Screening of oxylipins for control of oilseed rape (Brassica napus) fungal pathogens.
Oxylipins are products of oxygenase-catalyzed reactions of fatty acids. Oxylipins have been found or implied to participate in a variety of different functions in or between organisms. In this report we investigated the potential of various naturally occurring oxylipins found in plants for their effects as fungicides on a number of fungal pathogens interfering with Brassica cultivation. The fungi investigated were Alternaria brassicae, Leptosphaeria maculans, Sclerotinia sclerotiorum and Verticillium longisporum. An in vitro growth inhibition assay was used, where the relative growth rate of the fungi were determined in the presence of various concentrations of oxylipins. While no universal fungicidic effect was found for the 10 compounds investigated there were examples of oxylipins having inhibitory effects. In certain cases the inhibitory effects was overcome by time, however. Since several of the oxylipins tested were found to be stable in the absence of the fungus this effect could be explained by induction of the degrading capacity of the fungus or increased tolerance. Several of the oxylipins also inhibited germination of L. maculans spores but the relative potency differed compared to the effects on hyphae. The study suggests that selected oxylipins may be used for disease control on Brassica plants.
Granér
Georg
G
Department of Plant Biology, Genetics Center, POBox 7080, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
Hamberg
Mats
M
Meijer
Johan
J
D029688:Brassica napus / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D010935:Plant Diseases / Q000382:microbiology; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors
D005231:Fatty Acids, Unsaturated