Taxonomy of Juniperus deppeana varieties and formas based on nrDNA ( ITS ) , petN - psbM , trnS - trnG , trnD - trnT , trnL - trnF sequences

Juniperus deppeana has numerous disjunct populations that include four taxonomic varieties and three forms. All four varieties and two forms of Juniperus deppeana from the southwest United States, Mexico and Guatemala were analyzed by sequencing nrDNA (ITS), petN-psbM, trnS-trnG, trnD-trnT, trnL-trnF. A Bayesian tree gave support for clades of var. deppeana, NM, var. patoniana, and var. gamboana. However, several clades with high support contain mixtures of different varieties and forms. A minimum spanning network based on 91 mutational events (MEs) showed that the varieties and forms are extremely closely related, differing by only 1 to 2 bp (out of 4411 bp). The taxon with the largest diffentiation was var. deppeana, Sacramento Mtns., NM that differed by 4 MEs from the Oak Creek canyon, AZ individuals. The lack of variation among J. deppeana taxa may be due to the mixing of populations during the Wisconsin glacial maximum (70,000 13,000 ybp) when life zones descended about 800 m. Published on-line: www.phytologia.org Phytologia 95(2): 161-166 (May 1, 2013).