Black cherry (Prunus serotina) is a common secondary forest species with a wide endemic distribution, ranging from Nova Scotia into Mexico. Although sometimes planted for its valued lumber within the U.S.,P. serotina is essentially a wild species, with fruit approximately 0.5 cm in diameter. In Mexico and Ecuador, however, domesticants and feral populations of this species called "capulin," have much larger (2 cm) edible fruit. It is generally accepted that the large fruited capulin resulted from domestication by native peoples in Central America. The origins of this unique group of edible black cherries, one of the 'lost crops of the Inca's,' and their relationships with the native black cherries of the U.S. and Canada, has yet to be studied. Our objective is to determine the patterns of genetic diversity within and among black cherry germplasm collected from Michigan, central Mexico, and Ecuador using the following molecular markers: 4 isozyme loci (6-Pgd-1, 6-Pgd-2, Pgi-1, and Pgi-2), two SSR loci from Prunus cerasus (PceGA77 and PceGA34), and one chloroplast PCR product corresponding to a region between the trnT and trnL genes. 6-Pgd-1 and 6-Pgd-2 resolved two and three putative alleles, respectively. The Mexican and Ecuadorian germplasm shared common alleles except for one 6-Pgd-2 allele in a Mexican accession. Pgi-1 was fixed for one allele, while Pgi-2 revealed three putative alleles in the Mexican and Ecuadorian germplasm. To date, the two SSR loci each exhibit 5 alleles. All accessions tested have a similar chloroplast fragment [approx. 146 bp] except for one Mexican accession, PH1 [approx. 149 bp]. Although PH1 had a unique chloroplast fragment, it shared the common isozyme alleles with the other capulin accessions. This set of germplasm will be scored for the complete set of markers.

Key words: Prunus serotina Ehrh., black cherry, genetic diversity, isozymes, SSRs