Levels Of Genetic Differentiation Research Articles

Genetic Diversity and Population Structure Analysis in the Chinese Endemic Species Michelia crassipes Based on SSR Markers

Michelia crassipes Y. W. Law (Magnoliaceae) is endemic to China and is the only species with purple flowers in the genus Michelia. It is commonly used as an important parent for flower color improvement and hybrid breeding. M. crassipes is recognized as an endangered plant. An urgent need exists to explore the genetic diversity of M. crassipes to efficiently select hybrid parents and develop efficient conservation strategies. In this study, a total of 128 samples were selected from seven natural populations of M. crassipes to explore their genetic diversity and structure. A total of 14 microsatellite (SSR) markers with high polymorphism and repeatability were developed, and 218 alleles were detected. This study mainly revealed three results: (1) The parameters of expected heterozygosity (He = 0.536) and mean Shannon’s information index (I = 1.121) revealed moderately high levels of genetic diversity for the M. crassipes natural population; (2) The genetic differentiation coefficient (Fst = 0.108) showed that there was a low level of genetic differentiation, and AMOVA indicated that genetic variation existed mainly within populations and that there was frequent gene exchange between populations; and (3) The population genetic structure analysis showed that seven natural populations originated from two ancestral groups, and the Mantel test revealed that genetic and geographical distances between populations were significantly correlated. Our study is the first to explore the genetic diversity and structure of the M. crassipes natural population, which provides an important reference for the collection, conservation and utilization of Michelia crassipes germplasm resources.

Genetic monitoring on the world’s first MSC eco-labeled common octopus (O. vulgaris) fishery in western Asturias, Spain

Octopus vulgaris (Cuvier, 1797) is a cephalopod species with great economic value. In western Asturias (northwest of Spain), O. vulgaris artisanal fisheries are relatively well monitored and conditionally eco-labeled by the Marine Stewardship Council (MSC). Despite this, the Asturian octopus stocks have not been genetically assessed so far. In order to improve the current fishery plan and contrast the octopus eco-label validity in Asturias, 539 individuals from five regions of the O. vulgaris geographic distribution, including temporal samplings in Asturias, were collected and genotyped at thirteen microsatellite loci. All the samples under analysis were in agreement with Hardy–Weinberg expectations. Spatial levels of genetic differentiation were estimated using F-statistics, multidimensional scaling, and Bayesian analyses. Results suggested that the O. vulgaris consists of at least four genetically different stocks coming from two ancestral lineages. In addition, temporal analyses showed stability in terms of genetic variation and high NE (> 50) for several generations in different localities within Asturias, pointing out to indeed sustainable fishery exploitation levels. Even though, the current Asturias fishery plan shows no significant genetic damages to the stocks, the regional-specific management plans need systematic genetic monitoring schemes as part of an efficient and preventive regional fishery regulation strategy.

Genetic Diversity and Differentiation of Chinese Fir around Karst Landform in Guangxi

The karst geo-ecosystems are fragile environments. The largest karst region in the world is located in southwestern China, within which the Guangxi province is one of the main areas. Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), an evergreen species, is an important fast-growing timber tree in southern China. In the present study, we examined the genetic diversity and spatial genetic differentiation of Chinese fir in sampling localities around the karst landform region of Guangxi by genotyping 330 individuals from 11 sampling localities with 22 novel polymorphic microsatellite loci. High levels of gene flow have homogenized Chinese fir in Rongshui, Nandan, and Tiane sites, which are speculated to be the primary center of gene exchange and diversity for Chinese fir around the karst landform in Guangxi. Significant isolation by distance pattern was found among nine sampling localities. A moderate level of genetic differentiation (FST = 0.089, Dest = 0.139) between sampling localities was detected. Structure analysis divided Chinese fir into three subgroups (K = 3). With higher differentiation and less genetic variation than in the central population, marginal populations of Cangwu and Pubei were identified in the south of the karst landform. An effective conservation strategy focusing on the maintenance of genetic variation for marginal populations of the species was proposed.

Analysis of genetic diversity and population structure in sweetpotato using SSR markers

Sweetpotato, Ipomoea batatas (L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376 landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat (SSR) primer pairs with high polymorphism. Based on the population structure analysis, these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136 and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis (PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance (AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types. These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.

Genetic variations in four geographical isolates of Gohieria fusca based on cytochrome b and internal transcribed spacer genes

To investigate the genetic diversity and genetic differentiation of different geographical isolates of Gohieria fusca. G. fusca isolates were sampled from Wuhu (WH), Bengbu (BB) and Bozhou cities (BZ) of Anhui Province and Jiaxing City of Zhejiang Province (JX). Mitochondrial cytochrome b (Cytb) and ribosomal internal transcribed spacer (ITS) genes were amplified in WH, BB, BZ and JX isolates of G. fusca using PCR assay. The gene sequences were edited and aligned using the software Chromas 2 and DNASTAR 1.00, and the haplotype, haplotype diversity (Hd) and nucleotide polymorphism (Pi) of each isolate were calculated using the software DnaSP 5.10.00. The genetic differentiation among isolates (Fst) and gene flow value (Nm) were estimated using the software MEGA 10.2, and a phylogenetic tree was built. Tests of neutrality and analysis of molecular variance (AMOVA) were performed using the software Arlequin 3.1 and a haplotype network was built based on the Median-Joining network using the software Network 10.2. PCR assay showed that the sizes of the Cytb and ITS genes were 372 bp and 1 301 to 1 320 bp, respectively. All four isolates of G. fusca presented high genetic diversity based on mitochondrial Cytb and ITS genes (Hd = 0.804, Pi = 0.006 91). AMOVA showed genetic differentiation among geographical isolates of G. fusca (Fst = 0.202 40, P < 0.05), and the genetic variation was mainly caused by intra-population variations (79.76%). Gene flow analysis showed a high level of gene flow among G. fusca isolates (Nm > 1). Tests of neutrality based on Cytb gene measured a Tajima's D value of -1.796 31 (P < 0.05) and a Fu's FS value of -3.293 98 (P < 0.05) in WH isolate of G. fusca, indicating population expansion in WH isolate of G. fusca. Haplotype network analysis and phylogenetic analysis revealed no remarkable geographical distribution pattern among different geographical isolates of G. fusca. All four isolates of G. fusca presented high genetic diversity (Hd = 0.985, Pi = 0.011 97). AMOVA showed moderate level of genetic differentiation between four isolates (Fst = 0.104 62, P < 0.05). The tests of neutrality based on ITS genes measured a Tajima's D value of -6.088 20 and a Fu's FS value of -1.935 99 (both P > 0.05) in the whole isolate of G. fusca, indicating no obviously population expansion. The four geographical isolates of G. fusca have high genetic diversity and remarkable genetic differentiation. Since a high level of gene flow is detected among different geographical isolates of G. fusca, no obvious geographical distribution pattern of G. fusca is found.

Spatial genetic differentiation correlates with species assemblage turnover across tropical reef fish lineages

AbstractAimEvaluating the similarity of diversity patterns across micro‐ to macroevolutionary scales in natural communities, such as species–genetic diversity correlations (SGDCs), may inform on processes shaping community assembly. However, whether SGDCs not only hold across communities but also across lineages has never been explored so far. Here we investigated SGDCs across co‐distributed taxa for different spatial components (α, β, γ), and formally tested the influence of dispersal traits on β‐SGDCs.LocationWestern Indian Ocean.Time period2016–2017.Major taxa studiedTropical reef fish species with contrasting dispersal traits.MethodsUsing double‐digest restriction‐site associated DNA sequencing (ddRADseq) Single Nucleotide Polymorphism data for 20 tropical reef fishes and distribution data of 2,446 species belonging to 12 families, we analysed the correlations between within‐species genetic diversity and within‐family species diversity (i.e., lineage diversity) for the three spatial components (α, β, γ‐SGDCs). We then related the strength of β‐SGDCs per species to proxies of larval dispersal abilities.ResultsWe detected positive and significant lineage‐based SGDC only for the β component, that is, the families showing the greatest level of species turnover among sites contain the species with the greatest levels of genetic differentiation. We showed that the Monsoon Drift mainly explained the β‐diversity patterns at both intraspecific and interspecific levels. Higher β‐SGDCs were found for species with short pelagic larval duration and weak larval swimming capacity.Main conclusionsOur study reveals a strong correlation between genetic and species β‐diversity, a result explained by the presence of a ‘soft’ barrier and mediated by larval dispersal processes. This suggests that vicariance and dispersal limitation are major processes shaping β‐diversity patterns from microevolutionary to macroevolutionary scales in tropical reef fishes.

Genetic diversity and structure of the 4th cycle breeding population of Chinese fir (Cunninghamia lanceolata (lamb.) hook).

Studying population genetic structure and diversity is crucial for the marker-assisted selection and breeding of coniferous tree species. In this study, using RAD-seq technology, we developed 343,644 high-quality single nucleotide polymorphism (SNP) markers to resolve the genetic diversity and population genetic structure of 233 Chinese fir selected individuals from the 4th cycle breeding program, representing different breeding generations and provenances. The genetic diversity of the 4th cycle breeding population was high with nucleotide diversity (Pi ) of 0.003, and Ho and He of 0.215 and 0.233, respectively, indicating that the breeding population has a broad genetic base. The genetic differentiation level between the different breeding generations and different provenances was low (Fst < 0.05), with population structure analysis results dividing the 233 individuals into four subgroups. Each subgroup has a mixed branch with interpenetration and weak population structure, which might be related to breeding rather than provenance, with aggregation from the same source only being in the local branches. Our results provide a reference for further research on the marker-assisted selective breeding of Chinese fir and other coniferous trees.

Characterization and Application of EST-SSR Markers Developed from Transcriptome Sequences in Elymus breviaristatus (Poaceae: Triticeae).

Elymus L. is the largest genus in the Triticeae tribe. Most species in this genus are highly stress resistant, with excellent forage value. Elymus breviaristatus, a rare species endemic to the Qinghai-Tibet Plateau (QTP), is declining due to habitat fragmentation. However, genetic data for E. breviaristatus are limited, with expressed sequence tag (EST) markers being particularly rare, hampering genetic studies and protection measures. We obtained 9.06 Gb clean sequences from the transcriptome of E. breviaristatus, generating 171,522 unigenes, which were assembled and functionally annotated against five public databases. We identified 30,668 SSRs in the E. breviaristatus transcriptome, from which 103 EST-SSR primer pairs were randomly selected. Of these, 58 pairs of amplified products of the expected size, and 18 of the amplified products were polymorphic. Model-based Bayesian clustering, the unweighted pair group method with arithmetic average (UPGMA), and principal coordinate analysis (PCoA) of 179 wild E. breviaristatus in 12 populations using these EST-SSRs were generally consistent, grouping the 12 populations into two major clades. Analysis of molecular variance (AMOVA) found 70% of the genetic variation among the 12 populations and 30% within the populations, indicating a high level of genetic differentiation (or low gene exchange) among the 12 populations. The transferability of the 58 successful EST-SSR primers to 22 related hexaploid species was 86.2-98.3%. UPGMA analysis generally grouped species with similar genome types together. Here, we developed EST-SSR markers from the transcriptome of E. breviaristatus. The transferability of these markers was evaluated, and the genetic structure and diversity of E. breviaristatus were explored. Our results provide a basis for the conservation and management of this endangered species, and the obtained molecular markers represent valuable resources for the exploration of genetic relationships among species in the Elymus genus.

Genetic diversity analysis and fingerprint construction of Korean pine (Pinus koraiensis) clonal seed orchard.

Korean pine is a native tree species in Northeast China. In order to meet the needs of germplasm resource evaluation and molecular marker-assisted breeding of Korean pine, we collected Korean pine clones from 7 populations in Northeast China, analyzed the genetic diversity and genetic structure by SSR molecular marker technology and clustered them to revealed the inter- and intrapopulation differentiation characteristics of each clone. The fingerprint profiles of 161 Korean pine clones were also constructed. 77 alleles were detected for 11 markers, and 18 genotypes were identified on average for each marker. The PIC of the different markers ranged from 0.155-0.855, and the combination of PI and PIsibs for the 11 markers was 3.1 × 10-8 and 1.14 × 10-3, respectively. MANOVA showed that genetic variation existed mainly within populations, accounting for 98% of the total variation. The level of genetic differentiation among populations was low, with an average Nm between populations of 11.036. Genetic diversity is lower in the Lushuihe population and higher in the Tieli population. The 161 Korean pine clones were divided into 4 or 7 populations, and the 7 populations were not clearly distinguished from each other, with only the Lushuihe population showing partial differentiation. There is no significant correlation between the genetic distance of Korean pine populations and the geographical distance of their superior tree sources. This result can provide recommendations for future Korean pine breeding programs. The combination of 11 markers could completely distinguish 161 clones and establish the fingerprint. Genetic diversity of Korean pine clones from the 7 populations was abundant, and the genetic distances of individuals and populations were evenly dispersed. The fingerprint map can be used for the identification of Korean pine clones.

Genetic Diversity and Population Structure of Shoshone Sculpin Cottus greenei in the Hagerman Valley of South-Central Idaho

The Shoshone sculpin Cottus greenei is a micro-endemic species and an extreme habitat specialist, geographically restricted to the spring outlets that flow from the Snake River Plain Aquifer into the Snake River within the Hagerman Valley of south central Idaho. Although previous studies documented the range of the species and its relative abundance, no studies have assessed genetic diversity and structure. We sampled 20 populations from throughout the species range and genotyped 1311 with a panel of 12 microsatellite loci. Results indicate very high levels of genetic differentiation among most populations (average pairwise FST = 0.24), indicating limited gene flow. Preservation of the genetic diversity of this species will require the protection and preservation of multiple isolated populations.

Effects of Wild Forest Fires on Genetic Diversity and Population Structure of a Boreal Conifer, White Spruce (Picea glauca (Moench) Voss): Implications for Genetic Resource Management and Adaptive Potential under Climate Change

Climate change is predicted to increase forest fires in boreal forests, which can threaten the sustainability of forest genetic resources. Wildfires can potentially impact genetic diversity and population structure in forest trees by creating population bottlenecks, and influencing demography, effective population size (Ne) and various evolutionary processes. We have investigated this critical issue in a widely-distributed, transcontinental, ecologically and economically important and fire-intolerant boreal conifer, white spruce (Picea glauca (Moench) Voss). We tested the hypothesis that in a predominantly outcrossing species with long distance gene flow, such as white spruce, located in primary undisturbed forests, normal forest fires do not adversely affect genetic diversity and population structure. We used 10 nuclear genic and genomic microsatellite loci to examine genetic diversity and population structure of post-fire pristine old-growth (PF-OG) and adjacent post-fire naturally regenerated young (PF-YR) stands. The genetic diversity, inbreeding and genetic differentiation levels, Bayesian population structure, Ne and latent genetic potential were statistically similar between the PF-OG and PF-YR populations. None of the microsatellites showed any signature of selection. Our study demonstrates that normal wild forest fires do not adversely affect genetic diversity, differentiation, and population genetic structure in white spruce. The results should have wide significance for sustainable forest management.

Survey and Molecular Characterization of Echinococcus granulosus sensu stricto from Livestock and Humans in the Altai Region of Xinjiang, China

Cystic echinococcosis (CE), caused by the metacestode Echinococcus granulosus sensu stricto (s.s.), is an important zoonotic parasite, endemic in the Altai region of China. It is a serious human health risk and causes livestock losses. To evaluate the prevalence, genetic variation, and population structure of CE, 2898 sheep and 703 cattle were examined from October 2019 to mid-February 2020 in the Altai region (Altai, Habahe, Fuhai, and Buerjin). Sheep had an infection rate of 4.52% (131/2898) and cattle had an infection rate of 4.84% (34/703). In total, 180 cyst isolates were obtained, including 131 sheep, 34 cattle, and 15 from CE human patients. The cysts were investigated using mitochondrial cytochrome C oxidase subunit 1 (cox1). Polymerase Chain Reaction (PCR) results showed that, among the two genotypes of E. granulosus s.s., there were 22 different haplotypes (Haps). Phylogenetic analysis and parsimony network indicated that seventeen (77.27%) Haps belonged to the sheep strain (G1 genotype) and five Haps (22.73%) belonged to the buffalo strain (G3 genotype). Hap3 was the most common haplotype (65.00%, 112/180), which belongs to the G1 genotype. Hap18−Hap22 were found in human samples, indicating that sheep and cattle reservoirs of human CE. Molecular diversity indices revealed the high levels of haplotype diversity and relatively low levels of nucleotide diversity. Tajima’s D and Fu’s Fs tests displayed that the Altai population had a significant deviation from neutrality. Based on pairwise fixation index (Fst) values, a low level of genetic differentiation was found between the populations of E. granulosus s.s. isolated from different regions. The present survey findings represent an epidemiological survey of CE in the Altai region where there were two genotypes simultaneously and will provide more information on the genetic structure of E. granulosus s.s. within this region.

Water transfer determines the regional spread dynamics of non-native fish species

Interbasin water transfer projects (IBWT's) have emerged as dispersal corridors for aquatic species. However, little is known about how water transfer affects regional spread dynamics, or shapes the genetic diversity patterns of non-native populations. Shimofuri Goby Tridentiger bifasciatus is a globally introduced fish species with many well-established populations in IBWT's. Here, we used nuclear microsatellites to assess the genetic diversity and population structure of the Shimofuri Goby in its native and introduced sites belonging to two IBWT's in China. Our objectives were to (1) reveal the genetic diversity patterns of the Shimofuri Goby during regional spread, and (2) identify its mode of spreading in water transfer systems. We observed (1) a high level of genetic diversity in non-native populations without evidence of bottleneck effects, (2) that non-native populations with a longer water transfer times had a higher private allele richness, and (3) that non-native populations showed a highly mixed genetic structure, low level of genetic differentiation, and no significant relationship between geographical and genetic distances. Our results indicate that the genetic patterns of diversity of non-native populations are mainly shaped by a linear cascade spread processes due to long-distance movement of larvae, and are probably related to propagule pressure caused by the construction of water transfer. To manage the non-native populations of T. bifasciatus, preventive actions and physical removal should be implemented in IBWT's.

Genetic Diversity and Population Structure of Scots Pine (Pinus sylvestris L.) in Middle Siberia

Scot pine (Pinus sylvestris L.) is one the main forest-forming tree species in Russia, and is of great ecological, economic and social value. In order to manage the genetic resources of this important forest tree species efficiently, knowledge of its genetic diversity and structure is needed. Here, we assessed the genetic variation of 17 populations representing different parts of Scots pine range in Russia by using nuclear microsatellite markers (nSSR). Specifically, 14 populations were chosen within the natural distribution range of the species in Middle Siberia and three distant populations were sampled from the European part of Russia, the West Siberia and the Russian Far East. All populations showed high values of genetic diversity (HE = 0.514) and AR = 4.150. However, the easternmost population has shown the lowest level of genetic diversity (HE = 0.433) and allelic richness (AR = 3.505). Five genetic groups could be detected that correspond to: the European part of Russia, the south of Middle Siberia, the northwest of Middle Siberia, West and Middle Siberia, and the Russian Far East. However, the European population was the most genetically distinct one. The variation among Scots pine populations accounted for only 5% of the total variance. The highest level of genetic differentiation was found only between westernmost and easternmost populations (FST = 0.097). Our genetic data may contribute to a better understanding of the pattern of genetic diversity of Scots pine populations in Middle Siberia and help the conservation efforts of these genetic resources.

Population Structure and Genetic Diversity of Colletotrichum gloeosporioides on Citrus in China

To analyze the genetic structure and genetic diversity of Colletotrichum gloeosporioides as the dominant Colletotrichum species on Citrus, the Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genetic diversity, including 63 strains isolated and selected from 8 different sites and 5 different citrus species, was studied. A total of 19 GAPDH haplotypes were identified by genetic analysis, and the main haplotype (haplotype 5) was distributed in 28 isolates, mainly from Citrus unchiu Hort. ex Tanaka (WG) and Citrus reticulata Blanco cv. Succosa (BDZ) in Huangyan (HY), Linhai (LH), and Jiande (JD) of Zhejiang province, and Mashui tangerine (MSJ) in Mengshan of Guangxi province (GX). Using the genetic differentiation index, Fst revealed significant genetic differentiation in C. gloeosporioides populations between Jiangxi province (JXGZ) and GX, HY, LH, JD, and Chun’an (CA) of Zhejiang province, and also revealed slightly less genetic differentiation for C. gloeosporioides populations between HY, LH, JD, GX, Shaanxi province (SX), and Quzhou (QZ) of Zhejiang province. In addition, Fst revealed great genetic differentiation between the C. gloeosporioides populations obtained from MSJ and Citrus paradise Macf (PTY), and also revealed weak genetic differentiation between the C. gloeosporioides populations obtained from Citrus sinensis Osbeck (QC), WG, and BDZ. The AMOVA test showed that the levels of genetic differentiation for C. gloeosporioides were 19% and 81% among and within geographic populations, respectively. It also showed that C. gloeosporioides had levels of genetic differentiation among and within host populations of 12% and 88%, respectively. The Mantel test showed that the genetic distance was not linearly correlated with geographical distance and the haplotype phylogenetic analysis showed that C. gloeosporioides from different regions and hosts were scattered in the phylogenetic tree, implying that the genetic differentiation was independent of host variety and geographical origin. We speculated that genetic differentiation may be mainly due to gene mutation, gene recombination, or gene migration within native populations and has nothing to do with natural selection triggered by geography or host variety.

Diversification of Sinorhizobium populations associated with Medicago polymorpha and Medicago lupulina in purple soil of China.

The double selection of environment adaptation and host specificity forced the diversification of rhizobia in nature. In the tropical region of China, Medicago polymorpha and Medicago lupulina are widely distributed, particularly in purple soil. However, the local distribution and diversity of rhizobia associated with these legumes has not been systematically investigated. To this end, root nodules of M. polymorpha and M. lupulina grown in purple soil at seven locations in Yunnan Province of China were collected for rhizobial isolation. The obtained rhizobia were characterized by RFLP of 16S-23S rRNA intergenic spacer, BOXAIR fingerprinting, and phylogeny of housekeeping and symbiosis genes. As result, a total of 91 rhizobial strains were classified into species Sinorhizobium medicae and S. meliloti, while three nodC gene types were identified among them. S. medicae containing nodC of type I was dominant in farmlands associated with M. polymorpha; while S. meliloti harboring nodC of type III was dominant in wild land nodulated by M. lupulina. For both rhizobial species, greater genetic diversity was detected in the populations isolated from their preferred host plant. A high level of genetic differentiation was observed between the two Sinorhizobium species, and gene flow was evident within the populations of the same species derived from different soil types, indicating that rhizobial evolution is likely associated with the soil features. To examine the effects of environmental features on rhizobial distribution, soil physicochemical traits and rhizobial genotypes were applied for constrained analysis of principle coordinates, which demonstrated that soil features like pH, nitrogen and sodium were the principle factors governing the rhizobial geographical distribution. Altogether, both S. medicae and S. meliloti strains could naturally nodulate with M. polymorpha and M. lupulina, but the rhizobium-legume symbiosis compatibility determined by both the host species and soil factors was also highlighted.

Genetic diversity and population structure of the upriver orange mangrove Bruguiera sexangula along the coastlines of Thailand

Upriver orange mangrove Bruguiera sexangula is a member of the Rhizophoraceae family and is usually distributed in the intertidal zones of the tropical and subtropical coastal areas. The analyses of genetic diversity and population structure of B. sexangula are essential for their conservation and management. In the present study, the genetic diversity and structure of 101 B. sexangula individuals from mangrove forests in Thailand were evaluated using single nucleotide polymorphisms (SNPs) through restriction site-associated DNA sequencing (RAD-seq). A total of 3482 high-quality SNPs were obtained after filtration for genetic study. All 3 genetic structure analyses (Bayesian analysis, principal components analysis, and maximum likelihood tree) revealed that these individuals can be clustered into 2 groups corresponding to geographical regions, namely the Andaman Sea and Gulf of Thailand. The level of genetic differentiation between the clusters was moderate (FST = 0.122, p &lt; 0.001), and the analysis of molecular variance (AMOVA) indicated that the individual differences within groups were greater than the differences between the 2 groups. A moderate level of genetic diversity (Shannon's information index, I = 0.458; observed heterozygosity, Ho = 0.416; expected heterozygosity, He = 0.295) of B. sexangula was observed. These results give us a better understanding of the genetic variations and will provide a framework for the conservation of B. sexangula.

The assessment of genetic diversity and population structure of endemic Scutellaria yildirimlii (Lamiaceae) for conservation purposes

Scutellaria yildirimlii is an endangered perennial endemic species from Turkey and belongs to the family Lamiaceae, which has a high number of medicinal and aromatic plants. It is crucial to determine genetic diversity and population structure of this species for its conservation measures; therefore, 111 individuals from five natural populations of S. yildirimlii were investigated by using 15 inter simple sequence repeats (ISSR) primers. The percentage of polymorphic loci (PPL), Nei?s gene diversity (H), and Shannon?s information index (I) at the species and population-level were determined as 93.9%, 0.183, 0.292 and 56.5%, 0.158, 0.242, respectively. The analysis of molecular variance (AMOVA) showed that there is more genetic variation within populations (84%) than among populations (16%). Nei?s differentiation coefficient (GST = 0.144) was determined to be moderate, which was confirmed by the level of genetic differentiation among populations. Gene flow (Nm = 2.984) showed high genetic exchange among populations. Pairwise genetic distance values among populations ranged from 0.0219 to 0.0512. The Mantel test revealed a statistically significant positive correlation between genetic and geographical distance (r = 0.493, p < 0.001). The Unweighted Pair Group Method with Arithmetic Averages (UPGMA) dendrogram and Principal Coordinate Analysis (PCoA) showed similar results. STRUCTURE analysis (?K = 3) revealed that the K test yielded maximum peaks for 3 clusters. Based on the findings, measures for genetic conservation and management of this species were presented.

ГЕНЕТИЧЕСКАЯ СТРУКТУРА СОБОЛЯ (MARTES ZIBELLINA LINNAEUS, 1758) ПРИАМУРЬЯ: КЛАСТЕРНЫЙ АНАЛИЗ СУБПОПУЛЯЦИЙ

The Amur region sable sub-populations monitoring of the allelic composition in the hunting seasons of 2011–2021 showed the presence of alleles marking the differences between the sable population at the Amur River left and right banks. A pairwise comparison of seasonal collections of left- and right-bank sub-populations revealed a spread in the level of genetic differentiation from almost zero values to intermediate ones. It became clear that in order to determine the number of different genetic groups of sable in this region, we need additional mathematical methods to work with the obtained data. The purpose of this work is to determine and visualize the most likely number of different genetic groups of sables in the territory under consideration. It was studied three sub-populations of the Bureinsky Highland sable (left bank of the Amur River). For comparison, it was taken a species sub-population from the Sikhote-Alin western slopes (the Amur River right bank). The analysis of data for two microsatellite loci Ma3 and Mer041, on the material of hunting winter seasons from 2011 to 2022, was carried out using the programs Structure 2.3.4 and Structure Harvester. Based on the results obtained with these programs, it can be assumed that in the territory under consideration, this species is represented by two genetic groups (clusters) – “the left-bank” and “the right-bank”. The structure remains the same for both the collection material of the 2012–2013 winter hunting seasons and those of 2013–2014, as well as for the total collections of 2011–2022. The formation of such a structure is undoubtedly the result of both the historical formation of the species habitat and the genetic specifics of anthropogenic introductions from two different geographical areas.

Genetic Structure of the Endemic Fiddler Crab Uca (Xeruca) formosensis on the West Coast of Taiwan.

Xeruca formosensis is the only endemic species of fiddler crab on the west coast of Taiwan. However, its natural habitats and populations have been compromised by excessive anthropogenic activities and improper land use over the past four decades. In light of these changes, we sought to evaluate the genetic diversity and gene flow of the species by examining the genetic variation of X. formosensis at different sampling locations. To this end, we performed molecular analyses of three endonuclease-amplified fragment length polymorphisms (TE-AFLP) and the cytochrome oxidase subunit I (COI) marker from leg muscle samples. We found that the genetic variation within sampling locations was higher than that among sampling locations, and the expected heterozygosity of genetic diversity (Hj) was 0.152 for TE-AFLP data. Meanwhile, the COI marker showed high haplotype diversity (h = 0.976 ± 0.008) and a low genetic differentiation level (FST = 0.021) in X. formosensis populations. Importantly, the genetic connectivity of X. formosensis may be influenced by larval-stage crabs drifting between coastal and marine habitats. As such, crab gene flow is promoted among populations by larval exchange via nearshore currents. Although X. formosensis has high gene flow, the species could undergo an extinction crisis if the population sizes continue to decline, as with most endangered species. In order to maintain the natural habitats and population size of X. formosensis, long-term monitoring and investigation will be necessary.