DIFFERENT ASSESSMENT TECHNIQUES OF LEAF BLOTCH (RHYNCHOSPORIUM-SECALIS (OUD) DAVIS,J.) IN WINTER BARLEY AFTER ARTIFICIAL INOCULATION

Seven winter barley cultivars expressing different field resistance ag ainst leaf blotch (Rhynchosporium secalis) and 60 doubled haploid (DH) lines descending from an F-1 hybrid resistant x susceptible were used to develop a test for the quantitative determination of disease sever ity. Differences in the level of resistance could be measured very pre cisely after artificial infection of seedlings at the 4-leaf-stage and a subsequent incubation at 7 degrees C. The protein of six isolates w as used for antiserum production which was subsequently supplied for s erological testing (Enzyme-Linked-Immunosorbent-Assay) of infected lea ves. The results of visible scoring of the seedlings was significantly correlated with measuring with the ELISA reader. The results of the s eedling test also corresponded to field scores after natural infection .