This study supports the utility of direct sequences for detecting intra-individual polymorphism and for partially inferring the ITS copies involved, given previous knowledge of the variability. The main evolutionary implication at the organism level is that gene-flow and concerted evolution shape the geographic structure of ITS variation.

In contrast to northern European areas where large-scale migrations occurred to recolonize territories after glacial periods, species in southern regions survived and diverged without large geographical displacements. As a result of the importance of orography in much of the southern areas, such displacements must have involved populations ascending or descending mountains. The present study provides support for glacial-induced altitudinal migrations from chloroplast phylogeographic patterns in Armeria (Plumbaginaceae) in southeast Spain. One hundred and five sequences of the trnL-F spacer were obtained from seven species. Fifteen different haplotypes were recognized, their genealogy was inferred, and associations with geography were explored using nested clade analysis. Seven instances were detected in which the same haplotype is shared by two or three species within a particular massif. In all the cases, at least one of the species involved displayed different haplotypes in other areas; in most, the haplotype shared is predominant either in one of the species involved or in the massif. These patterns of haplotype sharing strongly suggest horizontal transfer between species. In one of the massifs (Sierra Nevada) the three species involved in haplotype sharing (A. splendens, A. filicaulis ssp. nevadensis, A. villosa ssp. bernisii) occur at markedly different altitudinal belts. It is argued that altitudinal migrations within the contraction-expansion model provide the best explanation for the current pattern, and that at least in one case it resulted in the formation of a new hybrid taxon, A. filicaulis ssp. nevadensis.

Fuertes Aguilar, J., Gutiérrez Larena, B. & Nieto Feliner, G. 2011. Genetic and morphological diversity in Armeria (Plumbaginaceae) is shaped by glacial cycles in Mediterranean refugia. Anales Jard. Bot. Madrid 68(2): 175-197.Little is known of the direct effects of Quaternary glaciationdeglaciation cycles in plants within southern European refugia. This study, centered in the Sierra Nevada (S Spain), used RAPD and morphometric data from 36 populations of Armeria (Plumbaginaceae) from five taxa belonging to three species that are endemic to that region: A. filicaulis subsp. nevadensis, A. fili caulis subsp. trevenqueana, A. filicaulis subsp. alfacarensis, A. splendens, and A. villosa subsp. bernisii. The results based on genetic analyses at the population level (AMOVA, genetic diversity, genetic distance) and genetic and morphological analyses at individual level (haplotype phenetic distance, PCO, morphometrics) indicate that: (1) genetic diversity decreases with altitude, probably as a result of the postglacial recolonization processes, except in some secondary contact zones between taxa; (2) gene flow among interspecific populations, most likely facilitated by contraction of vegetation belts, led to the formation of hybrid taxa; (3) genetic distances among populations provide a useful basis for studying scenarios with frequent interspecific gene-flow since it allows distinguishing eventual cases of introgression from hybridogenous taxa.

A new subspecies of the Betic-Riffean species Armeria filicaulis is formally described -subsp. alfacarensis-from crystalline dolomitic sands NE of Granada (SE Spain). Its representatives exhibit a consistent morphological combination of characters on the inflorescence and flowers that support its taxonomic recognition. This is shown by means of a multivariate morphometric analysis. In one of the sites of the new taxon, where it is sympatric with A. villosa subsp. bernisii, nuclear ribosomal ITS sequences reveal gene flow between the two species, which is congruent with RAPD data and chloroplast trnL-F haplotypes. It is discussed that gene flow detected is not responsible for the origin of the new subspecies but a recent event. According to this, a differentiated biological entity related to other forms of A. filicaulis inhabiting dolomitic sands in eastern Andalusia, existed previously to gene flow events. The patterns detected (and inferred events) in A. filicaulis throughout its area suggest that the compilospecies model fits the evolution of this species as does that in A. villosa (as reported elsewhere) although not as closely.Key words: Armeria, compilospecies, ITS, morphometrics, Plumbaginaceae, RAPDs, taxonomy, trnL-F. ResumenSe describe una nueva subespecie de la bético-rifeña Armeria filicaulis, que habita en arenas dolomíticas cristalinas del nordeste de Granada (sudeste de España): subsp. alfacarensis. Su reconocimiento taxonómico se apoya en una combinación constante de caracteres relativos a la inflorescencia y flores, como se comprueba en el análisis morfométrico multivariante que presentamos. En una de las localidades donde vive la nueva subespecie de forma simpátrica con A. villosa subsp. bernisii, las secuencias de ITS del ADN ribosómico nuclear revelan flujo génico entre ambos táxones, lo cual es congruente con los resultados que se presentan de RAPDs y con los haplotipos detectados de secuencias cloroplásticas (trnL-F). Se argumenta que el flujo génico detectado no es responsable del origen de la nueva subespecie sino consecuencia de un suceso más reciente. De acuerdo con esta interpretación, con anterioridad al flujo génico aludido, existiría una entidad biológica diferenciada en la zona, afín a otras formas de A. filicaulis que habitan en arenas dolomíticas del este de Andalucía. Los patrones detectados en A. filicaulis a lo largo de su área de distribución, así como los procesos inferidos, sugieren que el modelo de evolución de esta especie se ajusta al de compiloespecie, tal como propusimos para A. villosa en otro trabajo, aunque no de forma tan patente.

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