This study postulates that the invasive black cherry has originated from east of the Appalachian Mountains (mainly the Allegheny plateau) and its invasiveness in north-western Europe is mainly due to multiple introductions containing high numbers of individuals.

We used empirical models and three dispersal functions (Weibull, lognormal and 2Dt) to model seed distributions derived from the black cherry (Prunus serotina Ehrh.) understorey of a pine-dominated stand. Two different approaches were used to disentangle the overlapping seed shadows: the traditional inverse modeling approach and the genetic approach that uses microsatellite markers to assign a dispersed seed to its maternal parent. The distinction was made between the seeds passively dispersed by gravity (fruits with mesocarp) and those dispersed by birds (fruits without mesocarp). Our main objectives were to compare the three dispersal functions and assess the differences between the two approaches used. The functions performed equally well, but the lognormal function often showed a better data correlation. The best dispersal curves obtained by both traditional and genetic approaches were quite similar for the seeds dispersed by gravity, and 95% of these seeds were predicted to fall 5 and 3 m away from the parent tree for the traditional and genetic approaches, respectively. Differences were more important for the seeds dispersed by birds. The traditional approach predicted a lower number of seeds near the parent plant and a higher dispersal distance. Microsatellites provided accurate information on individual dispersal events and led to a better insight into the dispersal process.

No abstract

The utility of microsatellite markers to characterize the genetic diversity of a polyploid species with disomic inheritance is often hampered by the impossibility of determining allele frequencies and the complexity of inheritance patterns. The objective of this study was to solve these problems in the allotetraploid Prunus serotina Ehrh. by finding genome-specific primers (i.e., primers that are specific to one of the two genomes that initially formed the species). Sixty-seven microsatellite primers described in cultivated Prunus L. species were tested for cross-amplification in P. serotina, and evidence that conserved markers were genome-specific was found by demonstrating their typical Mendelian diploid inheritance in embryos resulting from controlled crosses. Among the 67 microsatellite markers tested, 26 produced successful amplification and five were genome-specific. No linkage disequilibrium was detected for these loci, but evidence was found for the presence of a null allele at one locus. We found both a high number of alleles per locus (three to 12) and a high mean expected heterozygosity (0.71), which were nonsignificantly different from the number of alleles and estimates of expected heterozygosity calculated for three non-genome-specific markers in the same population. The potential use of these genome-specific markers in population genetic studies is discussed.

Tetraploid black cherry (Prunus serotina) is the only Prunus L. species that has commercial importance as a timber tree in North America and is well known in Europe for its invasive behavior. Inheritance studies have never been performed and it is not known whether the species is allo or autotetraploid. Six microsatellite nuclear markers were used to test the inheritance in progenies of controlled crosses. Inheritance was proven to be disomic at all loci and a typical diploid mendelian inheritance was found at two loci. A first screening of a population in the invasive range showed high number of alleles per locus (ranging from 6 to 16) and high level of observed heterozygosity (0.75 to 1). Knowing that inheritance is disomic at six microsatellite loci and that at least two of them can be treated as codominant, diploid markers will be beneficial for future genetic studies.