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

Abstract

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.