Physiological Basis for Differences in Resistance to Microdochium nivale (Fr.) Samuels and Hallett in Two Androgenic Genotypes of Festulolium Derived from Tetraploid F1 Hybrids of Festuca pratensis × Lolium multiflorum (Festulolium)

The aim of this study was to investigate the physiological basis for differences in resistance to pink snow mould (Microdochium nivale) in two androgenic genotypes of Festulolium (Festuca pratensis · Lolium multiflorum) which differed in terms of their resistance to M. nivale. Genotype 716 was more resistant than genotype 729. The study consisted of two experiments. The aim of the first experiment was to estimate the ability of the plants to survive winter conditions. The aim of the second experiment was to find physiological markers of resistance to snow mould. Festulolium plants were infected with M. nivale mycelium after pre-hardening and hardening. After 2 weeks in the dark at 2 C, there was a sharp increase in the phenolic content in both genotypes. The increase was greater in the more resistant genotype 716 than in genotype 729. Phenolics therefore may play a very important role in overwintering in grasses, similar to carbohydrates. Based on the differences between the two genotypes, potential indicators of resistance to M. nivale in Festulolium include increased soluble carbohydrate content, increased phenolic content, increased hydrogen peroxide accumulation, decreased catalase activity, increased abscisic acid content and reduced heat emission