Contribution to identify the causal gents of Dutch elm disease in the Czech Republic

This study provides new data on Dutch elm disease in the Czech Republic. Ophiostoma novo-ulmi is reported for the first time in the area of the Czech Republic, as well as both subspecies ssp. novo-ulmi (indigenous in the area of the Ukraine and Moldavia), and ssp. Americana indigenous in North America. The majority of the recorded strains belonged to O. n.-u. ssp. novo-ulmi, while O. n.-u. ssp. Americana and hybrids of these two subspecies were found less frequently. On the other hand, Ophiostoma ulmi was not found at all in the investigated samples. Identification on the subspecies level was performed by methods of molecular biology, i.e. PCR and RFLP of gene regions cu and col1.