Genetic diversity and spatial structure in the rare, endemic orophyte Campanula pseudostenocodon Lac. (Apennines, Italy), as inferred from nuclear and plastid variation

Analysis of ISSR markers revealed a large variation within samples, with polymorphic loci (P) ranging from 42 to 82%, inrelation to population size. A consistent genetic differentiation (Gst¼0.207; Fst 29.71%) was found among the fourexamined populations. Based on changes in the chloroplast trnLEU intron, three distinct haplotypes were identified. Threeout of the four populations were fixed for a single haplotype, with the two northernmost populations, which aregeographically closest (65 km apart), sharing the same one. These findings suggest that a relatively long period of restrictedgene flow originated the present-day spatial structure of C. pseudostenocodon. Application of both nuclear and organellemarkers in estimating genetic diversity may be advisable in conservation studies, since they may reveal a peculiar localdiversity.