Question

Which mechanism of fungicide resistance development in plant pathogen populations occurs when repeated, exclusive use of a single-site-mode-of-action fungicide selectively favours the survival and reproduction of naturally occurring resistant mutant strains of the pathogen, eventually shifting the population to be dominated by resistant individuals?

Q: Answer-Which mechanism of fungicide resistance development in plant pathogen populations occurs when repeat...

Repeated, exclusive use of a single-site-mode-of-action fungicide exerts strong selection pressure on a pathogen population, favouring the survival and reproduction of naturally occurring resistant mutant strains over sensitive ones over successive pathogen generations, this directional selection can shift the population to be dominated by resistant individuals, reducing the fungicides field effectiveness, which is why resistance management strategies recommend rotating fungicides with different modes of action.