Genetic diversity and relationships among<i>Prunus cerasifera</i>(cherry plum) clones

Abstract

Prunus cerasifera (Ehrh.) (cherry or Myrobalan plum) is a diverse species with several recognized subspecies and natural forms. It is used as rootstock or as an ornamental tree, and is considered to be one progenitor of the garden plum ( Prunus domestica L.). This study considers the genetic relationships among different P. cerasifera clones, including horticultural cultivars. Twenty nine P. cerasifera accessions of the Prunus Genetic Resources Collection of INRA were analysed using morphological traits, maternally inherited chloroplastic DNA (cpDNA) markers, and biparentally inherited microsatellite (SSR) markers. Ploidy information was obtained by flow cytometry. Multiple factorial correspondence analysis of morphological descriptors shows important differences between some clones, but most of the samples are grouped. Fifteen haplotypes of cpDNA were identified and clustered into three groups after statistical parsimony analysis. SSR markers revealed a total of 74 alleles, with a mean value of 10.6 alleles per locus. After analysis of ploidy level, P. cerasifera subsp. caspica was shown to have a hexaploid genome. Morphological and molecular data suggest that the taxonomic classification of some subspecies and of P. cerasifera subsp. caspica may need to be revised after analysis of additional individuals.