Summary:

Qualification of Phytophthora by Zentmayer as the destructive factor for plants indicates on that group of pathogens as very dangerous. Results obtained from previous studies showed on Phytophthora species as the threat of all group of plants growing in open field, under covering and natural ecosystem. Phytophthora spp. were detected in all analyzed water sources such as water reservoirs and canals localized in nurseries and in rivers flowing through horticulture, agriculture and forest areas. Results of the studies indicate on P. plurivora, P. cambivora, P. cinnamomi, P. citrophthora, P. cryptogea, P. lacustris and P. megasperma as the dominant species in Polish watercourses and reservoirs. Obtained results confirmed the pathogenicity of Phytophthora isolates received from different water sources