Resistance to Alternaria brassicae and phytoalexin-elicitation in rapeseed and other crucifers

An accession of Brassica campestris ssp. rapifera was less susceptible to Alternaria brassicae than B. campestris ssp. oleifera and B. napus ssp. oleifera. Accessions of Camelina sativa and Capsella bursa-pastoris were very resistant to A. brassicae, showing no symptoms. Production of phytoalexins of different types and amounts was found in all the above mentioned crucifers in response to A. brassicae. The differences in the susceptibility of these plants may be due, in part, to qualitative and/or quantitative differences in phytoalexin production. This appears to be the first report of elicitation of phytoalexins in crucifers upon being challenged by a fungal pathogen.