Zymograms to fingerprint genotypes within three closely adjacent North Carolina subpopulations of the salt marsh cord grass, Spartina patens, revealed considerable heterogeneity in the distribution of clones among subpopulations. The dune subpopulation was dominated by a small number of large clones, while the marsh subpopulation was characterized by a large number of small clones with little overlap in genotypic composition. The swale subpopulation was intermediate in character. Allozymic analysis of three loci showed significant and very localized heterogeneity in gene frequency. Clinal trends were apparent for two loci. The population subdivision was hypothesized, primarily, to result from differential selection among the subpopulations and, secondarily, to inbreeding associated with restricted gene flow. The genetic divergence among subpopulations was similar to that among populations of inbreeding plant species or among disjunct populations of outbreeders. A comparison of ramets and genets showed that larger and more successful clones tended to be less heterozygous than smaller clones. Genetic diversity decreased from marsh (central) to dune (peripheral) subpopulations. There was no evidence for significant linkage disequilibria among the three loci examined.
No takes yet. Share an insight, caveat, or question.
John A. Silander (1984) studied this question.