produced. In this study, we examined the mating types of F. culmorum CR strains isolated across Iraq, including more arid regions within the country. The result showed two mating compatibility (MAT) type idiomorphs of F. culmorum are present in Iraq, with 27.6% of the isolates examined representing the MAT-1 type and 72.4% representing the MAT-2 type. The MAT-1 type was commonly found among isolates from the mid-latitudes of Iraq, this being a warmer and drier region as compared to the country's northern region; however, it was also detected from one isolate from a northern site. The MAT-2 type, however, was more broadly distributed across Iraq and was also detected among many isolates from the mid-latitude region. Thus specific biogeographic patterns were not apparent for mating compatibility idiomorphs. The mating types characterized here were also compared to chemotypes known for these same isolates and characterized in a previous study. This comparison revealed the MAT-1 type was found only among DON chemotype isolates, while the MAT-2 type was found among both DON and NIV chemotype isolates. Thus, there does not appear to be a direct correspondence between chemotype and mating compatibility idiomorphs within Iraq. Overall, a broader sampling across the country with more isolates being examined at each site is advised.