The composition and taxonomic significance of fatty acid patterns in three white rust species: <Emphasis Type="Italic">Albugo amaranthi,A. candida and A. tragopogonis</Emphasis> (Peronosporales,Albuginaceae)

The fatty acid composition of the biotrophic white rust species A. amaranthi, A. candida and A. tragopogonis was identified by means of GC and GC/MS analysis. Besides the common saturated fatty acids of C14 to C22 chain length, several unusual monounsaturated and polyunsaturated fatty acids were present in significant amounts in the lipid profiles of the three species. Each taxon revealed its own characteristic pattern which was uniform among populations of different geographic origin and independent from the host species. Fatty acids were obtained from minute amounts of sporangia collected from the surface of desiccated host plants. Comparison of herbarium specimens revealed a decrease of polyunsaturated compounds after storage for 30 months at room temperature, but still allowed unquestionable species differentiation.