Charakterisierung der Resistenz von Winterweizensorten gegenüber Steinbrand (Tilletia caries)

Attack with common bunt (Tilletia caries) is a potential threat to wheat production in organic farming. The situation may even become worse if (in agreement with EUlegislation) only organically produced seed is used in organic farming. The targeted use of resistant varieties could be a way to alleviate the problem. However, knowledge regarding bunt resistance of wheat varieties on the one hand and aggressiveness in populations of the bunt pathogen on the other hand is still insufficient. In the frame of a federal research programme for organic farming (BÖL),30 winter wheat varieties and breeding lines were studied at five different locations using spores of local origin in order to assess the natural level of resistance (WÄCHTER et al. 2004). In addition, the different spore accessions were analysed with a set of differential varieties supplied by B. Goates (USDA-ARS, Aberdeen, ID). Since the impact of bunt is only obvious after ear appearance, utilization of early (leaf) symptoms (KOCH & SPIESS, 2002) and immunological detection of T. caries in planta with an enzyme-linked immunosorbent assay (ELISA) (EIBEL 2002) were evaluated as diagnostic tools to characterise the level of resistance.