Susceptibility of germinating seedlings of European and Eurasian populations of to damping-off caused by .

The effect of inoculation with on survival of seed and seedlings of 19 populations of was examined under environmentally controlled conditions, with four treatments (0, 50, 10, 10 spores ml). A single seed source of was included as a positive control. Germination (emergence of the plumule above the compost) and health of seedlings was assessed daily, for 85 days. Spore density had a significant effect on germination: at 50 spores ml, only germination of a Northeast Scotland population was reduced. Treatment with 1000 spores ml, however, reduced germination of six populations of and of Survival of emerged seedlings also varied with inoculum dose. Approximately 75% of seedlings survived 85 days after germination after inoculation with 50 spores ml. Seedlings of all populations were killed within 12-16 days of germination by the 10 and 10 spores ml treatments. Emerged seedlings of the Austrian populations showed the highest susceptibility to following treatment with 50 spores ml, although 15% of seedlings of one Austrian population (AU3) survived to the end of the experiment (85 days after germination). There was no clear pattern in survival rates of the seedlings from other populations treated with 1000 or 1 million spores ml due to death of all emerged seedlings within a short period. Variations in susceptibility of different populations of to may be used in future selection and breeding programmes to reduce the impact of the pathogen as it spreads over wider areas in Europe and Eurasia.