Microorganisms and global climate change

Today, a global climate change is speeding up (Intergovernmental Panel on Climate Change - IPCC, Switzerland) that limits leaving organisms' adaptation to the environment. As a result, the distribution of phytopathogenic fungi may obviously change. Particularly, in 1985 a new disease of wheat yellow leaf spot appeared in the European south of Russia (Krasnodar Region) (E.F. Granina et al., 1989). In 2005-2007 the causal agent of yellow leaf spot Pyrenophora tritici-repentis was found on wheat in North-Western Region of Russia. On some cultivars the disease severity reached 70 %, and pathogens become more virulent and viable. Despite the North Caucasus and the Far East were specific areas for Fusarium graminearum in Russia, since 2003 F. graminearum appeared on the territory of the Russian North-West. The average disease severity on cereals was 93.3 % in 2007 and 87.3 % in 2008. Recently F. graminearum predominates on cereals in the Netherlands (J. Arts et al., 2003), GB (P. Jennings et al., 2004), North Germany (T. Miedaner et al., 2008) and Finland (T. Yli-Mattila et al., 2010). In the south of Russia, Septoria tritici predominates among species causing wheat glum blotch, and in the North-West it is Stagonospora nodorum. In 2003-2005, S. tritici became the main wheat pathogen in the North-Western Russia. On susceptible spring wheat cultivars the disease was found in 51 to 100 % plants, with a severity of 8 to 30 %. These observations suggest that global warming of climate leads to an expansion of thermophilic fungi species, and pathogens begin to spread from the south to the north. Pythium, Rhizoctonia, Sclerotinia soil fungi are influenced by climatic factors. They form the overwintering structures that protect them from external influences. Increasing the temperature can lead to a decrease of the latent period and to increase of pathogens aggressiveness. Temperature can influence the function of the parasites virulence genes and resistance genes in plants. Thus, it is necessary to control the emergence of new plant diseases, improve protective measures, and develop cultivars with high adaptability.