Allozyme variation in different species of deciduous oaks from northwestern Italy

Abstract

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 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 using Principal Coordinate Analysys. The latter was also found to be useful for separating Q. petraea and Q. robur populations. 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).