Genetic Diversity of the Pepper Pathogen <i>Phytophthora capsici</i> on Farms in the Amazonian High Jungle of Peru

Phytophthora capsici is an important oomycete pathogen of Capsicum peppers worldwide. Populations of P. capsici recovered from coastal regions in Peru were previously shown to be dominated by a single clonal lineage referred to as PcPE-1. During 2008, 219 isolates of P. capsici were collected from Capsicum pubescens (Rocoto), C. annum (Pimento), and C. baccatum (Aji) at 9 farms in the Amazonian high jungle in the areas surrounding Oxapampa, and one coastal location, Carabayllo. Two isolates of P. capsici were also recovered from Cyclanthera pedata (Caigua fruit) near one field. All isolates were characterized using a panel of eight single nucleotide polymorphism (SNP) markers that are fixed for heterozygosity in the PcPE-1 lineage. A subset of isolates was also characterized using amplified fragment length polymorphism (AFLP) markers. Nine discreet SNP multi-locus genotypes were identified, and the PcPE-1 lineage was recovered from all of the field sites. Both A1 and A2 mating types were recovered from two sites. The implications of the genotypic diversity and distribution identified in this study are discussed