Severe outbreaks of Phytophthora infestans on potato in Turkey caused by recent changes in the pathogen population structure

Cooke, David/0000-0002-9154-7954WOS: 000509100200009Potato late blight, caused by Phytophthora infestans, has been the most damaging disease in Turkey since 2010. In this study, 127 isolates of P. infestans were obtained from the main growing areas of Turkey between 2015 and 2017. Their phenotypic and genotypic features were revealed and presented with those of reference isolates. These isolates were categorized by their mating type, in vitro mefenoxam sensitivity, mtDNA haplotype, RG57 DNA fingerprinting patterns, simple sequence repeat (SSR) markers, and aggressiveness on a set of potato differential lines. All isolates were of the A2 mating type and mtDNA haplotype Ia, were resistant to mefenoxam, and had RG57 and SSR fingerprints similar to the 13_A2 clonal lineage reported in Europe. This is the first report of 13_A2 in Turkey. Virulence abilities against potato resistance (R) genes R1, R2, R3, R4, R6, R7, R10, and R11 were observed in most of the isolates. The mating type ratios and SSR marker analysis indicate that in Turkey, the sexual reproduction of P. infestans is limited. These results underline that the movement of asexual individuals and the generation of sub-clonal difference are the factors driving the population structure of P. infestans in Turkey.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [116O329]This research was supported by TUBITAK (grant 116O329)