Variation in resistance of camelina (Camelina sativa [L.] crtz.) to downy mildew (Peronospora camelinae Gaum.)

Camelina (Camelina sativa) is a potential oilseed crop for both food and no n-food utilization cultivated on a limited acreage in Europe and North Amer ica. An important low-input feature of camelina. is its high level of resis tance against plant diseases, which may partly be due to the production of antimicrobially efficient phytoalexins. In Central European countries such as Austria, downy mildew (Peronospora camelinae) is the only disease of cam elina which has been found repeatedly, whereas other diseases and pests hav e been observed only occasionally. Therefore, the genotypic variation of do wny mildew incidence was evaluated in two camelina field experiments carrie d out within a breeding programme. In both experiments, totally resistant b reeding lines were identified and a continuous pattern of variation in dise ase incidence was observed, suggesting a horizontal type of resistance. In bi-parental populations, disease incidence of progeny appeared to be associ ated with disease scores of the parent genotypes, and transgressive segrega tion in disease incidence was also found. In 1998, the rate of downy mildew in camelina was lower than in 1999; in the latter growing season, grain yi eld was significantly affected by the disease, whereas other agronomic char acters remained unaffected.