Phylogeographic relationships within Packera sanguisorboides (Asteraceae), a narrow endemic species that straddles a major biogeographic boundary

Abstract

Packera sanguisorboides is endemic to the Sangre de Cristo and Sacramento Mountains of New Mexico, USA. As such, its distribution spans the boundary between two major floristic regions: the southern Rocky Mountain region and the Madrean region. Chloroplast DNA haplotype polymorphism patterns in populations from both regions show that most of the molecular variance exists among populations rather than between mountain ranges and that hybridization with at least one other Packera species containing distinct cpDNA haplotypes has contributed to the cpDNA diversity within P. sanguisorboides. Based on morphological and cpDNA data, the closest relatives to P. sanguisorboides are thought to be mesic species similar to P. glabella and P. sanguisorbae.

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

“…The low haplotype diversity (n e and $ π) and high Φ st values recorded for P. pauciflora are consistent with the notion that (Bain and Jansen 1996;Golden and Bain 2000;Bain and Golden 2003). Groups A-D described in Golden and Bain (2000) and Bain and Golden (2003).…”

“…1 are loosely based on haplotype distribution patterns. Groups A and B are the coastal and interior groups, respectively, that were originally described in Golden and Bain (2000) while groups C and D (Golden and Bain 2003) include haplotypes from Mexico and the southwestern United States.…”

“…Because the sample represents only a single individual, it was not analyzed in the same manner as the other population samples. Haplotype data from other Packera species examined in Bain and Jansen (1996), Golden and Bain (2000), and Bain and Golden (2003) were combined with the haplotypes identified in P. pauciflora, and a minimum spanning network constructed showing the number of mutational steps separating pairs of haplotypes ( Fig. 1).…”

“…Phylogeographic studies (sensu Avise 2000) that concentrate on the effects of the above two processes have become more common in plants, as more variable markers are discovered in the chloroplast genome (e.g., Dobes et al 2004;Petit et al 2003). Our own studies of Packera have revealed high levels of intrapopulational chloroplast DNA diversity within most species and regions in western North America (Bain and Golden 2003;Bain and Jansen 1996;Golden and Bain 2000;Yates et al 1999). Results support the notion first proposed by Barkley (1962Barkley ( , 1988) that hybridization and (or) introgression, facilitated by distribution patterns altered by glaciation, has been important in the evolution of the genus.…”

Genetic structure of the endangered Leucomeris decora (Asteraceae) in China inferred from chloroplast and nuclear DNA markers

“…In population genetics and phylogeographic studies, chloroplast (cp) DNA has been extensively used (Bain and Golden 2003;Ikuyo and Noriaki 2009;Li et al 2008;Mousadik and Petit 1996;Yang et al 2008), for it is maternally inherited and non-recombining in most angiosperms (Reboud and Zeyl 1994). Furthermore, chloroplast genomes are particularly sensitive to the effects of fragmentation as a result of their small effective population sizes and restricted seed-mediated gene dispersal.…”