Resistance To Powdery Mildew In Selected Czech Winter Barley Breeding Lines
Powdery mildew resistances in Czech winter barley breeding lines were postulated on the basis of their reaction types to 32 pathotypes of the pathogen with different combinations of virulence genes. The results from testing 38 lines represent a substantial part of found variability in the examined trait with 13 found resistances. The resistances typical of winter barley cultivars dominated in six-row lines whereas the resistances typical of spring barley cultivars were more frequent in two-row lines. None of these resistances was effective enough to all used pathotypes. Desired effectiveness is present neither in the lines with a combination of corresponding resistances nor in the cases when their resistance is controlled by more (up to six) postulated genes. Resistances “Ch” (detected in the line CH 669) and “Lu” (detected in the line LU 1258/A/02) are novel, the former without any practical importance. A need of breeding winter barley cultivars resistant to powdery mildew is discussed since they are required for both conventional and particularly low-input farming systems.