Absence Of Genetic Structure Research Articles

A novel tomato interspecific (Solanum lycopersicum var. cerasiforme and Solanum pimpinellifolium) MAGIC population facilitates trait association and candidate gene discovery in untapped exotic germplasm.

We developed a novel eight-way tomato multiparental advanced generation intercross (MAGIC) population to improve the accessibility of tomato relatives genetic resources to geneticists and breeders. The interspecific tomato MAGIC population (ToMAGIC) was obtained by intercrossing four accessions each of Solanum lycopersicum var. cerasiforme and Solanum pimpinellifolium, which are the weedy relative and the ancestor of cultivated tomato, respectively. The eight exotic ToMAGIC founders were selected based on a representation of the genetic diversity and geographical distribution of the two taxa. The resulting MAGIC population comprises 354 lines, which were genotyped using a new 12k tomato single primer enrichment technology panel and yielded 6488 high-quality single-nucleotide polymorphism (SNPs). The genotyping data revealed a high degree of homozygosity, an absence of genetic structure, and a balanced representation of the founder genomes. To evaluate the potential of the ToMAGIC population, a proof of concept was conducted by phenotyping it for fruit size, plant pigmentation, leaf morphology, and earliness. Genome-wide association studies identified strong associations for the studied traits, pinpointing both previously identified and novel candidate genes near or within the linkage disequilibrium blocks. Domesticated alleles for fruit size were recessive and were found, at low frequencies, in wild/ancestral populations. Our findings demonstrate that the newly developed ToMAGIC population is a valuable resource for genetic research in tomato, offering significant potential for identifying new genes that govern key traits in tomato. ToMAGIC lines displaying a pyramiding of traits of interest could have direct applicability for integration into breeding pipelines providing untapped variation for tomato breeding.

Absence of genetic structure among ecologically diverse populations indicate high plasticity in a pantropical seabird

Absence of genetic structure among ecologically diverse populations indicate high plasticity in a pantropical seabird

Absence of Genetic Structure among Streaked Shearwaters Calonectris leucomelas Breeding in Japan, Despite Limited Dispersal Events

Absence of Genetic Structure among Streaked Shearwaters Calonectris leucomelas Breeding in Japan, Despite Limited Dispersal Events

Molecular characterization of Fasciola hepatica in endemic regions of Colombia.

Fasciola hepatica is a zoonotic trematode that affects a wide range of hosts, including cattle, sheep, and goats. The economic impact of the parasite on the cattle industry is significant, with high losses reported worldwide. While its impact on human health was previously underestimated, recent years have seen a rise in fascioliasis cases, leading to increased interest among researchers globally. To characterize the genetic diversity and intraspecific variation of this parasite in South America, specifically in Colombia, we collected 105 adult parasites from cattle bile ducts in seven Colombian departments (Antioquia, Boyacá, Santander, Cauca, Cundinamarca, Nariño, Norte de Santander, and Santander) to assess the parasite's phenotypic analyses, genetic diversity, and population structure. A computer image analysis system (CIAS) was applied based on standardized morphological measurements. Liver-fluke size was studied by principal component analysis (PCA). DNA sequences were obtained for nuclear markers such as the 28S, β-tubulin 3, ITS1, ITS2, and the mitochondrial marker Cytochrome Oxidase I (COI). Multiple statistical tests were performed, and the parasite's population structure was analyzed. Maximum Likelihood (ML) phylogenetic reconstructions were carried out using the sequences obtained herein and sequences available in GenBank. Morphological results revealed that all the obtained individuals matched F. hepatica's morphology. There was no evidence of high genetic diversity, and the absence of genetic structure at the country-level was notable, possibly caused by a demographic expansion of this trematode in Colombia or the low resolution of the molecular markers employed. Future studies are still needed to unveil the genetic population structure of F. hepatica across the country.

Stock Discrimination of Gilthead Seabream (Sparus aurata Linnaeus, 1758) through the Examination of Otolith Morphology and Genetic Structure

Reliable stock identification constitutes an integral component of effective fishery management. Current methods for the identification of putative stock units comprise the analysis of both phenotypic and genetic variability. The present study examined the spatial variation in otolith morphology (shape and asymmetry) and genetic composition of 395 wild-caught Gilthead seabream (Sparus aurata) specimens, collected from the Aegean and Ionian Seas (eastern Mediterranean) between 2014–2018. The degree of scale regeneration (SRD, % of regenerated scales) was used as an indicator to assess the potential presence of aquaculture escapees in the wild-caught samples. Otolith shape and asymmetry analyses showed a phenotypic discrimination between northwestern Aegean and Ionian Gilthead seabream populations. Genetic analyses of nine microsatellite markers revealed higher levels of genetic variation in the wild compared with samples obtained from aquaculture farms. Despite the absence of genetic structure among the wild-caught seabream populations, a low but statistically significant genetic differentiation was found between reared fish and fish collected in the field. The SRD was considered effective in detecting the presence of aquaculture escapees that may have escaped in either early or late rearing phases.

Population Genetic Structure of the Blue Swimming Crab (Portunus pelagicus) Along the Andaman Sea Coast of Thailand

The blue swimming crab (Portunus pelagicus) is a valuable commercial species. In Thailand, the consumption of the blue swimming crab is increasing. To construct an effective sustainable management plan, genetic information is required. Knowledge of natural stock genetic information can help policymakers design fishing and conservation management policies to maintain genetic diversity. In our study, we examined the genetic structure of the blue swimming crab population on the Andaman Sea coast of Thailand. Partial sequences of the mitochondrial DNA control region (mtDNA CR) with a size of 369-371 base pairs were studied in 150 individuals collected from five sampling sites along Thailand's Andaman Sea coast. Seventy-one haplotypes were characterized by 127 polymorphic sites, indicating high haplotype diversity but low nucleotide diversity across five localities. The multiple tests of population genetic analysis showed a lack of genetic structure. The absence of genetic structure was possibly caused by a high level of gene flow due to the larval blue swimming crab's high dispersal ability. Demographic history findings indicate that the blue swimming crab population has expanded. The findings of our study can be used to guide the management of the blue swimming crab in this region of the Andaman Sea to conserve genetic diversity.

Assessing genetic diversity patterns at neutral and adaptive loci to inform population reinforcement of an endangered migratory vulture

One of the primary goals of conservation translocation programs should be the maintenance of both population demographic stability and genetic diversity. Here, we provide genetic management recommendations to inform a population reinforcement of the declining Egyptian Vulture population in the Balkans. Specifically, we examined whether the number of released individuals is sufficient to prevent genetic diversity loss due to random genetic drift and what the origin of the individuals should be that comprise the captive breeding pool. To this aim, we estimated and assessed genetic diversity levels and genetic structure of Egyptian Vulture populations across much of the species’ range using both neutral and non-neutral candidate loci involved in migration. We then evaluated the effects of the currently proposed population management scheme and candidate source populations on retaining allelic diversity. Our results show low differentiation values among populations and absence of genetic structure which point to past high gene flow. Furthermore, there was no predicted significant impact of different source populations on the genetic diversity of the recipient Balkan population. We also found that the declining Egyptian Vulture population in the Balkans still retains high levels of genetic diversity and therefore genetic diversity restoration is not currently needed. However, without any management, diversity is likely to decrease fast because of increased genetic drift as the population size continues to decline. Population reinforcement with nine birds per year for 20 years would provide sufficient demographic support for the population to retain > 85% of rare allelic diversity. Birds originating from the Balkans would ensure ecological and behavioral similarity and thus would be the best option for reinforcement. Nevertheless, our results demonstrate that to prevent further population contraction and loss of adaptive alleles, releasing individuals of different origin would also be appropriate.

Genetic Diversity of Paryphthimoides poltys (Nymphalidae: Satyrinae: Euptychiina) in a Fragmented Agricultural Landscape in the Brazilian Atlantic Forest

The species-level response of organisms to habitat loss and fragmentation relies on their dispersal ability, as well as trophic level, degree of habitat specialization and landscape structure. For butterflies, community composition is affected by the landscape configuration, by the surrounding habitat and by the matrix composition scattered around forest fragments, whereas higher dispersal ability is a significant advantage for persistence in highly fragmented landscapes. However, species of butterflies are highly variable in their dispersion capabilities, which affects their genetic variability as a whole and in how it is distributed within and between subpopulations in remaining fragments. In the present study, the genetic variability in subpopulations of Paryphthimoides poltys distributed through forest fragments was evaluated. Low diversity and the absence of genetic structure was found through eight fragments of semideciduous Atlantic Forest, surrounded by agricultural matrices, in Southeastern Brazil. Although P. poltys was the most common species found in the area in a previous study, its high abundance was not accompanied by high genetic variability. The species is usually found flying in forest edges and open environments and, although low, its genetic variability is expected to be preserved even if some of the investigated forest fragments are lost in the near future.

A genomic and morphometric analysis of alpinebumblebees: Ongoing reductions in tongue length but no cleargenetic component.

Over the last six decades, populations of the bumblebees Bombus sylvicola and Bombus balteatus in Colorado have experienced decreases in tongue length, a trait important for plant-pollinator mutualisms. It has been hypothesized that this observation reflects selection resulting from shifts in floral composition under climate change. Here we used morphometrics and population genomics to determine whether morphological change is ongoing, investigate the genetic basis of morphological variation, and analyse population structure in these populations. We generated a genome assembly of B.balteatus. We then analysed whole-genome sequencing data and morphometric measurements of 580samples of both species from seven high-altitude localities. Out of 281samples originally identified as B.sylvicola, 67 formed a separate genetic cluster comprising a newly-discovered cryptic species ("incognitus"). However, an absence of genetic structure within species suggests that gene flow is common between mountains. We found a significant decrease in tongue length between bees collected between 2012-2014 and in 2017, indicating that morphological shifts are ongoing. We did not discover any genetic associations with tongue length, but a SNP related to production of a proteolytic digestive enzyme was implicated in body size variation. We identified evidence of covariance between kinship and both tongue length and body size, which is suggestive of a genetic component of these traits, although it is possible that shared environmental effects between colonies are responsible. Our results provide evidence for ongoing modification of a morphological trait important for pollination and indicate that this trait probably has a complex genetic and environmental basis.

Molecular characterization and phylogeography of Mediterranean picarels (Spicara flexuosa, S. maena and S. smaris) along the coasts of Turkey and the Eastern Mediterranean

In this study, molecular taxonomy associated with Spicara flexuosa, Spicara maena, and Spicara smaris was examined with a geographical focus along the coasts of the Turkey and the Mediterranean. In addition, the effects of the Turkish Straits System on the evolutionary history and phylogeography of Spicara flexuosa were investigated. The mitochondrial cytochrome c oxidase I, cytochrome b, and the nuclear Interphotoreceptor retinoid–binding protein genes were used for these purposes. Our results indicated that the distinction of the three taxa under Spicara is possible with the two different mitochondrial DNA markers. Nuclear DNA analyses indicated that reproductive isolation of the S. maena and S. flexuosa was complete. Demographic analyses support the sudden population growth of S. flexuosa after a potential bottleneck. The result of the dating analyses suggested that the three Spicara species were differentiated during the early or middle Pliocene. An absence of genetic structure between Spicara flexuosa subpopulations from Turkey indicated the connectivity, within sampling locations, suggesting that the Turkish Straits System is a corridor for gene flow for this species. As picarel populations have experienced rapid decline in their distribution areas in recent years, separate population studies are necessary to help make informed conservation and management decisions for S. maena and S. flexuosa.

High levels of genetic diversity and an absence of genetic structure among breeding populations of the endangered Rufous-backed Bunting in Inner Mongolia, China: implications for conservation

BackgroundThe Rufous-backed Bunting, Emberiza jankowskii, is an endangered species that is primarily distributed in Inner Mongolia, China. The main threats to the continued persistence of this species are habitat loss and degradation. However, the impact of population loss on genetic diversity remains unclear. To support future conservation and management efforts, we assessed the genetic diversity and population structure of E. jankowskii using mitochondrial DNA and microsatellites.MethodsBlood samples were collected from 7‒8-day-old nestlings in Inner Mongolia, China between May and August of 2012 and 2013. Mitochondrial DNA sequences and microsatellite markers were used to assess the genetic diversity, genetic structure and inbreeding of E. jankowskii. The results of genetic diversity and inbreeding were compared to other avian species.ResultsWe found an unexpectedly high level of genetic diversity in terms of mitochondrial DNA and microsatellite compared to other avian species. However, there were high levels of gene flow and minimal genetic structuring, among the fragmented breeding populations of E. jankowskii in Inner Mongolia. These findings suggest that E. jankowskii in Inner Mongolia is a metapopulation. Despite the high genetic diversity of E. jankowskii, local populations in each small patch remain at risk of extinction due to habitat loss. In addition, the E. jankowskii population has a high risk of inbreeding.ConclusionsTo minimize further loss of genetic diversity of this endangered species, we suggest that the E. jankowskii in Inner Mongolia should be considered as a protected species for management purposes. Conservation efforts should concentrate on E. jankowskii habitat management. This may be most effectively achieved by protecting the current breeding habitats and prohibiting over-grazing.

Biometry, Distribution and Genetic Characterization of Blue Jack Mackerel Trachurus picturatus (Bowdich, 1825), a Rare Pelagic Fish Species in the Adriatic Sea

The blue jack mackerel Trachurus picturatus (Bowdich, 1825) specimens (N = 155) were collected during the MEDITS survey, done along the eastern side, precisely, of the Croatian fishing ground in July 2018. Biometrical analysis of ten morphometric and five meristic characters, as well as genetic analysis proved that the collected specimens were blue jack mackerel. The total length (TL) and weight (W) of all observed specimens ranged from 9.2 to 33.7 cm (12.15 ± 2.95 cm) and from 5.79 to 384.94 g (17.64 ± 39.42 g), respectively. All calculated length–length relationships were linear (r > 0.923). Sex was determined only on two larger specimens (28 cm < TL < 32.8 cm), which were females. In the length–weight relationship, positive allometry was established (b = 3.1789). Based on 37 partial cytochrome b sequences, the overall haplotype diversity (h) of 0.812 ± 0.048 and nucleotide diversity (π) of 0.0064 ± 0.0007 indicated high levels of haplotype and low nucleotide diversity. The obtained sequences were compared to previously published research within the Northeast Atlantic Ocean and the Mediterranean Sea, confirming the absence of genetic structure among these populations.

Examination of saffron cod Eleginus gracilis (Tilesius 1810) population genetic structure

Annual ice retreat in the northern Bering and Chukchi seas, which has occurred earlier in the past decades resulting in longer ice-free seasons and warmer ocean temperatures, is producing a cascade of ecological effects, and may open Arctic waters to commercial fishing and oil exploration. Baseline knowledge of population structure of a species is critical to developing strategies for management and conservation. There is little information for the saffron cod (Eleginus gracilis), an abundant forage fish inhabiting the coastlines of the North Pacific and Arctic oceans. We examined saffron cod population genetic structure with data from nine microsatellite loci designed to describe the genetic compositions of and variation among 40 collections of saffron cod from four regions (northwestern Alaska, Gulf of Alaska, western Pacific Ocean, and Gulf of Anadyr). The northwestern Alaska collections (Norton Sound and Chukchi Sea) exhibited little genetic divergence. The Gulf of Anadyr collection differed from other regions but was most similar to those of northwestern Alaska. The collections from the western Pacific Ocean (Sakhalin Island and Hokkaido Island) differed genetically, but not to the extent they did from other regions. Gulf of Alaska collections (Kodiak Island and Prince William Sound) comprised a lineage that was distinct from all of the other areas, including the geographically adjacent northwestern Alaska collections. The absence of genetic structure in northwestern Alaska probably reflects their recent expansion into previously unavailable habitat that became available after the Last Glacial Maximum (~ 16,000 years ago). Tracking and predicting the likely expansion of the eurythermal saffron cod may have parallels to its postglacial colonization.

Host Population Expansion and the Genetic Architecture of the Pinniped Hookworm Uncinaria lucasi

The long-term fidelity of pinniped hosts to their natal rookery site suggests the genetic architecture of their Uncinaria spp. hookworms should be strongly structured by host breeding biology. However, historical events affecting host populations may also shape parasite genetic structure. Sequences of the mitochondrial cytochrome c oxidase 1 (COI) gene of 86 Uncinaria lucasi individuals were obtained to assess genetic variation and structure of nematodes from 2 host species (68 hookworms from northern fur seals; 18 hookworms from Steller sea lions) and rookeries from 3 widely separated geographic regions: the western Bering Sea and Sea of Okhotsk, eastern Bering Sea, and the eastern Pacific Ocean. High COI haplotype (h = 0.96-0.98) and nucleotide (π = 0.014) diversity was found. The haplotype network showed a star-shaped pattern with a large number of haplotypes separated by few substitutions. The network did not show separation of U. lucasi by geographic region or host species. Fst values between U. lucasi individuals representing geographic regions showed no differentiation, consistent with the absence of genetic structure. At face value, this lack of genetic structure in U. lucasi suggests high gene flow but could also be explained by recent (post-glacial) population expansions of northern fur seals and their hookworms.

Urbanization without isolation: the absence of genetic structure among cities and forests in the tiny acorn ant Temnothorax nylanderi.

Urban alteration of neutral and adaptive evolutionary processes is still underexplored. Using a genome-wide SNP dataset, we investigated (i) urban-induced modifications of population demography, genetic diversity and population structure and (ii) signature of divergent selection between urban and forest populations in the ant species, Temnothorax nylanderi. Our results did not reveal an impact of urbanization on neutral processes since we observed: (i) analogous genetic diversity among paired urban/forest sites and two control populations; (ii) weak population genetic structure explained neither by habitat (urban versus forest) nor by geography; (iii) a remarkably similar demographic history across populations with an ancestral growth followed by a recent decline, regardless of their current habitat or geographical location. The micro-geographical home range of ants may explain their resilience to urbanization. Finally, we detected 19 candidate loci discriminating urban/forest populations and associated with core cellular components, molecular function or biological process. Two of these loci were associated with a gene ontology term that was previously found to belong to a module of co-expressed genes related to caste phenotype. These results call for transcriptomics analyses to identify genes associated with ant social traits and to infer their potential role in urban adaptation.

Comparative genetic differentiation study of three coexisting mangrove crabs in western Atlantic

ABSTRACT A multispecies approach may reveal the factors influencing the genetic differentiation of coexisting species along a wide geographic area. Our aim was to compare the genetic differentiation of mangrove crabs coexisting along the western Atlantic in order to verify if there are common barriers, using two mitochondrial DNA markers to quantify genetic differentiation, variance and diversity. In addition, we included a mismatch distribution to check demographic history. Our data revealed that species with similar pelagic larval duration had either high genetic differentiation or the absence of genetic structure. These results can be explained by factors that contribute to genetic differentiation, such as the presence of large estuarine areas (acting as barriers), ocean currents, and larval behaviour. Also, historical events that promoted the isolation of some areas in the past, such as glacial cycles during the Pleistocene, could have caused the observed high levels of genetic divergence in some species.

Genetic variability and demographic history of Anguilla mossambica (Peters, 1852) from continental Africa and Madagascar.

In this study, population genetic and demographic parameters were inferred using sequence data from 151 individuals of Anguilla mossambica originating from continental south and south-east Africa and Madagascar. The analyses were based on a 532 bp segment of the mitochondrial cytochrome b gene. The absence of genetic structuring was observed thereby supporting the hypothesis of panmixia for the endemic A. mossambica. The overall nucleotide diversity π = 0.002 and the haplotype diversity reached h = 0.691. Significant negative values from several tests of neutrality and mismatch analysis pointed to fluctuating historical population sizes. Bayesian averaging resulted in higher support for population growth models vs. a constant population-size model. Population decline and subsequent growth most likely predated the last glacial and were probably related to extended periods of extreme drought followed by wetter and more stable hydroclimate between 150 and 75,000 years before present (kBP). According to this scenario the female effective population size has increased since 110 kBP by c. two orders of magnitude to a recent level of about 650,000 (219,317-2,292,000).

High genetic connectivity among pink shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967) groups along the south-southeastern coast of Brazil

The pink shrimp Farfantepenaeus paulensis is one of the most important fishing resources along the south-southeast coast of Brazil. Its fishing zone includes two main reproductive stocks, located at the coasts of Santa Catarina and São Paulo states. The species life cycle includes an offshore reproductive stage and juvenile recruitment to estuarine areas; therefore, adults are caught in oceanic areas by industrial fisheries and juveniles in estuarine areas by artisanal fisheries. The unrestricted growth of the industrial fleet, along with the increase of artisanal fishing in estuarine areas and the low effectiveness of fishery legislation, led to a collapse of the pink shrimp fishery in the late 1990s. The present work aimed to assess the population genetics of the pink shrimp F. paulensis throughout its main distribution in the Southwestern Atlantic (SWA), to verify whether different fishing stocks also represent different genetic stocks. Based on the evaluation of the mtDNA control region (D-loop), we detected high connectivity and absence of genetic structure among F. paulensis groups in the SWA. Fixation indexes, Analysis of Molecular Variance and a haplotype network also showed no significant genetic differences, with individuals sharing haplotypes among more than one region. Mismatch analysis showed unimodal distributions for all the sampled populations with high haplotype diversity and low nucleotide diversity, showing a pattern of recent demographic expansion, which was corroborated by the Tajima's D and Fu's Fs neutrality tests. Estimates of migration rates indicated high gene flow, with a large number of migrants exchanged between regions. All obtained results are consistent with a panmitic population of F. paulensis. This scenario is a result of a complex interaction of several factors, from the influence of currents on larval dispersal to the effect of overfishing. The knowledge on the diversity and genetic structure of F. paulensis is a fundamental part of the scientific basis necessary for decision makers to elaborate adequate management strategies for pink shrimp stocks.

Whole Plastome Sequencing Within Silene Section Psammophilae Reveals Mainland Hybridization and Divergence With the Balearic Island Populations.

Reconstructing the phylogenetic relationships within Caryophyllaceae tribe Sileneae has been obscured by hybridization and incomplete lineage sorting. Silene is the largest genus in the Caryophyllaceae, and unraveling its evolutionary history has been particularly challenging. In order to infer the phylogenetic relationships among the five species in Silene section Psammophilae, we have performed a genome skimming approach to acquire the complete plastid genome (cpDNA), nuclear ribosomal cistron (nrDNA), and partial mitochondrial genome (mtDNA). We have included 26 populations, representing the range of each species' distribution. This section includes five morphologically similar species endemic to the Iberian Peninsula and Balearic Islands (Ibiza and Formentera), yet some of them occupy distinct edaphic habitats (e.g. maritime sands, calcareous sandstones). In addition to phylogeographic analyses, genetic structuring using the chloroplast data set was inferred with Discriminant Analysis of Principal Components (DAPC), analyses of molecular variance (AMOVA), and a partial Mantel test. Reference-guided assembly of 50 bp single-end and 250 bp paired-end Illumina reads produced the nearly complete cpDNA genome (154 kbp), partial mtDNA genome (from 81 to 114 kbp), and the nrDNA cistron (6.4 kbp). Selected variable regions of the cpDNA and mtDNA assemblies were confirmed by Sanger sequencing. Phylogenetic analyses of the mainland populations reveal incongruence among the three genomes. None of the three data sets produced relationships consistent with taxonomy or geography. In contrast, Silene cambessedesii, present in the Balearic Islands, is the only species that forms a strongly supported monophyletic clade in the cpDNA genome and is strongly differentiated with respect to the remaining taxa of the Iberian Peninsula. These results contrast with those obtained for mainland populations. Across the entire analysis, only one well-supported mainland clade of Silene littorea and Silene stockenii emerges from the southern region of the Iberian Peninsula. DAPC and AMOVA results suggest the absence of genetic structure among mainland populations of Silene section Psammophilae, whereas partial Mantel test discarded spatial correlation of genetic differentiation. The widespread incongruence between morphology-based taxonomic boundaries and phylogeography suggests a history of interspecific hybridization, in which only a substantial geographic barrier, like isolation by the Mediterranean Sea, was sufficient to create and maintain species boundaries in Silene section Psammophilae.

Multilocus approach reveals a complex evolutionary history of the invasive mile-a-minute plant, Mikania micrantha (Asteraceae), in its natural habitat

AbstractMikania micrantha is native to Central and South America and exhibits morphological and cytological polymorphism, and evidence of a non-monophyletic origin. In Brazil, the species is widely distributed in the Atlantic Forest, one of the most threatened biomes in the world. AFLP, ITS, ETS and rps16 markers were employed to estimate the genetic diversity and the existence of independent evolutionary lineages in the species, and chromosomes were counted to determine ploidy of 11 populations of M. micrantha. Molecular markers showed relatively high genetic diversity and absence of genetic structure, and chromosome counts revealed pure diploid and tetraploid populations and mixed-cytotype populations in M. micrantha. There was no significant genetic difference between cytotypes, suggesting an autopolyploid origin for tetraploids. However, analyses of species delimitation showed that two highly divergent genetic clusters, constituted of samples from different populations, consisted of two independent evolutionary lineages, demonstrating putative cryptic species in M. micrantha. Our data highlight the need for more genetic studies in M. micrantha to ensure effective conservation actions in its natural area of occurrence and the correct management of the species in introduced areas, where it causes severe damage to forests and plantations.