Genetic Variation within «Phaeoacremonium aleophilum» and «P. chlamydosporum» in Italy

Abstract

Genetic variation among isolates of Phaeoacremonium chlamydosporum (Pch) and P. aleophilum (Pal),
two hyphomycetous fungi involved in the development of symptoms of esca and in a decline of young grapevines, was
studied in eight Italian grapevine growing regions. Genetic variation was estimated by analysis of amplification
profiles obtained in RAPD- and RAMS-PCR experiments (RAPD = Random Amplified Polymorphic DNA; RAMS =
Random Amplified Micro- or Mini-Satellites). The genetic divergence between the two species suggests their assignment
to two different genera. Within each species, a low level of polymorphism was found; however a higher degree
of genetic variation was found with RAPD than with RAMS experiments, and more with Pal than with Pch isolates.
No relationship was found for either species between the clustering of isolates in statistically defined groups and the
geographic origin of those isolates. A low level of genetic disequilibrium was found in Pch and Pal, suggesting that
sexual reproduction may occur in both fungi.