Cold acclimation of forage grasses in relation to pink snow mould (Microdochium nivale) resistance

Abstract

The aim of our work is to investigate the changes in phenolic level, PAL activity and heat production rate induced during pre-hardening at 12°C and cold acclimation at 2°C of the forage grasses Festulolium, meadow fescue, tall fescue and Italian ryegrass in relation to their resistance to snow mould caused by Microdochium nivale. Meadow fescue and tall fescue were most resistant to M. nivale infection, while Italian ryegrass demonstrated the least resistance to this fungus inoculation. Festulolium, meadow fescue and tall fescue responded similarly to low temperature, while Italian ryegrass demonstrated considerable disturbance of energy balance and lower phenolic concentration, which could explain a higher susceptibility of the latter species to infection by M. nivale. The enhanced level of phenolic compounds, probably utilised for cell wall lignification as well as equilibrium of the metabolic activity observed in meadow fescue and tall fescue, is very important for both cold and pathogen-resistance mechanisms. The studied Festulolium cultivar ‘Felopa’, a hybrid of the Loliummultiflorum and Festucapratensis genomes, was characterised by changes in biochemical parameters similar to the resistant meadow fescue and tall fescue.