Global genomic analyses of wheat powdery mildew reveal association of pathogen spread with historical human migration and trade
Alexandros G. Sotiropoulos, Epifanía Arango-Isaza, Tomohiro Ban, Chiara Barbieri, Salim Bourras, Christina Cowger, Paweł Czembor, Roi Ben‐David, A. Dinoor, Simon R. Ellwood, Johannes Graf, Koichi Hatta, Marcelo Helguera, Javier Sánchez‐Martín, Bruce A. McDonald, Alexey Morgounov, Marion C. Müller, Владимир Шаманин, Kentaro K. Shimizu, Taiki Yoshihira, Helen Zbinden, Beat Keller, Thomas Wicker
Abstract
The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization.