Resistance of winter wheat cultivars to eyespot and characterisation of causal agents of the disease

The reaction of ten winter wheat cultivars grown in the Czech Republic to inoculation with Oculimacula yallundae and Oculimacula acuformis was evaluated in a small plot trial. In a parallel field trial the natural occurrence of stem-base disease complex in six of the tested cultivars was assessed. Lower severity of eyespot (and/or stem-base diseases) was observed in cultivars possessing the resistance gene Pch1 (cvs Hermann, Annie, Princeps, Manager, and Rebell) in plots inoculated with Oculimacula spp. as well as in natural field conditions. A total of 468 wheat stem bases from the Czech Republic was screened by PCR to study the frequency of eyespot causal agents. The plants were colonised significantly more often by both species Oculimacula yallundae and O. acuformis together than separately.