2004/03/01 by Steven Richard Griffin, Spencer C. H. Barrett · 1 citation
Biochemistry, Genetics and Molecular Biology · #Genetic diversity and population structure #Plant Pathogens and Fungal Diseases #Genomics and Phylogenetic Studies #Biological dispersal #Biology #Phylogeography #Gene flow #Ecology #Range (aeronautics) #Last Glacial Maximum #Glacial period #Seed dispersal #Genetic structure #Woodland #Genetic diversity #Population #Isolation by distance #Demographic history #Phylogenetics #Paleontology #Demography
paper · pdf · doi:10.3732/ajb.91.3.465
openalex publication_date 2004/03/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/26
Dispersal and migration are important processes affecting the evolutionary history and genetics of species. Here we investigate post-glacial migration and gene flow in Trillium grandiflorum (Melanthiaceae), a wide-ranging, forest herb from eastern North America. Using phylogeographic approaches, we examined cpDNA and allozyme diversity in 35 populations of T. grandiflorum sampled from throughout the geographic range of the species. Nested clade analysis (NCA) of cpDNA haplotypes indicated that T. grandiflorum likely survived in two refugia in the southeastern US during the last glaciation and that long-distance dispersal characterized the post-glacial recolonization of northern areas. There was no evidence for reduced allozyme diversity in populations from glaciated compared to ice-free regions, probably because of the greater abundance and larger effective size of populations in the north. An analysis of isolation-by-distance based on the allozyme data suggested a pattern of population differentiation consistent with restricted gene flow. Notwithstanding the significance of rare seed dispersal events for migration, a comparison of allozyme and cpDNA genetic structure indicates that pollen flow between populations is more likely than seed dispersal. These results for T. grandiflorum represent the first phylogeographic analysis of a temperate woodland herb in eastern North America and support the importance of occasional long-distance dispersal events in the post-glacial migration of plants.