Genetic structure and aggressiveness of Erysiphe necator populations during grapevine powdery mildew epidemics

The coexistence of the isolates of the casual ascomycete of grapevine powdery mildew, Erysiphe necator, is analyzed by examining temporal changes in the genetic and phenotypic structures of E. necator populations. The results are consistent with a temporal differentiation of niches, preventing recombination and have indicated an association between the disease level and the frequencies of genetic groups.