Investigation of resistance mechanism and hereditary against Pseudoperonospora cubensis in some cucumber genotypes

Downy mildew (DM) pathogen Pseudoperonospora cubensis is causing high yield loss in cucumber crop, both in greenhouses and open fields. Because of that, it's important to gain resistance in cucumbers against P. cubensis. In this study, Beith Alpha type DM susceptible parent 31259 and resistant parent A064949 originated from Pakistan and F1 plants, F2, one backcross with susceptible parent and backcross with resistant parent populations are created and being tried to help breeding studies by developing in vitro DM test. Achieved observation data analysed by statistically and correlations were evaluated between the characters phenotyped. Beside, pathologic characters, some agronomic characters were observed. The DNAs isolated from the F2 population, genotyped by using 90 SNP markers. The linkage between the mapped QTLs and susceptible/resistance known genes or QTLs were investigated. According to this research results, it was seen that there is no correlation between in vivo and in vitro DM tests (0.2