Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 14, 2004
Publication Date: December 14, 2004
Citation: Journal of Phytopathology 153:108-119 (2005)
Interpretive Summary: Diseases caused by snow moulds and other fungi cause serious winter injury to winter cereals and to turf grass. The effects of two different chemical treatments that might increase plant survival were studied in rye grass, and one chemical treatment was tried in winter wheat infected with snow mold and kept under simulated snow cover for several weeks. Neither treatment improved rye grass survival of snow mold infection and one of the treatments actually reduced survival. Treatment of winter wheat was slightly improved by the chemical treatment. These results are of interest to growers of winter cereals, and to golf course managers in northern temperature climates, where snow molds are common.
The effects of chitosan on resistance to pink snow mould (Microdochium nivale) were studied in young winter wheat (Triticum aestivum L. cultivar Folke) and perennial ryegrass (Lolium perenne L. cultivars Viris, Riikka and Norlea) under controlled environmental conditions. In perennial ryegrass, the putative defence activator Bion was also tested. Resistance was measured as regrowth of plants after inoculation with M. nivale and incubation in darkness at low temperature. In winter wheat, pre-treatment with chitosan at some concentrations increased resistance to subsequent infection by M. nivale. Chitosan-treated winter wheat plants expressed the gene for the PR-protein chitinase at higher levels than non-treated plants. Chitinase gene expression was also stimulated by M. nivale-infection in winter wheat. Perennial ryegrass pre-treated with Bion or chitosan and inoculated with M. nivale did not display better regrowth after incubation than non-treated, inoculated plants. Rather, regrowth was reduced in some of the Bion-treated plants after incubation. Bion and, to a lesser extent, chitosan reduced in vitro growth of the pathogen, suggesting that antifungal activity of both defence activators might play a role in the effect against pink snow mould.