Characterization of variability and genetic similarity of European pear using microsatellite loci developed in apple

Seven microsatellite loci (SSR) developed in apple were used for the identification of 63 European pear cultivars. A total of 46 fragments were amplified, with an average of 6.6 alleles per SSR. Only one microsatellite amplified more than one locus. The mean expected and observed heterozygosities over the six single-locus SSRs averaged 0.68 and 0.44, respectively, and the number of effective alleles per loci was 3.43. The amplified fragments produced 61 different fingerprinting patterns that allowed to unequivocally distinguish all the varieties analyzed. Only two varieties, which derive from mutations, could not be distinguished from the original variety. Cluster analysis of the estimated genetic similarity, grouped the varieties according to their pedigree and their geographic origin. The variability detected with the SSRs in European pear varieties was low when compared with the variability detected in other fruit crops in the Rosaceae. (C) 2007 Elsevier B.V. All rights reserved.