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Influence of the geological history of the T rans‐ M exican V olcanic B elt on the diversification of N olina parviflora ( A sparagaceae: N olinoideae)
Author(s) -
RuizSanchez Eduardo,
Specht Chelsea D.
Publication year - 2013
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/jbi.12073
Subject(s) - clade , population , biology , gene flow , haplotype , phylogenetic tree , chloroplast dna , evolutionary biology , genetic variation , genetics , gene , genotype , demography , sociology
Aim Our aims were to determine the pattern of genetic variation in the endemic shrub N olina parviflora , and to evaluate the influence of the geological history of the T rans‐ M exican V olcanic B elt ( TMVB ) and nearby mountainous regions on plant population divergence. Location Trans‐ M exican V olcanic B elt, Sierra Madre Occidental, Sierra Madre Oriental and Sierra Madre del Sur mountain ranges in Mexico. Methods Twenty‐eight populations (210 individuals) were sequenced for one nuclear ( rpb 2) and two chloroplast ( trn L–F and psb A –trn H) DNA markers. Intraspecific phylogenetic relationships among haplotypes were reconstructed, and molecular dating, population genetic analyses and group testing were performed on the data. Isolation‐by‐distance analysis was conducted for the populations spanning the distribution of the species. Results Twenty‐four chloroplast marker haplotypes and 36 rpb 2 haplotypes were recovered from the populations sampled. The combined marker phylogeny indicates the presence of two well‐supported clades within the N. parviflora populations. Clade 1 includes populations from Jalisco and Zacatecas and Clade 2 comprises the remaining populations. We found an east–west geographical pattern of chloroplast DNA (cp DNA ) haplotype distribution, indicating a lack of gene flow between these two regions. Divergence time estimates indicate an Oligocene to mid‐Miocene divergence between Nolina and Dasylirion . Divergence estimates for Clade 1 are from the mid‐Miocene to early Pleistocene, and for Clade 2 from the early Miocene to mid‐Pliocene. Values of cp DNA G ST (0.702) indicate a strong population structure and differentiation. A spatial analysis of molecular variance indicates 11 groups among the sampled populations and detects various well‐supported geographical barriers. Main conclusions Divergence time estimates suggest a correlation between the time of divergence between distinct N. parviflora populations and periods of uplift in the TMVB . We infer that the orogeny of this mountain range played an important role in driving the diversification of plant populations in central Mexico by creating topographical barriers that limited gene flow.