Coefficient Of Genetic Differentiation Research Articles

Genetic diversity of an Azorean endemic and endangered plant species inferred from inter-simple sequence repeat markers.

Knowledge of the levels and distribution of genetic diversity is important for designing conservation strategies for threatened and endangered species so as to guarantee sustainable survival of populations and to preserve their evolutionary potential. Picconia azorica is a valuable Azorean endemic species recently classified as endangered. To contribute with information useful for the establishment of conservation programmes, the genetic variability and differentiation among 230 samples from 11 populations collected in three Azorean islands was accessed with eight inter-simple sequence repeat markers. A total of 64 polymorphic loci were detected. The majority of genetic variability was found within populations and no genetic structure was detected between populations and between islands. Also the coefficient of genetic differentiation and the level of gene flow indicate that geographical distances do not act as barriers for gene flow. In order to ensure the survival of populations in situ and ex situ management practices should be considered, including artificial propagation through the use of plant tissue culture techniques, not only for the restoration of habitat but also for the sustainable use of its valuable wood.

Genetic diversity and population structure of wild Dipsacus asperoides in China as indicated by ISSR markers

In order to evaluate the genetic diversity and genetic structure of wild Dipsacus asperoides, we surveyed genetic polymorphisms in 288 individuals from 12 populations using ISSR. A total of 240 bands were amplified, among which 190 were polymorphic loci. At the species level, genetic diversity was found to be abundant: PPB = 79.17%, NE = 1.2152, H = 0.1361, and Hsp = 0.2213. At the population level, genetic diversity was lower: PPB = 30.76 %, NE = 1.0786, H = 0.0897, and Hpop = 0.1375. The calculated Nei genetic differentiation coefficient was 0.3406, which is consistent with the calculated Shannon population genetic differentiation coefficient of 0.3787. This is commonly taken to indicate that most of the genetic variation existed within the populations. Gene flow was calculated as Nm = 0.9679, suggesting that gene exchange only occurred at a low level. Based on the Nei genetic distance, the 12 populations were divided into 4 categories. Our results suggest that D. asperoides has abundant genetic diversity and provides a foundation for the protection and improvement of germplasm resources.

Genetic diversity and relationship of chicory (Cichorium intybus L.) using sequence-related amplified polymorphism markers.

Chicory is a crop with economically important roles and is cultivated worldwide. The genetic diversity and relationship of 80 accessions of chicories and endives were evaluated by sequence-related amplified polymorphism (SRAP) markers to provide a theoretical basis for future breeding programs in China. The polymorphic rate was 96.83%, and the average polymorphic information content was 0.323, suggesting the rich genetic diversity of chicory. The genetic diversity degree of chicory was higher (GS = 0.677) than that of endive (GS = 0.701). The accessions with the highest genetic diversity (effective number of alleles, NE = 1.609; Nei's genetic diversity, H = 0.372; Shannon information index, I = 0.556) were from Italy. The richest genetic diversity was revealed in a chicory line (NE = 1.478, H = 0.289, I = 0.443) among the 3 types (line, wild, and cultivar). The chicory genetic structure of 8 geographical groups showed that the genetic differentiation coefficient (GST) was 14.20% and the number of immigrants per generation (Nm) was 3.020. A GST of 6.80% and an Nm of 6.853 were obtained from different types. This observation suggests that these chicory lines, especially those from the Mediterranean region, have potential for providing rich genetic resources for further breeding programs, that the chicory genetic structure among different countries obviously differs with a certain amount of gene flow, and that SRAP markers could be applied to analyze genetic relationships and classifications of Cichorium intybus and C. endivia.

Analysis of geographic and pairwise distances among sheep populations.

This study investigated geographic and pairwise distances among seven Chinese local and four introduced sheep populations via analysis of 26 microsatellite DNA markers. Genetic polymorphism was rich, and the following was discovered: 348 alleles in total were detected, the average allele number was 13.38, the polymorphism information content (PIC) of loci ranged from 0.717 to 0.788, the number of effective alleles ranged from 7.046 to 7.489, and the observed heterozygosity ranged from 0.700 to 0.768 for the practical sample, and from 0.712 to 0.794 for expected heterozygosity. The Wright's F-statistic of subpopulations within the total (FST) was 0.128, the genetic differentiation coefficient (GST) was 0.115, and the average gene flow (Nm) was 1.703. The phylogenetic trees based on the neighbor-joining method by Nei's genetic distance (DA) and Nei's standard genetic distance (DS) were similar. Sheep populations clustered into group 1 (Ta, M, L, H, O, G, and Q breeds) and group 2 (PD, WS, B, and T breeds). These results will have an important value applied and directive significance for sheep breeding in the future.

Genetic diversity in wild populations of Paulownia fortune.

The genetic diversities of 16 Paulownia fortunei populations involving 143 individuals collected from 6 provinces in China were analyzed using amplified fragment length polymorphism (AFLP). A total of 9 primer pairs with 1169 polymorphic loci were screened out, and each pair possessed 132 bands on average. The percentage of polymorphic bands (98.57%), the effective number of alleles (1.2138-1.2726), Nei's genetic diversity (0.1566-0.1887), and Shannon's information index (0.2692-0.3117) indicated a plentiful genetic diversity and different among Paulownia fortunei populations. The genetic differentiation coefficient between populations was 0.2386, while the gene flow was 1.0954, and the low gene exchange promoted genetic differentiation. Analysis of variance indicated that genetic variation mainly occurred within populations (81.62% of total variation) rather than among populations (18.38%). The 16 populations were divided by unweighted pair-group method with arithmetic means (UPGMA) into 4 groups with obvious regionalism, in which the populations with close geographical locations (latitude) were clustered together.

基于CO I基因全长序列的假眼小绿叶蝉地理种群遗传分化研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于CO I基因全长序列的假眼小绿叶蝉地理种群遗传分化研究 DOI: 10.5846/stxb201404160745 作者: 作者单位: 中国计量学院,中国计量学院浙江省生物计量及检验检疫技术重点实验室,中国计量学院浙江省生物计量及检验检疫技术重点实验室,中国计量学院浙江省生物计量及检验检疫技术重点实验室,中国计量学院浙江省生物计量及检验检疫技术重点实验室,中国计量学院浙江省生物计量及检验检疫技术重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31071744);浙江省教育厅课题(Y201329611) Genetic variation of Empoasca vitis (Göthe) (Hemiptera: Cicadellidae) among different geographical populations based on mtDNA CO I complete sequence Author: Affiliation: China Jiliang University,,,,,Zhejiang Provincial Key Laboratory of Biometrology and Inspection Quarantine,College of Life Sciences of China Jiliang University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:假眼小绿叶蝉Empoasca vitis (Göthe) 是我国大陆茶区分布最广、为害最重的茶树害虫,其种群世代重叠严重,数量大。从我国13个主要产茶省份各选出一个重点产茶县(市),采集假眼小绿叶蝉标本,首次扩增得到其线粒体CO I基因全长序列,并以此探讨了假眼小绿叶蝉13个地理种群间的遗传多样性、分子变异、遗传分化程度及基因流水平。在13个地理种群中共得到了176条CO I基因序列,发现了113个变异位点,形成了105个CO I单倍型。总群体单倍型多样性Hd为0.9720,种群内单倍型多样性在0.804 -1.000范围内,总群体和各种群的Tajima's D检验结果均不显著,说明茶园假眼小绿叶蝉的进化符合中性模型,种群数量较为稳定。AMOVA分子变异分析结果表明,茶园假眼小绿叶蝉的遗传分化主要来自于种群内部。Mantel检验显示各地理种群的遗传距离与地理距离之间不具有显著的相关性。总群体的遗传分化系数Gst为0.03652,固定系数Fst为0.10876,基因流Nm为4.097,表明地理种群间存在较频繁的基因交流,遗传差异较小。推测,20世纪90年代以来的省际之间频繁的茶树鲜叶贩运、异地茶苗的大批量调拨等因素促进了假眼小绿叶蝉的长距离迁移,加强了不同种群间的基因交流。 Abstract:The tea green leafhopper, Empoasca vitis(Göthe), is one of the most important tea-plant pests that causes significant losses on tea leaf production throughout all growing regions in mainland of China. The multiple occurrences of the overlapping generations of this pest have led to serious infestation on tea leaves. Adults were collected from the thirteen primary tea-producing provinces respectively, with each representing one geographic population in the southeastern China. The complete sequences of the entire mtDNACO I gene (x bp) of E. vitis were compared among 13 populations. The genetic structure of these populations was further investigated based on the CO I DNA sequences. A total of 176 CO I gene complete sequences with 113 variable sites and 105 haplotypes were obtained. The haplotype diversity index (Hd) was 0.9720 among all populations, ranging from 0.804 to 1.000 within single population. The Tajima's D tests for all populations or each single population did not reach any significant level, which suggest that the evolution and the abundance of E. vitison tea plantations remained on quantitative level,which fits well with the neutral model. The Results of ANOVA analyses demonstrated that genetic differentiation of E. vitis mainly occurred within populations. The Mantel test disclosed that the genetic distance among populations was not correlated with the geographic distance. Among the 13 populations, the total genetic differentiation coefficient (Gst) was 0.03652, the total fixation index (Fst) was 0.10876, and the gene flow (Nm) was 4.097. This indicates that the high level of gene exchange does exist in the different geographical populations, but not in genetic variation. We believe that the massive and frequent transportation and plantation of fresh tea leaves and seedlings in different host plant locations among 13 provinces since the 1990s promote the long-distance migration of E. vitis and reinforce the gene flow among these geographically different populations. 参考文献 相似文献 引证文献

Conservation genetics of endangered medicinal plant Commiphora wightii in Indian Thar Desert

To ascertain the conservation priorities and strategies for Commiphora wightii, an endangered medicinal plant of Indian Thar Desert, genetic diversity was estimated within and among different populations. The total of 155 amplification products were scored using ten each of RAPD and ISSR primers, exhibiting an overall 86.72% polymorphism across 45 individuals representing eight populations. The cumulative data of two markers were used to compute pair-wise distances. The Neighbor-Joining tree revealed high genetic differentiation among populations except Kiradu population. Nei's gene diversity (h) ranged between 0.082 and 0.193 with total diversity at species level is 0.294. Shannon's information index (I) ranged between 0.118 and 0.275 with an overall diversity of 0.439. Analysis of molecular variance showed more diversity among population level (56.65%) than at within population level (43.35%). The low gene flow value (Nm=0.349) and high coefficient of genetic differentiation (GST=0.589) and high fixation index (FST=0.566) demonstrated elevated genetic differentiation among the population and can be predicted that these populations are not in Hardy–Weinberg proportions. Principal Co-ordinate Analysis confirms that Akal population has become phylogenetically more distinct and less diverse than the rest of the samples. Mantel's test revealed no correlation between genetic and geographical distances of populations (R2=0.122). Overall highest diversity was observed in the population of Machiya Safari Park and Kiradu, while lowest in Akal population, later may constitute an evolutionary significant unit, having merit for special management.

English

Genetic variation in seven selfed and unselfed Cucurbita pepo landraces from districts in KwaZulu- Natal Province was investigated using the random amplified polymorphic DNA (RAPD). Out of 36 primers screened nine were selected, which gave 100 clear and bright fragments, out of which 94 (94%) fragments were considered polymorphic. The sizes of bands ranged from 75 to 1800 bp. The number of bands per primer ranged between nine and 14. The genetic differentiation coefficient between populations (G ST ) varied between 0.0022 and 0.0100, while the gene flow ranged between 49.4545 and 223.7226. The effective number of alleles, Nei’s gene diversity index and Shannon’s information index were the highest in the selfed population from Zululand (yellow) district (ZS) population (Ne= 1.2046; H=0.1677; I=0.3060) and the lowest in unselfed population from uThungulu (yellow) (TNS) population (Ne=1.1512; H=0.1301; I=0.2518). The production of specific RAPD markers by different primers indicated gene diversity between: Selfed and unselfed populations from the same geographic origin; populations with yellow/orange mature fruit from a population with green mature fruit; and also among different populations in general. The selfed population from uThungulu (yellow) (TS) and TNS populations, both from uThungulu district, were the highest in genetic identity (I N = 0.9996) and the closest in the genetic distance (D = 0.0004). The unselfed population from Umkhanyakude (green) (CPSP) and unselfed population from Umkhanyakude (yellow (MNS) populations as well as CPSP and TNS populations were the lowest in genetic identity (I N = 0.9985) and the furthest in genetic distance (D = 0.0015). The dendrogram mainly grouped the populations according to their mature fruit colour, and then according to their geographical origin. All genetic parameters indicated that there was plentiful genetic diversity in C. pepo landraces of northern KwaZulu-Natal, South Africa. Key words: Cucurbita pepo landraces, genetic variation, self-pollination, random amplified polymorphic DNA (RAPD) markers, northern KwaZulu-Natal.

Genetic variation among wild and cultivated Agropyron desertorum populations based on total protein profiles and phenotypic traits

Genetic differentiation between co-occurring crops and their wild relatives will be greatly modified by crop-to-weed gene flow and variation between human and natural selective pressures. In this paper, the pattern of population differentiation within and among the wild and cultivated populations of Agropyron desertorum in Iran, with respect to both total protein profiles and phenotypic traits, is measured and compared. A total of 180 A. desertorum individuals from 14 wild and four cultivated populations were included in the study. The levels of genetic diversity in cultivated populations were similar to those in wild populations (mean percentage of polymorphic loci [PPL] = 53.26% versus PPL=51.66%, and mean expected heterozygosity [He] = 0.154 versus He=0.165). Neighbour-joining cluster analysis showed that wild populations and cultivated populations were not separated into two groups. The coefficient of genetic differentiation (Fst) between a cultivar and its wild progenitor was 0.060. For the 14 wild populations, a significant genetic differentiation among populations was found using AMOVA analysis (30% of total genetic variation resided among populations).

Genetic Diversity and Population Structure of Germplasm Resources in Sesame (<I>Sesamum indicum</I> L.) by SSR Markers

A total of 545 sesame accessions, including domestic and foreign germplasm resources, were analyzed systematically with 42 SSR primer pairs. The results showed that 106 allele bands were detected among the sesame accessions, and the Shannon’s information index (I) was 0.4092. Analysis results of UPGMA clustering, two-dimension principal components and population structure were basically consistent; 545 varieties were divided into three groups in UPGMA dendrogram or three subgroups in population structure. There were the lower genetic differentiation coefficient and the closer sibship in worldwide sesame. The similarity coefficient of seven ecological groups in China ranged from 0.9811 to 0.5462, and there was no close genetic relationship between varieties from northern regions and other regions in China. The similarity coefficients for foreign varieties were from 0.9726 to 0.7442, and the genetic relationships of varieties from Africa zone was close to those from Japan zone, but not from China. It showed that the genetic basis of varieties from China was relatively narrow, and the genetic diversities of varieties were not completely related to geographic distribution, but the genetic diversities of varieties from abroad presented abundance. Therefore, the introduction of foreign resources should be reinforced, and the domestic resources from different regions should be utilized in the future sesame breeding.

Application of restriction site amplified polymorphism (RSAP) to genetic diversity in Saccharina japonica

Restriction site amplified polymorphism (RSAP) was used, for the first time, to analyze the genetic structure and diversity of four, mainly cultivated, varieties of the brown alga, Saccharina japonica. Eighty-eight samples from varieties “ Rongfu ”, “ Fujian ”, “ Ailunwan ” and “ Shengchanzhong ” were used for the genetic analyses. One hundred and ninety-eight bands were obtained using eight combinations of primers. One hundred and ninety-one (96.46%) were polymorphic bands. Nei’s genetic diversity was 0.360, and the coefficient of genetic differentiation was 0.357. No inbreeding-type recession was found in the four brown alga varieties and the results of the “ Ailunwan ” variety using samples from 2 years showed that the variety was becoming less diverse during the selection inherent in the breeding program. Genetic diversity and cluster analyses results were consistent with these genetic relationships. The results show the RSAP method is suitable for genetic analysis. Continuous inbreeding and selection could reduce the genetic diversity effectively; therefore periodical supervision is required.

Genetic diversity and differentiation of a narrowly distributed and endemic species, Aster spathulifolius maxim (Asteraceae), revealed with inter simple sequence repeat markers

Aster spathulifolius Maxim is a narrowly distributed and endemic species occurring in coastal regions of Korea and Japan. The genetic diversity and differentiation of fifteen populations of the species were analyzed in eight-two loci using six Inter Simple Sequence Repeat primers. Total genetic diversity at species level was extremely high (P=98.78%, Hsp=0.333±0.144, I=0.501±0.180), whereas the genetic diversity at population level was relatively low (P=43.74%, Hpop=0.150±0.189, I=0.227±0.274). High genetic differentiation among populations was detected based on genetic differentiation coefficient (Gst=0.549) and analysis of molecular variance (AP=54.06%). These findings together with low gene flow estimates (Nm=0.205) suggest that genetic drift by isolation is the most critical factor for establishing the current genetic structure of the species. The decrease in abundance of A. spathulifolius along with low levels of genetic diversity indicates that conservation strategies are necessary.

Effects of anthropogenic intermixing on the genetic structure of Dybowski's frog populations in northeast China

The Dybowski's frog (Rana dybowskii) is mainly distributed in northeast China and the Russian Far East. Its dried oviduct, or frog oil, has been used in traditional Chinese medicine for thousands of years. Frogs from different geographic regions exhibit variations in their body mass and oil productivity. As a result, farmers usually import high quality breeding stock from different areas to increase oviduct productivity. This practice could alter the genetic structure of the frog populations. We used 10 microsatellite loci to investigate the level of genetic variation for 10 frog populations in the context of human-mediated disturbance. The study populations comprised the following: the Hebei, Tieli, and Jiamusi populations from the Lesser Khingan Mountains; the Mudanjiang, Jilin, Jiaohe, and Huadian populations from the north central Changbai Mountains; and the Tonghua, Benxi, and Xiuyan populations from the southern Changbai Mountains. Our results showed that the 3 Lesser Khingan Mountain populations exhibited highly significant differentiation values (FST = 0.047–0.071, P < 0.001). In addition, the Tonghua population differentiated significantly from the other 6 populations of the Changbai Mountains (P < 0.001). The genetic differentiation coefficient (FST) and gene flow (Nem) estimates showed that the Benxi and Jiaohe populations had a high degree of genetic similarity despite being geographically separated by mountains and river systems. We obtained similar results for the Xiuyan and Tieli populations. Furthermore, the degree of gene flow between the Jiamusi and the north central Changbai Mountain populations was greater than that observed between the Jiamusi and the other Lesser Khingan Mountain populations. These results therefore suggest that the Benxi, Xiuyan, and Jiamusi populations have undergone substantial intermixing because of human-mediated relocation. Economic demands make completely stopping the geographical relocation of Dybowski's frog in northeast China virtually impossible. Consequently, effective management strategies are now a high priority to ensure that conservationists and local economies can work together to guarantee the long-term survival of this species. © 2013 The Wildlife Society.

Analysis of Geographic and Pairwise Distances among Chinese Cashmere Goat Populations.

This study investigated the geographic and pairwise distances of nine Chinese local Cashmere goat populations through the analysis of 20 microsatellite DNA markers. Fluorescence PCR was used to identify the markers, which were selected based on their significance as identified by the Food and Agriculture Organization of the United Nations (FAO) and the International Society for Animal Genetics (ISAG). In total, 206 alleles were detected; the average allele number was 10.30; the polymorphism information content of loci ranged from 0.5213 to 0.7582; the number of effective alleles ranged from 4.0484 to 4.6178; the observed heterozygosity was from 0.5023 to 0.5602 for the practical sample; the expected heterozygosity ranged from 0.5783 to 0.6464; and Allelic richness ranged from 4.7551 to 8.0693. These results indicated that Chinese Cashmere goat populations exhibited rich genetic diversity. Further, the Wright’s F-statistics of subpopulation within total (FST) was 0.1184; the genetic differentiation coefficient (GST) was 0.0940; and the average gene flow (Nm) was 2.0415. All pairwise FST values among the populations were highly significant (p<0.01 or p<0.001), suggesting that the populations studied should all be considered to be separate breeds. Finally, the clustering analysis divided the Chinese Cashmere goat populations into at least four clusters, with the Hexi and Yashan goat populations alone in one cluster. These results have provided useful, practical, and important information for the future of Chinese Cashmere goat breeding.

Genetic Diversity of Leafy Liverwort Species (Jungermanniidae, Marchantiophyta) in Poland: Regional Genetic Differentiation of Leafy Liverworts

Abstract For each of 8 species of leafy liverworts, 9-10 populations were sampled in 2-3 regions of Poland. In total, 5 regions were taken into account: the Tatra National Park, Bieszczady Mts., Białowieża Forest, Pomeranian Lake District, and Suwałki Lake District. Populations of most of the studied species did not show any correlation between genetic differentiation and geographic distances. Clear differences between regional groups of populations were found in only 2 species. The other species showed a complete or partial lack of genetic differentiation between groups of populations from various geographic regions. Generally, however, mountain populations had greater genetic diversity (HT, HS) and coefficient of genetic differentiation (GST) than lowland populations. In the Tatra National Park all the studied liverworts turned out to be more diverse than in the Bieszczady Mts. Białowieża Forest created a uniform group, standing out markedly from mountainous populations but population in this region had slightly smaller genetic diversity, then in the mountains. In the Pomeranian and Suwałki Lake Districts, genetic diversity of liverworts was significantly lower than in mountains. The decrease in diversity in these regions is a likely consequence of habitat fragmentation (causing population depletion) combined with negative effects of urban development. Habitat fragmentation results in genetic drift and inbreeding depression, which cause a decrease in genetic diversity. In the Pomeranian Lake District the level of total diversity (HT) and intra-population diversity (HS) was markedly higher than in the Suwałki Lake District. It may be linked to differences in climate, in the Suwałki Lake District climate is stronger.

Genetic diversity of natural Miscanthus sinensis populations in China revealed by ISSR markers

Abstract Miscanthus sinensis is a typical perennial C4 grass in Asia. In the present study, ISSR markers were used to evaluate the genetic variation within and among grass populations that were sampled from the Zhejiang and Guangdong Provinces of China. Based on nine ISSR primers, 206 clear and reproducible DNA fragments were generated. Relatively low levels of genetic diversity were determined among the populations. The coefficient of genetic differentiation among the populations was 0.52, which indicates that 52.3% of the total molecular variance exists among the populations. Such a high level of divergence present among the populations might be caused by the complex topography and variable climatic conditions present in the two provinces. AMOVA revealed that the majority of the genetic variation was within the populations (50.6%). The application of a novel method, which combines geographical coordinates and genetic differentiation to detect barriers for gene flow, allowed us to identify two zones of lowered gene flow.

Molecular evidence supports hypervariability in Phytophthora colocasiae associated with leaf blight of taro

The oomycete Phytophthora colocasiae that causes taro leaf blight is the most devastating disease of taro and is widely distributed worldwide. Molecular and phenotypic techniques were employed for assessing and exploiting the genetic variability among four populations of P. colocasiae obtained from a fine spatial scale (multiple leaf blight lesions on single taro leaf). Phenotypic characters such as virulence, morphology and mating type showed no variation. ITS characterization revealed detectable polymorphism among isolates of P. colocasiae. The mean number of haplotypes (H), haplotype diversity (HD), nucleotide diversity (π), and nucleotide substitution rate (θ) among analyzed sequences were 6.75, 1.00, 0.069, and 0.088 respectively. High levels of inter and intra specific variation were detected by random amplified polymorphic DNA (RAPD) assays. Moderate genetic diversity (H = 0.2651) was observed among populations of P. colocasiae. Analysis of molecular variance (AMOVA) confirmed that most of the genetic variability was confined to within a population (63.54 %). The coefficient of genetic differentiation among populations (G ST ) was 0.2007 and estimates of gene flow (Nm) among populations was 1.991 migrants per generation. Cluster analysis using UPGMA revealed that individuals from the same population failed to cluster in one distinct group. The results of the study reveal considerable genetic diversity among and within populations of P. colocasiae obtained from fine spatial scale. The possible mechanisms and implications of this genetic variation are discussed.

Higher genetic diversity and gene flow in wild populations of Miscanthus sinensis in southwest China

Miscanthus sinensis , a C 4 perennial grass, is widely distributed in most parts of China. M. sinensis has been selected as a candidate for bioenergy resources, owing to its high biomass potential and good adaptability on marginal lands. In this study, we detected the genetic diversity in wild populations of M. sinensis in southwest China. The results showed the percentage of polymorphic bands is 93.2%, the average Nei's gene diversity in population was 0.3870 and mean Shannon index was 0.5589. The mean of total gene diversity ( H T ) was 0.3831 ± 0.0216, while the allelic diversity within populations ( H S ) and among populations ( D ST ) was 0.3127 ± 0.0161 and 0.0704, respectively. The genetic differentiation coefficient ( G ST ) was 0.1838, and the gene flow ( N m ) was 1.110. The wild populations of M. sinensis have high genetic diversity within each population than among populations. As M. sinensis has a large phenotypic variation in many traits that are important for biomass yield, the best yielding genotypes could be bred into hybrids with low input and high output bioenergy crops. ► Sorghum EST-SSR primers showed high efficiency for amplifying the Miscanthus sinensis genome. ► The wild populations of M. sinensis have high level genetic diversity. ► The genetic diversity within populations was higher than among populations. ► There was high frequency of gene flow between different populations.

Genetic diversity and genetic structure of endangered wild Sinopodophyllum emodi by start codon targeted polymorphism

Revealed the genetic diversity level and genetic structure characteristics in Sinopodophyllum emodi, a rare and endangered species in China. We detected the genetic polymorphism within and among six wild populations (45 individuals) by the approach of Start Codon Targeted (SCoT) Polymorphism. The associated genetic parameters were calculated by POP-GENE1.31 and the relationship was constructed based on UPGMA method. A total of 350 bands were scored by 27 primers and 284 bands of them were polymorphic. The average polymorphic bands of each primer were 10.52. At species level, there was a high level of genetic diversity among six populations (PPB = 79.27%, N(e) = 1.332 7, H = 0.210 9 and H(sp) = 0.328 6). At population level, the genetic diversity level was low (PPB = 10.48% (4.00% -23.71%), N(e) = 1.048 7 (1.020 7-1.103 7), H = 0.029 7 (0.012 9-0.063 1), H(pop) = 0.046 2 (0.019 9-0.098 6). The Nei's coefficient of genetic differentiation was 0.841 1, which was consistent with the Shannon's coefficient of genetic differentiation (0.849 4). Two calculated methods all showed that most of the genetic variation existed among populations. The gene flow (N(m) = 0.094 4) was less among populations, indicating that the degree of genetic differentiation was higher. Genetic similarity coefficient were changed from 0.570 8 to 0.978 7. By clustering analysis, the tested populations were divided into two classes and had a tendency that the same geographical origin or material of similar habitats clustered into one group. The genetic diversity of samples of S. emodi is high,which laid a certain foundation for effective protection and improvement of germplasm resources.

Genetic diversity in wild Dipsacus chinensis populations from China based on ISSR markers

Wild Dipsacus chinensis plants in China have become endangered owing to over-harvesting and habitat fragmentation. We examined the genetic diversity and genetic structure of 90 individuals from three populations using inter-simple sequence repeat markers and found that 106 of 173 bands amplified by 22 informative and reliable primers were polymorphic. These findings correspond to a medium level of genetic diversity. At the species level, the estimates of parameters of genetic diversity were as follows: polymorphic loci (61.27%); effective number of alleles (1.3873); Nei's genetic diversity (0.2202); Shannon's information index (0.3235). At the population level, the estimates were polymorphic loci (9.53%); effective number of alleles (1.0419); Nei's genetic diversity (0.0258); Shannon's information index (0.0402). Nei's coefficient of genetic differentiation was 0.8829, which is consistent with Shannon's coefficient of genetic differentiation (0.8757). Most of the genetic variation existed among populations, and some differentiation may have resulted from habitat fragmentation and barriers to gene flow (gene flow = 0.0663). Combining our results with those of on-site field investigation, we conclude that the present genetic diversity and genetic structure of natural populations of D. chinensis have been strongly affected by harvesting and habitat fragmentation. We also propose strategies for the conservation of this plant.