Structure Of Wild Populations Research Articles

Assessment of genetic diversity and population structure in wild populations of Crassostrea tulipa in Ghana

The West African Mangrove oyster, Crassostrea tulipa (Lamarck, 1819) is abundant in many coastal aquatic ecosystems. Despite their abundance, ecological, and economic importance, little is known about its diversity and evolutionary history. There are challenges associated with the use of morphological criteria only in the characterization of organisms, therefore, there has been a shift to the use of genetic markers to determine the diversity and taxonomy of this oyster species. This paper seeks to characterize and establish if the species of C. tulipa occurring along the coast of Ghana was the same or if there are cryptic species occurring. Therefore, a study was conducted, using microsatellite markers on seven (7) populations of oysters from the coast of Ghana. These populations are namely; Anyanui (Volta), Densu (Greater-Accra), Narkwa, Amisano and Benya (Central), Whin and Dominli (Western). Low genetic variability was observed within the populations (He = 0.391, FIS = 0.791) which was attributed to inbreeding and limited gene flow. Small to moderate genetic differentiation was observed between the populations where the FST range was between 0.033 and 0.100. Anyanui and Narkwa populations were more genetically differentiated whiles Densu and Dominli populations were the least differentiated. There was no relationship between genetic distance and geographical distance; therefore, the genetic structure of C. tulipa occurring along the coast of Ghana did not follow any geographical pattern of distribution. It appeared clearly that the populations of C. tulipa occurring along the coast of Ghana from the studied sites may be of multiple populations. This calls for the attention of interested parties to help in the sustainability of these oyster populations which are vulnerable to natural selection pressures that can lead to the driving down of their existence.

Population genetic structure of a major reef-building coral species Acropora downingi in northeastern Arabian Peninsula

Current seawater temperatures around the northeastern Arabian Peninsula resemble future global forecasts as temperatures > 35 °C are commonly observed in summer. To provide a more fundamental aim of understanding the structure of wild populations in extreme environmental conditions, we conducted a population genetic study of a widespread, regional endemic table coral species, Acropora downingi, across the northeastern Arabian Peninsula. A total of 63 samples were collected in the southern Arabian/Persian Gulf (Abu Dhabi and Qatar) and the Sea of Oman (northeastern Oman). Using RAD-seq techniques, we described the population structure of A. downingi across the study area. Pairwise G’st and distance-based analyses using neutral markers displayed two distinct genetic clusters: one represented by Arabian/Persian Gulf individuals, and the other by Sea of Oman individuals. Nevertheless, a model-based method applied to the genetic data suggested a panmictic population encompassing both seas. Hypotheses to explain the distinctiveness of phylogeographic subregions in the northeastern Arabian Peninsula rely on either (1) bottleneck events due to successive mass coral bleaching, (2) recent founder effect, (3) ecological speciation due to the large spatial gradients in physical conditions, or (4) the combination of seascape features, ocean circulation and larval traits. Neutral markers indicated a slightly structured population of A. downingi, which exclude the ecological speciation hypothesis. Future studies across a broader range of organisms are required to furnish evidence for existing hypotheses explaining a population structure observed in the study area. Though this is the most thermally tolerant acroporid species worldwide, A. downingi corals in the Arabian/Persian Gulf have undergone major mortality events over the past three decades. Therefore, the present genetic study has important implications for understanding patterns and processes of differentiation in this group, whose populations may be pushed to extinction as the Arabian/Persian Gulf warms.

Substantial gene flow caused by long‐term translocation between natural bank populations of the Peruvian scallop (Argopecten purpuratus) is supported by RAD‐Seq analyses

AbstractThe Peruvian scallop (Argopecten purpuratus, Lamarck 1989) is a marine bivalve of high commercial value in the aquaculture industry, with wild populations distributing from northern Peru to Chile. Growing demand for it in the world aquaculture markets and limited availability of hatchery‐based seeds caused long‐term seed translocations among wild populations to recover depleted local populations and for production needs. We investigated long‐term translocation effects on the genetic diversity and structure of wild populations using next‐generation RAD sequencing. We sampled individuals from Sechura, Lobos de Tierra, Samanco, and Bahia Independencia in Peru, and La Rinconada in Northern Chile. We identified 8,345 polymorphic RAD loci and 24,218 SNPs for the five populations. We estimated high observed heterozygosity for all populations and high SNP frequency compared to similar studies on marine bivalves. We detected no spatial divergence among populations in Peru (pairwise FST from 0 to 0.003), but strong differentiation with the population in Chile. Migration rate estimates suggested asymmetric directionality of seed translocation. Overall, our results support a remnant effect of an intense historic translocation and ongoing gene flow among wild populations in Peru, challenging the identification of outlier loci and certification of sustainable origin of cultured scallops using genetic markers.

Detecting community structure in wild populations: a simulation study based on male elephant, Loxodonta africana, data

Many social networks exhibit community structure, where individuals form discrete subgroups. The composition of such groupings is important for numerous research directions, but their characterization is challenged by data sampling issues. In wild populations, where individuals range over large distances and observation can be limited, social data required to resolve community structure are difficult to collect. Recent studies used simulated data sets to determine the robustness of individual level network metrics under suboptimal sampling conditions, but the sensitivity of community detection algorithms to imperfect sampling has not been assessed. Here, we used simulated data sets to determine how sampling effort and skew influence the ability of three community detection algorithms (fastgreedy, walktrap and louvain) to recover the ‘true’ community structure of networks under two sampling regimes (field-based observational sampling and sampling through biologgers, e.g. proximity detectors). We also examined the robustness of a measure of uncertainty in estimated community structure ( r com ). We based our simulated societies on contact patterns in wild male African elephants, a model system reflecting common sampling challenges of large wild populations. Our results indicate that the accuracy of the algorithms improved with increasing sampling effort and decreasing sampling skew. Under the field sampling regime, when sampling effort is constrained, mid-levels of sampling skew may provide a reasonable compromise between maximizing the mean numbers of observation per individual and minimizing sampling skew. Even with skewed data, r com can provide a reliable measure of uncertainty in the estimated community assignments, but it should be interpreted cautiously with highly skewed data. The network structures explored represent common sampling challenges for wild populations, but unexplored sampling regimes may drive somewhat different dynamics. Our simulations indicate that adequate sampling even when skewed can be informative and maximization of the number of observations among all individuals should be a general objective. • Useful information about community structure can be obtained with skewed sampling. • Accurate community assignment requires many observations of each individual. • Moderately skewed sampling can improve results while reducing sampling requirements. • r com is a robust measure of uncertainty even when sampling is skewed. • Results from biologgers are robust with as few as 30% of the population tagged.

Mapping the geographic origin of captive and confiscated Hermann’s tortoises: A genetic toolkit for conservation and forensic analyses

The illegal trade has been threatening tortoise populations worldwide for decades. Nowadays, however, DNA typing and forensic genetic approaches allow us to investigate the geographic origin of confiscated animals and to relocate them into the wild, providing that suitable molecular tools and reference data are available. Here we assess the suitability of a small panel of microsatellite markers to investigate patterns of illegal translocations and to assist forensic genetic applications in the endangered Mediterranean land tortoise Testudo hermanni hermanni. Specific allelic ladders were created for each locus and tested on several reference samples. We used the microsatellite panel to (i) increase our understanding of the population genetic structure in wild populations with new data from previously unsampled geographic areas (overall 461 wild individuals from 28 sampling sites); (ii) detect the presence of non-native individuals in wild populations; and (iii) identify the most likely geographic area of origin of 458 confiscated individuals hosted in Italian seizure and recovery centers. Our analysis initially identified six major genetic clusters corresponding to different geographic macro-areas along the Mediterranean range. Long-distance migrants among wild populations, due to translocations, were found and removed from the reference database. Assignment tests allowed us to allocate approximately 70 % of confiscated individuals of unknown origin to one of the six Mediterranean macro-areas. Most of the assigned tortoises belonged to the genetic cluster corresponding to the area where the respective captivity center was located. However, we also found evidence of long-distance origins of confiscated individuals, especially in centers along the Adriatic coast and facing the Balkan regions, a well-known source of illegally traded individuals. Our results clearly show that the microsatellite panel and the reference dataset can play a beneficial role in reintroduction and repatriation projects when confiscated individuals need to be re-assigned to their respective macro-area of origin before release, and can assist future forensic genetic applications in detecting the illegal trade and possession of Testudo hermanni individuals.

Virus-virus interactions and host ecology are associated with RNA virome structure in wild birds.

Little is known about the factors that shape the ecology of RNA viruses in nature. Wild birds are an important case in point, as other than influenza A virus, avian samples are rarely tested for viruses, especially in the absence of overt disease. Using bulk RNA‐sequencing (“meta‐transcriptomics”), we revealed the viral diversity present in Australian wild birds through the lens of the ecological factors that may determine virome structure and abundance. A meta‐transcriptomic analysis of four Anseriformes (waterfowl) and Charadriiformes (shorebird) species sampled in temperate and arid Australia revealed the presence of 27 RNA virus genomes, 18 of which represent newly described species. The viruses identified included a previously described gammacoronavirus and influenza A viruses. Additionally, we identified novel virus species from the families Astroviridae, Caliciviridae, Reoviridae, Rhabdoviridae, Picobirnaviridae and Picornaviridae. We noted differences in virome structure that reflected underlying differences in location and influenza A infection status. Red‐necked Avocets (Recurvirostra novaehollandiae) from Australia's arid interior possessed the greatest viral diversity and abundance, markedly higher than individuals sampled in temperate Australia. In Ruddy Turnstones (Arenaria interpres) and dabbling ducks (Anas spp.), viral abundance and diversity were higher and more similar in hosts that were positive for influenza A infection compared to those that were negative for this virus, despite samples being collected on the same day and from the same location. This study highlights the extent and diversity of RNA viruses in wild birds and lays the foundation for understanding the factors that determine virome structure in wild populations.

An optimized high quality male DNA extraction from spermatophores in open thelycum shrimp species.

The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality. Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species. However, all current protocols require invasive handling methods with males for DNA isolation. Using Aristeus antennatus as a model we tested a reliable non-invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum. The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping. This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs. More importantly, it can be applied to identify the mating pairs and male structure in wild populations of species as A. antennatus, where males are often difficult to capture. Our method could be also valuable for biological studies on other spermatophore-using species, such as myriapods, arachnids and insects.

Biochemical and cytogenetic studies of Poecilia from eastem Mexico. II. Frequency, perpetuation, and probable origin of triploid genomes in females associated with Poecilia formosa

Triploid female fishes that closely resemble the gynogenetic, diploid, unisexual species Poecilia formosa Girard and its sympatric, bisexual congener Poecilia mexicana Steindachner constitute a significant, but not static, component ef naturally occurring populations of Poecilia in headwater localities of the Rio Soto la Marina drainage in northeastern Mexico. The frequency of triploid females fluctuates markedly from year to year, from season to season, and from one locality to another. In laboratory breeding studies to assess the reproductive competence of triploid females as a factor influencing structure of wild populations of Poecilia spp., we have used electrophoresis oi blood plasmas and DNA-Feulgen cytophotometry of the nuclei from blobd cells or scale epithelium from live fishes to monitor the persistence of triploid genomes in four laboratory-reared generations of female progeny in stocks initially derived from gravid, triploid females collected from the Rio Purificacion at Barretal or from Vado el Moro, near Cd. Victoria, Mexico. We conclude that many of the triploid females are reproductively competent and regularly transmit triploid genomes to their unisexual offspring. They presumably reproduce by gynogenesis, since breeding stocks of triploids can be maintained in the laboratory by matings with sympatric males of P. mexicana .

Landscape relatedness: detecting contemporary fine-scale spatial structure in wild populations

ContextMethods for detecting contemporary, fine-scale population genetic structure in continuous populations are scarce. Yet such methods are vital for ecological and conservation studies, particularly under a changing landscape.ObjectivesHere we present a novel, spatially explicit method that we call landscape relatedness (LandRel). With this method, we aim to detect contemporary, fine-scale population structure that is sensitive to spatial and temporal changes in the landscape.MethodsWe interpolate spatially determined relatedness values based on SNP genotypes across the landscape. Interpolations are calculated using the Bayesian inference approach integrated nested Laplace approximation. We empirically tested this method on a continuous population of brown bears (Ursus arctos) spanning two counties in Sweden.ResultsTwo areas were identified as differentiated from the remaining population. Further analysis suggests that inbreeding has occurred in at least one of these areas.ConclusionsLandRel enabled us to identify previously unknown fine-scale structuring in the population. These results will help direct future research efforts, conservation action and aid in the management of the Scandinavian brown bear population. LandRel thus offers an approach for detecting subtle population structure with a focus on contemporary, fine-scale analysis of continuous populations.

Assessment of Genetic Structure in Wild Populations of Panulirus homarus (Linnaeus, 1758) across the South Coast of Sri Lanka Inferred from Mitochondrial DNA Sequences

Scalloped spiny lobster ( Panulirus homarus , Palinuridae) is an economically and ecologically important food species. Population structure of the scalloped spiny lobster across the southern coast of Sri Lanka (SCSL) (in Indian Ocean) was investigated using mitochondrial DNA (mtDNA) markers. Four sites belonging two regions were sampled (Hikkaduwa, Weligama in the southwest and Godawaya, Kirinda in the southeast) and DNA was isolated from tissues of pereiopod and used for PCR amplification. Genetic variation in DNA sequences were examined for two mtDNA gene regions; Cytochrome Oxidase I (COI) and Cytochrome B (CytB). High levels of haplotype diversity and nucleotide diversity were detected in all populations and estimated average fixation index (-0.026285 ( p < 0.01)) indicated essential homogeneity among population. Results of AMOVA analysis confirmed an absence of signi?cant population structure among sites. Tests of neutral evolution and analysis of mismatch distribution suggested that P. homarus populations across the SCSL might have experienced a recent population expansion. Information emerged from the current study could be utilized when people design appropriate management strategies for conserving this vital wild marine resource.

DNA BARCODING OF CAGED PANGASIIDS IN PAHANG RIVER MALAYSIA

The domestication aquaculture selection in farm environment can cause changes in phenotype and genotype of farmed fishes, which may later influence the demographic structure of wild populations if they accidentally escaped from cages. This is an alarming situation for conservation of native species of Pangasius sp. in Pahang River. Hence, the present study was aimed to investigate genetic variation among the fishes collected from different cages from Pahang River. We adopted conventional taxonomical approach to identify species and cross-examined using universal barcode gene Cytochrome Oxydase Subunit 1 (COX1) gene. Samples were collected from 6 commercial cages from Pahang River. Haplotype and genetic diversity among the fishes from different cages were determined. Results from Neighbor Joining tree showed that most of the samples were identified to be Pangasianodon hypothalamus despite having different morphometric character. This study also revealed that most of the caged Pangasius cultured in Pahang River are exotic and non-native to Malaysia. Thus, a continuous monitoring through studies on genetic variation of Pangasius sp. is an essential need for the sustainable development of this endangered fishes in Pahang River.

Effects of traditional management for mescal production on the diversity and genetic structure of Agave potatorum (Asparagaceae) in central Mexico

Agave potatorum is a wild endemic species of Mexico. Its stems are used for mescal production, which cancels sexual reproduction. Agaves extraction from forests decreases their reproductive success and demographic performance. We evaluated patterns of genetic diversity and structure of wild populations under and without extraction in order to identify effects of its use and actions required for conserving genetic variation. This study was conducted with seven SSR markers in 12 populations representing the entire distribution area of the species. Standard parameters of genetic diversity, differentiation, structure and genetic similarity of populations were calculated and analyzed. The populations studied showed intermediate to high genetic diversity (H e = 0.36–0.64), compared with other Agave species so far studied. The wild category was the most diverse (H T = 0.87), but without significant differences with respect to populations under extraction (H T = 0.72), and two germplasm banks sampled (H T = 0.69). High structure among populations (Φ PR = 0.38) and inbreeding levels (F IS = 0.26, F IT = 0.55) were identified; a 3 % of genetic diversity being distributed among management status where germplasm banks represent a genetic pool with incipient divergence from the other categories. Bayesian analysis indicated two genetic groups. Our study suggests slight effects of management on genetic diversity of A. potatorum, apparently related to alterations of reproductive biology and pollination patterns.

Identification of quantitative genetic components of fitness variation in farmed, hybrid and native salmon in the wild.

Feral animals represent an important problem in many ecosystems due to interbreeding with wild conspecifics. Hybrid offspring from wild and domestic parents are often less adapted to local environment and ultimately, can reduce the fitness of the native population. This problem is an important concern in Norway, where each year, hundreds of thousands of farm Atlantic salmon escape from fish farms. Feral fish outnumber wild populations, leading to a possible loss of local adaptive genetic variation and erosion of genetic structure in wild populations. Studying the genetic factors underlying relative performance between wild and domesticated conspecific can help to better understand how domestication modifies the genetic background of populations, and how it may alter their ability to adapt to the natural environment. Here, based upon a large-scale release of wild, farm and wild x farm salmon crosses into a natural river system, a genome-wide quantitative trait locus (QTL) scan was performed on the offspring of 50 full-sib families, for traits related to fitness (length, weight, condition factor and survival). Six QTLs were detected as significant contributors to the phenotypic variation of the first three traits, explaining collectively between 9.8 and 14.8% of the phenotypic variation. The seventh QTL had a significant contribution to the variation in survival, and is regarded as a key factor to understand the fitness variability observed among salmon in the river. Interestingly, strong allelic correlation within one of the QTL regions in farmed salmon might reflect a recent selective sweep due to artificial selection.

Multivariate sexual selection on male song structure in wild populations of sagebrush crickets, Cyphoderris strepitans (Orthoptera: Haglidae)

While a number of studies have measured multivariate sexual selection acting on sexual signals in wild populations, few have confirmed these findings with experimental manipulation. Sagebrush crickets are ideally suited to such investigations because mating imposes an unambiguous phenotypic marker on males arising from nuptial feeding by females. We quantified sexual selection operating on male song by recording songs of virgin and mated males captured from three wild populations. To determine the extent to which selection on male song is influenced by female preference, we conducted a companion study in which we synthesized male songs and broadcast them to females in choice trials. Multivariate selection analysis revealed a saddle-shaped fitness surface, the highest peak of which corresponded to longer train and pulse durations, and longer intertrain intervals. Longer trains and pulses likely promote greater mate attraction, but selection for longer intertrain durations suggests that energetic constraints may necessitate “time outs”. Playback trials confirmed the selection for longer train and pulse durations, and revealed significant stabilizing selection on dominant frequency, suggesting that the female auditory system is tightly tuned to the species-specific call frequency. Collectively, our results revealed a complex pattern of multivariate nonlinear selection characterized primarily by strong stabilizing and disruptive selection on male song traits.

Genetic diversity and genetic structure in wild populations of Mexican oregano (Lippia graveolens H.B.K.) and its relationship with the chemical composition of the essential oil

Mexican oregano is an aromatic plant traditionally harvested from wild populations by rural communities; however, there is little information about population genetics aspects of this species. Moreover, considering that the variation in essential oil production of aromatic plants has been attributed to several environmental as well as genetic factors, in this study we estimated the genetic diversity and genetic structure from 14 wild populations of L. graveolens located in four different bioclimatic regions in southeastern Mexico using AFLP markers. The overall genetic diversity of L. graveolens described as the percentage of polymorphic loci (PPL = 60.9 %) and Nei’s gene diversity (H j = 0.17) was moderate, but not associated with the bioclimatic conditions. Genetic variation was analyzed at chemotype and population levels. Regarding chemotypes, thymol had the highest genetic diversity (PPL = 82.8 % and H j = 0.22). PCoA revealed that chemotypes exhibit a certain level of genetic differentiation. Maximum parsimony dendrogram showed a grouping of individuals with a predominant chemotype. Bayesian analyses revealed a low, but significant differentiation among chemotypes (θ ΙΙ = 0.008). Regarding populations, gene diversity showed significant differences (F 13,1204 = 22.8, P < 0.001); populations dominated by individuals from the thymol chemotype showed the highest gene diversity (H j = 0.31–0.25), while populations with exclusively sesquiterpene chemotype showed the lowest value (H j = 0.058). Cluster and Bayesian analyses (θ ΙΙ = 0.027) revealed a low level of genetic differentiation among populations. Correlation analysis showed a significant association between the distance matrices based on the genetic markers (AFLP) and chemical compounds of essential oil (r = 0.06, P < 0.001). Our results suggest an important genetic influence on the observed chemical profiles. Nevertheless, other biotic and abiotic environmental pressures also play an important role in determining the chemotype and structure found in this aromatic species.

Genetic diversity and population structure in the Brazilian Cattleya labiata (Orchidaceae) using RAPD and ISSR markers

Brazilian orchids are currently threatened with extinction due to habitat loss and, because of their high ornamental value, intense collecting pressure. Genetic diversity can play a key role in the survival of endangered orchid species. Here we provide the first data on genetic diversity and structure of wild populations in the genus Cattleya, in particular C. labiata, using random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) markers. We studied 130 individuals, 117 belonging to Cattleya labiata and 13 from 10 other species in the same genus. Data generated from 12 ISSR and 12 RAPD primers were used to determine genetic variability via a model-based Bayesian procedure (Structure) and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were also estimated. The marker data indicated that C. labiata has a high level of polymorphism, and five reconstructed populations were identified by Structure. The unweighted pair group method with arithmetic mean dendrogram did not group the samples by origin, which was also confirmed by Bayesian analysis, demonstrating the complex genetic structure of C. labiata. Other Cattleya species showed no relationship with any C. labiata sample. This genetic characterization of Cattleya from northeast Brazil contributes to knowledge of the genetic structure of the species and can be used to define strategies for conservation and breeding programmes.

Isolation and characterization of 17 polymorphic microsatellites in the brown mud mussel Glauconome rugosa

The brown mud mussel Glauconome rugosa is a delicious mussel food species. Due to over-harvesting for food in the wild, some populations may be endangered. Seventeen di- and tetranucleotide microsatellites were isolated and characterized using 24 wild caught individuals. The average allele number of the 17 microsatellites was 8/locus with a range of 5–14, and the expected heterozygosity averaged at 0.80, ranging from 0.65 to 0.91. Eleven out of 17 microsatellites agreed with the Hardy–Weinberg equilibrium (HWE) and showed independent segregation. Extreme size difference (over 50 bp) between alleles was seen at five of the 17 loci. These microsatellites will facilitate the studying of the genetic diversity and population structure of wild populations of G. rugosa.

Genetic Structure in Wild Populations of Ayu Plecoglossus altivelis in Korea and Japan

We investigated the genetic structure of Korean and Japanese ayu Plecoglossus altivelis populations by examining 669 individuals from 14 populations using three microsatellite loci. Genetic variation did not differ significantly among the populations examined in terms of allelic number and heterozygosity. Korean populations were genetically close to each other, implying that persistent gene flow has occurred in these populations. This suggests that eastern populations in Korea form a single large population and all of the Korean populations are distinct from the Japanese populations. Pairwise population <TEX>$F_{ST}$</TEX> estimates, principal component analyses, and a neighbor-joining tree showed that genetic separation between the southern and pooled eastern coast populations was probably influenced by restricted gene flow. Hierarchical analysis of molecular variance (AMOVA) revealed a weak but significant genetic structure among three ayu groups (eastern and southern coasts of Korea and the Japan coast), and no genetic variation within groups. The estimated genetic population structure and potential applications of microsatellite markers may aid in the proper management of ayu populations.

Mitochondrial DNA reveals low population differentiation in elongate loach, Leptobotia elongata (Bleeker): implications for conservation

Elongate loach (Leptobotia elongata (Bleeker)), an endemic fish species to China, is a famous ornamental freshwater fish. Here, a comparative study of mtDNA control region (D-loop) (835 bp) sequences was performed to analyze its wild population structure and evaluate the genetic diversity for 110 individuals from five locations in the upper reaches of the Yangtze River, China. A total of 49 polymorphic sites and 45 haplotypes yielded high haplotype diversity (h = 0.952), but low nucleotide diversity (π = 0.00454) as that of many fish species. Sequence divergences between haplotypes ranged from 0.0033 ± 0.0011 to 0.0050 ± 0.0012 in intra-groups, and from 0.0037 ± 0.0.0011 to 0.0050 ± 0.0012 between groups. Significant values of Tajima’s D (−1.86383, P < 0.01) and Fu’s F S (−25.93, P < 0.01), together with uni-modal mismatch distribution, indicated a recent genetic bottleneck or population expansion of the species. Analysis of molecular variance (AMOVA) indicated a small amount of differentiation among groups (1.7%); most of the total variation occurred within groups (98.3%). Also, there was no significant population structure (F ST = 0.017, P > 0.05), and estimates of gene flows among groups were extremely high (Nm = 28.88), suggesting low genetic divergence between populations in the species. The lack of genetic differentiation among groups is most likely due to the combined gene flow from the downstream movement of eggs and larvae with currents and the upstream or downstream migration of adults throughout the distribution. These groups of L. elongata distributed in upper reaches of the Yangtze River should be considered as a single management unit.

Isolation and characterization of microsatellite loci in Santalum lanceolatum and Santalum leptocladum (Santalaceae)

Microsatellite primers were developed for the first time in the native Australian sandalwood species Santalum lanceolatum. • Using an enrichment cloning protocol, five novel polymorphic codominant loci were developed and characterized in S. lanceolatum and S. leptocladum. In addition to these, three existing microsatellite loci from other sandalwood species were successfully amplified and characterized for S. lanceolatum and S. leptocladum. Among the eight loci, allelic diversity ranged from 4 to 29. • Primers will be useful for studies of clonality, genetic diversity and spatial genetic structure in wild populations. When coupled with other molecular techniques will help investigate the relationship between S. lanceolatum and S. leptocladum, species of commercial and conservation interest.