Snow mould resistance under controlled conditions and winter survival in the field in populations of perennial ryegrass, meadow fescue, andFestuloliumare partly dependent on ploidy level and degree of northern adaptation

Abstract

Pink snow mould caused by Microdochium nivale is a serious cereal and grass disease in several temperate regions. In this study, resistance to snow mould was evaluated under controlled conditions in nine promising breeding populations and two cultivars of Festulolium, three cultivars of Festuca pratensis, six cultivars and two breeding populations of Lolium perenne and one cultivar of hybrid ryegrass using non-hardened plants. In addition, winter survival was evaluated in field plots inoculated with M. nivale. Under controlled conditions, tetraploid entries of Festulolium had a significantly better resistance to snow mould than diploid entries in three out of four tests. Diploid and tetraploid entries of L. perenne showed similar levels of resistance under controlled conditions. In the field trial, entries of both L. perenne and Festulolium that had been exposed to natural selection in northern Norway (above 65°N) showed good levels of winter survival. In general, under controlled conditions snow mould resistance of Festulolium entries was associated with ploidy level, whereas under field conditions winter survival of L. perenne entries was associated with their degree of northern adaptation. However, resistance to snow mould in non-hardened plants tested under controlled conditions was not correlated with winter survival in the field.

Perennial Ryegrass Yield Performance under Abiotic Stress

“…Although the temperatures were critical or close to critical (-10°C or lower), the plants were covered with snow (3-5 cm) during these periods, and therefore the damages after winter were minimal: 1.09 to 1.12 score after first and 2.90 to 3.19 score after second winter (Table 1). Some researchers show that tetraploid ryegrasses are less resistant to freezing temperatures, to the point that there was no overlap in cold resistance trait between genotypes of different ploidy level (Sugiyama, 1998), while others state that adaptation of cultivars to local environments, rather than their ploidy level, determines winter survival under field conditions (Abdelhalim et al, 2016). Numerous studies focus on genetic factors behind perennial ryegrass freezing tolerance as a key component in successful overwintering (Aleliūnas et al, 2015;Yu et al, 2015;Paina et al, 2016), yet most of them were conducted using only diploid genotypes, whereas the data on differences in resistance between diploid and tetraploid plants have been relatively scarce.…”

How can forage production in Nordic and Mediterranean Europe adapt to the challenges and opportunities arising from climate change?

“…For timothy, the priorities would likely be to improve tolerance to harvesting and grazing, better regrowth capacity and spring growth. Perennial ryegrass needs better winter survival, particularly improved timing of growth cessation and cold acclimation, as well as resistance to psycrophilic pathogenic fungi (Abdelhalim et al, 2016), while for tall fescue, work is ongoing to combine the high yield and drought tolerance with an acceptable digestibility and animal preference (Humphreys et al, 2012;Helgadóttir et al, 2014;Cougnon et al, 2015;Fariaszewska et al, 2016).…”

Local and systemic regulation of PSII efficiency in triticale infected by the hemibiotrophic pathogen Microdochium nivale

“…Physical barriers, i.e. the hydrophobic cuticle on the leaf surface or lignin in the cell wall (Szechyńska‐Hebda et al , Abdelhalim et al ), result in leaf tissue resistance to the mechanical and enzymatic forces of fungal hyphae and can thus define fungal behaviour (Szechyńska‐Hebda et al , ). These mechanisms can discriminate between the resistance and susceptibility of a plant infected with a weakly pathogenic fungus.…”