title: Genetic structure and aggressiveness of Erysiphe necator populations during grapevine powdery mildew epidemics.
abstract: Isolates of the causal ascomycete of grapevine powdery mildew, Erysiphe necator, correspond to two genetically differentiated groups (A and B) that coexist on the same host. This coexistence was analyzed by investigating temporal changes in the genetic and phenotypic structures of E. necator populations during three epidemics. Group A was present only at the start of the growing season, whereas group B was present throughout all three epidemics. Group A was less aggressive in terms of germination and infection efficiency but was more aggressive than group B in terms of the latency period, lesion diameter, and spore production. Our results are consistent with a temporal differentiation of niches, preventing recombination, and suggest an association between the disease level and the frequencies of genetic groups.
authors: INRA, ENITA, UMR1065 Santé Végétale, F-33883 Villenave d'Ornon, France. Josselin.Montarry@bordeaux.inra.fr
authors: Josselin
authors: J
authors: Montarry
authors: Philippe
authors: P
authors: Cartolaro
authors: François
authors: F
authors: Delmotte
authors: Jérôme
authors: J
authors: Jolivet
authors: Laetitia
authors: L
authors: Willocquet
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology*; D012720:Severity of Illness Index; D013997:Time Factors; D027843:Vitis / Q000382:microbiology*