Plant diversity ameliorates the evolutionary development of fungicide resistance in an agricultural ecosystem

1. Evolution of fungicide resistance in agricultural and natural ecosystems is associated with the biology of pathogens, the chemical property and application strategies of the fungicides. The influence of ecological factors such as host diversity on the evolution of fungicide resistance has been largely overlooked but is highly relevant to social and natural sustainability. In this study, we used an experimental evolution approach to understand how host population heterogeneity may affect the evolution of fungicide resistance in the associated pathogens.

2. Potato populations with six levels of genetic heterogeneity were grown in the same field and naturally infected by Phytophthora infestans. Pathogen isolates (~1200) recovered from the field experiment were molecularly genotyped. Genetically distinct isolates were selected form each population and 142 isolates were assayed for their tolerance to two fungicides differing in the mode of action. Tolerance was determined by calculatin...