Effect of different clonal lineages of Phytophthorainfestans and temperature on tuber disease development

Late blight caused by Phytophthora infestans is one of the most destructive diseases of potatoes and in the thesis study, it was aimed to determine the losses and damage of the tubers of potato varieties that are currently being marketed for cultivation purposes by farmers, in case of contamination of Phytophthora infestans (Mont.) de Bary genotypes which are still found in our country in the fields. For this purpose, seed tubers of cv. Agria, Lady Olympia, Madeleine, Marabel, Melody and Provento cultivars were inoculated with 13_A2, 37_A2 and 34_A1 genotypes of P. infestans and stored at 30C, 70C and 100C for 8 weeks. At the end of the storage; skin discoloration, disease severity at sprout of tuber, physical degradation on tuber surface, sporulation on tuber surface, and fresh cut tuber tissue deterioration were evaluated. According to the findings, although there was no negative change in any parameter related to the outer surface of the tuber at the end of the 30C storage, the inner tissue of the tuber was deteriorated. 37_A2 and 34_A1 genotypes may be more destructive than 13_A2 genotype nearly in all parameters measured at 70C and 100C storage conditions. As a result, the thesis study revealed that after the determination of the common pathogen genotype in the production areas of seed potatoes, the cultivation should be done by choosing the right variety and the tuber crop cannot be stored at temperatures higher than 30C.