QTL Mapping of Tomato Powdery Mildew (Oidium neolycopersici L. Kiss) Resistance

Current study was designed to fine map the Ol-qtl1 area by evaluation of F2, BC2 and BC2S1 progenies, obtained by hybridizing the susceptible L. esculentum cv Money Maker with the resistant L. parviflorum G1.1601, for segregation of resistance to Oidium lycopersici. Two flanking markers, ct21 and ct184 were used to screen recombinant plants. To monitor the targeted area effectively, 24 out of 54 new designed primers have been identified as SCAR and CAPS markers. The results confirmed the presence of resistant controlling area flanked by ct21 and ct184. Resistant homozygote individuals were resistant, with average 0.5 disease index (DI) value, heterozygote plants had intermediate responses and susceptible homozygote individuals showed susceptible performance. Results of recombinant screening showed that the targeted area is located in the upstream of tg25. Based on the results of this research, targeted area was narrowed down to a region of approximately 15 cM. Newly developed SCAR and CAPS markers can be used in marker assisted selection based breeding programs.