DNA fingerprinting of tetraploid cherry germplasm using simple sequence repeats

The U.S. Department of Agriculture (USDA), Agricultural Research Service (A RS) tetraploid cherry (Prunus L. sp.) collection at Geneva, N.Y., contains approximate to 75 accessions of sour cherry (P. cerasus L.), ground cherry (P. fruticosa Pall.), and their hybrids. Accurate and unambiguous identific ation of these accessions is essential for germplasm preservation and use, Simple sequence repeats (SSRs) are currently the markers of choice for germ plasm fingerprinting because they characteristically display high levels of polymorphism. Recently SSR primer pairs from sweet cherry (P. avium L.), s our cherry, and peach [(P. persica L, Batsch Peach Group)] have been report ed. Ten SSR primer pairs were tested on 59 tetraploid cherry accessions to determine if they could differentiate among the accessions. Scorable SSR fr agments were produced with all primer-accession combinations. The cherry ac cessions exhibited high levels of polymorphism with 4 to 16 different putat ive alleles amplified per primer pair. Most of the putative alleles were ra re with frequencies <0.05. Heterozygosity values ranged from 0.679 to 1.00, while gene diversity values ranged from 0.655 to 0.906. The primer pairs d ifferentiated all but two of the 59 cherry accessions. Based upon the abili ty of the SSR data to differentiate the cherry accessions and the high leve l of gene diversity, we propose that all the tetraploid cherry accessions i n the USDA/ARS collection be fingerprinted to provide a mechanism to verify the identity of the individual accessions. The fingerprinting data are ava ilable on the World Wide Web (http://www.ars-grin.gov/gen/cherry.html) so t hat other curators and scientists working with cherry can verify identities and novel types in their collections and contribute to a global database.