Spatial Genetic Structure of Campanula sabatia, a Threatened Narrow Endemic Species of the Mediterranean Basin

Campanula sabatia is endemic to NW Italy (Liguria) and it was included in the European Red list of endangered species due to the heavy human pressure on its habitat. AFLP markers were used to detect the genetic diversity within and among ten populations (totalling 83 individuals) representing the range of the species. In spite of the limited distribution of this endemic taxon, high levels in percentage of polymorphic bands (PPB), gene diversity (H (S) and H (T)) and Shannon's information index (I) were detected both at population (PPB = 60 %, H (S) = 0.1853, I = 0.2836) and at species level (PPB = 100 %, H (T) = 0.2415, I = 0.3871). The coefficient of genetic differentiation among population (G'(ST)) was 0.1935, while the level of gene flow (N' (m)) was estimated to be 2.0832. AMOVA analysis identified a genetic variation within populations of 83 % of the total. Bayesian clustering methods assigned individuals to two geographical groups partly found within the same population, probably due to a high rate of genetic exchange among its populations. Conservation measures are suggested on the basis of the genetic diversity detected to ensure an effective protection for this endemic species.