Inter-simple sequence repeat (ISSR)-PCR analysis to assess genetic diversity in a collection of wild cloudberry (Rubus chamaemorus L.) clones

Forty-eight wild cloudberry (Rubus chamaemorus L.) clones, collected from four Canadian Provinces, were assessed for genetic variability using inter-simple sequence repeat (ISSR)-PCR methods. Nine primers generated 138 polymorphic ISSR bands. A substantial degree of genetic diversity was found among the wild collection. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) separated the 48 wild clones into six main clusters, and identified the one remaining clone as an outlier. Furthermore, within four of the clusters, the clones tended to form sub-clusters that were in agreement with a principal coordinate (PCO) analysis. Geographical distribution explained 8% of the total variation revealed by analysis of molecular variance (AMOVA). The ISSR markers detected a sufficient degree of polymorphism to differentiate among cloudberry clones, making this technology valuable for germplasm management, and more efficient choices of parents in current cloudberry breeding programmes.