Adaptive and neutral genetic differentiation among Scottish and endangered Irish red grouse (<Emphasis Type="Italic">Lagopus lagopus scotica</Emphasis>)

Studying patterns of intra-specific genetic variation among populations allows for a better understanding of population structure and local adaptation. However, those patterns may differ according to the genetic markers applied, as neutral genetic markers reflect demographic processes and random genetic drift, whereas adaptive markers also carry the footprint of selection. In combination, neutral and adaptive genetic markers permit to assess the relative roles of drift and selection in shaping population structure. Among the best understood adaptive genetic loci are the genes of the major histocompatibility complex (MHC). We here study variation and differentiation at neutral SNP markers and MHC class II genes in red grouse (Lagopus lagopus scotica) from Ireland and Scotland. Irish red grouse populations are fragmented and drastically declining, but red grouse are abundant in Scotland. We find evidence for positive selection acting on the MHC genes and variation in MHC gene copy numbers among Irish individuals. Furthermore, there was significant population differentiation among red grouse from Ireland and Scotland at the neutral SNP markers (F_ST = 0.084) and the MHC-BLB genes (F_ST: BLB1 = 0.116, BLB2 = 0.090, BLB3 = 0.104). Differentiation at the MHC-BLB1 was significantly higher than at the neutral SNP markers, suggesting that selection plays an important role in shaping MHC variation, in addition to genetic drift. We speculate that the observed differentiation pattern might be due to local adaptation to different parasite regimes. These findings have strong conservation implications and we advise against the introduction of Scottish red grouse to supplement Irish populations.     

Museum samples provide novel insights into the taxonomy and genetic diversity of Irish red grouse

The taxonomic status of red grouse in Ireland has been the subject of considerable debate over the past century. Irish red grouse are usually classified as Lagopus lagopus scoticus, which is the same subspecies as that found in Britain, but some ornithologists believe that native Irish red grouse constitute an endemic subspecies, namely L. lagopus hibernicus. The considerable decline of Irish red grouse over the past century, along with possible hybridization with introduced grouse from Britain, have highlighted the need to resolve their taxonomic status as part of a biodiversity management plan. However, genetic analysis of samples from a single point in time will provide limited insight into potentially confounding historical events such as hybridization and introgression. We therefore compared mtDNA sequences from both current and historical samples of the two putative subspecies, scoticus and hibernicus, to see if they are or were genetically distinct. Red grouse from Britain and Ireland shared mitochondrial haplotypes, and our historical data suggest that this is unlikely to be the result of recent hybridization and introgression. These findings, combined with a general lack of documented differences in behaviour and ecology, suggest that Irish red grouse should remain classified as L. lagopus scoticus. At the same time, we found evidence that a significant amount of genetic diversity has been lost from Irish red grouse over the past century, presumably as a result of diminishing population sizes and fragmentation of extant populations. A loss of habitat, combined with the declining numbers and genetic diversity of Irish red grouse, justify their designation as an All-Ireland Priority (Red List) species and a Northern Ireland Priority Species for conservation.     

Origin of, and conservation units in, the Irish red squirrel (Sciurus vulgaris) population

Knowledge of genetic relationships among wildlife populations is fundamental to their conservation, particularly where translocations are concerned. This study involved a survey of mitochondrial DNA variation in the Irish red squirrel population. Our main aims were: (1) to determine whether the Irish red squirrel population is distinct from that found in Britain, given known translocations that took place from Britain in the 1800’s; and (2) whether inclusion of Irish data into a reanalysis of European red squirrel data could reveal patterns of postglacial spread in Ireland. We found evidence that the current Irish red squirrel population may be a mixture of native and translocated stock, and relationships between Irish and European haplotypes supported a number of colonisation events of the island. Although only one haplotype was common to both Ireland and Britain, it is probable that the most common haplotypes in Ireland are British introductions that have since become extinct in Britain. There was a significant regional genetic structure in Ireland (P < 0.001), as well as between all Irish and British regions. Although it is likely that the red squirrel will not be fundamental in tracing the colonisation of Ireland by mammals, the data demonstrated that individual regions within Ireland, as well as the Irish population as a whole, are distinct both from the British population and from each other and, therefore, these populations should be treated as separate Management Units (MU) in conservation strategies.     

Morphological diversity of the red squirrel, <Emphasis Type="Italic">Sciurus vulgaris</Emphasis>, in Ireland

The red squirrel in Britain and Ireland has been described as a separate subspecies, Sciurus vulgaris leucourus, based on bleaching of the tail and ear tufts. However, recent investigations in northern England found this light colour confined to one area, probably due to the rapid spread of introduced continental European red squirrels. This study reports the first detailed survey of tail colour and cranial measurements in the Irish red squirrel population to (1) investigate the distribution of the light colour morph in Ireland and (2) determine whether the Irish red squirrel population is morphologically divergent from populations elsewhere in the species range. The light tail colour was found in 57% of individuals and in all regions, although it was most common in the northwest. The mixture of different colour morphs indicates the Irish population is a mixture of different subspecies, including S. vulgaris leucourus, while the cranial measurements suggest the Irish squirrel may be morphologically divergent from populations elsewhere. Combined, these results support previous suggestions that conservation measures seek to maintain the diversity within the Irish red squirrel population.     

Genetic structure of Eurasian badgers Meles meles (Carnivora: Mustelidae) and the colonization history of Ireland

The present study examined the contemporary genetic composition of the Eurasian badger, Meles meles, in Ireland, Britain and Western Europe, using six nuclear microsatellite loci and a 215‐bp fragment of the mitochondrial DNA control region. Significant population structure was evident within Europe (global multilocus microsatellite F_ST = 0.205, P < 0.001; global mitochondrial control region Φ_ST = 0.399, P < 0.001). Microsatellite‐based cluster analyses detected one population in Ireland, whereas badgers from Britain could be subdivided into several populations. Excluding the island populations of Ireland and Britain, badgers from Western Europe showed further structuring, with evidence of discrete Scandinavian, Central European, and Spanish populations. Mitochondrial DNA cluster analysis grouped the Irish population with Scandinavia and Spain, whereas the majority of British haplotypes grouped with those from Central Europe. The findings of the present study suggest that British and Irish badger populations colonized from different refugial areas, or that there were different waves of colonization from the source population. There are indications for the presence of an Atlantic fringe element, which has been seen in other Irish species. We discuss the results in light of the controversy about natural versus human‐mediated introductions. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Retracing the history and planning the future of the red squirrel (<Emphasis Type="Italic">Sciurus vulgaris</Emphasis>) in Ireland using non-invasive genetics

The Eurasian red squirrel’s (Sciurus vulgaris) history in Ireland is largely unknown, but the original population is thought to have been driven to extinction by humans in the seventeenth century, and multiple records exist for its subsequent reintroduction in the nineteenth century. However, it is currently unknown how these reintroductions affect the red squirrel population today, or may do so in the future. In this study, we report on the development of a DNA toolkit for the non-invasive genetic study of the red squirrel. Non-invasively collected red squirrel samples were combined with other samples collected throughout Ireland and previously published mitochondrial DNA (mtDNA) data from Ireland, Great Britain and Continental Europe to give an insight into population genetics and historical introductions of the red squirrel in Ireland. Our findings demonstrate that the Irish red squirrel population is on a national scale quite genetically diverse, but at a local level contains relatively low levels of genetic diversity, and there is also evidence of genetic structure. This is likely an artefact of the introduction of a small number of genetically similar animals to specific sites. A lack of continuous woodland cover in Ireland has prevented further mixing with animals of different origins that may have been introduced even to neighbouring sites. Consequently, some of these genetically isolated populations are or may in the future be at risk of extinction. The Irish red squirrel population contains mtDNA haplotypes of both a British and Continental European origin, the former of which are now extinct or simply not recorded in contemporary Great Britain. The Irish population is therefore important in terms of red squirrel conservation not only in Ireland, but also for Great Britain, and should be appropriately managed.     

Genetic diversity and differentiation among Lagopus lagopus populations in Scandinavia and Scotland: evolutionary significant units confirmed by SNP markers

Single Nucleotide Polymorphism in four Scandinavian populations of willow grouse (Lagopus lagopus) and two Scottish populations of red grouse (Lagopus lagopus scoticus) were assessed at 13 protein‐coding loci. We found high levels of diversity, with one substitution every 55 bp as an average and a total of 76 unlinked parsimony informative SNPs. Different estimators of genetic diversity such as: number of synonymous and non‐synonymous sites, average number of alleles, number and percentage of polymorphic loci, mean nucleotide diversity (π_s, π_a) and gene diversity at synonymous and non‐synonymous sites showed higher diversity in the northern populations compared to southern ones. Strong levels of purifying selection found in all the populations together with neutrality tests conforming to neutral expectations agree with large effective population sizes. Assignment tests reported a clear distinction between Scandinavian and Scottish grouse suggesting the existence of two different evolutionary significant units. The divergence time between willow and red grouse ranging between 12 500 and 125 000 years, in conjunction with the presence of ‘specific’ markers for each subspecies prompt a reassessment of the taxonomical status of the Scottish red grouse.     

A survey of the hybridisation status of Cervus deer species on the island of Ireland

Red deer (Cervus elaphus) did not recolonise Ireland after the last glaciation, but the population in Co. Kerry is descended from an ancient (c. 5000 BP) introduction and merits conservation. During the mid-19th century exotic species including North American wapiti (C. canadensis) and Japanese sika deer (C. nippon nippon) were introduced to Ireland, mainly via Powerscourt Park, Co. Wicklow. While wapiti failed to establish, sika thrived, dispersed within Co. Wicklow and were translocated to other sites throughout Ireland. Red deer and sika are known to have hybridised in Ireland, particularly in Co. Wicklow, but an extensive survey with a large, highly diagnostic marker panel is required to assess the threat hybridisation potentially poses to the Co. Kerry red deer population. Here, 374 individuals were genotyped at a panel of 22 microsatellites and at a single mtDNA marker that are highly diagnostic for red deer and Japanese sika. The microsatellites are also moderately diagnostic for red deer and wapiti. Wapiti introgression was very low [trace evidence in 2 (0.53 %) individuals]. Despite long-standing sympatry of red deer and sika in the area, no red deer-sika hybrids were detected in Co. Kerry suggesting strong assortative mating by both species in this area. However, 80/197 (41 %) of deer sampled in Co. Wicklow and 7/15 (47 %) of deer sampled in Co. Cork were red-sika hybrids. Given their proximity and that hybrids are less likely to mate assortatively than pure individuals, the Co. Cork hybrids pose a threat to the Co. Kerry red deer.     

Phylogeography of Chinese cherry (Prunus pseudocerasus Lindl.) inferred from chloroplast and nuclear DNA: insights into evolutionary patterns and demographic history

Chinese cherry (Prunus pseudocerasus Lindl.) is a commercially valuable fruit crop in China. In order to obtain new insights into its evolutionary history and provide valuable recommendations for resource conservation, phylogeographic patterns of 26 natural populations (305 total individuals) from six geographic regions were analyzed using chloroplast and nuclear DNA fragments. Low levels of haplotype and nucleotide diversity were found in these populations, especially in landrace populations. It is likely that a combined effect of botanical characteristics impact the effective population size, such as inbreeding mating system, long life span, as well as vegetative reproduction. In addition, strong bottleneck effect caused by domestication, together with founder effect after dispersal and subsequent demographic expansion, might also accelerate the reduction of the genetic variation in landrace populations. Interestingly, populations from Longmen Mountain (LMM) and Daliangshan Mountain (DLSM) exhibited relatively higher levels of genetic diversity, inferring the two historical genetic diversity centers of the species. Moreover, moderate population subdivision was also detected by both chloroplast DNA (G_ST = 0.215; N_ST = 0.256) and nuclear DNA (G_ST = 0.146; N_ST = 0.342), respectively. We inferred that the episodes of efficient gene flow through seed dispersal, together with features of long generation cycle and inbreeding mating system, were likely the main contributors causing the observed phylogeographic patterns. Finally, factors that led to the present demographic patterns of populations from these regions and taxonomic varieties were also discussed.     

Genetic structure of Pyrenophora teres net and spot populations as revealed by microsatellite analysis

The population structure of the fungal pathogen Pyrenophora teres, collected mainly from different regions of the Czech and Slovak Republics, was examined using a microsatellite analyses (SSR). Among 305 P. teres f. teres (PTT) and 82 P. teres f. maculata (PTM) isolates that were collected, the overall gene diversity was similar (? = 0.12 and ? = 0.13, respectively). A high level of genetic differentiation (F_ST = 0.46; P < 0.001) indicated the existence of population structure. Nine clusters that were found using a Bayesian approach represent the genetic structure of the studied P. teres populations. Two clusters consisted of PTM populations; PTT populations formed another seven clusters. An exact test of population differentiation confirmed the results that were generated by Structure. There was no difference between naturally infected populations over time, and genetic distance did not correlate with geographical distance. The facts that all individuals had unique multilocus genotypes and that the hypothesis of random mating could not be rejected in several populations or subpopulations serve as evidence that a mixed mating system plays a role in the P. teres life cycle. Despite the fact that the genetic differentiation value between PTT and PTM (F_ST = 0.30; P < 0.001) is lower than it is between the populations within each form (F_ST = 0.40 (PTT); F_ST = 0.35 (PTM); P < 0.001) and that individuals with mixed PTT and PTM genomes were found, the two forms of P. teres form genetically separate populations. Therefore, it can be assumed that these populations have most likely undergone speciation.     

Genetic diversity and population structure of the red stingray,Dasyatis akajei inferred by AFLP marker

To examine population genetic diversity and variation of the red stingray Dasyatis akajei, samples from 1 freshwater region and 6 coastal localities within its distribution range were analyzed by using amplified fragment length polymorphism (AFLP) technology. A total of 207 loci were identified by 4 primer combinations from 87 individuals, 174 of which were polymorphic (84.1%). A high level of Nei's gene diversity was observed with the overall value of 0.230 ± 0.179. No significant genealogical clusters associated with sampling sites were revealed on the UPGMA tree. Both analysis of molecular variance (AMOVA, Φ_ST = 0.085, P = 0.00) and pairwise F_ST indicated significant genetic differentiation among four marine samples. However, no particular genetic differentiation was detected between marine and the limited sampling freshwater populations (AMOVA, Φ_CT = 0.056, P > 0.05). Except for the TZ vs. WZ (5.193), the gene flow estimates (N_m) demonstrated the effective immigrants were 1.918-2.976, suggesting low level dispersal between pairwise marine populations. Species-specific habits (demersal and sluggish habits) are probably responsible for the population structuring.     

Genotypic and phenotypic consequences of reintroduction history in the black-footed ferret (<Emphasis Type="Italic">Mustela nigripes</Emphasis>)

Population augmentation with translocated individuals has been shown to alleviate the effects of bottlenecks and drift. The first step to determine whether restoration for genetic considerations is warranted is to genetically monitor reintroduced populations and compare results to those from the source. To assess the need for genetic restoration, we evaluated genetic diversity and structure of reintroduced (n = 3) and captive populations of the endangered black-footed ferret (Mustela nigripes). We measured genotypic changes among populations using seven microsatellite markers and compared phenotypic changes with eight morphometric characters. Results indicated that for the population which rapidly grew post-reintroduction, genetic diversity was equivalent to the captive, source population. When growth languished, only the population that was augmented yearly maintained diversity. Without augmentation, allelic diversity declined precipitously and phenotypic changes were apparent. Ferrets from the genetically depaupertate population had smaller limbs and smaller overall body size than ferrets from the two populations with greater diversity. Population divergence (F _ST = 0.10 ± 0.01) was surprisingly high given the common source of populations. Thus, it appears that 5–10 years of isolation resulted in both genotypic divergence and phenotypic changes to populations. We recommend translocation of 30–40 captive individuals per annum to reintroduction sites which have not become established quickly. This approach will maximize the retention of genetic diversity, yet maintain the beneficial effects of local adaptation without being swamped by immigration.     

Phylogeographic mitogenomics of Atlantic cod Gadus morhua: Variation in and among trans‐Atlantic,trans‐Laurentian,Northern cod,and landlocked fjord populations

The historical phylogeography, biogeography, and ecology of Atlantic cod (Gadus morhua) have been impacted by cyclic Pleistocene glaciations, where drops in sea temperatures led to sequestering of water in ice sheets, emergence of continental shelves, and changes to ocean currents. High‐resolution, whole‐genome mitogenomic phylogeography can help to elucidate this history. We identified eight major haplogroups among 153 fish from 14 populations by Bayesian, parsimony, and distance methods, including one that extends the species coalescent back to ca. 330 kya. Fish from the Barents and Baltic Seas tend to occur in basal haplogroups versus more recent distribution of fish in the Northwest Atlantic. There was significant differentiation in the majority of trans‐Atlantic comparisons (Φ_ST = .029–.180), but little or none in pairwise comparisons within the Northwest Atlantic of individual populations (Φ_ST = .000–.060) or defined management stocks (Φ_ST = .000–.023). Monte Carlo randomization tests of population phylogeography showed significantly nonrandom trans‐Atlantic phylogeography versus absence of such structure within various partitions of trans‐Laurentian, Northern cod (NAFO 2J3KL) and other management stocks, and Flemish Cap populations. A landlocked meromictic fjord on Baffin Island comprised multiple identical or near‐identical mitogenomes in two major polyphyletic clades, and was significantly differentiated from all other populations (Φ_ST = .153–.340). The phylogeography supports a hypothesis of an eastern origin of genetic diversity ca. 200–250 kya, rapid expansion of a western superhaplogroup comprising four haplogroups ca. 150 kya, and recent postglacial founder populations.     

Genetic discontinuity among regional populations of <Emphasis Type="Italic">Lophelia pertusa</Emphasis> in the North Atlantic Ocean

Knowledge of the degree to which populations are connected through larval dispersal is imperative to effective management, yet little is known about larval dispersal ability or population connectivity in Lophelia pertusa, the dominant framework-forming coral on the continental slope in the North Atlantic Ocean. Using nine microsatellite DNA markers, we assessed the spatial scale and pattern of genetic connectivity across a large portion of the range of L. pertusa in the North Atlantic Ocean. A Bayesian modeling approach found four distinct genetic groupings corresponding to ocean regions: Gulf of Mexico, coastal southeastern U.S., New England Seamounts, and eastern North Atlantic Ocean. An isolation-by-distance pattern was supported across the study area. Estimates of pairwise population differentiation were greatest with the deepest populations, the New England Seamounts (average F _ST = 0.156). Differentiation was intermediate with the eastern North Atlantic populations (F _ST = 0.085), and smallest between southeastern U.S. and Gulf of Mexico populations (F _ST = 0.019), with evidence of admixture off the southeastern Florida peninsula. Connectivity across larger geographic distances within regions suggests that some larvae are broadly dispersed. Heterozygote deficiencies were detected within the majority of localities suggesting deviation from random mating. Gene flow between ocean regions appears restricted, thus, the most effective management scheme for L. pertusa involves regional reserve networks.     

Genetic divergence in nuclear genomes between populations of <Emphasis Type="Italic">Fagus crenata</Emphasis> along the Japan Sea and Pacific sides of Japan

Genetic diversity and structure in Fagus crenata were studied by analyzing 14 nuclear microsatellite loci in 23 populations distributed throughout the species’ range. Although population differentiation was very low (F _ST = 0.027; R _ST = 0.041), both neighbor-joining tree and Bayesian clustering analyses provided clear evidence of genetic divergence between populations along the Japan Sea (Japan Sea lineage) and Pacific (Pacific lineage) sides of Japan, indicating that physical barriers to migration and gene flow, notably the mountain ranges separating the populations along the Japan Sea and Pacific sides, have promoted genetic divergence between these populations. The two lineages of the nuclear genome are generally consistent with those of the chloroplast genome detected in a previous study, with several discrepancies between the two genomes. Within-population genetic diversity was generally very high (average H _E = 0.839), but decreased in a clinal fashion from southwest to northeast, largely among populations of the Japan Sea lineage. This geographical gradient may have resulted from the late-glacial and postglacial recolonization to the northeast, which led to a loss of within-population genetic diversity due to cumulative founder effects.     

Landscape genetic structure of <Emphasis Type="Italic">Betula maximowicziana</Emphasis> in the Chichibu mountain range,central Japan

We evaluated the genetic structure of 16 Betula maximowicziana populations in the Chichibu mountain range, central Japan, located within a 25-km radius; all but two populations were at altitudes of 1,100–1,400 m. The results indicate the effects of geographic topology on the landscape genetic structure of the populations and should facilitate the development of local-scale strategies to conserve and manage them. Analyses involving 11 nuclear simple sequence repeat loci showed that most populations had similar intrapopulation genetic diversity parameters. Population differentiation (F _ST = 0.021, G′_ST = 0.033) parameters for the populations examined were low but were relatively high compared to those obtained in a previous study covering populations in a much larger area with a radius of approximately 1,000 km (F _ST = 0.062, G′_ST = 0.102). Three populations (Iriyama, Kanayamasawa, and Nishizawa) were differentiated from the other populations by Monmonier’s and spatial analysis of molecular variance algorithms or by STRUCTURE analysis. Since a high mountain ridge (nearly 2,000 m) separates the Kanayamasawa and Nishizawa populations from the other 14 populations and the Kanayamasawa and Nishizawa populations are themselves separated by another mountain ridge, the genetic structure appears to be partly due to mountain ridges acting as genetic barriers and restricting gene flow. However, the Iriyama population is genetically different but not separated by any clear geographic barrier. These results show that the landscape genetic structure is complex in the mountain range and we need to pay attention, within landscape genetic studies and conservation programs, to geographic barriers and local population differentiation.     

Genetic variation of wild litchi (<Emphasis Type="Italic">Litchi chinensis</Emphasis> Sonn. subsp. <Emphasis Type="Italic">chinensis</Emphasis>) revealed by microsatellites

Understanding the amount and distribution of genetic diversity in natural populations can inform the conservation strategy for the species in question. In this study, genetic variation at eight nuclear microsatellite loci was used to investigate genetic diversity and population structure of wild litchi (Litchi chinensis Sonn. subsp. chinensis). Totally 215 individuals were sampled, representing nine populations of wild litchi. All eight loci were polymorphic, with a total of 51 alleles. The expected heterozygosity in the nine populations ranged from 0.367 to 0.638 with an average value of 0.526. Inbreeding within wild litchi populations was indicated by a strong heterozygote defect. Significant bottleneck events were detected in the populations from Yunnan and Vietnam, which could be responsible for lower levels of genetic diversity in these populations. Measures of genetic differentiation (F _ST = 0.269) indicated strong differentiation among wild litchi populations. Significant correlation was found between genetic differentiation and geographical distance (r = 0.655, P = 0.002), indicating a strong isolation by distance in these populations. Bayesian clustering suggested genetic separation among three regional groups, namely, the western group, the central group and the eastern group. Some conservation strategies for wild litchi populations were also proposed based on our results.     

Genetic analysis of two Portuguese populations of <Emphasis Type="Italic">Ruditapes decussatus</Emphasis> by RAPD profiling

The clam Ruditapes decussatus is commercially important in the south of Portugal. The random amplified polymorphic DNA (RAPD) technique was applied to assess the genetic diversity and population structure of two Portuguese populations occurring in the Ria Formosa (Faro) and the Ria de Alvor, respectively. Twenty-five individuals of each population were investigated by RAPD profiles. Genetic diversity within populations, measured by the percentage of polymorphic loci (%P), varied between 68.57% (Alvor) and 73.88% (Faro). Shannon’s information index (H) and Nei’s gene diversity (h) were 0.281 and 0.176, respectively, for the Alvor population and 0.356 and 0.234 for the Faro population. Overall, genetic variation within R. decussatus populations was high. The total genetic diversity (H _T) was explained by a low variation between populations (G _ST = 0.145), which is consistent with high gene flow (N _m = 2.9). The analysis of molecular variance (AMOVA) showed that 65% of variability is within populations and 35% between populations (Φ_PT = 0.345; P ≥ 0.001). The value of Nei’s genetic distance was 0.0881, showing a low degree of population genetic distance, despite the different geographic origin. This is the first study on the population genetics of R. decussatus by RAPD technique. The results may be useful for restocking programs and aquaculture.     

Plastid DNA variation in highly fragmented populations of <Emphasis Type="Italic">Microbiota decussata</Emphasis> Kom. (Cupressaceae), an endemic to Sikhote Alin Mountains

Microbiota decussata Kom. (Cupressaceae) is a subalpine species endemic to the Sikhote Alin Mountains with populations scattered throughout the range. We used sequence data for four noncoding regions of chloroplast DNA to characterize the genetic diversity in populations sampled from different parts of M. decussata natural range. No variation was observed in the trnT–trnF region, whereas the trnH–psbA, trnS–trnfM, and trnS–trnG regions showed polymorphisms. At the species level, we found a low nucleotide diversity (π = 0.0009) and high haplotype diversity (h = 0.981) as well as high differentiation (Φ_ST = 0.420). N _ST and G _ST values suggested the existence of a phylogeographic structure in M. decussata. The observed patterns of diversity could be explained in part by ecological features of the species and its long-term persistence throughout the range with population expansion, successive fragmentation and isolation.