Inter-intraspecific variation of chloroplast DNA of European Plantago spp

Chloroplast haplotype diversity patterns inPackera pauciflora(Asteraceae) are affected by geographical isolation, hybridization, and breeding system

Packera pauciflora (Pursh) Löve & Löve is a wide ranging alpine or subalpine species that is disjunct in three regions of North America: the northern Rocky mountains, Quebec–Labrador, and the Sierra Nevada of California. It is one of two Packera species known to be self-fertile. We assessed intrapopulational chloroplast haplotype diversity (n) and haplotype nucleotide diversity ([Formula: see text]) and found it was lower and population structure (Φst), higher than all but one of the five other Packera species examined to date. In addition, distinct differences exist between populations from California and those from the Rocky mountains and eastern Canada. Our results suggest that geographical isolation, hybridization, and breeding system have all played a role in the formation of haplotype diversity patterns, and that, in spite of the wide disjunctions, the species is monophyletic.Key words: Asteraceae, cpDNA, haplotypes, Packera, phylogeography, self-fertility.

A population genetic analysis of chloroplast DNA in Phacelia

Hierarchical sampling from populations, incipient and recognized varieties within Phacelia dubia and P. maculata has revealed high levels of intraspecific polymorphism in chloroplast DNA. Much of the variation is partitioned between populations as evidenced by population-specific variants at fixation in all three populations of P. dubia var. interior and in both populations of P. maculata. Nine of 16 populations were polymorphic for cpDNA haplotypes. A total of 16 haplotypes was found in a sample of 106 individuals; the most common occurred in eight of the 16 populations and in 31 per cent of the individuals in the entire sample. A phylogenetic analysis revealed four basic plastome types. The two major groups of plastomes were separated by four independent base-pair mutations which suggests an ancient split in the evolution of plastid genomes. Representatives from each major plastome division were found in each of five populations spanning two allopatric varieties of P. dubia. The geographical distribution of haplotypes and lack of evidence for recent admixture argue against migration as a source of the polymorphism. It is more likely that the current taxonomic varieties are descendants of a polymorphic common ancestor.