Evidence for genetic association between East Asian and western North American Crataegus L. (Rosaceae) and rapid divergence of the eastern North American lineages based on multiple DNA sequences

• Published in: Molecular phylogenetics and evolution Vol. 51; no. 2; pp. 157 - 168
• Main Authors: Lo, Eugenia Y.Y., Stefanović, Saša, Christensen, Knud Ib, Dickinson, Timothy A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2009
• Subjects: Bayes Theorem; Beringian land bridge; Cell Nucleus - genetics; Crataegus; Crataegus - classification; Crataegus - genetics; Dispersal-vicariance; DNA, Chloroplast - genetics; DNA, Plant - genetics; East Asia–western North America disjunction; Evolution, Molecular; Far East; Genetic Speciation; Geography; Homoplasy; Hybrid origins; Likelihood Functions; North America; Phylogeny; Rapid divergence; Rosaceae; Sequence Alignment; Sequence Analysis, DNA; Topological incongruence; Far East; North America; Topological incongruence; Dispersal-vicariance; Hybrid origins; East Asia–western North America disjunction; Beringian land bridge; Rapid divergence; Crataegus; Homoplasy
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2009.01.018

Phylogeographic relationships were constructed for 72 Old and New World Crataegus species using combinations of four chloroplast and up to five nuclear regions. Maximum parsimony, maximum likelihood, and Bayesian results yield consistent relationships among major lineages. The close associations of the East Asian and western North American species point toward ancient trans-Beringian migrations. Relationships among eastern North American species are poorly resolved and few groups are identified that are congruent with existing classifications. Scant variation and short internal branches among these species suggest rapid divergence associated with polyploidy and hybridization. Incongruence between the chloroplast and nuclear data, and morphology suggest hybrid origins of three species from an extinct European lineage (the male parent) and three different North American female parents. Europe and eastern North America are suggested as the most recent common areas for Crataegus; at least four dispersal events are inferred to explain the present distribution of the genus.