Investigating the emerging threat to oilseed rape posed by the newly identified phoma stem canker pathogen subclade

This project aims to investigate the threat posed by the new Lbc subclade to OSR. Firstly, the pathogenicity of the newly identified Lbc isolates will be compared with (1) with that of Lbc isolates from Canada and Australia and (2) of the existing UK and European Lbb isolates on different OSR cultivars. Lm isolates will be included as controls. The pathogenicity tests will be done by cotyledon inoculation.
Secondly, effects of temperature on disease severity caused by Lm, Lbb and Lbc isolates will be investigate. Previous results showed that temperature affected host resistance against Lm. However, there is no information about effects of temperature on resistance against Lb (Lbb, Lbc). Plants will be inoculated using existing methods. The severity of leaf lesions will be assessed using image-based methods and the growth of the pathogen in the leaves will be assessed by qPCR. In addition, the student will visit field experiments to learn how to recognize phoma stem canker symptoms and how to assess the severity of phoma stem canker and other oilseed rape diseases, such as light leaf spot.