Variation in Resistance of Camelina (Camelina sativa [L.] Crtz.) to Downy Mildew (Peronospora camelinae Gäum.)

Abstract

Camelina (Camelina sativa) is a potential oilseed crop for both food and non‐food utilization cultivated on a limited acreage in Europe and North America. An important low‐input feature of camelina is its high level of resistance 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 camelina which has been found repeatedly, whereas other diseases and pests have been observed only occasionally. Therefore, the genotypic variation of downy mildew incidence was evaluated in two camelina field experiments carried out within a breeding programme. In both experiments, totally resistant breeding lines were identified and a continuous pattern of variation in disease incidence was observed, suggesting a horizontal type of resistance. In bi‐parental populations, disease incidence of progeny appeared to be associated with disease scores of the parent genotypes, and transgressive segregation 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 yield was significantly affected by the disease, whereas other agronomic characters remained unaffected.