Isolation of microsatellites from almond and apricot genomic libraries and testing for their transportability across different Prunus species

We have isolated 44 SSRs from almond and 99 SSRs from apricot from genomic libraries enriched for AC- and AG-repeats, respectively. The efficiency of the isolation procedure was higher in apricot (99 SSRs from 127 positive plaques) than in almond (44 SSRs from 93 positive plaques) although both libraries had a high percentage of positive plaques. The reason for the low number of markers recovered from almond was the presence of duplicates (26 cases) and the shortness of the cloned inserts that did not allow for primer design (23 cases). Primers were synthesized and twenty SSRs from each library were tested on eight different Prunus species, i.e. almond, peach, nectarine, apricot, European plum, Japanese plum, sweet cherry, sour cherry, and Malus x domestica, the apple. A wide transportability across the different Prunus was observed in both sets of SSRs.