The phylogeographic structure of Lycianthes dejecta and Lycianthes peduncularis is explained by Pleistocene oscillations and reveals a new lineage

Diversification of xerophilous linages in Mexico is result of the expansion and isolation due by the geological and climatic events in the past 15 Ma. Lycianthes dejecta and L . peduncularis have a sister relationship. Both are endemic to the xerophilous scrubs of Mexico and have disjunct populations. We anticipate they represent phylogeographically structured linages. The objectives were first, analyzing their genetic variation, structure and genealogical relationships. Second, described the demographic history and inferred they paleodistribution. Two cpDNA ( rpl 32- trn L and ycf 1) regions were amplified and sequenced for 137 individuals and 16 populations. The data matrix included 92 individuals of 10 populations of Lycianthes dejecta and 45 individuals of six populations of L . peduncularis . The haplotype network included 22 haplotypes. Lycianthes dejecta and L . peduncularis formed two haplogroups within each. Our results showed phylogeographic structure in both species. The highest genetic differentiation for L. dejecta was found in Baja California (BC). The populations of L. peduncularis isolated showed moderate levels of differentiation. The demographic history exposed expansion in the Chihuahuan Desert (CHD) populations of L. dejecta . In contrast, in L . peduncularis we found no evidence of population expansion or reduction. In both species, we observed contraction and expansion of its suitable climatic conditions. Orography and Pleistocene glacial cycles shaped the diversity and genetic structure of Lycianthes dejecta and L . peduncularis in the CHD. The evidence suggested that the BC population should be considered as an independent lineage. Transmexican Volcanic Belt (TVB) played a filter role in both species.