Phylogenetic reconstruction of key traits in the evolution of ivies (Hedera L.)

The Mediterranean harbours the highest number of Hedera (Araliaceae) species, lineages, ploidy levels, and trichome morphologies of any area where the genus occurs. Previous molecular and cytogenetic studies identified two main centres of diversity for Hedera (Araliaceae), the eastern and western parts of the Mediterranean region. An explicit analysis of key traits was performed to investigate geographical patterns and ancestral character states of ivy lineages. Interestingly, the greatest diversity of Hedera was found in the western Mediterranean, including the three species of Macaronesia (H. azorica in the Azores, H. maderensis in Madeira and H. canariensis in the Canary Islands). Phylogenetic and phylogeographical analyses of the nrITS and plastid trnT-L sequences revealed multiple connections between the Mediterranean region and Asia, and suggest recurrent colonization between these two areas. Reconstruction of three important characters long used to distinguish members of the genus (trichome types, ploidy levels, and geographical areas) suggests that a diploid species with scale-like trichomes from the Mediterranean basin was the most recent common ancestor of the extant species of Hedera.     

The key role of accompanying species in the response of the critically endangered <Emphasis Type="Italic">Naufraga balearica</Emphasis> (Apiaceae) to climatic factors

This study addressed the response of Naufraga balearica, a critically endangered plant endemic to Mallorca (Balearic Islands, western Mediterranean Basin), and its adjacent community to climatic factors by assessing whether climate influences plant cover in N. balearica, including oscillation associated with seasonality, and whether the accompanying species influences its response to climatic factors. The cover of N. balearica and two other accompanying species (Erodium reichardii and Dactylis glomerata) were estimated quarterly from permanent plots over 12 years. The original time series of plant cover and climatic variables were transformed to obtain a smoothed and a detrended time series. The tendency of all variables was assessed using a simple linear regression of the smoothed series. The relationship among plant cover and climatic variables were tested by correlation. Naufraga balearica showed a declining trend, while E. reichardii and D. glomerata experienced a stable and an increasing population trend, respectively. However, all species showed an annual cover oscillation with a similar pattern. A new bioclimatic index combining temperature and precipitation variables was a good predictor although extreme meteorological events substantially altered the trends and patterns of the three species. The response of N. balearica to climatic factors, including extreme weather events, is exacerbated by the presence of other species, mainly those grasses with caespitose growth form and with a faster response to the changing environmental factors. In a climate change scenario, N. balearica would be limited to the shadiest grass-free zones. The current situation emphasises the importance of taking conservation action to guarantee the species conservation.     

Patterns of chloroplast DNA polymorphism in the endangered polyploid Centaurea borjae (Asteraceae): implications for preserving genetic diversity.

A previous study with amplified fragment length polymorphism (AFLP) fingerprints found no evidence of genetic impoverishment in the endangered Centaurea borjae and recommended that four management units (MUs) should be designated. Nevertheless, the high ploidy (6x) of this narrow endemic plant suggested that these conclusions should be validated by independent evidence derived from non-nuclear markers. Here, the variable trnT-F region of the plastid genome was sequenced to obtain this new evidence and to provide an historical background for the current genetic structure. Plastid sequences revealed little genetic variation; calling into question the previous conclusion that C. borjae does not undergo genetic impoverishment. By contrast, the conclusion that gene flow must be low was reinforced by the strong genetic differentiation detected among populations using plastid sequences (global F_ST = 0.419). The spatial arrangement of haplotypes and diversity indicate that the populations currently located at the center of the species range are probable sites of long-persistence whereas the remaining sites may have derived from a latter colonization. From a conservation perspective, four populations contributed most to the allelic richness of the plastid genome of the species and should be given priority. Combined with previous AFLP results, these new data recommended that five, instead of four, MUs should be established. Altogether, our study highlights the benefits of combining markers with different modes of inheritance to design accurate conservation guidelines and to obtain clues on the evolutionary processes behind the present-day genetic structures.     

Taxonomic revision of European Apium L. s.l.: Helosciadium W.D.J.Koch restored

European representatives of Apium sensu lato (Apiaceae), and Apium prostratum and Naufraga balearica, were studied with morphological, fruit anatomical, and palynological methods. Morphometric data were compared with phylogenetic results from previous molecular studies. This confirms that most of the European Apium species belong to a separate group corresponding to the previously named genus Helosciadium. All these species had previously been formally named as Helosciadium species, except for the new combination Helosciadium bermejoi, which is formally described here. Molecular studies place Apium prostratum and Naufraga balearica close to Apium graveolens, the type species of Apium. Our morphometric results show similarities of Naufraga with H. bermejoi, but fruit anatomy distinguishes it both from Helosciadium and from A. graveolens/prostratum. The placement of Cyclospermum leptophyllum in a separate genus is confirmed. Diagnostic keys to the genera and Helosciadium species, and an annotated checklist are given.     

Phylogeny,biogeography, and morphological ancestral character reconstruction in the Mediterranean genus Fumana (Cistaceae)

Fumana is a diverse genus of the Cistaceae family, consisting of 21 currently accepted species. In this study, nuclear (ITS) and plastid (matK, trnT‐L) molecular markers were used to reconstruct the phylogeny and to estimate divergence times, including 19 species of Fumana. Phylogenetic analyses (Bayesian Inference, Maximum Parsimony and Maximum Likelihood) confirmed the monophyly of Fumana and did not support the infrageneric divisions previously established. The results support four main clades that group species that differ in vegetative and reproductive characters. Given the impossibility to define morphological characters common to all species within the clades, our proposal is to reject infrageneric divisions. Molecular dating and ancestral area analyses provide evidence for a Miocene diversification of the genus in the north‐western Mediterranean. Ancestral state reconstructions revealed ancestral character states for some traits related to xeric and arid habitats, suggesting a preadaptation to the Mediterranean climate.     

Genetic diversity of Allium munzii (Amaryllidaceae), a rare southern California species and implication for its conservation

An understanding of genetic diversity within and among populations of rare plant species is a prerequisite to develop effective conservation management strategies and reintroduction programs. Allium munzii is a narrow endemic species distributed in western Riverside County, California, USA and known from 18 extant element occurrences. We sampled 119 individuals from 11 element occurrences and investigated within and among population genetic diversity using two variable chloroplast markers (rpL32–trnL intergenic spacer and rpoC1 intron). Of the total genetic variation detected in A. munzii, 87.65% was due to differences among occurrences. Furthermore, our results revealed that most of the element occurrences are strongly genetically differentiated. There are low levels of gene flow between occurrences, not due to isolation by distance but possibly resulting from habitat fragmentation. Non-significant values of Tajima's D and Fu's Fs were found in all occurrences suggesting no demographic expansion in A. munzii. Ex situ seed and bulb conservation is recommended to enable introduction of individuals to occurrences with low abundance and genetic diversity.     

Geographical diversity and genetic relationships among Cedrus species estimated by AFLP

Genetic diversity was described in 17 cedar populations covering the geographical range of the four species of the genus Cedrus. The study was conducted using amplified fragment length polymorphism (AFLP) on haploid tissues (megagametophytes). Eleven selective AFLP primer pairs generated a total of 107 polymorphic amplification products. Correspondence and genetic distance analyses indicated that Cedrus deodara constitutes a separate gene pool from the Mediterranean cedars. Within Mediterranean cedars, we distinguished two groups: the first one is made of Cedrus atlantica, while the second one is made of Cedrus libani and Cedrus brevifolia, these latter two species being genetically similar despite important divergence previously observed for morphological and physiological traits. The lowest intrapopulation variability was found in the two C. deodara populations analyzed. Surprisingly, C. brevifolia, the endemic taxon from the island of Cyprus that is found in small and fragmented populations, showed one of the highest levels of diversity. This unexpected pattern of diversity and differentiation observed for C. brevifolia suggests a recent divergence rather than a relictual, declining population. Patterns of diversity within- and among-populations were used to test divergence and fragmentation hypotheses and to draw conclusions for the conservation of Cedrus gene pools.     

Conservation genetics of an endemic from the Mediterranean Basin: high genetic differentiation but no genetic diversity loss from the last populations of the Sicilian Grape Hyacinth Leopoldia gussonei

The Mediterranean Basin is a biodiversity hotspot, housing >11.000 narrowly endemic plant species, many of which are declining due to mass tourism and agricultural intensification. To investigate the genetic resource impacts of ongoing habitat loss and degradation, we characterized the genetic variation in the last known populations of Leopoldia gussonei, a self-compatible endangered Sicilian Grape Hyacinth numbering less than 3,000 remaining individuals, using AFLP. Results demonstrated significant genome-wide genetic differentiation among all extant populations (Φ_ST = 0.05–0.56), and genetic clustering according to geographic location. Gene diversity was fairly constant across population (mean H_E = 0.13) and was neither affected by current population size nor by spatial isolation. Vegetation analysis showed the presence of known invasive weeds in a quarter of the populations, but we found no relation between genetic diversity and plant community composition. The marked genetic differences among populations and the profusion of rare and private alleles indicate that any further population loss will lead to significant losses of genetic diversity. Conservation efforts should therefore focus on the preservation of all sites where L. gussonei still occurs, yet the deliberate introduction of diverse material into the smallest populations seems unneeded as clonality likely mitigated genetic drift effects thus far. More generally, our findings support the view that endemic plant species with a narrow ecological amplitude, as many specialists in Mediterranean coastal ecosystems, are highly genetically differentiated and that conservation of their genetic diversity requires preservation of most, if not all of their extant populations.     

Analysis of genetic variability and population structure of the endemic medicinal Limonium sinense using molecular markers

Limonium sinense is an endemic medicinal herb used to treat fever, hemorrhage and other disorders. In the present study, population genetic diversity was elucidated using random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR) and amplified fragment length polymorphism (AFLP) primers. Percentage of polymorphic bands, Nei's gene diversity and Shannon's information index revealed a high level of genetic diversity at species level. The analysis of molecular variance revealed that 69.88% (RAPD), 71.19% (ISSR) and 70.97% (AFLP) of variability were partitioned among individuals within populations, which indicated the coherent trend by Gst (0.3849/0.3577/0.3670). Gene flow number (Nm) was 0.581/0.618/0.612, which indicated that there was a limited gene exchange between populations. The UPGMA clustering results showed that the genetic distance had no significant correlation with geographic distance. These results indicate that these markers were reliable tools for the differentiation and determination of the genetic diversity among the populations of L. sinense and the conservation of existing natural population is necessary.     

High genetic diversity and significant population structure in Cedrus brevifolia Henry, a narrow endemic Mediterranean tree from Cyprus

Endemic island plant species with a narrow distribution are often, but not always, linked to low genetic variation within populations and a lack of differentiation among populations. Cedrus brevifolia is a narrow endemic island tree species of Cyprus. Its range is restricted to a single forest, divided into five neighbouring sites. This study, using biparentally inherited nuclear microsatellites and paternally inherited plastid (chloroplast) microsatellites, assessed the genetic variation of C. brevifolia within its sole population and the level of genetic differentiation among formed sites. The results from both markers showed high diversity (nuclear H _T?=?0.70; plastid H _T?=?0.93), strongly suggesting that the species did not experience severe bottleneck events or extensive genetic drift. Besides, the maintenance of a high genetic diversity in C. brevifolia may suggest that it originates from a widespread congener species. Significant genetic differentiation at nuclear (G _ST?=?0.052) and plastid (G _ST?=?0.119) markers was found among the formed sites. Remarkably, the relatively high genetic differentiation found at plastid markers was comparable to values observed in two widespread congener cedar species. The genetic differentiation probably occurred due to fragmentation of a previously uniform population. This would lead to the shaping of different genetic groups (Bayesian analysis) and to significant population substructure. Furthermore, significant values observed for both isolation by distance and large-scale spatial genetic structure could indicate ineffective gene flow among sites and the early geographical isolation of the more isolated sites from the core population.     

The genetic diversity and spatial genetic structure of the Corso‐Sardinian endemic Ferula arrigonii Bocchieri (Apiaceae)

Corsica and Sardinia represent major hotspots of plant diversity in the Mediterranean area and are priority regions for conservation due to their high number of endemic plant species. However, information supporting human decision‐making on the conservation of these species is still scarce, especially at the genetic level. In this work, the first assessment is reported of the species‐wide spatial genetic structure and diversity of Ferula arrigonii Bocchieri, a Corso‐Sardinian endemic located in a few coastal sites and on small islands. Nine populations covering the entire natural range of the species were investigated by means of AFLP (amplified fragment length polymorphism) markers. Results indicate that this species is characterised by high levels of genetic polymorphism (92% polymorphic fragments) and of genetic diversity (H_w = 0.317) and by relatively low differentiation among populations (F_st = 0.057). PCoA, Bayesian analysis and neighbour‐joining clustering were also employed to investigate the genetic structure of this species. Three genetically distinct groups were detected, although with considerable overlap between populations.     

Narrow endemics on coastal plains: Miocene divergence of the critically endangered genus Avellara (Compositae)

Critically endangered species representing ancient, evolutionarily isolated lineages must be given priority when allocating resources for conservation projects. Sound phylogenetic analyses and divergence time estimations are required to detect them, and studies on their population genetics, ecological requirements and breeding system are needed to understand their evolutionary history and to design efficient conservation strategies. Here we present the paradigmatic case of Avellara, a critically endangered monotypic genus of Compositae inhabiting a few swamps in the west–southwest Iberian coastal plains. Our phylogenetic and dating analyses based on nuclear (ITS) and plastid (matK) DNA sequences support a Miocene (>8.6 Ma) divergence between Avellara and closely related genera, resulting in marked morphological and ecological differentiation. We found alarmingly low levels of genetic diversity, based on AFLPs and plastid DNA sequences, and confirmed the prevalence of clonal reproduction. Species distribution modelling suggested a large macroclimatically suitable area for Avellara in the western Iberian Peninsula, but its apparently narrow microecological requirements restrict its distribution to peatlands with low‐mineralised waters. Although five populations have been recorded from Spain and Portugal in the past, its current distribution may be reduced to only one population, recurrently found in the last decade but threatened by herbivory and habitat degradation. All this confirms the consideration of Avellara as a threatened species with high phylogenetic singularity, and makes it a flagship species for plant conservation in both Spain and Portugal that should be given priority in the design of in situ and ex situ conservation programmes.     

AFLP and ISSR analysis reveals high genetic variation and inter-population differentiation in fragmented populations of the endangered Litsea szemaois (Lauraceae) from Southwest China

Litsea szemaois (Lauraceae) is an endemic and endangered species from the tropical rain forests of Xishuangbanna, southern Yunnan, SW China, but habitat fragmentation, especially exacerbated by rubber planting, has caused a decline in population size of the species. AFLP and ISSR were used to investigate the genetic diversity and population structure of eight populations from across its known distribution. Three AFLP and ten ISSR primer combinations produced a total of 203 and 77 unambiguous and repeatable bands respectively, of which 164 (80.8%) and 67 (87.0%) were polymorphic for the two markers. These two markers showed that Litsea szemaois exhibits comparatively high genetic diversity at species level (heterozygosity (hs) = 0.2109) relative to some other Lauraceae. Most of the genetic variation was partitioned within populations, but genetic differentiation between populations was significant and relatively high (Φ _st = 0.2420, θ^B = 0.1986) compared with other tropical plants. The genetic characteristics of L. szemaois may be related to its outbreeding system, insect pollination and fragmented distribution. Because L. szemaois is dioecious and slow to mature, ex situ conservation across its genetic diversity is unlikely to succeed, although seedlings grow well under cultivation. Thus, in situ conservation is very important for this endangered species, especially as only 133 adult individuals are known in the wild. In particular, the Nabanhe and Mandian populations should be given a high conservation priority due to their higher genetic diversity, larger population size and better field condition, but wider sampling is required across all populations to determine additional areas with significant genetic conservation value.     

Molecular phylogeny of the genus Helix (Pulmonata: Helicidae)

The vast diversity of land snail forms is insufficiently understood even in seemingly familiar taxa. This holds for Helix Linnaeus, 1758, a genus with several common edible species which comprises the largest Western Palearctic snails. The taxonomy of this genus, which has a centre of diversity in the eastern Mediterranean, has recently undergone significant changes, in both the delimitation of the genus itself and its species‐level systematics. Here, we compare the lineage diversity of Helix, as revealed by two mitochondrial markers, with the conclusions of the recently published morphology‐based taxonomic revision. For the molecular analysis, we assembled a representative data set covering almost all species of the genus as recognized by the mentioned revision. We obtained sequences not only from fresh and preserved soft tissues but also from dried tissue remains (some of them decades old) from shell collections. Our results show that the genus Helix, in the narrow sense proposed by recent studies, is paraphyletic because the genus Tacheopsis was unambiguously revealed as one of the tip branches of Helix. The monophyly of several species, as presently recognized, was not supported; partly, this may be attributed to a lineage diversity overlooked so far. This holds also for the type species of the genus, H. pomatia, which comprises at least one additional lineage. Greece, the Aegean and western Turkey is the core area for the diversity of Helix and its relatives, and the region is probably a major long‐term refuge for large Helicidae. The highest species diversity is found along the Alpide belt from the western Balkans to southern Turkey. The diversity of Helix in Europe, north of Greece and the Apennines, is a result of a single European radiation. Our data also suggest that past human activities likely influenced the present‐day distributions of some species.     

Chloroplast sequences reveal a diversity gradient in the Mediterranean Ruppia cirrhosa species complex

Two subcosmopolitan species Ruppia maritima and Ruppia cirrhosa are recognized throughout Europe, whereas Ruppia drepanensis is endemic to SW Europe. We aimed at characterizing the geographic structure of the chloroplast DNA haplotype diversity of 56 Ruppia populations across the European part of the Mediterranean. On the basis of five cpDNA markers (total length of 2300 bp) 16 haplotypes were obtained for 1546 individuals. Three populations of R. maritima showed a single haplotype and differed in five insertions/deletions and 16 substitutions from a highly variable R. cirrhosa species complex, which included R. drepanensis. The haplotype diversity of this species complex was much higher in the western Mediterranean basin than in the eastern basin. Analysis of molecular variance (AMOVA) showed significant differentiation of R. cirrhosa between the two basins and also within the western Mediterranean thereby suggesting the latter as an important centre of Ruppia diversity. An isolation-by-distance (IBD) pattern was stronger between the West-East basin populations than within basins. A PCO analysis of the western basin populations indicated a diversity gradient with those of Sardinia as polymorph intermediates. The low diversity within the eastern basin suggests that the observed gradient could be hypothesized as a historical dispersal of only a limited number of haplotypes from west to east.     

Evaluation of AFLP markers to reveal genetic diversity in Typha

We investigated to what extent DNA-markers can assist species determination in the genus Typha. A set of AFLP markers was used to discriminate samples of the species Typha latifolia and Typha angustifolia collected in Flanders (North Belgium). The T. latifolia samples formed a compact cluster while the T. angustifolia samples were divided into smaller groups. It was not clear whether interspecific hybrids or higher levels of diversity present in the T. angustifolia dataset could account for this. As in previous surveys, using isozyme and VNTR markers, AFLP markers revealed an almost complete lack of genetic variation in Flemish T. latifolia. Despite the low degree of diversity, a significant level of genetic differentiation was found between the T. latifolia samples originating from different river basins. Whether this differentiation has any ecological relevance remains to be investigated. The methodology applied was not able to detect clonal reproduction in T. latifolia. Probably, the low levels of diversity present in this species can account for this, indicating that the usefulness of the methodology applied depends on the level of diversity present in the species studied.     

Quaternary range dynamics of ecologically divergent species (Edraianthus serpyllifolius and E. tenuifolius,Campanulaceae) within the Balkan refugium

Aim We investigated Quaternary range dynamics of two closely related but ecologically divergent species (cold‐tolerant Edraianthus serpyllifolius and thermophilic Edraianthus tenuifolius) with overlapping distribution ranges endemic to the western Balkan Peninsula, an important yet understudied Pleistocene refugium. Our aims were: to test predictions of the ‘refugia‐within‐refugia’ model of strong genetic subdivisions due to population isolation in separate refugia; to explore whether two ecologically divergent species reacted differently to Pleistocene climatic fluctuations; and to test predictions of the displacement refugia model of stronger differentiation among populations in the thermophilic E. tenuifolius compared with the cold‐tolerant E. serpyllifolius. Location The western Balkan Peninsula. Methods We gathered amplified fragment‐length polymorphism (AFLP) data and plastid DNA sequences from two to five individuals from 10 populations of E. serpyllifolius and 22 populations of E. tenuifolius, spanning their entire respective distribution areas. AFLP data were analysed using a Bayesian clustering approach and a distance‐based network approach. Plastid sequences were used to depict relationships among haplotypes in a statistical parsimony network, and to obtain age estimates in a Bayesian framework. Results In E. serpyllifolius, both AFLP and plastid sequence data showed clear geographic structure. Western populations showed high AFLP diversity and a high number of rare fragments. In E. tenuifolius, both markers congruently identified a major phylogeographic split along the lower Neretva valley in central Dalmatia. The most distinct and earliest diverging chloroplast DNA (cpDNA) haplotypes were found further south in the south‐easternmost populations. North‐western populations, identified as a separate cluster by Bayesian clustering, were characterized by low genetic diversity and a low number of rare AFLP markers. Main conclusions Clear evidence for multiple Pleistocene refugia is found not only in the high‐elevation E. serpyllifolius, but also in the lowland E. tenuifolius, despite the lack of obvious dispersal barriers, in line with the refugia‐within‐refugia model. Genealogical relationships and genetic diversity patterns support the hypothesis that cold‐adapted E. serpyllifolius responded to climatic oscillations mostly by elevational range shifts, whereas thermophilic E. tenuifolius did so mainly by latitudinal range shifts, with different phases (and probably extents) of range expansion. In contrast to the displacement refugia hypothesis, the two elevationally differentiated species do not differ in their genetic diversity.     

A Phylogeographic Split in Buxus balearica (Buxaceae) as Evidenced by Nuclear Ribosomal Markers: When ITS Paralogues Are Welcome

Sequences from the ribosomal nuclear internal transcribed spacers (ITS) have been widely used to infer evolutionary hypotheses across a broad range of living organisms. Intraspecific sequence variation is assumed to be absent or negliable in most species, but few detailed studies have been conducted to assess the apportionment of ITS sequence variation within and between plant populations. Buxus balearica was chosen as a model species to assess the levels of infraspecific and intragenomic ITS variation in rare and endangered species occurring in disjunct populations around the Mediterranean basin. Intragenomic polymorphic sites were detected for western and eastern accessions of B. balearica and in two accessions of the sister species B. sempervirens. Overall, 19 different ribotypes were found in B. balearica after sequencing 48 clones, whereas 15 ribotypes were detected in 19 clones of B. sempervirens. The integrity and secondary structure stability of the ribosomal sequences suggest that they are not pseudogenes. The high number of ribotypes recovered through cloning suggested that some sequences could be chimeric or generated in vivo by partial homogenization through gene conversion or unequal crossing-over. Average sequence divergence among B. balearica clones was 0.768%, and the most divergent sequences differed by 1.62%. Available evidence does not suggest that B. balearica paralogues have been obtained from other extant Buxus species through interspecific hybridization. The presence of several ribosomal sequences in box implies that the molecular forces driving the concerted evolution of this multigene family are not fully operational in this genus. Phylogenetic analyses of cloned ITS sequences from B. balearica displayed very poor resolution and only two clades received moderate bootstrap support. Despite the marked intragenomic sequence divergence found, ribosomal data suggest a clear phylogeographic split in B. balearica between western and eastern accessions. The distinct, nonchimeric sequences that are postulated as being present in each biogeographic group suggest that box populations from Anatolia (eastern Mediterranean) are relict. [Reviewing Editor: Dr. Rafael Zardoya]     

Genetic Diversity in Lens Species Revealed by EST and Genomic Simple Sequence Repeat Analysis

Low productivity of pilosae type lentils grown in South Asia is attributed to narrow genetic base of the released cultivars which results in susceptibility to biotic and abiotic stresses. For enhancement of productivity and production, broadening of genetic base is essentially required. The genetic base of released cultivars can be broadened by using diverse types including bold seeded and early maturing lentils from Mediterranean region and related wild species. Genetic diversity in eighty six accessions of three species of genus Lens was assessed based on twelve genomic and thirty one EST-SSR markers. The evaluated set of genotypes included diverse lentil varieties and advanced breeding lines from Indian programme, two early maturing ICARDA lines and five related wild subspecies/species endemic to the Mediterranean region. Genomic SSRs exhibited higher polymorphism in comparison to EST SSRs. GLLC 598 produced 5 alleles with highest gene diversity value of 0.80. Among the studied subspecies/species 43 SSRs detected maximum number of alleles in L. orientalis. Based on Nei’s genetic distance cultivated lentil L. culinaris subsp. culinaris was found to be close to its wild progenitor L. culinaris subsp. orientalis. The Prichard’s structure of 86 genotypes distinguished different subspecies/species. Higher variability was recorded among individuals within population than among populations.     

Low Genetic Diversity in the Rare Madeiran Endemic Armeria maderensis (Plumbaginaceae)

The genetic diversity and possible geographic structure of the Madeiran endemic Armeria maderensis have been assessed with AFLP. Its scarce distribution (less than 3 km between the two most distant localities) and restricted habitat (vertical pastures on the highest elevations of Madeira), at least in part due to grazing by goats, suggest an assessment of its conservation status. Diversity estimates obtained for A. maderensis were evaluated through comparison with reference values of AFLP diversity for outcrossing plants and, in order to correct for phylogenetic constraints, with a widespread congener analyzed with the same AFLP markers. Our results reveal that low levels of genetic diversity and a weak intraspecific genetic structure underlie the restricted distribution of A. maderensis.