Analysis of populations of Pyrenophora  teres on barley in the Czech Republic

Abstract

One of t he diseases that have become i mportant in the Czech Republ ic recently is net blotch of ba rley caused by Pyrenophora teres (Died.) Drechs., with the imperfect stale Drechslera teres. In 1 995-1997 infected leaves of both spring and winter barley were collected in various stands and climatic regions. Al most 400 isolates of the pathogen were obtained and tested for virulence using a differential set (Cl 5791. CI 2750, CI 9819, C 8755, Stcudclli, Harbin, C 29192, CI 739, Tifang. and the suscepti ble control Beate). To assess their reaction, the laboratory method for testing leaf segments on benzimidazole was used. The most stable resistant responses, compared also with previous tests from 1991-1994, were found in Cl 739 and Tifang where the frequency of viru lent isolates did not exceed I 0% of all tested ones. These genotypes should be involved in practical breeding of barley for resistance to the pathogen.