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;BARBIERI C

Investigation

;Salim Bourras;Christina Cowger;Paweł C Czembor;Roi Ben-David;Amos Dinoor;Simon R Ellwood;Johannes Graf;Koichi Hatta;Marcelo Helguera;Javier Sánchez-Martín;Bruce A McDonald;Alexey I Morgounov;Marion C Müller;Vladimir Shamanin;Kentaro K Shimizu;Taiki Yoshihira;Helen Zbinden;Beat Keller;Thomas Wicker

2022-01-01

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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.