Consequences of geographical habitats on population structure and genetic diversity in Campanula spp.

Characterization of populations by means of DNA techniques provides a tool for precise identification and a quantitative estimate of genetic diversity, crucial in evaluation of genetic fragmentation within and among populations. NBS profiling are PCR-based approaches that sample genetic variation in resistance genes (R-gene), and R gene analogs (RGA). To date, myb patterns have not been used for evaluating genetic diversity in other species. NBS primers are homologous to the conserved sequences in the Nucleotide-Binding-Site of the NBS-LRR class of R-genes. A total of 12 populations from five Campanula species (C. barbata L., C. latifolia L., C. rapunculoides L., C. spicata L. and C. trachelium L.), autochthonous of the West Italian Alps, were genotyped via nucleotide-binding site (NBS) and myb gene profiling. The selected markers produced a total of 361 bands, showing high levels of polymorphism. Genetic diversity among and within species and population structure was evaluated by different statistical analyses performed using TREECON software, Mantel Nonparametric Test, NTSYS package, AMOVA and STRUCTURE. The correlation between genetic variability and geographical location suggests that the five Campanula species have been subjected to long-term evolutionary processes consistent with the natural fragmentation of continuous mountains areas.