Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #335440
Title: High levels of diversity and population structure in the potato late blight pathogen at the Mexico centre of origin

Author
item WANG, JIANAN - University Of Florida
item FERNANDEZ-PAVIA, SYLVIA - Universidad Michoacana De San Nicolas De Hidalgo
item Larsen, Meredith
item GARAY-SERRANO, EDITH - Universidad Michoacana De San Nicolas De Hidalgo
item GREGORIO-CIPRIANO, ROSARIO - Universidad Michoacana De San Nicolas De Hidalgo
item RODRIGUEZ-ALVARADO, GERARDO - Universidad Michoacana De San Nicolas De Hidalgo
item Grunwald, Niklaus - Nik
item GOSS, ERICA - University Of Florida

Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2016
Publication Date: 2/7/2017
Citation: Wang, J., Fernandez-Pavia, S.P., Larsen, M.M., Garay-Serrano, E., Gregorio-Cipriano, R., Rodriguez-Alvarado, G., Grunwald, N.J., Goss, E.M. 2017. High levels of diversity and population structure in the potato late blight pathogen at the Mexico centre of origin. Molecular Ecology. 26(4):1091-1107. doi: 10.1111/mec.14000.

Interpretive Summary: Globally destructive crop pathogens emerge by migrating out of their native ranges. These pathogens are often diverse at their center of origin, and may exhibit adaptive variation in the invaded range via multiple introductions from different source populations. However, source populations are generally unidentified or poorly studied compared to invasive populations. Phytophthora infestans, the causal agent of late blight and associated with the Irish potato famine, is one of the most costly plant pathogens of potato and tomato worldwide. Mexico is the center of origin and diversity of P. infestans and migration events out of Mexico have enormously impacted disease dynamics in North America and Europe. We examined the genetic diversity across central Mexico, including samples from Michoacán, Tlaxcala, and Toluca. We found high levels of diversity across central Mexico expanding our understanding of genetic diversity in this pathogen at the center origin.

Technical Abstract: Globally destructive crop pathogens emerge by migrating out of their native ranges. These pathogens are often diverse at their center of origin, and may exhibit adaptive variation in the invaded range via multiple introductions from different source populations. However, source populations are generally unidentified or poorly studied compared to invasive populations. Phytophthora infestans, the causal agent of late blight and associated with the Irish potato famine, is one of the most costly plant pathogens of potato and tomato worldwide. Mexico is the center of origin and diversity of P. infestans and migration events out of Mexico have enormously impacted disease dynamics in North America and Europe. The long-standing debate over the origin of the pathogen, and population studies of P. infestans in Mexico, have focused on the Toluca Valley, whereas neighboring production regions have been little studied. We examined the population structure across central Mexico, including samples from Michoacán, Tlaxcala, and Toluca. We found high levels of diversity consistent with regular cycles of sexual reproduction in Michoacán and Tlaxcala, and population subdivision that was strongly associated with geographical region. We inferred higher migration from Tlaxcala and Michoacán into Toluca than vice versa, which may contribute to the diversity of the Toluca population. To determine if population structure in Central Mexico has contributed to diversity in introduced populations, we examined the relatedness of US clonal lineages to Mexican isolates. We found evidence for multiple introductions from different Mexican populations into the United States. The evolutionary history of P. infestans should be revised and considered in the context of a larger potential ‘center of origin’.