<i>Phytophthora betacei</i>, a new species within <i>Phytophthora</i> clade 1c causing late blight on <i>Solanum betaceum </i>in Colombia

Over the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genus Phytophthora have not been completely characterized. In this study, a new Phytophthora species was described in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit grown in northern South America. Comprehensive phylogenetic, morphological, population genetic analyses, and infection assays to characterize this new species, were conducted. All data support the description of the new species, Phytophthora betacei sp. nov. Phylogenetic analyses suggest that this new species belongs to clade 1c of the genus Phytophthora and is a close relative of the potato late blight pathogen, P. infestans. Furthermore, it appeared as the sister group of the P. andina strains collected from wild Solanaceae (clonal lineage EC-2). Analyses of morphological and physiological characters as well as host specificity showed high support for the differentiation of these species. Based on these results, a complete description of the new species is provided and the species boundaries withinPhytophthora clade 1c in northern South America are discussed

Ecological speciation within the<i>Phytophthora</i>genus

AbstractOver the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genusPhytophthorahave not been completely characterized. In this study, we used an integrative approach that leveraged morphological, ecological, and genetic approaches to explore cryptic speciation withinP. infestans sensu lato. We described a newPhytophthoraspecies collected in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit. All morphological traits and population genetic analyses, using microsatellite data and a reduced representation of single nucleotide polymorphism (SNP) data, support the description of the new species,Phytophthora betaceisp. nov. We have demonstrated that ecological differences are important in the persistence ofP. infestansandP. betaceias genetically isolated units across an overlapping area in the northern Andes.</jats:p