Genotypic and Phenotypic Variation among Pepper Accessions Resistant to Phytophthora capsici

Developing high levels of resistance to Phytophthora blight (Phytophthora capsici Leonian) of pepper (Capsicum annuum L.) is a goal of many pepper breeding programs. Genetic diversity and plant characteristics were evaluated on 21 pepper accessions previously identified as having high levels of Phytophthora root rot resistance. Accessions were evaluated for plant height, fruit size and shape, pericarp thickness, and pungency. Accessions varied widely from very unadapted material to those with more obvious breeding potential. Genetic diversity among the accessions was estimated using 22 simple sequence repeat (SSR) loci. Phytophthora capsici resistant accessions were identified that were not closely related to previously described sources of resistance. This information will allow breeders and researchers to further identify and incorporate novel sources of resistance to P. capsici into breeding programs. Accessions PI 201237 and PI 640532 appear to have the most potential for introgressing P. capcisi resistance into bell pepper.