Elucidating mechanisms of Phytophthora pathogen emergence in the genomics era
N. GRUNWALD (1), B. Knaus (2), J. Tabima (3) (1) USDA ARS, U.S.A.; (2) USDA ARS, U.S.A.; (3) Oregon State University, U.S.A.

Plant pathogens appear to emerge at increasing rates, be it due to a combination of climate change, increased human travel, and more frequent global trade among other factors. The genus Phytophthora harbors some of the most notorious invasive and emerging pathogens affecting forests, landscape and crop plants. These pathogens cause billion dollar losses annually. Notable examples include the sudden oak death pathogen P. ramorum and the Irish famine pathogen P. infestans. P. ramorum emerged repeatedly by at least five global migrations, three into North America and two into Europe. In both North America and Europe, P. ramorum populations remain clonal. Despite the fact that both mating types coexist in North America, sexual reproduction has not been observed. P. infestans populations show a similar pattern, but clearly undergo an apparently ‘random’ succession of clonal lineages as novel lineages emerge and older lineages are displaced. The South American tomato tree pathogen P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species. This talk will provide insights into mechanisms of emergence in the genus Phytophthora using evolutionary, population genetic, bioinformatic and genomic approaches. It is becoming increasingly clear that this pathogen uses an arsenal of tools and mechanisms such as effectors, hybridization, migration, and adaptation to continually reemerge. This work provides a current assessment of Phytophthora biology with an emphasis on genomics that facilitates development of translational approaches such as targeted best management practices to manage these pathogens.    

Abstract Number: C23-4, P13-416
Session Type: Concurrent