CaDMR1 Cosegregates with QTL Pc5.1 for Resistance to Phytophthora capsici in Pepper (Capsicum annuum)

Abstract

A major problem for the pepper () industry is the root rot disease caused by (), to which all commercial varieties suffer yield losses despite good management practices and available landraces with high levels of resistance. A high-density map with 3887 markers was generated in a set of recombinant inbred lines (RIL) derived from the highly resistant accession Criollo de Morelos-334 and Early Jalapeño. These lines have been systematically screened for resistance against a set of isolates collected from Mexico, New Mexico, New Jersey, California, Michigan and Tennessee. Quantitative trait loci (QTL) associated with effective resistance across isolates have been identified and validated with SNP markers across additional segregating populations. By leveraging transcriptomic and genomic information, we describe , a homoserine kinase (HSK), as a candidate gene responsible for the major QTL on chromosome P5 for resistance to . SNP markers for the resistant allele were validated to facilitate gene pyramiding schemes for recurrent selection in pepper.