Black root rot on lupins -: an early species-specific detection of the pathogen Thielaviopsis basicola

Black root-rot, caused by the soil-borne pathogen Thielaviopsis basicola leads to potential problems with a wide range of crops including grain legumes. During the 2007 growing season this pathogen was isolated from naturally infected narrow-leafed lupines (Lupinus angustifolius) in several areas. A first screening of disease resistance performed with a collection of L. angustifolius cultivars indicated a range from highly susceptible to moderate tolerant. In order to accelerate the screening procedure and to improve the identification of field samples a nested PCR-based detection was developed based on pathogen specific primers derived from the internal transcribed spacer regions (ITS) of T. basicola. Tests conducted on a wide range of potential lupin pathogens showed a high T. basicola specificity without any cross-reactions on other fungal pathogens. In more than 80% of the analysed field samples T. basicola-DNA was detected. For further resistance screenings the presented diagnostic test will contribute to an early and specific identification of T. basicola in plants.