Conservation genetics of highly isolated populations of the xerothermic beetle Crioceris quatuordecimpunctata (Chrysomelidae)

Xerothermic species are rare and threatened in central and eastern Europe. In light of the continuing loss of steppe‐like habitats due to anthropogenic fragmentation and degradation, the evaluation of genetic variation in populations inhabiting them is of immediate importance if appropriate conservation measures are to be undertaken. Here we report on the genetic diversity of the rare leaf beetle Crioceris quatuordecimpunctata, whose populations in central and eastern Europe inhabit highly geographically isolated areas. All of the studied populations (in Poland, Ukraine, and Slovakia) were differentiated at the mitochondrial marker COI. However, with respect to the nuclear marker ITS1, Polish populations were monomorphic, but distinct from all other populations. The distinctiveness of the studied populations was confirmed by Wolbachia screening, which showed that all populations carried different strains (one or two), which were probably transferred independently from other insects. On the other hand, no diversity was found in any marker within particular populations, which could be caused (at least for mtDNA) by a Wolbachia selective sweep. Crioceris quatuordecimpunctata probably consists of isolated populations, which went through narrow bottlenecks leading to a drastic reduction in their genetic diversity. As these populations are reciprocally monophyletic for mtDNA haplotypes and show a significant divergence of allele frequencies at nuclear loci, they could be classified as evolutionarily significant units (ESUs). In addition, DNA barcodes were used to identify Asparagus officinalis as the host plant for members of all studied populations. These data should be valuable in efforts to conserve populations of C. quatuordecimpunctata (e.g., for guiding reintroductions).     

Conservation genetics of xerothermic beetles in Europe: the case of <Emphasis Type="Italic">Centricnemus leucogrammus</Emphasis>

Xerothermic habitats are closely related to continental steppes of Eurasia and contain communities rich in rare and endemic species, especially insects. Considering the dramatic loss of xerothermic habitats due to climatic and anthropogenic changes the evaluation of genetic variation and phylogeographical patterns in xerothermic species is a matter of utmost importance if appropriate conservation measures are to be undertaken. In this paper 3 mitochondrial genes and 3 nuclear markers were used for evaluation of genetic diversity of populations of the weevil Centricnemus leucogrammus from central-east Europe. These data were used for the recognition of conservation units as well as centers of genetic diversity which could be considered as present “warm-stage” refugia for xerothermic beetle assemblages. The most diverse are eastern and central populations from Ukraine and central Poland, however, also isolated groups of populations from the Pannonian Basin and northern Poland possessed a unique genetic signature. This lead to the conclusion that all three regional groups of populations are significantly isolated from each other and represent distinct evolutionary lineages so they should be considered as separate Management Units and Evolutionary Significant Units. C. leucogrammus can be regarded as an excellent representative for typically xerothermophilous, flightless beetles and knowledge about its genetic diversity may be used for the conservation and management of entire xerothermic communities, especially for those with low mobility invertebrate taxa. Further research on the genetic diversity of various organisms with varying levels of mobility should be undertaken to broaden our knowledge on the conservations needs of xerothermic assemblages.     

A study of the genetic variation of the aquatic fern Marsilea quadrifolia L. preserved in botanical collections in Poland and originated from natural populations in Europe

Aim of the present study was to evaluate the genetic diversity of selected European populations of Marsilea quadrifolia L. and to assess the applicability of those genetic resources of Marsilea quadrifolia L. that have been preserved in Polish botanical gardens, for the reintroduction of this species into its historical range in Poland. Three Polish populations that originated from botanical collections (Zabrze, ?arów and Pu?awy) and four natural populations (two from Slovakia (Slovakia I and Slovakia II), one from France and one from Germany) were analyzed using Amplified Fragment Length Polymorphism (AFLP) markers. A very low level of genetic variation was found both within and between the populations in the study, which likely resulted from a genetic bottleneck probably caused by human activities. Plants with the same AFLP fingerprint were found across several populations; however, singleton samples with a unique AFLP band pattern were also present within all of the populations. The presence of singletons led to relatively high values of Simpson's diversity index, which may suggest a considerable effect of mutations and some possibility of sexual reproduction as sources of the observed variation. The partitioning of molecular variance was calculated using hierarchical AMOVA, which showed that a negligible value of only 0.81% of the variation was explained by the category of population, i.e. plants originating from the botanical collections or from the natural habitats. This result indicates that M. quadrifolia populations from botanical collections resemble natural populations in terms of the level of their genetic variation and that the populations that were obtained from the Polish collections could be used for the successful reintroduction of this species into its historical range in Poland, and a similar situation may be given also in other areas of occurrence of this plant that is under threat throughout its area of occurrence in Europe.     

Dispersal ecology of the endangered woodland lichen Lobaria pulmonaria in managed hemiboreal forest landscape

Changes in the forest management practices have strongly influenced the distribution of species inhabiting old-growth forests. The epiphytic woodland lichen Lobaria pulmonaria is frequently used as a model species to study the factors affecting the population biology of lichens. We sampled 252 L. pulmonaria individuals from 12 populations representing three woodland types differing in their ecological continuity and management intensity in Estonia. We used eight mycobiont-specific microsatellite loci to quantify genetic diversity among the populations. We calculated the Sørensen distance to estimate genetic dissimilarity among individuals within populations. We revealed that L. pulmonaria populations have significantly higher genetic diversity in old-growth forests than in managed forests and wooded meadows. We detected a significant woodland-type-specific pattern of genetic dissimilarity among neighbouring L. pulmonaria individuals, which suggests that in wooded meadows and managed forests dominating is vegetative reproduction. The vegetative dispersal distance between the host trees of L. pulmonaria was found to be only 15–30 m. Genetic dissimilarity among individuals was also dependent on tree species and trunk diameter. Lobaria pulmonaria populations in managed forests included less juveniles compared to old-growth forests and wooded meadows, indicating that forest management influences life stage structure within populations. We conclude that as intensive stand management reduces the genetic diversity of threatened species in woodland habitats, particular attention should be paid to the preservation of remnant populations in old-growth habitats. Within managed habitats, conservation management should target on maintenance of the stand’s structural diversity and availability of potential host trees.     

Genetic Diversity and Population Structure of the Rare and Endangered Plant Species Pulsatilla patens (L.) Mill in East Central Europe

Pulsatilla patens s.s. is a one of the most endangered plant species in Europe. The present range of this species in Europe is highly fragmented and the size of the populations has been dramatically reduced in the past 50 years. The rapid disappearance of P. patens localities in Europe has prompted the European Commission to initiate active protection of this critically endangered species. The aim of this study was to estimate the degree and distribution of genetic diversity within European populations of this endangered species. We screened 29 populations of P. patens using a set of six microsatellite primers. The results of our study indicate that the analyzed populations are characterized by low levels of genetic diversity (H_o = 0.005) and very high levels of inbreeding (F_IS = 0.90). These results suggest that genetic erosion could be partially responsible for the lower fitness in smaller populations of this species. Private allelic richness was very low, being as low as 0.00 for most populations. Average genetic diversity over loci and mean number of alleles in P. patens populations were significantly correlated with population size, suggesting severe genetic drift. The results of AMOVA point to higher levels of variation within populations than between populations.The results of Structure and PCoA analyses suggest that the genetic structure of the studied P. patens populations fall into three clusters corresponding to geographical regions. The most isolated populations (mostly from Romania) formed a separate group with a homogeneous gene pool located at the southern, steppic part of the distribution range. Baltic, mostly Polish, populations fall into two genetic groups which were not fully compatible with their geographic distribution.Our results indicate the serious genetic depauperation of P. patens in the western part of its range, even hinting at an ongoing extinction vortex. Therefore, special conservation attention is required to maintain the populations of this highly endangered species of European Community interest.     

Cryptic genetic subdivision in the San Benito evening primrose (Camissonia benitensis)

When rare plants are distributed across a range of habitats, ecotypic differentiation may arise requiring customized conservation measures. The rate of local adaptation may be accelerated in complex landscapes with numerous physical barriers to gene flow. In such cases, examining the distribution of genetic diversity is essential in determining conservation management units. We investigated the distribution of genetic diversity in the federally threatened Camissonia benitensis (Onagraceae), which grows in two distinct serpentine habitats across several watersheds in San Benito, Fresno, and Monterey Cos., CA, USA. We compared genetic diversity with that of its two widespread relatives, C. contorta and C. strigulosa, and examined the potential for hybridization with the latter species. Genotyping results using seven heterospecific microsatellite markers indicate that differentiation between habitat types was weak (F _ST = 0.0433) and in an AMOVA analysis, there was no significant partitioning of molecular variation between habitats. Watersheds accounted for 11.6 % of the molecular variation (pairwise F _ST = 0.1823–0.4275). Three cryptic genetic clusters were identified by InStruct and STRUCTURE that do not correlate with habitat or watershed. C. benitensis exhibits 5–11× higher inbreeding levels and 0.54× lower genetic diversity in comparison to its close relatives. We found no evidence of hybridization between C. benitensis and C. strigulosa. To maximize conservation of the limited amount of genetic diversity in C. benitensis, we recommend mixing seed representing the three cryptic genetic clusters across the species’ geographic range when establishing new populations.     

Population Structure of and Conservation Strategies for Wild Pyrus ussuriensis Maxim. in China

Pyrus ussriensis Maxim. is native to the northern part of China, but whose habitats are currently being destroyed by environmental changes and human deforestation. An investigation of population structure and genetic diversity of wild Ussurian pear is a priority in order to acquire fundamental knowledge for conservation. A total of 153 individuals of wild Ussurian pear from the main habitats, Heilongjiang, Jilin, and Inner Mongolia in China, possessed low genetic diversity as a result of habitat fragmentation. The genetic diversity of the populations in Inner Mongolia and north east of Heilongjiang was especially low and there was the possibility of inbreeding. Wild Ussurian pears were divided into 5 groups based on the Bayesian clustering method using 20 nuclear SSRs (nSSRs) and 5 groups by haplotype distributions using 16 chloroplast SSRs (cpSSRs), and the populations in Inner Mongolia and north east of Heilongjiang represented unique genotypes. AMOVA indicated there was a 20.05% variation in nSSRs and a 44.40% variation in cpSSRs among populations. These values are relatively high when compared to those of other tree species. Haplotype E, positioned in the center of the cpSSR analysis network and showed the largest number of connections with other haplotypes, represented the most important haplotype. Inner Mongolia and the north east of Heilongjiang are two areas that need urgent conservation because of their genetic vulnerability and peculiarity. We determined 4 conservation units based on the clustering by nSSRs and cpSSRs, and geographic factor. This information is helpful in deciding the conservation strategies for wild Ussurian pear in China.     

Patterns of geographic distribution have a considerable influence on population genetic structure in one common and two rare species of Rhododendron (Ericaceae)

Genetic diversity is essential for species to sustain their populations and evolutionary potential. In order to develop effective conservation strategies for rare species, it is necessary to understand differences in patterns of genetic diversity between common and rare species. Data about population genetic structure is important to design effective conservation strategies for rare species. In this study, we compared the genetic diversity and population genetic structure of a common species, Rhododendron weyrichii, to those of two rare species, Rhododendron sanctum and Rhododendron amagianum, with different geographic distributions. We analyzed five microsatellite loci in 16 populations of R. weyrichii, 9 populations of R. sanctum, and 6 populations of R. amagianum. As expected, the level of genetic diversity indicated by allelic richness and gene diversity was lower for the rare species R. sanctum than for the common species R. weyrichii. However, there was no statistically significant difference in genetic diversity between R. weyrichii and the other rare species, R. amagianum. Analyses of the isolation-by-distance pattern, neighbor-joining trees, and Bayesian clustering indicated that R. sanctum had a strong population genetic structure whereas R. amagianum exhibited very weak genetic structure among populations and that there was moderate population genetic structure for R. weyrichii. Therefore, the degree and pattern of population genetic structure in each species was unrelated to its rarity and instead merely reflected its geographic distribution.     

Comparative molecular studies on the genetic diversity of an ex situ garden collection and its source population of the critically endangered polish endemic plant <Emphasis Type="Italic">Cochlearia polonica</Emphasis> E. Fröhlich

Cochlearia polonica (Brassicaceae) is a narrow endemic plant extinct in the wild, known only from one transplanted population in southern Poland. The suitable habitats for this species are confined to shallow water courses and springs on sandy ground. During the second half of twentieth century the natural populations of C. polonica declined due to anthropogenic effects (primarily due to a major change of ground water levels). Consequently, 14 individuals were transplanted in the 1970 s into a secondary locality of similar habitat conditions of Centuria river. In the late 1980s five individuals from the transplanted population were used to establish an artificial ex situ site in the Botanical Garden of the Polish Academy of Sciences in Warsaw. In order to investigate the effect of 18 years of ex situ conservation, the level of genetic diversity and genetic structure of the ex situ conserved botanical garden population and its source population were sampled and analyzed using inter simple sequence repeat markers. The percentage values of polymorphic bands and Nei’s gene diversity indicated average genetic variation at species level, whereas at the population level it was relatively low, especially for the garden population. The results suggested differences in genetic composition of the analyzed populations and implied homogenization of the genetic structure of the ex situ conserved population. Ex situ conservation resulted in a decrease of the species’ genetic diversity, implying that the artificial population only partly represents the primary genetic variability found in the source population.     

Genetic Population Structure of Local Populations of the Endangered Saltmarsh Sesarmid Crab Clistocoeloma sinense in Japan

During recent decades, over 40% of Japanese estuarine tidal flats have been lost due to coastal developments. Local populations of the saltmarsh sesarmid crab Clistocoeloma sinense, designated as an endangered species due to the limited suitable saltmarsh habitat available, have decreased accordingly, being now represented as small remnant populations. Several such populations in Tokyo Bay, have been recognised as representing distributional limits of the species. To clarify the genetic diversity and connectivity among local coastal populations of Japanese Clistocoeloma sinense, including those in Tokyo Bay, mitochondrial DNA analyses were conducted in the hope of providing fundamental information for future conservation studies and an understanding of metapopulation dynamics through larval dispersal among local populations. All of the populations sampled indicated low levels of genetic diversity, which may have resulted from recent population bottlenecks or founder events. However, the results also revealed clear genetic differentiation between two enclosed-water populations in Tokyo Bay and Ise-Mikawa Bay, suggesting the existence of a barrier to larval transport between these two water bodies. Since the maintenance of genetic connectivity is a requirement of local population stability, the preservation of extant habitats and restoration of saltmarshes along the coast of Japan may be the most effective measures for conservation of this endangered species.     

Decreasing genetic diversity in wild and captive populations of endangered Itasenpara bittering (Acheilognathus longipinnis) in the Himi region,central Japan,and recommendations for conservation

Biodiversity is increasingly declining as a result of direct human impact and structural alteration of ecosystems resulting from changes in human life styles. Itasenpara bittering (Acheilognathus longipinnis), which has been maintained in floodplain and paddy fields, is a threatened cyprinid fish endemic to central Japan. To aid in the preservation of this species, information on genetic diversity and demographic variables in wild and captive populations was obtained using microsatellite DNA analysis. Temporal changes in genetic diversity and effective population size (N _e) tended to be relatively stable in the wild Moo River population, although lower values were detected in the wild Busshouji River population, suggesting an extremely high risk of extinction in the latter. Captive populations derived from the Busshouji River population demonstrated significant genetic divergence even among intrapopulational cohorts, suggesting the influence of genetic drift caused by geographic isolation and small population size. Active maintenance of genetic diversity in captive population is a necessary part of conservation programs, as are continuous addition of wild individuals and replacement of individuals among captive populations. In addition, increasing or maintaining suitable floodplain areas and artificial habitats such as paddy fields might contribute to the conservation of genetic diversity in the Itasenpara bittering.     

Pollen-mediated gene flow promotes low nuclear genetic differentiation among populations of <Emphasis Type="Italic">Cycas debaoensis</Emphasis> (Cycadaceae)

Cycas debaoensis is a critically endangered cycad species endemic to China. This species is found on two kinds of habitats according to the edaphic differences, sand and karst. A previous chloroplast DNA (cpDNA) study indicated that C. debaoensis had low genetic variation within populations and high genetic differentiation among populations. Because maternally inherited cpDNA does not fully characterize genetic structure of the species, we screened seven low-copy nuclear genes and 17 nuclear microsatellite loci to detect the nuclear genetic diversity, differentiation, and the population structure of C. debaoensis. The nuclear genes revealed higher level of genetic diversity. There were both the same and region-specific haplotypes or alleles between the karst and sand regions. Nuclear gene flow among all the populations was much greater than that of cpDNA, which indicated that pollen-mediated gene flow was much greater than seed-mediated gene flow. This promoted low nuclear genetic differentiation among populations of C. debaoensis. The study suggests that both genetic and anthropogenic disturbances have resulted in the critically endangered status of C. debaoensis.     

Genetic biodiversity in the Baltic Sea: species-specific patterns challenge management

Information on spatial and temporal patterns of genetic diversity is a prerequisite to understanding the demography of populations, and is fundamental to successful management and conservation of species. In the sea, it has been observed that oceanographic and other physical forces can constitute barriers to gene flow that may result in similar population genetic structures in different species. Such similarities among species would greatly simplify management of genetic biodiversity. Here, we tested for shared genetic patterns in a complex marine area, the Baltic Sea. We assessed spatial patterns of intraspecific genetic diversity and differentiation in seven ecologically important species of the Baltic ecosystem—Atlantic herring (Clupea harengus), northern pike (Esox lucius), European whitefish (Coregonus lavaretus), three-spined stickleback (Gasterosteus aculeatus), nine-spined stickleback (Pungitius pungitius), blue mussel (Mytilus spp.), and bladderwrack (Fucus vesiculosus). We used nuclear genetic data of putatively neutral microsatellite and SNP loci from samples collected from seven regions throughout the Baltic Sea, and reference samples from North Atlantic areas. Overall, patterns of genetic diversity and differentiation among sampling regions were unique for each species, although all six species with Atlantic samples indicated strong resistence to Atlantic-Baltic gene-flow. Major genetic barriers were not shared among species within the Baltic Sea; most species show genetic heterogeneity, but significant isolation by distance was only detected in pike and whitefish. These species-specific patterns of genetic structure preclude generalizations and emphasize the need to undertake genetic surveys for species separately, and to design management plans taking into consideration the specific structures of each species.     

Conservation genetics in hypersaline inland waters: mitochondrial diversity and phylogeography of an endangered Iberian beetle (Coleoptera: Hydraenidae)

Saline inland waters are globally threatened habitats harbouring many specialised endemic species, which often have restricted geographic ranges, and occur as highly isolated populations. We studied the genetic variation and phylogeography of Ochthebius glaber Montes and Soler, a rare and endangered water beetle endemic to hypersaline streams in the South and Southeast of the Iberian Peninsula. We used a 633 bp fragment of cytochrome oxidase subunit 1 gene to determine the genetic diversity and phylogeographic structure within this species, and interpret this in the light of the speciesȁ9 conservation requirements. Thirteen populations were sampled across the speciesȁ9 geographic range, and genetic diversity found to be very high, with 37 haplotypes across the 71 specimens examined (p-distance 0.2–7.3%, average 3.1±0.4). Phylogeographic analyses revealed a surprisingly high degree of geographical structure, detectable among populations separated by relatively short geographical distances, with three main groups of haplotypes which have apparently been isolated for significant periods of time. Past fragmentation and contiguous range expansion events were inferred as the main causes of the detected geographical associations of haplotypes. The establishment of independent evolutionary lineages as conservation units is particularly important for species inhabiting saline habitats such as O. glaber, which is endangered by habitat loss across most of its distribution. However, given the natural instability of hypersaline environments, the conservation of a network of populations and potential habitats would be necessary to enable the preservation of the process generating and maintaining the diversity of the species.     

Genetic differences in the response to landscape fragmentation by a habitat generalist,the bobcat,and a habitat specialist,the ocelot

The ecology of a species strongly influences genetic variation and population structure. This interaction has important conservation implications because taxa with low dispersal capability and inability to use different habitats are more susceptible to anthropogenic stressors. Ocelots (Leopardus pardalis albescens) and bobcats (Lynx rufus texensis) are sympatric in Texas and northeastern Mexico; however, their ecology and conservation status are markedly different. We used 10 microsatellite loci and a 397-bp segment of the mitochondrial control region to examine how historical and ecological differences in these two species have influenced current patterns of genetic diversity in a landscape heavily altered by anthropogenic activities. Substantially higher genetic diversity (heterozygosity and haplotype diversity) and population connectivity was observed for bobcats in comparison to ocelots. The level of divergence among proximate ocelot populations (<30 km) was greater than between bobcat populations separated by >100 km. Ocelot populations in the US have never recovered from reductions experienced during the twentieth century, and their low genetic variation and substantial isolation are exacerbated by strong preference for dense native thornshrub and avoidance of open habitat. In contrast, despite continued legal harvesting and frequent road-related mortality, bobcats have maintained wide distribution, high abundance, and population connectivity. Our study illustrates that sympatric species with a similar niche can still have sufficient ecological differences to alter their response to anthropogenic change. Sensitive species, such as the ocelot, require additional conservation actions to sustain populations. Ecological differences among species occupying a similar guild are important to consider when developing conservation plans.     

Genetic diversity and differentiation in the critically endangered orchid (Amitostigma hemipilioides): implications for conservation

Amitostigma hemipilioides is an endangered terrestrial orchid endemic to China. In the Southwestern China, the species is found restricted growing in the karst limestone or rock in the edge of farmland, moist hillsides or river. In the present study, the genetic diversity and differentiation was estimated within and among habitats, populations and groups of this species by ISSR markers. Using 13 polymorphic primers, an intermediate level of genetic diversity was found at the species level and population level with the percentage of polymorphic bands (P) of 64.7 and 50.9 %, Shannon index of diversity (I) of 0.3873 and 0.2949, respectively. The analysis of molecular variance (AMOVA) showed that the high level of population differentiation was presented with 45.63 % relative to the total genetic variation residing among eight populations. It was noteworthy that as much as 69.17 % of the total diversity was most likely attributed to the difference among the populations in fragmentation habitat conditions, while 16.32 % of the total diversity could be attributed to the difference among the populations in stable and favorable habitat conditions. The in situ conservation is a top strategy, thus the mycorrhizal fungi and pollinators are protected by protecting habitat and avoiding fragmentation which is helpful to the cycle of this endangered orchid species and recovery of its wild populations. In addition, to maintaining the germplasm bank of this species, the ex situ conservation by habitat simulation and reintroduction has been considered in the living collection at Kaili University ecological garden and Yuntai Mountain scenic spot using the plants collected in this study.     

Genetic Diversity and Conservation Implications of Four Cupressus Species in China as Revealed by Microsatellite Markers

Understanding the extent and distribution of genetic diversity is crucial for the conservation and management of endangered species. Cupressus chengiana, C. duclouxiana, C. gigantea, and C. funebris are four ecologically and economically important species in China. We investigated their genetic diversity, population structure, and extant effective population size (35 populations, 484 individuals) employing six pairs of nuclear microsatellite markers (selected from 53). Their genetic diversity is moderate among conifers, and genetic differentiation among populations is much lower in C. gigantea than in the other three species; the estimated effective population size was largest for C. chengiana, at 1.70, 2.91, and 3.91 times the estimates for C. duclouxiana, C. funebris, and C. gigantea, respectively. According to Bayesian clustering analysis, the most plausible population subdivision scheme within species is two groups in C. chengiana, three groups in C. duclouxiana, and a single group for both C. funebris and C. gigantea. We propose a conservation strategy for these cypress species.     

Characterization of chloroplast microsatellite loci from whole chloroplast genome of Camellia taliensis and their utilization for evaluating genetic diversity of Camellia reticulata (Theaceae)

This study characterized chloroplast microsatellite markers for Camellia reticulata, a famous ornamental and edible economic tree species only distributed in Southwestern China. Thirty-two chloroplast microsatellite markers were originally annotated in the whole chloroplast genome of Camellia taliensis, ten polymorphic microsatellite markers were tested in 96 individuals from four natural populations of C. reticulata. Alleles numbered from two to four, and average value of Shannon's Information index, Nei's gene diversity, total genetic diversity, genetic diversity within populations, gene differentiation coefficient and gene flow index were 0.408, 0.225, 0.217, 0.102, 0.530 and 0.443, respectively. Our results showed high genetic differentiation and limited gene flow among the studied populations, which may be explained by recent fragmentation of the remnant populations due to human destruction and disturbance of natural habitats of the species. The identified cpSSR markers will be useful for the future studies on population genetics, conservation biology and phylogeography of C. reticulata.     

Genetic variation and clonal diversity in populations of Nelumbo nucifera (Nelumbonaceae) in central China detected by ISSR markers

To obtain accurate estimates of population structure for purposes of conservation planning for wild lotus (Nelumbo nucifera Gaertn.) in central China, genetic diversity among and within six populations, and clonal diversity within another two populations of the species were analyzed. The genetic diversity was high (percentage of polymorphic bands, PPB = 90.0%; Shannon's information index, I = 0.383 ± 0.234) at the species level, but low within individual study populations (PPB = 35.8%; Shannon's information index I = 0.165 ± 0.241). The mean coefficient of gene differentiation (G_st) was 0.570, indicating that 43.0% of the genetic diversity resided within the population. Analysis of molecular variance (AMOVA) indicated that 50.47% of the genetic diversity among the study populations was attributed to geographical location while 12.3% was attributed to differences in their habitats. An overall value of mean estimated number of gene flow (N_m = 0.377) indicated that there was limited gene flow among the sampled populations. The level of clonal diversity found within the populations was considerably high (Simpson's diversity index, D = 0.985) indicating that clonal diversity contributes to a major extent to the overall genetic variation in the genetic structure of N. nucifera. On the basis of the high G_st and D values detected in this study we recommend that any future conservation plans for this species should be specifically designed to include those representative populations with the highest genetic variation for both in situ conservation and germplasm collection expeditions.