Differential interactions of Phytophthora capsici isolates with perper genotypes and characterization of resistance resources

ABSTRACTPhD THESISDIFFERENTIAL INTERACTIONS OF Phytophthora capsici ISOLATESWITH PEPPER GENOTYPES AND CHARACTERIZATION OFRESISTANCE RESOURCESMünevver GÖÇMENDEPARTMENT OF HORTICULTURE INSTITUTE OF NATURAL ANDAPPLIED SCIENCES UNIVERSITY OF ÇUKUROVASupervisor : Prof. Dr. Kazım ABAKYear : 2006, Pages:159Jury : Prof.Dr. Kazım ABAKProf. Dr. Salih MADENProf. Dr. Kemal KOÇProf. Dr. Nebahat SARIProf.Dr. Saadet BÜYÜKALACAThis study encompasses an investigation of inheritance of resistance against P.capsici Leon on pepper. The study was carried out at four major steps. The first stepwas to test 35 different pepper genotypes obtained domestically or brought fromabroad with nine P. capsici isolates, eight of which originating from Turkey and onefrom USA in order to study genotype x isolate interactions. Our findings revealed theexistence of physiological races of P. capsici in Turkey. The second step was todevelop transgressive segregants for enhanced resistance against P. capsici by crossbreeding out of a population. The resulting four resistant genotypes identified in thefirst part of the study were intercrossed and transgressive segregants with enhancedresistance were selected and selfed, giving rise to resistant lines useful for cropimprovement. The third step was to investigate the heritability of resistance of thepartially resistant domestic genotype KM2-11 which was tested with three isolateswith varying virulence levels. It was shown that heritability values changeddepending on the isolates and the developmental stages of the disease isolates. Thefourth and the last step was to investigate the phylogenetic relationship of peppergenotypes, both resistant and susceptible ones, via molecular techniques (SSR andSRAP). It was shown that resistant genotypes were genetically diverse and that thepartially resistant KM2-11 genotype was genetically close to the susceptible?KMAE-12? genotype.KeyWords: Capsicum annuum L., resistance, host-pathogen interaction, heritability,phylogenetic relationship.PDF created with pdfFactory trial version www.pdffactory.com