Population genetic structure of Microdochium majus and Microdochium nivale associated with foot rot of cereals in the Czech Republic and adaptation to penthiopyrad

Microdochium nivale and Microdochium majus cause brown foot rot and snow mould in cereals. The aim of the present study was to evaluate the population genetic structure of Microdochium spp. associated with foot rot of wheat in the Czech Republic and the reaction of that population to the succinate dehydrogenase inhibitor (SDHI) fungicide penthiopyrad. Using amplified fragment length polymorphism (AFLP) analysis to examine genetic structure, agar dilution to measure inhibitory effect, and various statistical methods to analyse populations, two genetic populations were found corresponding to the species Microdochium majus and M. nivale and restricted gene flow in populations between years was determined. This study demonstrates for the first time the occurrence of SDHI-insensitive reaction in populations of M. nivale and M. majus. Low sensitivity was identified in both species, but it was observed more frequently in M. majus populations.