A comparison of genetic relationship measures in strawberry (Fragaria x ananassa Duch.) based on AFLPs, RAPDs, and pedigree data

Nineteen of the major strawberry (Fragaria x ananassa Duch.) cultivars grown in the United States and Canada were examined for AFLP marker polymorphisms. For the AFLP reactions, the EcoRI-ACC primer was used in combination with four MseI primers (MseI-CAC, MseI-CAG, MseI-CAT, or MseI-CTT). Each set of primers produced 46-66 scorable fragments ranging in size between 50 and 500 bp. The polymorphic fragments produced from each set of primers were more than sufficient to distinguish among all the cultivars, demonstrating the usefulness of AFLP markers for cultivar identification. Similarity coefficients were calculated based on data from 228 AFLP markers and data from 15 previously characterized RAPD markers. The RAPD markers had been specifically selected for fingerprinting purposes because they succesfully distinguish 41 strawberry cultivars, including the 19 cultivars analyzed in this study. Separate dendrograms were constructed based on analysis of the AFLP and RAPD marker data using a neighbor-joining algorithm. The dendrograms were compared and found to be very different. Correlations between similarity coefficients calculated from AFLP marker data, similarity coefficients calculated from RAPD marker data, and coefficients of coancestry calculated from pedigree information were evaluated. Interestingly, a better correlation with the coefficients of coancestry was observed with the RAPD marker data than with the AFLP marker data.