Poster Session: Biology of Pathogens - Oomycetes

534-P

Species recognition and evolutionary history of Phytophthora infestans in South America .
M. F. Mideros (1), M. Cardenas (1), S. Cañas-Duarte (2), D. Botero (2), L. Gonzalez (2), D. Riaño-Pachon (3), S. RESTREPO (4)
(1) Universidad de los Andes, Bogotá, Colombia; (2) Universidad de los Andes, Bogota, Colombia; (3) Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, Brazil; (4) Universidad de Los Andes, Bogota, Colombia

Species recognition criteria are a central topic to evolutionary biology of plant pathogens. Among the Phytophthora group, species recognition criteria have been the subject of considerable debate and extensive revision. Species recognition has been based on morphological characteristics, host range and sequence analysis of mitochondrial and nuclear genes. However, recently, speciation started to be studied using novel genetic/genomic approaches. In South America, two major clonal lineages of Phytophthora infestans have been reported in Ecuador and Peru (EC-2 and EC-3), and recently new divergent P. infestans populations have been reported in Colombia. However, the phylogenetic relationship among these groups has not been clearly resolved. Here, we used sexual crosses tests and analysis of genotyping-by-sequencing (GBS) to elucidate the evolutionary history of this group. Results of genotyping-by-sequencing (GBS) showed 147,694 putative SNPs for all isolated evaluated. Phylogenetic analysis of SNPs data confirmed the complexity of evolutionary relationships among Phytophthora species from Ic, and show important insights about the relationship of EC-2, EC-3 lineage, and the new divergent aggressive P. infestans populations in Colombia. In addition, pre and post mating isolating mechanisms were confirmed, highlighting the importance of mating-type tests for the species recognition on this group.