Genetic variations and migration pathway of Juniperus thurifera L. (Cupressaceae) in the western Mediterranean region

Abstract

Random amplified polymorphic DNA (RAPD) analysis and length variations in the chloroplast trnL-trnF intergenic spacer were used to analyze the geographic structure of Juniperus thurifera L. populations in Spain and North Africa. The chloroplast DNA analysis indicated three size classes of the spacer, but was uninformative of any geographic pattern. In contrast, the RAPD data based on 127 polymorphous bands clearly showed the existence of three population groups: (a) a group comprising two populations from northeastern Spain and two from southern Spain, (b) a group comprising the rest of the Spanish populations, and (c) a group which consisted of the two Moroccan populations. Analysis of molecular variance (AMOVA) showed that 24% of the variation is found between groups of populations, 15% between populations within groups, and 61% within populations. The results are consistent with a hypothetical migration of J. thurifera starting from central Europe, passing through France and Spain, and finally reaching North Africa.

Morphological differentiation supports the genetic pattern of the geographic structure of Juniperus thurifera (Cupressaceae)

“…These authors pointed out a lack of gene flow between Moroccan and Iberian populations after glacial periods (Terrab et al 2008). Our result is generally in accordance with the separate taxonomic position of the Moroccan populations (Gauquelin et al 1988;Barbero et al 1994;Adams et al 2003;Jiménez et al 2003;Romo and Boratyński 2005), treated as subspecies africana or Table 4 Analysis of hierarchical variance between Juniperus thurifera groups of populations for morphological characters (acronyms as in ultimately proposed as maroccana (till now nomen nudum) (Vela and Gauquelin 2011). The more recently published results of the studies on the genetic differentiation of conifers across the Strait of Gibraltar confirmed a high level of differences (Terrab et al 2007;Jaramillo-Correa et al 2010;Dzialuk et al 2011), however, some taxa did not follow this rule (Jaramillo-Correa et al 2010).…”

“…Differences between subsp. thurifera and africana have also been found in the biochemical composition (Gauquelin et al 1988(Gauquelin et al , 1999Lebreton 1990;Akkad et al 2001) and genetic structure (Adams et al 2001(Adams et al , 2003Jiménez et al 2003;Terrab et al 2008). The latter study revealed strong differences between European and African populations of J. thurifera, and confirmed subsp.…”

“…The African populations, the most isolated from the others, appeared to be the most distant genetically and morphologically (Adams et al 2003;Jiménez et al 2003;Romo and Boratyński 2007;Terrab et al 2008). The morphological differences between European and African individuals of J. thurifera were the reason for the distinguishing of subsp.…”

“…The genetic variation of J. thurifera, tested on the random amplified polymorphic DNA (RAPD) by Jiménez et al (2003), suggests that the species migrated from the European mountain systems southward and westward towards Corsica, the Iberian Peninsula and then the Atlas Mountains in N Africa. The African populations, the most isolated from the others, appeared to be the most distant genetically and morphologically (Adams et al 2003;Jiménez et al 2003;Romo and Boratyński 2007;Terrab et al 2008).…”

“…The aim of the present study was (1) to determine morphological dissimilarities between populations by performing a biometrical comparison of morphological characters of female cones, seeds and shoots, and (2) to evaluate to what extend the multivariate biometrical analysis would resemble the pattern of variation and differentiation described by Jiménez et al (2003) and Terrab et al (2008) based on RAPDs and AFLP analyses, respectively.…”