Evolutionary analysis of Pinus leiophylla: A study using an intron II sequence fragment of mitochondrial nad1

A phylogenetic analysis was done using a mitochondrial marker to study the relationship between Pinus leiophylla Schiede & Deppe and Californian, Mesoamerican, European, and Asian pines. The type II intron between the nad1 b and c exons was chosen for the analysis. Nineteen otus (15 species with mitotypes in two species) from the Pinus and Picea genera were used. Amplification using the two primers generated an approximately 1000 bp product, depending on species. Parsimony branch and bound analysis resulted in 135 shortest trees with 1323 steps (CI = 0.9131 and RI = 0.9511). The strict consensus tree showed P. leiophylla associated with Eurasian pines. Though unusual, it is not the first time this association has been proposed. Given these results, P. leiophylla is likely one of the oldest pine species in the Americas and probably arose from a Eurasian ancestor that initially invaded North America at between 25°N and 35°N latitude and later colonized Mexico.