Genetic structure and phylogeography of Juniperus phoenicea complex throughout Mediterranean and Macaronesian regions: different stories in one

Abstract

& Key message The genetic structure of Juniperus phoenicea in the Mediterranean Basin is inferred using amplified fragment length polymorphism markers (AFLP) markers. As other Mediterranean conifers, J. phoenicea populations show moderate levels of genetic diversity and interpopulational differentiation. The pattern of distribution of genetic diversity seems highly influenced by the climatic fluctuations which occurred in the Pleistocene. & Context It has been stated that the genetic structure of Mediterranean conifers is mediated by the historical climatic changes and the geological rearrangements which occurred in the Mediterranean Basin. J. phoenicea provides an excellent example to test how its genetic structure is influenced by these events. & Aims In this work, we study the amount and distribution of genetic diversity of J. phoenicea complex, in order to evaluate its taxonomic status and to reveal underlying phylogeographic patterns. & Methods The molecular diversity was analyzed for 805 individuals from 46 populations throughout its distribution range using AFLP markers. Principal coordinate analysis, analysis of molecular variance (AMOVA), and Bayesian-based analysis were applied to examine the population structure.

High genetic diversity within and low differentiation among Juniperusexcelsa M. Bieb. populations: Molecular markers reveal their genetic structure patterns

“…Heterozygote excess at loci JT02, JT37 and JT38, low Fis and Fst averages, high percentage of intra-population variance (98%), values of Shannon's Information index indicated moderate-high genetic diversity in the populations. Long distance dispersal of pollen and seed, longevity and outcrossing make junipers and other conifers had high level of genetic diversity within populations and low level of interpopulation differentiation (Hamrick et al, 1992;Sánchez-Gómez et al, 2018). It prevents effect of habitat fragmentation on genetic structure of populations.…”

Past, present, and future geographic range of the relict Mediterranean and Macaronesian Juniperus phoenicea complex

“…Data on the occurrence of the J. phoenicea complex were obtained from the Global Biodiversity Information Facility (GBIF.org), the literature, herbaria, and the authors’ field notes. The data originally did not distinguish J. phoenicea s.s from J. turbinata, and thus, taxa were segregated using published results of biochemical (Lebreton & Pérez de Paz, 2001; Lebreton & Rivera, 1989), genetic (Adams et al., 2002, 2009, 2010, 2013, 2014; Boratyński et al., 2009; Dzialuk et al., 2011; Jiménez et al., 2017; Sánchez‐Gómez et al., 2018), and biometric (Mazur et al., 2010, 2016, 2018) research. Additionally, their taxonomic status was reviewed according to geographic and ecological criteria.…”

“…We examined the realized, retrospective, and predicted niches separately for J. phoenicea s.s ., J. turbinata, and J. canariensis and for the entire J. phoenicea complex. Additionally, we analyzed separately the data from the groups of localities of J. turbinata detected in the genetic study (Sánchez‐Gómez et al., 2018:7, Figure 2), namely (I) from the Atlantic, African coast and from Europe, eastward to Almeria in Spain (TURAT), (II) central Mediterranean (TURCM), and (III) eastern Mediterranean (TUREM). To these three groups we added a fourth one (IV) from the Arabian Peninsula, the southeastern most group (TURAR).…”

“…The J. phoenicea complex includes three species: J. phoenicea L. sensu stricto (s.s.), J. turbinata Guss., and J. canariensis Guyot in Mathou & Guyot (Romo et al, 2019). The species differ from each other in terms of genetics (Adams, 2014;Adams et al, 2002Adams et al, , 2009Adams et al, , 2010Adams et al, , 2014Boratyński et al, 2009;Dzialuk et al, 2011;Jiménez et al, 2017;Sánchez-Gómez et al, 2018), biochemistry (Adams et al, 2002(Adams et al, , 2009Lebreton & Pérez de Paz, 2001;Lebreton & Rivera, 1989;Lebreton & Thivend, 1981), morphological characters of cones and seeds (Mazur et al, 2010(Mazur et al, , 2016(Mazur et al, , 2018Pinna et al, 2014), and phenology (Romo et al, 2019). All three species of J. phoenicea aggr.…”

“…Our aim was to verify this hypothesis by modeling the current distribution data. Additionally, J. turbinata appears to be genetically (Sánchez‐Gómez et al., 2018) and morphologically (Mazur et al., 2018) differentiated into four population groups (see below).…”