Allozyme Variation in Different Species of Deciduous Oaks From Northwestern Italy.

Allozyme variation was studied by electrophoresis at 11 loci in 14 populations of Quercus petraea, Q. robur, Q. cerris and Q. pubescens from Piedmont, northwestern Italy. The aim of the work was to characterize the genetic resources and to suggest effective measures for in situ preservation of biodiversity, as well as to identify the most valuable stands for the production of high quality seeds. As expected, most of the genetic variability was found at the within population level, and genetic differentiation accounted for about 14% of it. The study confirmed the low level of genetic variability among the species studied: only Q. cerris populations could be clearly distinguished. Q. pubescens could be separated from Q. petraea and Q. robur adopting neighbour joining as a method of population clustering. Discriminant analysis was found to be useful for separating Q. petraea and Q. robur. However, in mixed populations, the differentiation between the latter species was similar to that scored among populations belonging to the same species. A significant deviation from random mating was observed, although it was variable among species: Q. pubescens had the highest value for the inbreeding coefficient FIS (0.159).