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The current application is a follow up of the ESF grant 4734 Occurrence of avirulence genes, fungicide resistance and mating types in estonian population of Phytophthora infestans (2001-2004). There are raised needs for more detailed studies on characterization of populations of P. infestans, epidemiology of potato late blight and description of resistance of cultivated potato varieties. The aims of studies are obtaining of new theoretical information on establishment and evolution of local populations of P. infestans and improvement of late blight forecasting and control. Genotypic characterisation of late blight isolates (isozymes, genetic fingerprinting, mtDNA haplotypes) enables more exact and reliable detection of diversities between isolates and populations than that is possible by means of phenotypic characters.Prolongation of existing time series in phenotypic characters (avirulence genes, mating types, metalaxyl resistance) and studies of additional characters (aggressiveness and its subcomponents) provide information about existing pathogen population structure and help us to predict its ongoing evolution. Populations of P. infestans should be handled in smaller as well in bigger scale than that is Estonian population. Characterization of isolates from regions differing in potato cultivation practises (organic production, intensive fungicide use, different varieties etc.) provides information for understanding of influences of fungicides and varieties on characteristics of local populations of P. infestans. Adding Estonian data about characters of P. infestans isolates into the databases of EU 5th Framework project EUCABLIGHT will provide additional information to determine the mechanisms of genetic change within populations as well as determination of spatial distribution and patterns of migration in European metapopulation.Detailed characterization of resistance of potato varieties cultivated in Estonia (resistance genes, length of the latent period, lesion growth rate, production of conides and oospores) is important by means of better understanding of late blight epidemiology and implementation of integrated control measures. |