Abstract
During 2008-2012, field tests of resistance to Mycosphaerella graminicola (Fuckel) J. Schröt. were conducted on a set of selected wheat varieties and related forms. Various M. graminicola isolates obtained from the Crop Research Institute in Prague were used for infection. Resistance of genotypes to three different isolates was tested in each year with the exception of 2009 and 2010, when identical isolates were used. A variant without artificial infection was used as control. Assorted varieties of winter and spring wheat, synthetic hexaploid wheat (SW), tritordeum (×Tritordeum Ascherson et Graebner), and one sample of haynaldoticum (×Haynaldoticum sardoum Meletti et Onnis) were tested. The aim was to select potential donors of resistance. The average infection rate for the set of spring wheat varieties over the 5 years was 6.7% (con-trol 0.5%), for tritordeum it was 0.3% (control 0.1%), for SW it was 0.7% (control 0.1%), and for haynaldoticum it was 1.7% (control 0.2%). The infection of winter wheat was 18.6% (control 3.8%). High average resistance was found in tritordeum, haynaldoticum, and some forms of SW. Lower resistance was found in conventional wheat varieties. The results were influenced by the degree of isolate virulence, growing season, and developmental stages of plants at the time of inoculation.