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Sample records for based genetic diversity

  1. Soybean parent selection based on genetic diversity

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    Valéria Carpentieri-Pípolo

    2000-01-01

    Full Text Available Thirty-four soybean lines were assessed for twelve traits. The genetic distances were estimates using multivariate techniques, to identify parents to be included in breeding programs for hybridization. Grouping by the Tocher method, from generalized Mahalanobis distances, divided the 34 lines into four groups. The most important agronomic traits, weight of seeds per plot, plant height, height of first pod and days to maturity were considered when recommending for crossing. The following crosses were recommended based on the genetic divergence and the key agronomic traits: lines 23, 10, 2, 27 and 25 (group I with genotype 6 (group II and genotype 16 (group III. Thus only ten crosses would be made, representing only 2% of the total crosses which could be made in the partial diallel among the 34 lines assessed, which would allow up to 561 combinations.Trinta e quatro linhagens de soja foram avaliadas para doze características. As distâncias genéticas foram estimadas utilizando técnicas multivariadas com objetivo de identificar parentais a serem incluidos em um programa de melhoramento envolvendo hibridação. O agrupamento pelo método de Tocher, a partir das distâncias generalizadas de Mahalanobis, dividiu as 34 linhagens em 4 grupos. As caracterísiticas agronômicas mais importantes, peso de sementes por parcela, altura de planta, altura da primeira vagem e dias para maturação foram consideradas para a recomendação dos cruzamentos. Os seguintes cruzamentos foram recomendados baseado na divergência genética e nas características agronômicas chave: linhagens 23, 10, 2, 27 e 25 (grupo I com genótipo 6 (grupoII e com o genótipo 16 (grupo III. Portanto somente 10 cruzamentos poderiam ser realizados representando somente 2% do total de cruzamentos qu poderiam ser realizados em um dialelo parcial entre as 34 linhagens avaliadas as quais admitiriam até 561 combinações.

  2. Genetic diversity in Hemileia vastatrix based on RAPD markers.

    Science.gov (United States)

    Gouveia, M Manuela C; Ribeiro, Ana; Várzea, Vítor M P; Rodrigues, Carlos J

    2005-01-01

    Random amplified polymorphic DNA (RAPD) was used to assess the genetic structure of Hemileia vastatrix populations. Forty-five rust isolates with different virulence spectra and from different hosts and geographical regions were analyzed. Out of 45 bands, generated with three RAPD primers, 35 (78%) were polymorphic and scored as molecular markers. Cluster analysis exhibits unstructured variability of this pathogen with regard to physiological race, geographical origin or host. The genotypic diversity (H') inferred from Shannon's index was higher than gene diversity (Ht), suggesting that diversity is distributed among clonal lineages. Estimates of gene diversity in Africa and Asia populations were higher in total (Ht) as compared to within population diversity (Hs). Genetic differentiation was considerable among coffee rust isolates from Africa (Gst = 0.865) and Asia (Gst = 0.768) but not among isolates from South America (Gst = 0.266). We concluded that genetic diversity in H. vastatrix was moderately low and that the genetic differentiation among populations shows that asexual reproduction is likely to play an important role in the population biology of this fungus. This should be taken into account for the development of breeding programs.

  3. Genetic diversity analysis of common beans based on molecular markers.

    Science.gov (United States)

    Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

    2011-10-01

    A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  4. Genetic diversity analysis of common beans based on molecular markers

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    Homar R. Gill-Langarica

    2011-01-01

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  5. Genetic Diversity Based on Allozyme Alleles of Chinese Cultivated Rice

    Institute of Scientific and Technical Information of China (English)

    TANG Sheng-xiang; WEI Xing-hua; JIANG Yun-zhu; D S Brar; G S Khush

    2007-01-01

    Genetic diversity was analyzed with 6 632 core rice cultivars selected from 60 282 Chinese rice accessions on the basis of 12 allozyme loci, Pgil, Pgi2, Ampl, Amp2, Amp3, Amp4, Sdh1, Adh1, Est1, Est2, Est5 and Est9, by starch gel electrophoresis. Among the materials examined, 52 alleles at 12 polymorphic loci were identified, which occupied 96.3% of 54 alleles found in cultivated germplasm of O.sativa L. The number of alleles per locus ranged from 2 to 7 with an average of 4.33. The gene diversity (He) each locus varied considerably from 0.017 for Amp4 to 0.583 for Est2 with an average gene diversity (Ht) 0.271, and Shannon-Wiener index from 0.055 to 0.946 with an average of 0.468. The degree of polymorphism (DP) was in a range from 0.9 to 46.9% with an average of 21.4%. It was found that the genetic diversity in japonica (Keng) subspecies was lower in terms of allele's number, Ht and S-W index, being 91.8, 66.2 and 75.7% of indica (Hsien) one, respectively. Significant genetic differentiation between indica and japonica rice has been appeared in the loci Pgil, Amp2, Pgi2, and Est2, with higher average coefficient of genetic differentiation (Gst) 0.635, 0.626, 0.322 and 0.282, respectively. Except less allele number per locus (3.33) for modern cultivars, being 76.9% of landraces, the Ht and S-W index showed in similar between the modern cultivars and the landraces detected. In terms of allozyme, the rice cultivars in the Southwest Plateau and Central China have richer genetic diversity. The present study reveals again that Chinese cultivated rice germplasm has rich genetic diversity, showed by the allozyme allele variation.

  6. Genetic diversity studies of Kherigarh cattle based on microsatellite markers

    Indian Academy of Sciences (India)

    A. K. Pandey; Rekha Sharma; Yatender Singh; B. B. Prakash; S. P. S. Ahlawat

    2006-08-01

    We report a genetic diversity study of Kherigarh cattle, a utility draught-purpose breed of India, currently declining at a startling rate, by use of microsatellite markers recommended by the Food and Agriculture Organization. Microsatellite genotypes were derived, and allelic and genotypic frequencies, heterozygosities and gene diversity were estimated. A total of 131 alleles were distinguished by the 21 microsatellite markers used. All the microsatellites were highly polymorphic, with mean (± s.e.) allelic number of 6.24 ± 1.7, ranging 4–10 per locus. The observed heterozygosity in the population ranged between 0.261 and 0.809, with mean (± s.e.) of 0.574 ± 0.131, indicating considerable genetic variation in this population. Genetic bottleneck hypotheses were also explored. Our data suggest that the Kherigarh breed has not experienced a genetic bottleneck in the recent past.

  7. Genetic diversity and disease susceptibility.

    OpenAIRE

    Bodmer, W F

    1997-01-01

    The range of genetic diversity within human populations is enormous. Genetic susceptibility to common chronic disease is a significant part of this genetic diversity, which also includes a variety of rare clear-cut inherited diseases. Modern DNA-based genomic analysis can now routinely lead to the identification of genes involved in disease susceptibility, provides the basis for genetic counselling in affected families, and more widely for a genetically targeted approach to disease prevention...

  8. Analysis of genetic diversity of certain species of Piper using RAPD-based molecular markers.

    Science.gov (United States)

    Chowdhury, Utpal; Tanti, Bhaben; Rethy, Parakkal; Gajurel, Padma Raj

    2014-09-01

    The utility of RAPD markers in assessing genetic diversity and phenetic relationships of six different species of Piper from Northeast India was investigated. Polymerase chain reaction (PCR) with four arbitrary 10-mer oligonucleotide primers applied to the six species produced a total of 195 marker bands, of which, 159 were polymorphic. On average, six RAPD fragments were amplified per reaction. In the UPGMA phenetic dendrogram based on Jaccard's coefficient, the different accessions of Piper showed a high level of genetic variation. This study may be useful in identifying diverse genetic stocks of Piper, which may then be conserved on a priority basis.

  9. GENETIC DIVERSITY OF TRITICALE CULTIVARS BASED ON MICROSATELLITE AND RETROTRANSPOSON-BASED MARKERS

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    Želmíra Balážová

    2014-02-01

    Full Text Available The aim of our work was to detect genetic variability in the set of 59 winter and spring triticale (x Triticosecale Witt. varieties using combination of 4 wheat SSR and 4 retrotransposon-based markers. The number of alleles for SSR markers ranged from 8 to 10 with an average number of 8,75 alleles per locus. For IRAP markers the number of alleles ranged from 9 to 10 with an average number of 9,25 alleles per locus Totally, 72 alleles were detected, 37 alleles for IRAP markers and 35 alleles for SSR markers. For the assessment of genetic diversity the dendrogram, based on the hierarchical cluster analysis using UPGMA algorithm was prepared. Fifty nine triticale cultivars were grouped into two major groups. The first group contained all winter triticale varieties and in the second cluster were included all spring triticale varieties. The closest relationship was found out between two Polish winter triticale cultivars, Alekto and Pizarro. Results showed the utility of combination of microsatellite and retrotransposon-based markers for estimation of genetic diversity of triticale genotypes leading to genotype identification.

  10. Estimation of the genetic diversity in tetraploid alfalfa populations based on RAPD markers for breeding purposes.

    Science.gov (United States)

    Nagl, Nevena; Taski-Ajdukovic, Ksenija; Barac, Goran; Baburski, Aleksandar; Seccareccia, Ivana; Milic, Dragan; Katic, Slobodan

    2011-01-01

    Alfalfa is an autotetraploid, allogamous and heterozygous forage legume, whose varieties are synthetic populations. Due to the complex nature of the species, information about genetic diversity of germplasm used in any alfalfa breeding program is most beneficial. The genetic diversity of five alfalfa varieties, involved in progeny tests at Institute of Field and Vegetable Crops, was characterized based on RAPD markers. A total of 60 primers were screened, out of which 17 were selected for the analysis of genetic diversity. A total of 156 polymorphic bands were generated, with 10.6 bands per primer. Number and percentage of polymorphic loci, effective number of alleles, expected heterozygosity and Shannon's information index were used to estimate genetic variation. Variety Zuzana had the highest values for all tested parameters, exhibiting the highest level of variation, whereas variety RSI 20 exhibited the lowest. Analysis of molecular variance (AMOVA) showed that 88.39% of the total genetic variation was attributed to intra-varietal variance. The cluster analysis for individual samples and varieties revealed differences in their population structures: variety Zuzana showed a very high level of genetic variation, Banat and Ghareh were divided in subpopulations, while Pecy and RSI 20 were relatively uniform. Ways of exploiting the investigated germplasm in the breeding programs are suggested in this paper, depending on their population structure and diversity. The RAPD analysis shows potential to be applied in analysis of parental populations in semi-hybrid alfalfa breeding program in both, development of new homogenous germplasm, and identification of promising, complementary germplasm.

  11. SSR-based genetic diversity and structure of garlic accessions from Brazil.

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    da Cunha, Camila Pinto; Resende, Francisco Vilela; Zucchi, Maria Imaculada; Pinheiro, José Baldin

    2014-10-01

    Garlic is a spice and a medicinal plant; hence, there is an increasing interest in 'developing' new varieties with different culinary properties or with high content of nutraceutical compounds. Phenotypic traits and dominant molecular markers are predominantly used to evaluate the genetic diversity of garlic clones. However, 24 SSR markers (codominant) specific for garlic are available in the literature, fostering germplasm researches. In this study, we genotyped 130 garlic accessions from Brazil and abroad using 17 polymorphic SSR markers to assess the genetic diversity and structure. This is the first attempt to evaluate a large set of accessions maintained by Brazilian institutions. A high level of redundancy was detected in the collection (50 % of the accessions represented eight haplotypes). However, non-redundant accessions presented high genetic diversity. We detected on average five alleles per locus, Shannon index of 1.2, HO of 0.5, and HE of 0.6. A core collection was set with 17 accessions, covering 100 % of the alleles with minimum redundancy. Overall FST and D values indicate a strong genetic structure within accessions. Two major groups identified by both model-based (Bayesian approach) and hierarchical clustering (UPGMA dendrogram) techniques were coherent with the classification of accessions according to maturity time (growth cycle): early-late and midseason accessions. Assessing genetic diversity and structure of garlic collections is the first step towards an efficient management and conservation of accessions in genebanks, as well as to advance future genetic studies and improvement of garlic worldwide.

  12. Genetic diversity and population genetic structure analysis of Echinococcus granulosus sensu stricto complex based on mitochondrial DNA signature.

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    Monika Sharma

    Full Text Available The genetic diversity and population genetics of the Echinococcus granulosus sensu stricto complex were investigated based on sequencing of mitochondrial DNA (mtDNA. Total 81 isolates of hydatid cyst collected from ungulate animals from different geographical areas of North India were identified by sequencing of cytochrome c oxidase subunit1 (coxi gene. Three genotypes belonging to E. granulosus sensu stricto complex were identified (G1, G2 and G3 genotypes. Further the nucleotide sequences (retrieved from GenBank for the coxi gene from seven populations of E. granulosus sensu stricto complex covering 6 continents, were compared with sequences of isolates analysed in this study. Molecular diversity indices represent overall high mitochondrial DNA diversity for these populations, but low nucleotide diversity between haplotypes. The neutrality tests were used to analyze signatures of historical demographic events. The Tajima's D test and Fu's FS test showed negative value, indicating deviations from neutrality and both suggested recent population expansion for the populations. Pairwise fixation index was significant for pairwise comparison of different populations (except between South America and East Asia, Middle East and Europe, South America and Europe, Africa and Australia, indicating genetic differentiation among populations. Based on the findings of the present study and those from earlier studies, we hypothesize that demographic expansion occurred in E. granulosus after the introduction of founder haplotype particular by anthropogenic movements.

  13. Identification and Analysis of Genetic Diversity Structure Within Pisum Genus Based on Microsatellite Markers

    Institute of Scientific and Technical Information of China (English)

    ZONG Xu-xiao; Rebecca Ford; Robert R Redden; GUAN Jian-ping; WANG Shu-min

    2009-01-01

    To assesse the genetic diversity among wild and cultivated accessions of 8 taxonomic groups in 2 species, and 5 subspecies under Pisum genus, and to analyze population structure and their genetic relationships among various groups of taxonomy,the study tried to verify the fitness of traditionally botanical taxonomic system under Pisum genus and to provide essential information for the exploration and utilization of wild relatives of pea genetic resources. 197 Pisum accessions from 62 counties of 5 continents were employed for SSR analysis using 21 polymorphic primer pairs in this study. Except for cultivated field pea Pisum sativum ssp. sativum vat. sativum (94 genotypes), also included were wild relative genotypes that were classified as belonging to P. fulvum, P. sativum ssp.abyssinicum, P. sativum ssp. asiaticum, P. sativum ssp. transcaucasicum, P. sativum ssp. elatius vat. elatius, P. sativum ssp. elatius vat. pumilio and P. sativum ssp.sativum vat. arvense (103 genotypes). The PCA analyses and 3-dimension PCA graphs were conducted and drawn by NTSYSpe 2.2d statistical package. Nei78 genetic distances among groups of genetic resources were calculated, and cluster analysis using UPGMA method was carried out by using Popgene V1.32 statistical package, the dendrogram was drawn by MEGA3.1 statistical package. Allelie statistics were carried out by Popgene V1.32. The significance test between groups of genotypes was carried out by Fstat V2.9.3.2 statistical package. 104 polymorphic bands were amplified using 21 SSR primer pairs with unambiguous unique polymorphic bands. 4.95 alleles were detected by each SSR primer pair in average, of which 65.56% were effective alleles for diversity. PSAD270, PSAC58, PSAA18, PSAC75, PSAA175 and PSAB72 were the most effective SSR pairs. SSR alleles were uniformly distributed among botanical taxon units under Pisum genus, but significant difference appeared in most pairwise comparisons for genetic diversity between taxon unit based

  14. Microsatellite based genetic diversity and relationships among ten Creole and commercial cattle breeds raised in Brazil

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    Almeida Leonardo D

    2007-12-01

    Full Text Available Abstract Background Brazil holds the largest commercial cattle populations worldwide. Local cattle breeds can be classified according to their origin, as exotic or Creole. Exotic breeds imported in the last 100 years, both zebuine and taurine, currently make up the bulk of the intensively managed populations. Locally adapted Creole breeds, originated from cattle introduced by the European conquerors derive from natural selection and events of breed admixture. While historical knowledge exists on the Brazilian Creole breeds very little is known on their genetic composition. The objective of this study was to assess the levels of genetic diversity, phylogenetic relationships and patterns of taurine/zebuine admixture among ten cattle breeds raised in Brazil. Results Significant reduction of heterozygosity exists due both to within-population inbreeding and to breed differentiation in both subspecies (taurine and zebuine. For taurine breeds the number of markers that contribute to breed differentiation is larger than for zebuine. A consistently similar number of alleles was seen in both subspecies for all microsatellites. Four Creole breeds were the most genetically diverse followed by the zebuine breeds, the two specialized taurine breeds and the Creole Caracu. Pairwise genetic differentiation were all significant indicating that all breeds can be considered as genetically independent entities. A STRUCTURE based diagram indicated introgression of indicine genes in the local Creole breeds and suggested that occasional Creole introgression can be detected in some Zebuine animals. Conclusion This study reports on a comprehensive study of the genetic structure and diversity of cattle breeds in Brazil. A significant amount of genetic variation is maintained in the local cattle populations. The genetic data show that Brazilian Creole breeds constitute an important and diverse reservoir of genetic diversity for bovine breeding and conservation. The

  15. Estimation of the Genetic Diversity in Tetraploid Alfalfa Populations Based on RAPD Markers for Breeding Purposes

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    Slobodan Katic

    2011-08-01

    Full Text Available Alfalfa is an autotetraploid, allogamous and heterozygous forage legume, whose varieties are synthetic populations. Due to the complex nature of the species, information about genetic diversity of germplasm used in any alfalfa breeding program is most beneficial. The genetic diversity of five alfalfa varieties, involved in progeny tests at Institute of Field and Vegetable Crops, was characterized based on RAPD markers. A total of 60 primers were screened, out of which 17 were selected for the analysis of genetic diversity. A total of 156 polymorphic bands were generated, with 10.6 bands per primer. Number and percentage of polymorphic loci, effective number of alleles, expected heterozygosity and Shannon’s information index were used to estimate genetic variation. Variety Zuzana had the highest values for all tested parameters, exhibiting the highest level of variation, whereas variety RSI 20 exhibited the lowest. Analysis of molecular variance (AMOVA showed that 88.39% of the total genetic variation was attributed to intra-varietal variance. The cluster analysis for individual samples and varieties revealed differences in their population structures: variety Zuzana showed a very high level of genetic variation, Banat and Ghareh were divided in subpopulations, while Pecy and RSI 20 were relatively uniform. Ways of exploiting the investigated germplasm in the breeding programs are suggested in this paper, depending on their population structure and diversity. The RAPD analysis shows potential to be applied in analysis of parental populations in semi-hybrid alfalfa breeding program in both, development of new homogenous germplasm, and identification of promising, complementary germplasm.

  16. Microsatellite-based genetic diversity patterns in disjunct populations of a rare orchid.

    Science.gov (United States)

    Pandey, Madhav; Richards, Matt; Sharma, Jyotsna

    2015-12-01

    We investigated the patterns of genetic diversity and structure in seven disjunct populations of a rare North American orchid, Cypripedium kentuckiense by including populations that represented the periphery and the center of the its range. Eight nuclear and two chloroplast microsatellites were used. Genetic diversity was low across the sampled populations of C. kentuckiense based on both nuclear (average An = 4.0, Ho = 0.436, He = 0.448) and cpDNA microsatellites (average An = 1.57, Nh = 1.57 and H = 0.133). The number of private alleles ranged from one to four per population with a total of 17 private alleles detected at five nuclear microsatellites. One private allele at one cpDNA microsatellite was also observed. Although the absolute values for nuclear microsatellite based population differentiation were low (Fst = 0.075; ϕPT = 0.24), they were statistically significant. Pairwise Fst values ranged from 0.038 to 0.123 and each comparison was significant. We also detected isolation by distance with nDNA microsatellites based on the Mantel test (r(2) = 0.209, P = 0.05). STRUCTURE analysis and the neighbor joining trees grouped the populations similarly whereby the geographically proximal populations were genetically similar. Our data indicate that the species is genetically depauperate but the diversity is distributed more or less equally across its range. Population differentiation and isolation by distance were detectable, which indicates that genetic isolation is beginning to manifest itself across the range in this rare species.

  17. Genetic diversity analysis among pigeonpea genotypes adapted to South American regions based on microsatellite markers

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    Adna Cristina Barbosa de Sousa

    2011-08-01

    Full Text Available The pigeonpea [Cajanus cajan (L Millspaugh] is one of the most important perennial legume crops utilized in the food, fodder, soil conservation, crop-livestock integrated systems, reclaiming of degraded pastures and symbiotic nitrogen fixation. Microsatellite markers were used to estimate the genetic diversity of 77 pigeonpea genotypes selected from the germplasm collections at Embrapa Cattle-Southeast and, to evaluate their transferability to Phaseolus vulgaris and Vigna unguiculata species. The number of alleles per locus ranged from 2 to12, with an average of 5.1 alleles. The PIC values ranged from 0.11 to 0.80 (average 0.49 and the D values from 0.23 to 0.91 (average 0.58. The averages of observed and expected heterozygosity were 0.25 and 0.47, respectively, showing a deficit in heterozygosity. A model-based Bayesian approach implemented in the software STRUCTURE was used to assign genotypes into clusters. A dendrogram was constructed based on the modified Roger's genetic distances using a neighbor-joining method (NJ. A total of four clusters were assembled by STRUCTURE and a strong tendency of correspondence between the Bayesian clusters in the NJ tree was observed. The genetic distance ranged from 0.09 to 0.62 (average 0.37, showing a low genetic diversity in the pigeonpea genotypes. Transferability of pigeonpea-specific microsatellites revealed a cross-amplification and the presence of polymorphic alleles in P. vulgaris and V. unguiculata.

  18. Genetic Diversity of Japonica Rice (Oryza sativa L. Based on Markers Corresponding to Starch Synthesizing Genes

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    Puji Lestari

    2016-06-01

    Full Text Available Genes related to starch synthesis and the metabolism contribute to a variety of physicochemical properties that determine the eating/cooking qualities of rice. Our previous study suggested that a set of molecular markers was able to estimate the eating quality of japonica rice. The present study reports the genetic diversity of 22 japonica rice varieties based on markers corresponding to starch synthesizing genes. The mean of the polymorphic information content (PIC: 0.135 value and the diversity index (0.171 indicated a low genetic diversity in these varieties. The phylogenetic tree clearly demonstrated three main clusters: 1 cluster I contained seven varieties with similar physicochemical properties; 2 cluster II only showed a Japanese variety, Koshihikari, and 3 cluster III included the most Korean varieties (14 varieties. This phylogenetic analysis did not completely represent the physicochemical properties differentiation of the japonica varieties, although it did reveal an initial clue to the close relationship between Korean rice and the Japanese and Chinese varieties. Notably, these markers were also able to identify a premium japonica rice. The molecular markers and information concerning the genetic relationship would be useful in improving the japonica rice along with its starch quality of in breeding program.

  19. Analysis of the diversity of population and convergence of genetic algorithms based on Negentropy

    Institute of Scientific and Technical Information of China (English)

    Zhang Lianying; Wang Anmin

    2005-01-01

    With its wide use in different fields, the problem of the convergence of simple genetic algorithms (GAs) has been concerned. In the past, the research on the convergence of GAs was based on Holland' s model theorem. The diversity of the evolutionary population and the convergence of GAs are studied by using the concept of negentropy based on the discussion of the characteristic of GA. Some test functions are used to test the convergence of GAs, and good results have been obtained. It is shown that the global optimization may be obtained by selecting appropriate parameters of simple GAs if the evolution time is enough.

  20. Genetic Diversity of Bali Cattle Based on Microsatellite Marker in Indonesian Breeding Centre

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    W. A. Septian

    2015-04-01

    Full Text Available Genetics characterization in livestock based on microsatellite has been widely implemented including for Bali cattle in three different breeding centres in Indonesia. This study aimed to determine diversity of Bali cattle microsatellites in three breeding centers namely BPTU Bali cattle in Bali, BPT-HMT Serading Sumbawa in West Nusa Tenggara, and Village Breeding Center in South Sulawesi. The number of animals used in this study was 95 head of cattle consisted of 32 heads from BPTU Bali Province, 32 heads from BPT-HMT Serading Sumbawa, and 31 heads from Village Barru Breeding Center Barru distric. Microsatellite loci used to determine the diversity was the locus SPS115, INRA037, MM12, and ETH185 based on flourescently labeled fragment method. Data analysis of microsatellite in Bali cattle at three different locations was performed by using POPGEN 1.2, Cervus, and POPTREE2 programs. The results showed that microsatellite diversity in Bali cattle detected 32 alleles from three different locations, and there were specific alleles at each location. Average values of observed heterozygosity (Ho and expected heterozygosity (He were 0.418 and 0.604 respectively, while the average value of polymorphism informative content (PIC was 0.579. The Hardy-Weinberg equilibrium in general suggested that the loci used in the Bali cattle in three populations were in equilibrium, except INRA037 and ETH185. The genetic diversity between populations of Bali cattle was 0.033 (3%, while the inbreeding coefficient index in all populations was 0.296 (29.6 %. Bali cattle phylogeny tree with three populations showed that the populations of Bali cattle in BPTU Bali and VBC Barru had close genetic distance compared to the population of Bali cattle in BPT-HMT Serading Sumbawa. The results of this study provide information that the characteristics of Bali cattle breeding centers in three locations are different, so we need a directed breeding program in each population.

  1. Genetic diversity among melon accessions (Cucumis melo) from Turkey based on SSR markers.

    Science.gov (United States)

    Kaçar, Y A; Simsek, O; Solmaz, I; Sari, N; Mendi, Y Y

    2012-12-19

    Melon (Cucumis melo) is an important vegetable crop in Turkey, where it is grown in many regions; the most widely planted lines are local winter types belonging to the var. inodorous. We examined 81 melon genotypes collected from different provinces of Turkey, compared with 15 reference melon genotypes obtained from INRA/France, to determine genetic diversity among Turkish melons. Twenty polymorphic primers were used to generate the SSR markers. PCR amplification was performed and electrophoresis was conducted. SSR data were used to generate a binary matrix. For cluster analysis, UPGMA was employed to construct a clustering dendrogram based on the genetic distance matrix. The cophenetic correlation was compared with the similarity matrix using the Mantel matrix correspondence test to evaluate the representativeness of the dendrogram. A total of 123 alleles were amplified using the 20 SSR primer sets. The number of alleles detected by a single primer set ranged from 2 to 12, with an average of 6.15. The similarity ranged from 0.22 to 1.00 in the dendrogram developed from microsatellite analysis. Based on this molecular data, we concluded that genetic diversity among these Turkish accessions is relatively high.

  2. Evaluation of genetic diversity in jackfruit (Artocarpus heterophyllus Lam.) based on amplified fragment length polymorphism markers.

    Science.gov (United States)

    Shyamalamma, S; Chandra, S B C; Hegde, M; Naryanswamy, P

    2008-07-22

    Artocarpus heterophyllus Lam., commonly called jackfruit, is a medium-sized evergreen tree that bears high yields of the largest known edible fruit. Yet, it has been little explored commercially due to wide variation in fruit quality. The genetic diversity and genetic relatedness of 50 jackfruit accessions were studied using amplified fragment length polymorphism markers. Of 16 primer pairs evaluated, eight were selected for screening of genotypes based on the number and quality of polymorphic fragments produced. These primer combinations produced 5976 bands, 1267 (22%) of which were polymorphic. Among the jackfruit accessions, the similarity coefficient ranged from 0.137 to 0.978; the accessions also shared a large number of monomorphic fragments (78%). Cluster analysis and principal component analysis grouped all jackfruit genotypes into three major clusters. Cluster I included the genotypes grown in a jackfruit region of Karnataka, called Tamaka, with very dry conditions; cluster II contained the genotypes collected from locations having medium to heavy rainfall in Karnataka; cluster III grouped the genotypes in distant locations with different environmental conditions. Strong coincidence of these amplified fragment length polymorphism-based groupings with geographical localities as well as morphological characters was observed. We found moderate genetic diversity in these jackfruit accessions. This information should be useful for tree breeding programs, as part of our effort to popularize jackfruit as a commercial crop.

  3. Relationship Between Hybrid Performance and Genetic Diversity Based on SSRs and ISSRs in Brassica napus L.

    Institute of Scientific and Technical Information of China (English)

    SHEN Jin-xiong; FU Ting-dong; YANG Guang-sheng

    2003-01-01

    To investigate the relationship between genetic distance (GD) and hybrid performance, twotypes of molecular markers, microsatellites (simple sequence repeats, SSRs) and intro-simple sequence repeats(ISSRs), were employed to detect the genetic diversity of 3 double low self-incompatible lines and 22 male pa-rental varieties of Brassica napus from different geographical origins. Hybrids were produced in a NC Ⅱ mat-ing design by hand-pollination. The result indicated that 25 parental varieties (lines) could be divided into sixgroups by Un-weighted Pair Group Mathematics Average (UPGMA) clustering based on GDs. SI-1300 and SI-1320 could be singly clustered into one group, respectively. Varieties from China could be separated into an-other group, SI-1310 and varieties from foreign countries could be separated into other three groups. Thegrouping was generally consistent with parental pedigrees and geographical origins. Significant differences inyield, quality and phenological period traits were observed among these parent groups. Although hybrid yield/plant showed significantly positive correlation with genetic distance based on SSR and ISSR markers, but thedetermination coefficient was iow. It appeared to be unsuitable for using the genetic distance based on SSR andISSR markers to predict heterosis and hybrid performance in Brassica napus.

  4. Genetic diversity in cultivated carioca common beans based on molecular marker analysis

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    2011-01-01

    Full Text Available A wide array of molecular markers has been used to investigate the genetic diversity among common bean species. However, the best combination of markers for studying such diversity among common bean cultivars has yet to be determined. Few reports have examined the genetic diversity of the carioca bean, commercially one of the most important common beans in Brazil. In this study, we examined the usefulness of two molecular marker systems (simple sequence repeats - SSRs and amplified fragment length polymorphisms - AFLPs for assessing the genetic diversity of carioca beans. The amount of information provided by Roger's modified genetic distance was used to analyze SSR data and Jaccards similarity coefficient was used for AFLP data. Seventy SSRs were polymorphic and 20 AFLP primer combinations produced 635 polymorphic bands. Molecular analysis showed that carioca genotypes were quite diverse. AFLPs revealed greater genetic differentiation and variation within the carioca genotypes (Gst = 98% and Fst = 0.83, respectively than SSRs and provided better resolution for clustering the carioca genotypes. SSRs and AFLPs were both suitable for assessing the genetic diversity of Brazilian carioca genotypes since the number of markers used in each system provided a low coefficient of variation. However, fingerprint profiles were generated faster with AFLPs, making them a better choice for assessing genetic diversity in the carioca germplasm.

  5. ASSESSMENT OF GENETIC DIVERSITY OF REHMANNIA GLUTINOSA LIBOSCH BASED ON ISSR MARKERS

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    YANQING ZHOU, WUJUN GAO, HONGYING DUAN, FENGPING GU

    2007-08-01

    Full Text Available In order to assess the genetic diversity of Rehmannia glutinosa Libosch cultivars ( lines in Huai zone, Inter-simple sequence repeat (ISSR was performed. Ten appropriate ISSR primers were selected from a total of 44 ISSR ones for ISSR PCR amplification. The ten primers could amplify one hundred and ten bands. Based on them, A Jaccard’s genetic similarity matrix and a dendrogram for these ten cultivars were established using SPSS 10.0 software. In this dendrogram, they could be divided into two groups : Group1 contained six individuals such as Zupei 85.5, Datian 85.5, Zupei 9302, Jinbai, Jinzhuangyuan and Datian9302; Group2 consisted of four ones such as Beijing No.1, Dahongpao, Dihuang9104 and wild dihuang. Furthermore, Principal coordinate analysis (PCA supported the above cluster analysis; Shannon\\'s Information index (I is 0.3577, effective number of alleles (Ne is 1.4037, the percentage of polymorphic loci is 71.82 % by means of POPGENE32 software; A DNA fingerprint was developed with a single primer, ISSR6, in which each of ten individuals tested had its unique fingerprint pattern and was distinguished from each other. The results revealed that ISSR method is suitable for DNA fingerprinting, identification and genetic diversity analysis of Rehmannia glutinosa in Huai zone.

  6. Microsatellite based genetic diversity study in indigenous chicken ecotypes of Karnataka

    Directory of Open Access Journals (Sweden)

    B. H. Rudresh

    2015-08-01

    Full Text Available Aim: The current study was the first of its kind taken upon indigenous ecotypes of the Karnataka in order to unravel the diversity details at 20 chicken microsatellite regions. Materials and Methods: 210 indigenous chicken belonging to six districts of Bangalore and Mysore division formed the target sample for the present study. The genomic deoxyribonucleic acid was isolated by phenol chloroform isoamyl alcohol method. A panel of 20 microsatellite regions, including 14 recommended by FAO and six identified from published scientific literature became the targeted chicken genomic region. 27-33 samples were successfully genotyped in each of the six ecotypes through simplex or multiplex polymerase chain reactions, polyacrylamide gel electrophoresis and silver staining for the selected microsatellite panel. Results: The chickens of Ramanagara and Chamrajnagara were most distant with a Nei’s genetic distance value of 0.22. The chickens of Bangalore rural and Mysore were least distant with a value of 0.056. The Ramanagara and Chamrajnagara pair had Nei’s genetic identity value of 0.802, which is least among all pairs of ecotypes. There were five main nodes from which the six ecotypes evolved on the basis 20 microsatellite markers used in this study. This study indicates that the four ecotypes Ramnagara, Bangalore Rural, Chickaballapura and Mysore are genetically identical due to their common ancestral evolution while, Mandya and Chamrajnagara ecotypes formed a relatively different cluster due to a separate common ancestral chicken population and less number of generations since drifting from bifurcation node. Conclusion: Twenty microsatellite markers based genetic diversity study on six indigenous ecotypes indicated lower genetic distances as well as lower FST values compared to the distinguished breeds reported. There were two main clusters, which differentiated into six ecotypes. They may differentiate into more distinct varieties if bred in

  7. Sampling strategy for wild soybean (Glycine soja) populations based on their genetic diversity and fine-scale spatial genetic structure

    Institute of Scientific and Technical Information of China (English)

    ZHU Weiyue; ZHOU Taoying; ZHONG Ming; LU Baorong

    2007-01-01

    A total of 892 individuals sampled from a wild soybean population in a natural reserve near the Yellow River estuary located in Kenli of Shandong Province (China) were investigated.Seventeen SSR (simple sequence repeat) primer pairs from cultivated soybeans were used to estimate the genetic diversity of the population and its variation pattern versus changes of the sample size (sub-samples),in addition to investigating the fine-scale spatial genetic structure within the population.The results showed relatively high genetic diversity of the population with the mean value of allele number (A) being 2.88,expected heterozygosity (He) 0.431,Shannon diversity index (/) 0.699,and percentage of polymorphic loci (P) 100%.Sub-samples of different sizes (ten groups) were randomly drawn from the population and their genetic diversity was calculated by computer simulation.The regression model of the four diversity indexes with the change of sample sizes was computed.As a result,27-52 individuals can reach 95% of total genetic variability of the population.Spatial autocorrelation analysis revealed that the genetic patch size of this wild soybean population is about 18 m.The study provided a scientific basis for the sampling strategy of wild soybean populations.

  8. Mitochondrial DNA-based genetic diversity of genus Lygus (Hemiptera: Miridae) in North America

    Science.gov (United States)

    The genus Lygus is widely distributed in North American and Eurasian continents. It is the most-studied genus in the family Miridae. However, very less information on the genetic diversity of this genus is available. Studying genetic variation among Lygus pest species and thereby constructing a ...

  9. Assessment of Genetic Diversity in Seed Plants Based on a Uniform π Criterion

    Directory of Open Access Journals (Sweden)

    Bin Ai

    2014-12-01

    Full Text Available Despite substantial advances in genotyping techniques and massively accumulated data over the past half century, a uniform measurement of neutral genetic diversity derived by different molecular markers across a wide taxonomical range has not yet been formulated. We collected genetic diversity data on seed plants derived by AFLP, allozyme, ISSR, RAPD, SSR and nucleotide sequences, converted expected heterozygosity (He to nucleotide diversity (π, and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform π criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level π values across seed plants were 0.00374 (966 taxa, 155 families, 47 orders and 0.00569 (728 taxa, 130 families, 46 orders, respectively. Significant differences were recovered for breeding system (p < 0.001 at the population level and geographic range (p = 0.023 at the species level. Selfing taxa had significantly lower π values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower π values than widely distributed taxa. Despite significant differences between the two extreme threat categories (critically endangered and least concern, the genetic diversity reduction on the way to extinction was difficult to detect in early stages.

  10. Assessing Genetic Diversity Based on Gliadin Proteins in Aegilops cylindrica Populations from Northwest of Iran

    Directory of Open Access Journals (Sweden)

    Toraj KHABIRI

    2013-02-01

    Full Text Available Wild wheat progenitors served as a valuable gene pool in breeding perspectives. In this respect, gliadins could be an important tool in assessing genetic variability as protein markers. Thus, genetic diversity of gliadin protein patterns in seventeen populations of Aegilops cylindrica collected from northwest of Iran were investigated using acid polyacrylamide gel electrophoresis. Results showed that the highest number of bands in the electrophoregrams were related to the ω type of geliadins. Conversely, the lowest number of bands were pertained to the β type of gliadins. Genetic diversity between populations was greater than within population variation. Assessment of total variation for the three gliadin types indicated that the highest total variation was related to β type while, the lowest one was belonged to ω type. Cluster analysis using complete linkage method divided populations into two separated groups in which genetic diversity does not follow from geographical distribution.

  11. Genetic diversity of perch rhabdoviruses isolates based on the nucleoprotein and glycoprotein genes.

    Science.gov (United States)

    Talbi, Chiraz; Cabon, Joelle; Baud, Marine; Bourjaily, Maya; de Boisséson, Claire; Castric, Jeannette; Bigarré, Laurent

    2011-12-01

    Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in

  12. Genetic diversity based on SSR analysis of the cultured snakehead fish, Channa argus, (Channidae) in China.

    Science.gov (United States)

    Zhu, S-R; Li, J-L; Xie, N; Zhu, L-M; Wang, Q; Yue, G-H

    2014-02-13

    The snakehead fish Channa argus is an important food fish in China. We identified six microsatellite loci for C. argus. These six microsatellite loci and four other microsatellite markers were used to analyze genetic diversity in four cultured populations of C. argus (SD, JX, HN, and ZJ) and determine their relationships. A total of 154 alleles were detected at the 10 microsatellite loci. The average expected and observed heterozygosities varied from 0.70-0.84 and 0.69-0.83, respectively, and polymorphism information content ranged between 0.66 and 0.82 in the four populations, indicating high genetic diversity. Population JX deviated from mutation-drift equilibrium and may have experienced a recent bottleneck. Analysis of pairwise genetic differentiation revealed FST values that ranged from 0.028 to 0.100, which indicates a moderate level of genetic differentiation. The largest distances were observed between populations HN and SD, whereas the smallest distances were obtained between populations HN and JX. Genetic clustering analysis demonstrated that the ZJ and HN populations probably share the same origin. This information about the genetic diversity within each of the four populations, and their genetic relationships will be useful for future genetic improvement of C. argus through selective breeding.

  13. Genetic diversity in a Brazilian bovine herd based on four microsatellite loci

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    Almeida Sabrina E. Matos

    2000-01-01

    Full Text Available Microsatellites or short tandem repeats (STRs, DNA markers relatively abundant in the genome, have a high degree of polymorphism and therefore great potential for characterizing populations. The present study estimates genetic variability in a set of four microsatellites (BMS3013, BMS3004, HEL10 and TGLA122 in a Brazilian hybrid bovine breed (5/8 Aberdeen Angus x 3/8 Nelore. The objectives were to determine the effect of crossbreeding and selection in these animals' genetic diversity as well as to discover the herd's genetic relationship with that of other breeds. Low diversity was verified in BMS3013 and high diversity was detected in BMS3004, HEL10 and TGLA122. Two alleles in TGLA122 are described here for the first time (TGLA122*155 and TGLA122*163. These genes are possibly characteristics of Zebu animals since they have not been found in other taurine samples so far investigated. Low interpopulational diversity was observed among taurine cattle populations, and clusters obtained on TGLA122 phylogenetic trees agreed with the bovine herd's geographic origin. Therefore, despite TGLA122's high polymorphism and high levels of intrapopulational diversity, the system engenders consistent bovine phylogenies. We detected an intriguingly high similarity between Brangus Ibagé and Red Angus since the former is a hybrid having 3/8 of Nelore genes. Either these animals' environment or genetic selective practices applied to the breed probably favor the Angus genotype.

  14. Entamoeba dispar: genetic diversity of Iranian isolates based on serine-rich Entamoeba dispar protein gene.

    Science.gov (United States)

    Haghighi, A; Rasti, S; Nazemalhosseini Mojarad, E; Kazemi, B; Bandehpour, M; Nochi, Z; Hooshyar, H; Rezaian, M

    2008-12-01

    The nucleotide sequences of Serine-Rich Entamoeba histolytica Protein (SREHP) gene have already exhibited stable and significant polymorphism in the gene studies. Serine-rich protein is also present and polymorphic in Entamoeba dispar which called SREDP. The polymorphism of the Serine-Rich Entamoeba dispar Protein (SREDP) gene among 8 isolates obtained from Iranian cyst carriers were analyzed by a nested PCR-RFLP followed by sequencing of the PCR products. From those isolates, six distinct DNA patterns were observed after PCR-RFLP of the nested PCR, whereas sequencing showed 8 different patterns among the isolates. The results demonstrate an extensive genetic variability among Iranian E. dispar isolates. The repeat-containing region of the SREDP was found extensively polymorphic in size, number and order of repeat units. Genetic diversity of Iranian E. dispar isolates based on the SREDP was more polymorphic in comparison of Serine-Rich Entamoeba histolytica Protein (SREHP) of the E. histolytica isolates as well as were different from a few known SREDP genes.

  15. Identifying predictors of activity based anorexia susceptibility in diverse genetic rodent populations.

    Directory of Open Access Journals (Sweden)

    Eneda Pjetri

    Full Text Available Animal studies are very useful in detection of early disease indicators and in unravelling the pathophysiological processes underlying core psychiatric disorder phenotypes. Early indicators are critical for preventive and efficient treatment of progressive psychiatric disorders like anorexia nervosa. Comparable to physical hyperactivity observed in anorexia nervosa patients, in the activity-based anorexia rodent model, mice and rats express paradoxical high voluntary wheel running activity levels when food restricted. Eleven inbred mouse strains and outbred Wistar WU rats were exposed to the activity-based anorexia model in search of identifying susceptibility predictors. Body weight, food intake and wheel running activity levels of each individual mouse and rat were measured. Mouse strains and rats with high wheel running activity levels during food restriction exhibited accelerated body weight loss. Linear mixed models for repeated measures analysis showed that baseline wheel running activity levels preceding the scheduled food restriction phase strongly predicted activity-based anorexia susceptibility (mice: Beta  =  -0.0158 (±0.003 SE, P<0.0001; rats: Beta  =  -0.0242 (±0.004 SE, P<0.0001 compared to other baseline parameters. These results suggest that physical activity levels play an important role in activity-based anorexia susceptibility in different rodent species with genetically diverse background. These findings support previous retrospective studies on physical activity levels in anorexia nervosa patients and indicate that pre-morbid physical activity levels could reflect an early indicator for disease severity.

  16. Conservation of eelgrass (Zostera marina genetic diversity in a mesocosm-based restoration experiment.

    Directory of Open Access Journals (Sweden)

    Brian S Ort

    Full Text Available Eelgrass (Zostera marina forms the foundation of an important shallow coastal community in protected estuaries and bays. Widespread population declines have stimulated restoration efforts, but these have often overlooked the importance of maintaining the evolutionary potential of restored populations by minimizing the reduction in genetic diversity that typically accompanies restoration. In an experiment simulating a small-scale restoration, we tested the effectiveness of a buoy-deployed seeding technique to maintain genetic diversity comparable to the seed source populations. Seeds from three extant source populations in San Francisco Bay were introduced into eighteen flow-through baywater mesocosms. Following seedling establishment, we used seven polymorphic microsatellite loci to compare genetic diversity indices from 128 shoots to those found in the source populations. Importantly, allelic richness and expected heterozygosity were not significantly reduced in the mesocosms, which also preserved the strong population differentiation present among source populations. However, the inbreeding coefficient F IS was elevated in two of the three sets of mesocosms when they were grouped according to their source population. This is probably a Wahlund effect from confining all half-siblings within each spathe to a single mesocosm, elevating F IS when the mesocosms were considered together. The conservation of most alleles and preservation of expected heterozygosity suggests that this seeding technique is an improvement over whole-shoot transplantation in the conservation of genetic diversity in eelgrass restoration efforts.

  17. Genetic diversity in Silene sennenii Pau (Caryophyllaceae assayed through DNA-based techniques

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    Blanché, C.

    2012-12-01

    Full Text Available Silene sennenii is a narrow endemic species from the NE of the Iberian Peninsula. It is considered as EN (“Endangered” according to the IUCN criteria and is under legal protection in Catalonia. In the present work we report an assay using three different approaches for surveying the genetic diversity in this rare, endangered campion: analysis of chloroplast haplotypes, AFLPs and transferability of microsatellites previously developed for Silene latifolia. None of the nine chloroplast regions sequenced showed any variability. Five out of the 21 microsatellite loci tested were polymorphic although more loci are required in order to perform a robust population genetics study. Regarding the AFLP analysis, five out of the 26 pairs of primers tested exhibited moderate levels of variability and therefore they could be useful for further investigating the genetic structure of S. sennenii. Although preliminary, our results based on three different genetic markers are in agreement with the low values of genetic variation already reported for this species employing allozymes.Silene sennenii es una especie endémica, circunscrita a un área extremadamente reducida al NE de la Península Ibérica. Está catalogada como EN («En Peligro» según criterios UICN y se encuentra legalmente protegida en Cataluña. En el presente trabajo se expone el ensayo de tres aproximaciones diferentes al estudio de su diversidad genética: análisis de haplotipos cloroplásticos, AFLPs y transferibilidad de microsatélites diseñados previamente para Silene latifolia. Ninguna de las nueve regiones cloroplásticas secuenciadas ha presentado variabilidad. Se han obtenido cinco loci microsatélites polimórficos de los 21 ensayados, cantidad insuficiente para llevar a cabo un estudio robusto sobre genética poblacional. En cuanto a AFLPs, cinco combinaciones de cebadores de las 26 probadas han mostrado niveles moderados de variabilidad siendo así útiles para posteriores

  18. Genetic diversity of populations and clones of Rhopilema esculentum in China based on AFLP analysis

    Institute of Scientific and Technical Information of China (English)

    QIAO Hongjin; LIU Xiangquan; ZHANG Xijia; JIANG Haibin; WANG Jiying; ZHANG Limin

    2013-01-01

    Amplified fragment length polymorphisms (AFLP) markers were developed to assess the genetic variation of populations and clones of Rhopilema esculentum Kishinouye (Scyphozoa,Rhizostomatidae).One hundred and seventy-nine loci from 56 individuals of two hatchery populations and two wild populations were genotyped with five primer combinations.The polymorphic ratio,Shannon's diversity index and average heterozygosity were 70.3%,0.346 and 0.228 for the white hatchery population,74.3%,0.313,and 0.201 for the red hatchery population,79.3%,0.349,and 0.224 for the Jiangsu wild population,and 74.9%,0.328 and 0.210 for the Penglai wild population,respectively.Thus,all populations had a relatively high level of genetic diversity.A specific band was identified that could separate the white from the red hatchery population.There was 84.85% genetic differentiation within populations.Individual cluster analysis using unweighted pair-group method with arithmetic mean (UPGMA) suggested that hatchery populations and wild populations could be divided.For the hatchery populations,the white and red populations clustered separately; however,for the wild populations,Penglai and Jiangsu populations clustered together.The genetic diversity at the clone level was also determined.Our data suggest that there are relatively high genetic diversities within populations but low genetic differentiation between populations,which may be related to the long-term use of germplasm resources from Jiangsu Province for artificial seeding and releasing.These findings will benefit the artificial seeding and conservation of the germplasm resources.

  19. The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers

    Indian Academy of Sciences (India)

    Shi Ying Yang; Rachit A. Saxena; Pawan L. Kulwal; Gavin J. Ash; Anuja Dubey; John D. I. Harper; Hari D. Upadhyaya; Ragini Gothalwal; Andrzej Kilian; Rajeev K. Varshney

    2011-04-01

    With an objective to develop a genetic map in pigeon pea (Cajanus spp.), a total of 554 diversity arrays technology (DArT) markers showed polymorphism in a pigeon pea F2 mapping population of 72 progenies derived from an interspecific cross of ICP 28 (Cajanus cajan) and ICPW 94 (Cajanus scarabaeoides). Approximately 13% of markers did not conform to expected segregation ratio. The total number of DArT marker loci segregating in Mendelian manner was 405 with 73.1% ($P \\gt 0.001$) of DArT markers having unique segregation patterns. Two groups of genetic maps were generated using DArT markers. While the maternal genetic linkage map had 122 unique DArT maternal marker loci, the paternal genetic linkage map has a total of 172 unique DArT paternal marker loci. The length of these two maps covered 270.0 cM and 451.6 cM, respectively. These are the first genetic linkage maps developed for pigeon pea, and this is the first report of genetic mapping in any grain legume using diversity arrays technology.

  20. Estimating genetic diversity and sampling strategy for a wild soybean (Glycine soja) population based on different molecular markers

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhong; ZHAO Ru; GU Senchang; YAN Wen; CHENG Zhou; CHEN Muhong; LU Weifeng; WANG Shuhong; LU Baorong; LU Jun; ZHANG Fan; XIANG Rong; XIAO Shangbin; YAN Pin

    2006-01-01

    Genetic diversity is the basic and most important component of biodiversity. It is essential for the effective conservation and utilization of genetic resources to accurately estimate genetic diversity of the targeted species and populations. This paper reports analyses of genetic diversity of a wild soybean population using three molecular marker technologies (AFLP, ISSR and SSR), and computer simulation studies of randomly selected subsets with different sample size (5-90 individuals) drawn 50 times from a total of 100 wild soybean individuals. The variation patterns of genetic diversity indices, including expected heterozygosity (He), Shannon diversity index (/), and percentage of polymorphic loci (P), were analyzed to evaluate changes of genetic diversity associated with the increase of individuals in each subset. The results demonstrated that (1) values of genetic diversity indices of the same wild soybean population were considerably different when estimated by different molecular marker techniques; (2) genetic diversity indices obtained from subsets with different sample sizes also diverged considerably; (3) P values were relatively more reliable for comparing genetic diversity detected by different molecular marker techniques; and (4) different diversity indices reached 90% of the total genetic diversity of the soybean population quite differently in terms of the sample size (number of individuals) analyzed.When using the P value as a determinator, 30-40individuals could capture over 90% of the total genetic diversity of the wild soybean population. Results from this study provide a strong scientific basis for estimating genetic diversity and for strategic conservation of plant species.

  1. ATPase 8/6 GENE BASED GENETIC DIVERSITY ASSESSMENT OF SNAKEHEAD MURREL, Channa striata (Perciformes, Channidae).

    Science.gov (United States)

    Baisvar, V S; Kumar, R; Singh, M; Singh, A K; Chauhan, U K; Nagpure, N S; Kushwaha, B

    2015-10-01

    The mitochondrial DNA (mtDNA) ATPase 8/6 gene has been used in phylogenetic as well as in phylogeographic studies along with other mtDNA markers. In this study, ATPase gene sequences were used to assess the genetic structuring and phylogeographic patterns in Channa striata. Out of 884 nucleotide positions generated in ATPase 8/6 genes, 76 were polymorphic. The study suggested 23 unique haplotypes from 67 individuals of nine populations collected from different riverine systems of India. The ATPase 8/6 sequence revealed highest haplotype as well as nucleotide diversities in Imphal River population and lowest diversities in Tapti River population. The pattern of genetic diversity and haplotype network indicated distinct mitochondrial lineages for Chaliyar population, whereas mismatch distribution strongly suggested a population expansion in mid pleistocene epoch (0.4 Mya) with distinct genetic structuring in C. striata. The baseline information on genetic variation and the population sub-structuring would facilitate conservation and management of this important snakehead murrel.

  2. Genetic diversity and DNA fingerprinting in jute(Corchorus spp.) based on SSR markers

    Institute of Scientific and Technical Information of China (English)

    Liwu; Zhang; Rongrong; Cai; Minhang; Yuan; Aifen; Tao; Jiantang; Xu; Lihui; Lin; Pingping; Fang; Jianmin; Qi

    2015-01-01

    Genetic diversity analysis and DNA finger printing are very useful in breeding programs,seed conservation and management. Jute(Corchorus spp.) is the second most important natural fiber crop after cotton. DNA fingerprinting studies in jute using SSR markers are limited. In this study, 58 jute accessions, including two control varieties(Huangma 179 and Kuanyechangguo) from the official variety registry in China were evaluated with 28 pairs of SSR primers. A total of 184 polymorphic loci were identified. Each primer detected 3 to 15 polymorphic loci, with an average of 6.6. The 58 jute accessions were DNA-fingerprinted with 67 SSR markers from the 28 primer pairs. These markers differentiated the 58 jute accessions from one another, with Co SSR305-120 and Co SSR174-195 differentiating Huangma 179 and Kuanyechangguo, respectively. NTSYS-pc2.10 software was used to analyze the genetic diversity in the 58 jute accessions. Their genetic similarity coefficients ranged from 0.520 to 0.910 with an average of 0.749, indicating relatively great genetic diversity among them. The 58 jute accessions were divided into four groups with the coefficient 0.710 used as a value for classification, consistent with their species and pedigrees. All these results may be useful both for protection of intellectual property rights of jute accessions and for jute improvement.

  3. Genetic diversity and DNA fingerprinting in jute (Corchorus spp. based on SSR markers

    Directory of Open Access Journals (Sweden)

    Liwu Zhang

    2015-10-01

    Full Text Available Genetic diversity analysis and DNA finger printing are very useful in breeding programs, seed conservation and management. Jute (Corchorus spp. is the second most important natural fiber crop after cotton. DNA fingerprinting studies in jute using SSR markers are limited. In this study, 58 jute accessions, including two control varieties (Huangma 179 and Kuanyechangguo from the official variety registry in China were evaluated with 28 pairs of SSR primers. A total of 184 polymorphic loci were identified. Each primer detected 3 to 15 polymorphic loci, with an average of 6.6. The 58 jute accessions were DNA-fingerprinted with 67 SSR markers from the 28 primer pairs. These markers differentiated the 58 jute accessions from one another, with CoSSR305-120 and CoSSR174-195 differentiating Huangma 179 and Kuanyechangguo, respectively. NTSYS-pc2.10 software was used to analyze the genetic diversity in the 58 jute accessions. Their genetic similarity coefficients ranged from 0.520 to 0.910 with an average of 0.749, indicating relatively great genetic diversity among them. The 58 jute accessions were divided into four groups with the coefficient 0.710 used as a value for classification, consistent with their species and pedigrees. All these results may be useful both for protection of intellectual property rights of jute accessions and for jute improvement.

  4. Genetic diversity among Brazilian soybean cultivars based on SSR loci and pedigree data

    Directory of Open Access Journals (Sweden)

    Regina Helena Geribello Priolli

    2010-06-01

    Full Text Available In this study, simple sequence repeats (SSR loci and pedigree data were used to investigate the genetic relationship in a group of 168 Brazilian soybean cultivars. Eighteen SSR loci produced an average of 5.06 alleles and a mean gene diversity of 0.58 for the cultivars studied. Genetic distance (GD was determined using the modified Roger's Wright distance, and a final dendrogram was in agreement with the cultivar pedigree. A distance matrix based on the coefficient of parentage scores was also generated for the cultivars, which ranged from 0 to 1, with a mean of 0.18, whereas SSR-based genetic similarity (1- GD ranged from 0.01 to 0.90, with a mean of 0.25. Mantel's Z test showed that the similarity matrices generated from both the data sets were low, but significantly correlated (r = 0.31, pLocos microssatélites e dados de genealogia foram utilizados para avaliar a diversidade genética de um grupo de 168 cultivares brasileiras de soja. Os dezoito locos utilizados apresentaram em média 5,06 alelos por loco e coeficiente de diversidade genética médio de 0,58. O dendrograma final resultante da matriz de distância genética de Roger modificado por Wright, apresentou boa concordância com a ancestralidade dos grupos formados. Também foi estimado os coeficientes de parentesco entre as cultivares, sendo observada variação de 0 a 1 com média de 0,18, enquanto que as similaridades para os locos microssatélites (1- GD variou de 0,01 a 0,90 com média de 0,25. A correlação entre as duas matrizes obtidas determinada pelo teste Z de Mantel apresentou valor baixo, 0,31, mas significativo (p<0,001. Os resultados obtidos sugerem que os locos microssatélites aliados às informações de genealogia proporcionam melhor análise da diversidade genética de cultivares de soja.

  5. Evaluation of genetic bases and diversity of Egyptian wheat cultivars released during the last 50 years using coefficient of parentage

    Directory of Open Access Journals (Sweden)

    Bhoja R. Basnet

    2011-04-01

    Full Text Available Discerning the genetic diversity of any crop species provides insight into the strength of an applied breeding program and directs future breeding strategies aimed at long-term genetic gain and minimized genetic vulnerability. The number and abundance of ancestral parents present in the pedigree of crop cultivars can provide an average estimation of the depth of the genetic base of the overall crop improvement program. The objectives of this study were to estimate (1 the genetic similarity among 33 Egyptian wheat (Triticum aestivum L. cultivars and different eras of release (1947-2004 and productivity groups based on COP values, and (2 the relative genetic contribution and abundance of ancestral parents from different geographical origins to the total gene pool of Egyptian wheat cultivars. Broad genetic diversity was observed among 33 Egyptian cultivars with average COP value of 0.11 and large numbers of ancestral parents (155 landraces traced to 31 countries. The genetic base ranged from very low in pre 1960’s cultivars such as ‘Giza 139’ (with only 3 landraces in the background to very high in modern cultivars such as ‘Gemmeiza-7’ (with 73 landraces in the background. ‘Hindi-62’, ‘Red Fife’, ‘Hard Red Calcutta’ and ‘Akagomughi’ were the major ancestors with 6, 5, 4, and 4% of total genetic contribution to the Egyptian wheat gene pool, respectively. Egypt, United States of America, Kenya and Ukraine were the major source countries with 16, 11, 9 and 7% of total genetic contribution to this gene pool, respectively. Though Marquis-Thatcher germplasm from North America has the greatest influence on overall Egyptian cultivars, Mexican-based sources of dwarfing and high yield, derived from ancestors such as ‘Akagomughi’ and ‘Daruma’ and exploited by the International Maize and Wheat Improvement Center (CIMMYT, were very prominent in Egyptian cultivars post 1970’s.

  6. Assessment of Genetic Diversity in Faba Bean Based on Single Nucleotide Polymorphism

    Directory of Open Access Journals (Sweden)

    Sukhjiwan Kaur

    2014-01-01

    Full Text Available Detection of genetic diversity is important for characterisation of crop plant collections in order to detect the presence of valuable trait variation for use in breeding programs. A collection of faba bean (Vicia faba L. genotypes was evaluated for intra- and inter-population diversity using a set of 768 genome-wide distributed single nucleotide polymorphism (SNP markers, of which 657 obtained successful amplification and detected polymorphisms. Gene diversity and polymorphism information content (PIC values varied between 0.022–0.500 and 0.023–1.00, with averages of 0.363 and 0.287, respectively. The genetic structure of the germplasm collection was analysed and a neighbour-joining (NJ dendrogram was constructed. The faba bean accessions grouped into two major groups, with several additional smaller sub-groups, predominantly on the basis of geographical origin. These results were further supported by principal co-ordinate analysis (PCoA, deriving two major groupings which were differentiated on the basis of site of origin and pedigree relationships. In general, high levels of heterozygosity were observed, presumably due to the partially allogamous nature of the species. The results will facilitate targeted crossing strategies in future faba bean breeding programs in order to achieve genetic gain.

  7. PCR-based VNTR core sequence analysis for inferring genetic diversity in the shrimp Litopenaeus vannamei

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    Freitas Patrícia Domingues de

    2002-01-01

    Full Text Available The genetic variation in two farmed strains (F3-Panama and F17-Venezuela of the shrimp Litopenaeus vannamei was examined based on DNA multiloci analyses. Eighteen adults of each strain were analyzed by PCR using a set of VNTR core sequence primers. Genetic similarity, mean allele frequency, mean heterozygosity and the frequency of polymorphic loci were determined for both strains. A dendrogram of genetic similarity was produced by UPGMA clustering. The results for three primers (INS, M13, YN73 revealed different levels of genetic variation within the strains. The higher genetic similarity seen within strain F17 was apparently related to inbreeding, although a bottleneck effect could not be discarded. The low level of genetic variability of this strain could account for the reduced adaptive advantage of these animals and their inability to adjust to breeding conditions in Brazil.

  8. [Application of genetic diversity in the researches on rodents].

    Science.gov (United States)

    Liu, Zhu; Yang, Chun-Wen; Xu, Yan-Chun; Jin, Zhi-Min; Ma, Jian-Zhang

    2014-02-01

    Genetic diversity is the base of the species diversity and ecosystem diversity, and also the foundation for biological evolution and species differentiation. Furthermore, genetic diversity is important evidence for evaluation of biological resources of nature. The genetic diversity data from a wide variety of rodents have many complex applications. We summarized the application of rodent prevention, the origin and differentiation including evolutionary history of rodents, the potential adaptation of rodents, the dynamics of population and regulatory mechanisms, and the conservation biology of rodents. Researches in the future should focus on the systematic study on the relationships between population dynamics and genetic diversity, and long-term monitoring of genetic diversity of rodents.

  9. Genetic diversity and phylogenetic relationships in local cattle breeds of Senegal based on autosomal microsatellite markers

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    Ndèye Penda Ndiaye

    2015-08-01

    Full Text Available Aim: In Senegal, uncontrolled cross-breeding of cattle breeds and changes in production systems are assumed to lead to an increase of gene flow between populations. This might constitute a relevant threat to livestock improvement. Therewith, this study was carried out to assess the current genetic diversity and the phylogenetic relationships of the four native Senegalese cattle breeds (Gobra zebu, Maure zebu, Djakoré, and N’Dama. Methods: Genomic DNA was isolated from blood samples of 120 unrelated animals collected from three agro-ecological areas of Senegal according to their phenotypic traits. Genotyping was done using 11 specific highly polymorphic microsatellite makers recommended by Food and Agriculture Organization. The basic measures of genetic variation and phylogenetic trees were computed using bioinformatics’ software. Results: A total of 115 alleles were identified with a number of alleles (Na at one locus ranging from 6 to 16. All loci were polymorphic with a mean polymorphic information content of 0.76. The mean allelic richness (Rs lay within the narrow range of 5.14 in N’Dama taurine to 6.10 in Gobra zebu. While, the expected heterozygosity (HE per breed was high in general with an overall mean of 0.76±0.04. Generally, the heterozygote deficiency (FIS of 0.073±0.026 was relatively due to inbreeding among these cattle breeds or the occurrence of population substructure. The high values of allelic and gene diversity showed that Senegalese native cattle breeds represented an important reservoir of genetic variation. The genetic distances and clustering trees concluded that the N’Dama cattle were most distinct among the investigated cattle populations. So, the principal component analyses showed qualitatively that there was an intensive genetic admixture between the Gobra zebu and Maure zebu breeds. Conclusions: The broad genetic diversity in Senegalese cattle breeds will allow for greater opportunities for improvement of

  10. Contrasting results from molecular and pedigree-based population diversity measures in captive zebra highlight challenges facing genetic management of zoo populations.

    Science.gov (United States)

    Ito, Hideyuki; Ogden, Rob; Langenhorst, Tanya; Inoue-Murayama, Miho

    2017-01-01

    Zoo conservation breeding programs manage the retention of population genetic diversity through analysis of pedigree records. The range of demographic and genetic indices determined through pedigree analysis programs allows the conservation of diversity to be monitored relative to the particular founder population for a species. Such approaches are based on a number of well-documented founder assumptions, however without knowledge of actual molecular genetic diversity there is a risk that pedigree-based measures will be misinterpreted and population genetic diversity misunderstood. We examined the genetic diversity of the captive populations of Grevy's zebra, Hartmann's mountain zebra and plains zebra in Japan and the United Kingdom through analysis of mitochondrial DNA sequences. Very low nucleotide variability was observed in Grevy's zebra. The results were evaluated with respect to current and historic diversity in the wild, and indicate that low genetic diversity in the captive population is likely a result of low founder diversity, which in turn suggests relatively low wild genetic diversity prior to recent population declines. Comparison of molecular genetic diversity measures with analogous diversity indices generated from the studbook data for Grevy's zebra and Hartmann's mountain zebra show contrasting patterns, with Grevy's zebra displaying markedly less molecular diversity than mountain zebra, despite studbook analysis indicating that the Grevy's zebra population has substantially more founders, greater effective population size, lower mean kinship, and has suffered less loss of gene diversity. These findings emphasize the need to validate theoretical estimates of genetic diversity in captive breeding programs with empirical molecular genetic data. Zoo Biol. 36:87-94, 2017. © 2016 Wiley Periodicals, Inc.

  11. Genetic diversity of Xanthomonas axonopodis pv. citri based on plasmid profile and pulsed field gel electrophoresis

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    Carvalho Flávia Maria de Souza

    2005-01-01

    Full Text Available Xanthomonas axonopodis pv. citri strains that cause disease in citrus were investigated by pulsed field and plasmid profile analysis. For the first method, genomic DNA was digested by the rare-cutting enzymes Xba I and Vsp I. The strains evaluated were collected in seven different States of Brazil and in Argentina, Bolivia, Paraguay and Uruguay. Genetic variability was found among strains of X. axonopodis pv. citri from different geographical areas Argentina, Bolivia and Uruguay, with similarities varying from 0.62 to 0.83. However, the strains collected in Brazil, despite being from different States, have shown a genetic similarity ranging from 0.83 to 1.00. Cluster analysis showed a relationship between genomic similarity and geographical origin of the strains. Plasmids were observed in all strains, with a total of five different plasmids, with sizes between 57.7 and 83.0 kilobases. The 72.6 kb plasmid was the most frequent, present in 15 out of 22 strains, while the 68.1 kb plasmid was observed in two strains only. Although the plasmid diversity detected in the present study was not very great, the X. axonopodis pv. citri strains evaluated showed a considerable degree of diversity with regard to this extrachromosomal genetic element.

  12. The study of genetic diversity within Carassius genera, based on sequencing some mitochondrial markers

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    Mihaela-Liliana IONESCU

    2013-05-01

    Full Text Available In this study we investigated the genetic diversity within Carassius genera, studying individuals from isolated aquatic populations in Romania, by analysing the sequences of three mitochondrial DNA genes: cytochrome b (Cyt b, mitochondrial control region (D-loop and cytochrome c oxidase I (COX I. The nucleotide sequence variation of the three genes were used to study the mtDNA divergence for Carassius genera individuals and to examine the phylogenetic relationships within analyzed populations.Based on the alignment of cytochrome b gene sequences from individuals belonging to Carassius genera from analyzed populations, 21 haplotypes have been identified: two of them were found in four of the six analyzed populations and one in two of studied populations. Regarding the D-loop sequences there were identified 20 haplotypes: four of them were found in two or more populations. Following COX I sequence alignment, from individuals of the Carassius genera, in the six populations were identified 22 haplotypes, but only one was found in four of the analyzed populations. Phylogeographic aspects of the D-loop showed that there are common haplotypes between Buzău (Buzău River, Buzău County, Romania, Sofroneşti (Sofroneşti Lake, Vaslui County, Romania Delta (Fortuna Lake, Danube Delta, Romania and Băile Felix (Bihor County, Romania populations, and for COX I between Buzău (Buzău River, Buzău County, Romania, Tăuteşti (Tăuteşti Lake, Iaşi County, Romania, Delta (Fortuna Lake, Danube Delta, Romania and Băile Felix (Bihor County, Romania populations. From the analysis of all sequences, it was found that the rate of occurrence of transitions is greater than the occurrence of transversions.

  13. DEVELOPMENT OF DNA BASED MICROSATELLITE MARKER TECHNOLOGY FOR STUDIES OF GENETIC DIVERSITY IN CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM) POPULATIONS

    Science.gov (United States)

    The level of genetic diversity of aquatic species is a critical indicator of stream system condition for which few data exist. There is strong evidence suggesting that environmental stressors affect the genetic diversity of exposed populations. In order to study genetic diversi...

  14. Genetic Diversity of Upland Rice Germplasm in Malaysia Based on Quantitative Traits

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    M. Sohrabi

    2012-01-01

    Full Text Available Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.

  15. Genetic diversity in South African Nguni cattle ecotypes based on microsatellite markers.

    Science.gov (United States)

    Sanarana, Yandisiwe; Visser, Carina; Bosman, Lydia; Nephawe, Khathutshelo; Maiwashe, Azwihangwisi; van Marle-Köster, Este

    2016-02-01

    The Nguni cattle breed is a landrace breed adapted to different ecological regions of South Africa. A number of ecotypes are recognised based on phenotype within the breed, but it is not known if they are genetically distinct. In this study, molecular characterisation was performed on Makhathini (MAK), Pedi (PED), Shangaan (SHA) and Venda (VEN) Nguni cattle ecotypes. Two Nguni cattle populations, not kept as separate ecotypes, from the University of Fort Hare (UFH) and Agricultural Research Council Loskop South farm (LOS) were also included. Genotypic data was generated for 189 unrelated Nguni cattle selected based on pedigree records using 22 microsatellite markers. The expected heterozygosity values varied from 69 % (UFH) to 72 % (PED) with a mean number of alleles ranging from 6.0 to 6.9. The F ST estimate demonstrated that 4.8 % of the total genetic variation was due to the genetic differentiation between the populations and 92.2 % accounted for differences within the populations. The genetic distances and structure analysis revealed the closest relationship between MAK, PEDI and SHA ecotypes, followed by SHA and VEN. The UFH population clustered with the MAK ecotype, indicating that they are more genetically similar, while the LOS cattle grouped as a distinct cluster. Results suggest that the genetic differentiation between the PED and SHA ecotypes is low and can be regarded as one ecotype based on limited genetic differences. The results of this study can be applied as a point of reference for further genetic studies towards conservation of Nguni cattle ecotypes.

  16. Evolution and genetic diversity of Theileria.

    Science.gov (United States)

    Sivakumar, Thillaiampalam; Hayashida, Kyoko; Sugimoto, Chihiro; Yokoyama, Naoaki

    2014-10-01

    Theileria parasites infect a wide range of domestic and wild ruminants worldwide, causing diseases with varying degrees of severity. A broad classification, based on the parasite's ability to transform the leukocytes of host animals, divides Theileria into two groups, consisting of transforming and non-transforming species. The evolution of transforming Theileria has been accompanied by drastic changes in its genetic makeup, such as acquisition or expansion of gene families, which are thought to play critical roles in the transformation of host cells. Genetic variation among Theileria parasites is sometimes linked with host specificity and virulence in the parasites. Immunity against Theileria parasites primarily involves cell-mediated immune responses in the host. Immunodominance and major histocompatibility complex class I phenotype-specificity result in a host immunity that is tightly focused and strain-specific. Immune escape in Theileria is facilitated by genetic diversity in its antigenic determinants, which potentially results in a loss of T cell receptor recognition in its host. In the recent past, several reviews have focused on genetic diversity in the transforming species, Theileriaparva and Theileriaannulata. In contrast, genetic diversity in Theileriaorientalis, a benign non-transforming parasite, which occasionally causes disease outbreaks in cattle, has not been extensively examined. In this review, therefore, we provide an outline of the evolution of Theileria, which includes T. orientalis, and discuss the possible mechanisms generating genetic diversity among parasite populations. Additionally, we discuss the potential implications of a genetically diverse parasite population in the context of Theileria vaccine development.

  17. Genetic diversity in Entamoeba histolytica

    Indian Academy of Sciences (India)

    C Graham Clark; Mehreen Zaki; Ibne Karim Md Ali

    2002-11-01

    Genetic diversity within Entamoeba histolytica led to the re-description of the species 10 years ago. However, more recent investigation has revealed significant diversity within the re-defined species. Both protein-coding and non-coding sequences show variability, but the common feature in all cases is the presence of short tandem repeats of varying length and sequence. The ability to identify strains of E. histolytica may lead to insights into the population structure and epidemiology of the organism.

  18. Genetic diversity of Brazilian and introduced olive germplasms based on microsatellite markers.

    Science.gov (United States)

    do Val, A D B; Ferreira, J L; Vieira Neto, J; Pasqual, M; de Oliveira, A F; Borém, A; Cançado, G M A

    2012-01-01

    Olive trees have been grown since the beginning of civilization, and the consumption of olives and olive products is increasing worldwide, due to their health benefits and organoleptic qualities. To meet the growing market for olives, commercial cultivation of this species is expanding from traditional areas to new regions. Although the Brazilian olive industry has just begun to be established, breeding programs are already developing cultivars that are more adapted to local conditions. We used 12 microsatellite markers to evaluate 60 olive accessions, including several cultivars that were developed in Brazil. The analyses identified 72 distinct alleles; the largest number of alleles per locus were at the markers GAPU 101 and GAPU 71B, which contained 10 and 9 alleles, respectively. The largest allelic diversity and polymorphic information contents were also found at the GAPU 101 and GAPU 71B markers, with values of 0.8399/0.8203 and 0.8117/0.7863, respectively. Additionally, the 12 microsatellite markers generated a cumulative identity probability of 1.51 x 10(-10), indicating a high level of accuracy of accession identification. The set of markers that we used allowed the identification of 52 of the 60 olive genotypes, in addition to the recognition of several varietal synonyms. The components of a two-dimensional principal coordinate analysis explained 48.6% of the total genetic variation. The results obtained from the microsatellite markers showed a substantial degree of genetic diversity in the olive tree accessions used in Brazil.

  19. Microsatellite based genetic diversity and population structure of the endangered Spanish Guadarrama goat breed

    Science.gov (United States)

    Serrano, Magdalena; Calvo, Jorge H; Martínez, Marta; Marcos-Carcavilla, Ane; Cuevas, Javier; González, Carmen; Jurado, Juan J; de Tejada, Paloma Díez

    2009-01-01

    Background Assessing genetic biodiversity and population structure of minor breeds through the information provided by neutral molecular markers, allows determination of their extinction risk and to design strategies for their management and conservation. Analysis of microsatellite loci is known to be highly informative in the reconstruction of the historical processes underlying the evolution and differentiation of animal populations. Guadarrama goat is a threatened Spanish breed which actual census (2008) consists of 3057 females and 203 males distributed in 22 populations more or less isolated. The aim of this work is to study the genetic status of this breed through the analysis of molecular data from 10 microsatellites typed in historic and actual live animals. Results The mean expected heterozygosity across loci within populations ranged from 0.62 to 0.77. Genetic differentiation measures were moderate, with a mean FST of 0.074, GST of 0.081 and RST of 0.085. Percentages of variation among and within populations were 7.5 and 92.5, respectively. Bayesian clustering analyses pointed out a population subdivision in 16 clusters, however, no correlation between geographical distances and genetic differences was found. Management factors such as the limited exchange of animals between farmers (estimated gene flow Nm = 3.08) mostly due to sanitary and social constraints could be the major causes affecting Guadarrama goat population subdivision. Conclusion Genetic diversity measures revealed a good status of biodiversity in the Guadarrama goat breed. Since diseases are the first cause affecting the census in this breed, population subdivision would be an advantage for its conservation. However, to maintain private alleles present at low frequencies in such small populations minimizing the inbreeding rate, it would necessitate some mating designs of animals carrying such alleles among populations. The systematic use of molecular markers will facilitate the

  20. Microsatellite based genetic diversity and population structure of the endangered Spanish Guadarrama goat breed

    Directory of Open Access Journals (Sweden)

    Jurado Juan J

    2009-09-01

    Full Text Available Abstract Background Assessing genetic biodiversity and population structure of minor breeds through the information provided by neutral molecular markers, allows determination of their extinction risk and to design strategies for their management and conservation. Analysis of microsatellite loci is known to be highly informative in the reconstruction of the historical processes underlying the evolution and differentiation of animal populations. Guadarrama goat is a threatened Spanish breed which actual census (2008 consists of 3057 females and 203 males distributed in 22 populations more or less isolated. The aim of this work is to study the genetic status of this breed through the analysis of molecular data from 10 microsatellites typed in historic and actual live animals. Results The mean expected heterozygosity across loci within populations ranged from 0.62 to 0.77. Genetic differentiation measures were moderate, with a mean FST of 0.074, GST of 0.081 and RST of 0.085. Percentages of variation among and within populations were 7.5 and 92.5, respectively. Bayesian clustering analyses pointed out a population subdivision in 16 clusters, however, no correlation between geographical distances and genetic differences was found. Management factors such as the limited exchange of animals between farmers (estimated gene flow Nm = 3.08 mostly due to sanitary and social constraints could be the major causes affecting Guadarrama goat population subdivision. Conclusion Genetic diversity measures revealed a good status of biodiversity in the Guadarrama goat breed. Since diseases are the first cause affecting the census in this breed, population subdivision would be an advantage for its conservation. However, to maintain private alleles present at low frequencies in such small populations minimizing the inbreeding rate, it would necessitate some mating designs of animals carrying such alleles among populations. The systematic use of molecular markers will

  1. GENETIC DIVERSITY OF S3 MAIZE GENOTYPES RESISTANT TO DOWNY MILDEW BASED ON SSR MARKERS

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    Amran Muis

    2016-02-01

    Full Text Available The compulsory requirement for releasing new high yielding maize varieties is resistance to downy mildew. The study aimed to determine the level of homozygosity, genetic diversity, and  genetic distance of 30 S3 genotypes of maize. Number of primers to be used were 30 polymorphic SSR loci which are distributed over the entire maize genomes. The S3 genotypes used were resistant to downy mildew with homozygosity level of >80%, genetic distance between the test and tester strains >0.7, and anthesis silking interval (ASI between inbred lines and tester lines was maximum 3 days. The results showed that 30 SSR primers used were spread evenly across the maize genomes which were manifested in the representation of SSR loci on each chromosome of a total of 10 chromosomes. The levels of polymorphism ranged from 0.13 to 0.78, an average of 0.51, and the number of alleles ranged from 2 to 8 alleles per SSR locus, an average of 4 alleles per SSR locus. The size of nucleotides in each locus also varied from 70 to 553 bp. Cophenetic correlation value (r at 0.67 indicated that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA was less reliable for differentiating genotypes in five groups. Of the total of 30 genotypes analyzed, 17 genotypes had homozygosity level of >80% so it can be included in the hybrid assembly program.

  2. Genetic diversity in Trichomonas vaginalis.

    Science.gov (United States)

    Meade, John C; Carlton, Jane M

    2013-09-01

    Recent advances in genetic characterisation of Trichomonas vaginalis isolates show that the extensive clinical variability in trichomoniasis and its disease sequelae are matched by significant genetic diversity in the organism itself, suggesting a connection between the genetic identity of isolates and their clinical manifestations. Indeed, a high degree of genetic heterogeneity in T vaginalis isolates has been observed using multiple genotyping techniques. A unique two-type population structure that is both local and global in distribution has been identified, and there is evidence of recombination within each group, although sexual recombination between the groups appears to be constrained. There is conflicting evidence in these studies for correlations between T vaginalis genetic identity and clinical presentation, metronidazole susceptibility, and the presence of T vaginalis virus, underscoring the need for adoption of a common standard for genotyping the parasite. Moving forward, microsatellite genotyping and multilocus sequence typing are the most robust techniques for future investigations of T vaginalis genotype-phenotype associations.

  3. Genetic Diversity of Some Sweet Cherry Cultivars Based on Molecular Markers

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    Ioana Virginia Berindean

    2016-11-01

    Full Text Available Sweet cherry (Prunus avium L., originated around the Caspian and Black Sea, is an important fruit tree species of economic interest, and hence, breeding and conservation are requested (. Genetic analysis at the molecular level can be used effectively to study molecular polymorphism existing between intraspecific and interspecific tree species and phylogenetic relationships between them and their hybrids. The purpose of this study was to characterize and determine genetic relationships among the sweet cherry native genotypes belonging to Fruit Research & Development Station Bistrita, Romania, using RAPD markers. To eliminate the existence of possible synonyms from national romanian collection, we collect four Van cultivars, from four different national collection. For molecular analysis of the 16 varieties of sweet cherry were considered 13 RAPD primers selected from the literature. They were later used to determine the genetic variability at the molecular level using PAST program, and the dendrogram was generated based on Jaccard’s genetic distance. The dendrogram constructed by PAST software. The quantity and quality of the DNA obtained was suitable to achieve PCR amplification step. Only seven out of the 13 RAPD primers have generate polymorphic bands. The rest of seven were monomorphics. The most polymorphic primer was OPB10 which generated 11 bands from which 100% were polymorphic.Seven RAPD primers generated a high level of polymorphism which allowed to divide these cherry varieties into two groups according to their genetic geographical origin and the pedigree.

  4. Molecular Genetic Diversity of Date (Phoenix dactylifera) Germplasm in Qatar based on Microsatellite Markers

    KAUST Repository

    Ahmed, Talaat

    2016-01-25

    Depending on morphological traits alone, studying the genetic diversity of date palm is a very difficult task since morphological characteristics are highly affected by the environment. DNA markers are excellent option that can help and enhance the discriminatory power of morphological characteristics. To study the genetic diversity among date palm cultivars grown in Qatar, fifteen Date palm samples were collected from Qatar University Experimental Farm. DNAs were extracted from fresh leaves by using commercial DNeasy Plant System Kit (Qiagen, Inc., Valencia, CA). Total of 18 (Inter Simple Sequence Repeat) ISSR single primers were used to amplify DNA fragments using genomic DNA of the 15 samples. First screening was done to test the ability of these primers to amplify clear bands using Date palm genomic DNA. All 18 ISSR primers successfully produced clear bands in the first screening. Then, each primer was used separately to genotype the whole set of 15 Date palm samples. Total of 4794 bands were generated using 18 ISSR primers for the 15 Date palm samples. On average, each primer generated 400 bands. The Number of amplified bands varied from cultivar to cultivar. The highest number of bands was obtained using Primers 2, 5 and 12 for the 15 (470 bands), while the lowest number of bands were obtained by Primers 1, 7 and 8 where they produced only 329 bands. Markers were scored for the presence and absence of the corresponding band among the different cultivars. Data were subjected to cluster analysis. A similarity matrix was constructed and the similarity values were used for cluster analysis.

  5. Genetic Diversity and Fingerprint Profiles of Commercial Lentinula edodes Cultivars Based on SSR Markers Developed from the Whole Genome Sequence

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dan; SONG Chunyan; ZHANG Lujun; WU Ping; BAO Dapeng; SHANG Xiaodong; TAN Qi

    2014-01-01

    Lentinula edodes is an important cultivated mushroom in China, and accurate and reliable identification of individual cultivars is a prerequisite for successful cultivation and variety protection.In this study,the whole genome sequence of L.edodes was used to generate 200 simple sequence repeat (SSR) markers for delineating 25 commercial cultivars and for determining their genetic diversity.Our data revealed a relatively high level of genetic similarity among the cultivars,with average,minimum and maximum genetic similarity coefficient values of 0.776,0.567 and 1.000,respectively.Seven SSR primer pairs delineated eleven of the cultivars (Cr-02,Minfeng-1,Xianggu 241-4,Senyuan-1,Senyuan-8404,Xiang-9,Guangxiang-51,Huaxiang-5,L952,L9319 and L808)based on their unique multilocus SSR fingerprint profiles.

  6. Evaluation of Genetic Diversity Using Parameters Based on Probability of Gene Origin in the Slovak Spotted Bulls

    Directory of Open Access Journals (Sweden)

    E. Hazuchová

    2012-05-01

    Full Text Available The aim of this study was to assess the diversity based on probability of gene origin in Slovak Spotted bulls. The pedigree information was available from The Breeding Services of the Slovak Republic, s. e. The pedigree file consisted of 752 individuals. The 62 sires born from 1995 to 2009 and registered in Herd book set up the analyzed reference (RP population. Total number of founders in the RP was 308, effective number of founders was 115 and the effective number of ancestors was 37. The number of ancestors explaining 50 % of the diversity was 15 and founder’s genome equivalent was 20.46. The sire GS Malf and Horwein were with 16 offspring’s the most frequently used bulls in the artificial insemination. We found that the genetic conservation index for RP was 16.34 %. Results will be used in genetic management of breeding work in Slovak Spotted and monitoring of parameters characterizing genetic diversity and their development, as well.

  7. Genetic Diversity of Methylotrophic Bacteria from Human Mouth Based on Amplified Ribosomal DNA Restriction Analysis (ARDRA

    Directory of Open Access Journals (Sweden)

    CINDY OKTAVIA SUSANTO

    2011-06-01

    Full Text Available Methylotrophs inhabit the human mouth. In this study, methylotrophic bacteria were isolated from the human mouth microflora of 63 subjects, especially from the tongue, gingival, and subgingival area using minimal agar supplemented with 1% methanol. The obtained isolates were subjected to biochemical assays, continued with antibiotics susceptibility testing using ampicillin (10 g, tetracycline (20 g, kanamycin (30 g, trimethoprim (5 g, and streptomycin (10 g. Genetic diversity was analyzed using ARDRA method. Isolates varying in morphology characteristics were amplified for 16S rRNA gene and continued with DNA sequencing. As many as 21 methylotrophic bacterial isolates were purified and divided into seven groups with different phenotypic profiles. A majority of the isolates were resistant to trimethoprim but sensitive to kanamycin, streptomycin, and tetracycline. Resistance to ampicillin was variable in each isolate. ARDRA showed nine different digestion profiles. DNA sequencing analysis of the 16S rRNA gene showed that six isolates with different phenotypic and digestion profiles were closely related to Methylobacterium radiotoleran (94%, Microbacterium esteraromaticum (99%, Pseudomonas sp. (100%, and three of them were exhibited 99, 99, and 98% sequence similarity with Gordonia sp., respectively. The results of this study revealed diversity among methylotrophic bacteria particularly in human mouth.

  8. Genetic diversity of Candidatus Liberibacter asiaticus based on two hypervariable effector genes in Thailand.

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    Thamrongjet Puttamuk

    Full Text Available Huanglongbing (HLB, also known as citrus greening, is one of the most destructive diseases of citrus worldwide. HLB is associated with three species of 'Candidatus Liberibacter' with 'Ca. L. asiaticus' (Las being the most widely distributed around the world, and the only species detected in Thailand. To understand the genetic diversity of Las bacteria in Thailand, we evaluated two closely-related effector genes, lasAI and lasAII, found within the Las prophages from 239 infected citrus and 55 infected psyllid samples collected from different provinces in Thailand. The results indicated that most of the Las-infected samples collected from Thailand contained at least one prophage sequence with 48.29% containing prophage 1 (FP1, 63.26% containing prophage 2 (FP2, and 19.38% containing both prophages. Interestingly, FP2 was found to be the predominant population in Las-infected citrus samples while Las-infected psyllids contained primarily FP1. The multiple banding patterns that resulted from amplification of lasAI imply extensive variation exists within the full and partial repeat sequence while the single band from lasAII indicates a low amount of variation within the repeat sequence. Phylogenetic analysis of Las-infected samples from 22 provinces in Thailand suggested that the bacterial pathogen may have been introduced to Thailand from China and the Philippines. This is the first report evaluating the genetic variation of a large population of Ca. L. asiaticus infected samples in Thailand using the two effector genes from Las prophage regions.

  9. Genetic Diversity Study Among Six Genera of Amaranth Family Found in Malang Based on RAPD Marker

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    Arik Arubil Fatinah

    2012-12-01

    Full Text Available Genera of amaranth family tend to have phenotypic variation partly caused by environmental factor. Phenotypic variation was the result of interaction between genetic and environmental factors. One of molecular markers that is widely used for detecting genetic variation is RAPD. RAPD is used for polymorphism detections and is now possible for identifiying a large number of loci and ascribes unambiguous taxonomic and genetic relationships among different taxa. Members of amaranth family found in Indonesia are Amaranthus, Celosia, Aerva, Alternanthera, Achyranthes, Gomphrena, Salsola, and Iresine. Six genera of which (Amaranthus, Celosia, Aerva, Alternanthera, Achyranthes, and Gomphrena were observed in this study. DNA was extracted from fresh young leaves using Doyle and Doyle’s method with modification in the extraction buffer used. RAPD analyses were carried out with 20 decamer primers from Kit A of Operon Technology. DNA was amplified using master cycler gradient Eppendorf with 35 cycles. RAPD products were separated on 1,5 % agarose gels and detected by staining with ethidium bromide. There were 374 bands generated in 18 random primers. The number of monomorphic bands, polymorphic bands, and the percentage of polymorphism were 21 bands, 353 bands, and 94,38 % respectively. The high number and percentage of polymorphic bands revealed genomic DNA variation. This variation is in accordance with phenotypic variation detected in this experiment. Therefore, it can be concluded that, based on DNA polymorphism detected by RAPD, Amaranth family can be classified into two sub families namely Amaranthoideae and Gomphrenoideae.

  10. New insights on the genetic diversity of the honeybee parasite Nosema ceranae based on multilocus sequence analysis.

    Science.gov (United States)

    Roudel, Mathieu; Aufauvre, Julie; Corbara, Bruno; Delbac, Frederic; Blot, Nicolas

    2013-09-01

    The microsporidian parasite Nosema ceranae is a common pathogen of the Western honeybee (Apis mellifera) whose variable virulence could be related to its genetic polymorphism and/or its polyphenism responding to environmental cues. Since the genotyping of N. ceranae based on unique marker sequences had been unsuccessful, we tested whether a multilocus approach, assessing the diversity of ten genetic markers – encoding nine proteins and the small ribosomal RNA subunit – allowed the discrimination between N. ceranae variants isolated from single A. mellifera individuals in four distant locations. High nucleotide diversity and allele content were observed for all genes. Most importantly, the diversity was mainly present within parasite populations isolated from single honeybee individuals. In contrast the absence of isolate differentiation precluded any taxa discrimination, even through a multilocus approach, but suggested that similar populations of parasites seem to infect honeybees in distant locations. As statistical evolutionary analyses showed that the allele frequency is under selective pressure, we discuss the origin and consequences of N. ceranae heterozygosity in a single host and lack of population divergence in the context of the parasite natural and evolutionary history.

  11. Genetic diversity analysis of sugarcane germplasm based on fluorescence-labeled simple sequence repeat markers and a capillary electrophoresis-based genotyping platform

    Science.gov (United States)

    Genetic diversity analysis, which refers to the elaboration of total extent of genetic characteristics in the genetic makeup of a certain species, constitutes a classical strategy for the study of diversity, population genetic structure, and breeding practices. In this study, fluorescence-labeled se...

  12. Genetic diversity and relatedness of sweet cherry (prunus avium L.) cultivars based on single nucleotide polymorphic markers.

    Science.gov (United States)

    Fernandez I Marti, Angel; Athanson, Blessing; Koepke, Tyson; Font I Forcada, Carolina; Dhingra, Amit; Oraguzie, Nnadozie

    2012-01-01

    Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD, and simple sequence repeat (SSR) markers. This study was carried out to assess the utility of single nucleotide polymorphism (SNP) markers generated from 3' untranslated regions (UTR) for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars, and old cultivars imported from different parts of the world were screened with seven SSR markers developed from other Prunus species and with 40 SNPs obtained from 3' UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity, and polymorphic information content values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, "Stella" was separated from "Compact Stella." This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3' UTR SNPs for genetic fingerprinting, parentage verification, gene mapping, and study of genetic diversity in sweet cherry.

  13. Genetic diversity and relatedness of sweet cherry (Prunus avium L. cultivars based on single nucleotide polymorphic (SNP markers

    Directory of Open Access Journals (Sweden)

    Angel eFernandez i Marti

    2012-06-01

    Full Text Available Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD and SSR markers. This study was carried out to assess the utility of SNP markers generated from 3’UTRs for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars and old cultivars imported from different parts of the world were screened with 7 SSR markers developed from other Prunus species and with 40 SNPs obtained from 3’UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity and polymorphic information content (PIC values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, ‘Stella’ was separated from ‘Compact Stella’. This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3’ UTR SNPs for genetic fingerprinting, parentage verification, gene mapping and study of genetic diversity in sweet cherry.

  14. Genetic diversity analyses of Lasiodiplodia theobromae on Morus alba and Agave sisalana based on RAPD and ISSR molecular markers

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    Hong-hui Xie

    2016-10-01

    Full Text Available Genetic diversity of 23 Lasiodiplodia theobromae isolates on Morus alba and 6 isolates on Agave sisalana in Guangxi province, China, was studied by using random amplified polymorphic DNA and inter-simple sequence repeat molecular markers. Results of two molecular markers showed that the average percentage of polymorphic loci of all isolates was more than 93%. Both dendrograms of two molecular markers showed obvious relationship between groups and the geographical locations where those strains were collected, among which, the 23 isolates on M. alba were divided into 4 populations and the 6 isolates on A. sisalana were separated as a independent population. The average genetic identity and genetic distance of 5 populations were 0.7215, 0.3284 and 0.7915, 0.2347, respectively, which indicated that the genetic identity was high and the genetic distance was short in the 5 populations. Average value of the gene diversity index (H and the Shannon’s information index (I of 29 isolates were significantly higher than 5 populations which showed that genetic diversity of those isolates was richer than the populations and the degree of genetic differentiation of the isolates was higher. The Gst and Nm of 29 isolates were 0.4411, 0.6335 and 0.4756, 0.5513, respectively, which showed that the genetic diversity was rich in those isolates.

  15. The molecular prevalence and MSA-2b gene-based genetic diversity of Babesia bovis in dairy cattle in Thailand.

    Science.gov (United States)

    Simking, Pacharathon; Saengow, Sinsamuth; Bangphoomi, Kunan; Sarataphan, Nachai; Wongnarkpet, Sirichai; Inpankaew, Tawin; Jittapalapong, Sathaporn; Munkhjargal, Tserendorj; Sivakumar, Thillaiampalam; Yokoyama, Naoaki; Igarashi, Ikuo

    2013-11-08

    Bovine babesiosis is an economically significant disease that affects dairy farming operations in Thailand. In the present study, 1824 blood-DNA samples prepared from cattle bred in 4 different regions of the country (North, Northeast, Central, and South) were screened using a nested PCR for the specific detection of Babesia bovis. While the overall prevalence of B. bovis was 8.8%, the Central region of Thailand was found to be a high-risk area of the country, as the prevalence of the parasite was 15.0%. The positive rate was relatively higher among the animals of 1-5 years of age. The genetic diversity among the B. bovis parasites was also studied based on their MSA-2b gene, and the findings showed that the Thai sequences were dispersed across 8 of 13 total clades observed in the phylogram. Three of these clades were formed only of Thai sequences. Similarity among the deduced MSA-2b amino acid sequences determined in the present study was 68.3-100%. In conclusion, the present study found that all the locations surveyed were infected with B. bovis and that the parasite populations in Thailand were genetically diverse. Our findings highlight the need for further studies in Thailand to generate more information before a sound control strategy could be implemented against B. bovis.

  16. Genetic diversity of eleven European pig breeds

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    Foulley Jean-Louis

    2000-03-01

    Full Text Available Abstract A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall FST = 0.27, and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

  17. Assessment of genetic diversity among Indian potato (Solanum tuberosum L.) collection using microsatellite and retrotransposon based marker systems.

    Science.gov (United States)

    Sharma, Vishakha; Nandineni, Madhusudan R

    2014-04-01

    Potato (Solanum tuberosum) is an important non-cereal crop throughout the world and is highly recommended for ensuring global food security. Owing to the complexities in genetics and inheritance pattern of potato, the conventional method of cross breeding for developing improved varieties has been difficult. Identification and tagging of desirable traits with informative molecular markers would aid in the development of improved varieties. Insertional polymorphism of copia-like and gypsy-like long terminal repeat retrotransposons (RTN) were investigated among 47 potato varieties from India using Inter-Retrotransposon Amplified Polymorphism (IRAP) and Retrotransposon Microsatellite Amplified Polymorphism (REMAP) marker techniques and were compared with the DNA profiles obtained with simple sequence repeats (SSRs). The genetic polymorphism, efficiency of polymorphism and effectiveness of marker systems were evaluated to assess the extent of genetic diversity among Indian potato varieties. A total of 139 polymorphic SSR alleles, 270 IRAP and 98 REMAP polymorphic bands, showing polymorphism of 100%, 87.9% and 68.5%, respectively, were used for detailed characterization of the genetic relationships among potato varieties by using cluster analysis and principal coordinate analysis (PCoA). IRAP analysis resulted in the highest number of polymorphic bands with an average of 15 polymorphic bands per assay unit when compared to the other two marker systems. Based on pair-wise comparison, the genetic similarity was calculated using Dice similarity coefficient. The SSRs showed a wide range in genetic similarity values (0.485-0.971) as compared to IRAP (0.69-0.911) and REMAP (0.713-0.947). A Mantel's matrix correspondence test showed a high positive correlation (r=0.6) between IRAP and REMAP, an intermediate value (r=0.58) for IRAP and SSR and the lowest value (r=0.17) for SSR and REMAP. Statistically significant cophenetic correlation coefficient values, of 0.961, 0.941 and 0

  18. The genetic diversity and evolution of field pea (Pisum studied by high throughput retrotransposon based insertion polymorphism (RBIP marker analysis

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    Smýkal Petr

    2010-02-01

    Full Text Available Abstract Background The genetic diversity of crop species is the result of natural selection on the wild progenitor and human intervention by ancient and modern farmers and breeders. The genomes of modern cultivars, old cultivated landraces, ecotypes and wild relatives reflect the effects of these forces and provide insights into germplasm structural diversity, the geographical dimension to species diversity and the process of domestication of wild organisms. This issue is also of great practical importance for crop improvement because wild germplasm represents a rich potential source of useful under-exploited alleles or allele combinations. The aim of the present study was to analyse a major Pisum germplasm collection to gain a broad understanding of the diversity and evolution of Pisum and provide a new rational framework for designing germplasm core collections of the genus. Results 3020 Pisum germplasm samples from the John Innes Pisum germplasm collection were genotyped for 45 retrotransposon based insertion polymorphism (RBIP markers by the Tagged Array Marker (TAM method. The data set was stored in a purpose-built Germinate relational database and analysed by both principal coordinate analysis and a nested application of the Structure program which yielded substantially similar but complementary views of the diversity of the genus Pisum. Structure revealed three Groups (1-3 corresponding approximately to landrace, cultivar and wild Pisum respectively, which were resolved by nested Structure analysis into 14 Sub-Groups, many of which correlate with taxonomic sub-divisions of Pisum, domestication related phenotypic traits and/or restricted geographical locations. Genetic distances calculated between these Sub-Groups are broadly supported by principal coordinate analysis and these, together with the trait and geographical data, were used to infer a detailed model for the domestication of Pisum. Conclusions These data provide a clear picture

  19. Genetic Diversity of Fragaria iinumae and F. nipponica Based on Microsatellite Markers

    Science.gov (United States)

    The United States Department of Agriculture (USDA) - Agricultural Research Service (ARS) - National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, is a genebank that preserves strawberry genetic resources. The Fragaria L. collection consists of accessions from 17 species and 37 countries. ...

  20. Tree-based genetic programming approach to infer microphysical parameters of the DSDs from the polarization diversity measurements

    Science.gov (United States)

    Islam, Tanvir; Rico-Ramirez, Miguel A.; Han, Dawei

    2012-11-01

    The use of polarization diversity measurements to infer the microphysical parametrization has remained an active goal in the radar remote sensing community. In view of this, the tree-based genetic programming (GP) as a novel approach has been presented for retrieving the governing microphysical parameters of a normalized gamma drop size distribution model D0 (median drop diameter), Nw (concentration parameter), and μ (shape parameter) from the polarization diversity measurements. A large number of raindrop spectra acquired from a Joss-Waldvogel disdrometer has been utilized to develop the GP models, relating the microphysical parameters to the T-matrix scattering simulated polarization measurements. Several functional formulations retrieving the microphysical parameters-D0 [f(ZDR), f(ZH, ZDR)], log10Nw [f(ZH, D0), f(ZH, ZDR, D0), and μ[f(ZDR, D0), f(ZH, ZDR, D0)], where ZH represents reflectivity and ZDR represents differential reflectivity, have been investigated, and applied to a S-band polarimetric radar (CAMRA) for evaluation. It has been shown that the GP model retrieved microphysical parameters from the polarization measurements are in a reasonable agreement with disdrometer observations. The calculated root mean squared errors (RMSE) are noted as 0.23-0.25 mm for D0, 0.74-0.85 for log10Nw (Nw in mm-1 mm-3), and 3.30-3.36 for μ. The GP model based microphysical retrieval procedure is further compared with a physically based constrained gamma model for D0 and log10Nw estimates. The close agreement of the retrieval results between the GP and the constrained gamma models supports the suitability of the proposed genetic programming approach to infer microphysical parameterization.

  1. Genetic diversity and population structure of black Dahe pig based on DNA sequences analyses of mitochondrial and nuclear genes.

    Science.gov (United States)

    Tang, Lizhou; Yu, Long; Wang, Junjie; Liu, Chao; Shi, Xiaodong; Ding, Wei; Zhu, Lei; Guo, Songchang

    2016-01-01

    To investigate the genetic diversity and population structure of black Dahe pigs, we collected 175 samples from 5 local populations and sequenced them using a combination of two selected molecular markers for mitochondrial cytochrome b and Major Histocompatibility Complex (MHC) DRB. Overall, the results of AMOVA and phylogenetic tree and gene flow analyses detected high levels of gene flow among the five populations, particularly individual pigs from Dahe town (Pop1) or Yingshang town (Pop2) to other populations (Pop3, Pop4, and Pop5). The genetic diversity analyses showed that the diversity indices of the five populations did not vary significantly, but they were much lower than those of other Chinese pig species. These results suggest that distinct gene flow, unstable population pattern, and lower genetic diversity have been influenced mainly by human introductions for economic ends. These findings provide genetic information that could be used for the preservation and further genetic improvement of the black Dahe pig, as well as an important reference for the evaluation, conservation, and utilization of the genetic resources of this breed.

  2. Genetic Diversity and Relatedness of Sweet Cherry (Prunus Avium L.) Cultivars Based on Single Nucleotide Polymorphic Markers

    Science.gov (United States)

    Fernandez i Marti, Angel; Athanson, Blessing; Koepke, Tyson; Font i Forcada, Carolina; Dhingra, Amit; Oraguzie, Nnadozie

    2012-01-01

    Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD, and simple sequence repeat (SSR) markers. This study was carried out to assess the utility of single nucleotide polymorphism (SNP) markers generated from 3′ untranslated regions (UTR) for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars, and old cultivars imported from different parts of the world were screened with seven SSR markers developed from other Prunus species and with 40 SNPs obtained from 3′ UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity, and polymorphic information content values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, “Stella” was separated from “Compact Stella.” This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3′ UTR SNPs for genetic fingerprinting, parentage verification, gene mapping, and study of genetic diversity in sweet cherry. PMID:22737155

  3. Assessment of Worldwide Genetic Diversity of Siberian Wild Rye (Elymus sibiricus L. Germplasm Based on Gliadin Analysis

    Directory of Open Access Journals (Sweden)

    Changbing Zhang

    2012-04-01

    Full Text Available E. sibiricus L., the type species of the genus Elymus, is a perennial, self-pollinating and allotetraploid grass indigenous to Northern Asia, which in some countries can be cultivated as an important forage grass. In the present study, eighty-six Elymus sibiricus accessions, mostly from different parts of Asia, were assayed by gliadin markers based on Acid Polyacrylamide Gel Electrophoresis to differentiate and explore their genetic relationships. The genetic similarity matrix was calculated by 47 polymorphic bands, which ranged from 0.108 to 0.952 with an average of 0.373. The total Shannon diversity index (Ho and the Simpson index (He was 0.460 and 0.302, respectively. Cluster analysis showed a clear demarcation between accessions from Qinghai-Tibetan Plateau, China and the others as separate groups. The clustering pattern was probably dependent on geographic origin and ecological adaptability of the accessions. The population structure analysis based on Shannon indices showed that the proportion of variance within and among the five geographic regions of the Northern Hemisphere was 55.9 and 44.1%, respectively, or 63.4 and 36.6% within and among six Chinese provinces. This distinct geographical divergence was perhaps depended on ecogeographical conditions such as climate difference and mountain distribution. The results of gladin analysis in this study are useful for the collection and preservation of E. sibiricus germplasm resources.

  4. Genetic diversity of diploid Japanese strawberry species based on microsatellite markers

    Science.gov (United States)

    The United States Department of Agriculture (USDA) - Agricultural Research Service (ARS) - National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, is a genebank that preserves strawberry genetic resources. In 2004, representatives of two Japanese diploid species, F. iinumae Makino and F. n...

  5. Genetic Diversity of RAPD Mark for Natural Davidia involucrata Populations

    Institute of Scientific and Technical Information of China (English)

    Congwen Song; Manzhu Bao

    2006-01-01

    The genetic diversity and genetic variation within and among populations of five natural Davidia involucrata populations were studied from 13 primers based on random amplified polymorphic DNA (RAPD) analysis.The results show that natural D.involucrata population has a rich genetic diversity,and the differences among populations are significant.Twenty-six percent of genetic variation exists among D.involucrata populations,which is similar to that of the endangered tree species Liriodendron chinense and Cathaya argyrophylla in China,but different from more widely distributed tree species.The analysis of the impacts of sampling method on genetic diversity parameters shows that the number of sampled individuals has little effect on the effective number of alleles and genetic diversity,but has a marked effect on the genetic differentiation among populations and gene flows.This study divides the provenances of D.involucrata into two parts,namely,a southeast and a northwest provenance.

  6. Genetic Diversity among Parents of Hybrid Rice Based on Cluster Analysis of Morphological Traits and Simple Sequence Repeat Markers

    Institute of Scientific and Technical Information of China (English)

    WANG Sheng-jun; LU Zuo-mei; WAN Jian-min

    2006-01-01

    The genetic diversity of 41 parental lines popularized in commercial hybrid rice production in China was studied by using cluster analysis of morphological traits and simple sequence repeat (SSR) markers. Forty-one entries were assigned into two clusters (I.e. Early or medium-maturing cluster; medium or late-maturing cluster) and further assigned into six sub-clusters based on morphological trait cluster analysis. The early or medium-maturing cluster was composed of 15 maintainer lines, four early-maturing restorer lines and two thermo-sensitive genic male sterile lines, and the medium or late-maturing cluster included 16 restorer lines and 4 medium or late-maturing maintainer lines. Moreover, the SSR cluster analysis classified 41 entries into two clusters (I.e. Maintainer line cluster and restorer line cluster) and seven sub-clusters. The maintainer line cluster consisted of all 19 maintainer lines, two thermo-sensitive genic male sterile lines, while the restorer line cluster was composed of all 20 restorer lines. The SSR analysis fitted better with the pedigree information. From the views on hybrid rice breeding, the results suggested that SSR analysis might be a better method to study the diversity of parental lines in indica hybrid rice.

  7. Microsatellite Marker Based Assessment of Genetic Diversity among Cultivars, Landraces and Wild Relatives in Rice

    Institute of Scientific and Technical Information of China (English)

    J.R. Kannan Bapu; S. Ganesh Ram; S. Vinothini; T.S. Raveendran

    2007-01-01

    @@ India being the primary center of origin for rice had a very large treasure of local land races, most of which are out of cultivation today. The exact genetic potential and their differences from commercial varieties and the magnitude of heterogeneity still present in them are not well catalogued. Hence the need to characterize the available land races has become imminent in the modem day concept of crop improvement (Rezai and Frey, 1990).

  8. Genetic diversity and structure of the zombi pea (Vigna vexillata (L.) A. Rich) gene pool based on SSR marker analysis.

    Science.gov (United States)

    Dachapak, Sujinna; Somta, Prakit; Poonchaivilaisak, Supalak; Yimram, Tarika; Srinives, Peerasak

    2017-04-01

    Zombi pea (Vigna vexillata (L.) A. Rich) is an underutilized legume species and a useful gene source for resistance to biotic and abiotic stresses, although there is little understanding on its genetic diversity and structure. In this study, 422 (408 wild and 14 cultivated) accessions of zombi pea from diverse origins (201 from Africa, 126 from America, 85 from Australia, 5 from Asia and 5 from unknown origin) were analyzed with 20 simple sequence repeat (SSR) markers to determine its genetic diversity and genetic structure. The SSR markers detected 273 alleles in total with a mean of 13.6 alleles per locus. Polymorphism information content values of the markers varied from 0.58 to 0.90 with an average of 0.76. Overall gene diversity was 0.715. Gene diversity and average allelic richness was highest in Africa (0.749 and 8.08, respectively) and lowest in America (0.435 and 4.10, respectively). Nei's genetic distance analysis revealed that the highest distance was between wild Australia and cultivated Africa (0.559), followed by wild West Africa and wild Australia (0.415). STRUCTURE, neighbor-joining (NJ), and principal coordinate analyses consistently showed that these zombi pea accessions were clustered into three major groups, viz. America, Africa and Asia, and Australia. NJ tree also suggested that American and Australian accessions are originated from East African zombi peas, and that the cultivated accessions from Africa and Asia were genetically distinct, while those from America were clustered with some cultivated accessions from Africa. These results suggest that Africa is the center of origin and diversity of zombi pea, and that domestication of this pea took place more than once in different regions.

  9. Microbial diversity - insights from population genetics

    NARCIS (Netherlands)

    Mes, T.H.M.

    2008-01-01

    Although many environmental microbial populations are large and genetically diverse, both the level of diversity and the extent to which it is ecologically relevant remain enigmatic. Because the effective (or long-term) population size, Ne, is one of the parameters that determines population genetic

  10. Genetic diversity based on 28S rDNA sequences among populations of Culex quinquefasciatus collected at different locations in Tamil Nadu, India.

    Science.gov (United States)

    Sakthivelkumar, S; Ramaraj, P; Veeramani, V; Janarthanan, S

    2015-09-01

    The basis of the present study was to distinguish the existence of any genetic variability among populations of Culex quinquefasciatus which would be a valuable tool in the management of mosquito control programmes. In the present study, population of Cx. quinquefasciatus collected at different locations in Tamil Nadu were analyzed for their genetic variation based on 28S rDNA D2 region nucleotide sequences. A high degree of genetic polymorphism was detected in the sequences of D2 region of 28S rDNA on the predicted secondary structures in spite of high nucleotide sequence similarity. The findings based on secondary structure using rDNA sequences suggested the existence of a complex genotypic diversity of Cx. quinquefasciatus population collected at different locations of Tamil Nadu, India. This complexity in genetic diversity in a single mosquito population collected at different locations is considered an important issue towards their influence and nature of vector potential of these mosquitoes.

  11. Skin-Based DNA Repair Phenotype for Cancer Risk from GCR in Genetically Diverse Populations

    Science.gov (United States)

    Guiet, Elodie; Viger, Louise; Snijders, Antoine; Costes, Sylvian V.

    2017-01-01

    Predicting cancer risk associated with cosmic radiation remains a mission-critical challenge for NASA radiation health scientists and mission planners. Epidemiological data are lacking and risk methods do not take individual radiation sensitivity into account. In our approach we hypothesize that genetic factors strongly influence risk of cancer from space radiation and that biomarkers reflecting DNA damage and cell death are ideal tools to predict risk and monitor potential health effects post-flight. At this workshop, we will be reporting the work we have done over the first 9 months of this proposal. Skin cells from 15 different strains of mice already characterized for radiation-induced cancer sensitivity (B6C3F; BALB/cByJ, C57BL/6J, CBA/CaJ, C3H/HeMsNrsf), and 10 strains from the DOE collaborative cross-mouse model were expanded from ear biopsy and cultivated until Passage 3. On average, 3 males and 3 females for each strain were expanded and frozen for further characterization at the NSRL beam line during the NSRL16C run for three LET (350 MeV/n Si, 350 MeV/n Ar and 600 MeV/n Fe) and two ion fluences (1 and 3 particles per cell). The mice work has established new metrics for the usage of Radiation Induced Foci as a marker for various aspect of DNA repair deficiencies. In year 2, we propose to continue characterization of the mouse lines with low LET to identify loci specific to high- versus low- LET and establish genetic linkage for the various DNA repair biomarkers. Correlation with cancer risk from each animals strain and gender will also be investigated. On the human side, we will start characterizing the DNA damage response induced ex-vivo in 200 human's blood donors for radiation sensitivity with a tentative 500 donors by the end of this project. All ex-vivo phenotypic data will be correlated to genetic characterization of each individual human donors using SNP arrays characterization as done for mice. Similarly, ex-vivo phenotypic features from mice will

  12. Genetic diversity in section Rhizomatosae of the genus Arachis (Fabaceae based on microsatellite markers

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    Carla M.L.C.D. Angelici

    2008-01-01

    Full Text Available The genus Arachis (Fabaceae native to South America, contains 80 species divided into nine sections, three of which contain species of special economic importance such as the cultivated peanut (Arachis hypogaea, belonging to the section Arachis, and some perennial forage species from sections Caulorrhizae and Rhizomatosae. We used microsatellite markers to assay genetic variability among 77 accessions of four species from section Rhizomatosae, the diploid Arachis burkartii (2n = 2x = 20 and the tetraploid Arachis glabrata, Arachis pseudovillosa and Arachis nitida (2n = 4x = 40. A total of 249 alleles were found in the fifteen loci analyzed and a high degree of intra and interspecific polymorphism was detected. The lowest intraspecific variation occurred in Arachis burkartii, while the smallest estimated interspecific value was between A. nitida and A. pseudovillosa and the largest was between A. burkartii and A. nitida. High observed heterozygosity was detected in A. glabrata. The diploid accessions grouped in one cluster and the tetraploid accessions in another. It was possible to distinguish all 77 accessions and the genetic distance between accessions could not be correlated with geographic origin.

  13. GENETIC STRUCTURE AND ALLEL DIVERSITY OF THREE BALINESE GENERATIONS BASED ON FIVE AUTOSOMAL MICROSATELLITE DNA LOCI

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    Ayu Saka Laksmita

    2015-09-01

    Full Text Available This research was aimed to find out the genetic structures of three generations of Balinese population, in order to determine the best loci used for paternity testing among this population, and observed the mutation rate of these loci. The DNA samples were taken from the epithelium cell of 25 families which were collected from the children, father, mother, grandfather and grandmother of the children, from both mother and father sides (family with three generations. The DNA was extracted in Phenol-Chloroform method with modifications. DNA amplification was conducted in PCR method using pairs of primer 5, namely: FGA, D18S51, D2S1338, TPOX, and D16S539, and its products were electrophoresed and visualized in 10% of PAGE, stained in silver nitrate. The genetic structures of the three family generations showed 30 variants with different frequencies in each locus. The highest heterozygosity value was detected in FGA (8 alleles, then followed by D18S51 (7 alleles, TPOX (6 alleles, D16S539 (5 alleles, and the lowest was in D2S1338 (4 alleles. The highest value of heterozigosity and Power of Discrimination were found in FGA, followed by TPOX, D18S51, D2S1338, and the lowest was in D16S539. Therefore, it can be concluded that out of five loci tested, 4 of them can be recommended to be used for paternity testing of Balinese population, except D16S539

  14. Genetic diversity of the Mycobacterium tuberculosis Beijing family based on SNP and VNTR typing profiles in Asian countries.

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    Yih-Yuan Chen

    Full Text Available The Mycobacterium tuberculosis (MTB Beijing strain is highly virulent, drug resistant, and endemic over Asia. To explore the genetic diversity of this family in several different regions of eastern Asia, 338 Beijing strains collected in Taiwan (Republic of China were analyzed by mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR typing and compared with published MIRU-VNTR profiles and by the Hunter-Gaston diversity index (HGDI of Beijing strains from Japan and South Korea. The results revealed that VNTR2163b (HGDI>0.6 and five other loci (VNTR424, VNTR4052, VNTR1955, VNTR4156 and VNTR 2996; HGDI>0.3 could be used to discriminate the Beijing strains in a given geographic region. Analysis based on the number of VNTR repeats showed three VNTRs (VNTR424, 3192, and 1955 to be phylogenetically informative loci. In addition, to determine the geographic variation of sequence types in MTB populations, we also compared sequence type (ST data of our strains with published ST profiles of Beijing strains from Japan and Thailand. ST10, ST22, and ST19 were found to be prevalent in Taiwan (82% and Thailand (92%. Furthermore, classification of Beijing sublineages as ancient or modern in Taiwan was found to depend on the repeat number of VNTR424. Finally, phylogenetic relationships of MTB isolates in Taiwan, South Korea, and Japan were revealed by a minimum spanning tree based on MIRU-VNTR genotyping. In this topology, the MIRU-VNTR genotypes of the respective clusters were tightly correlated to other genotypic characters. These results are consistent with the hypothesis that clonal evolution of these MTB lineages has occurred.

  15. Genetic diversity of a brazilian wine grape germplasm collection based on morphoagronomic traits

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    Patrícia Coelho de S. Leão

    2010-12-01

    Full Text Available The objectives of this study were to evaluate the performance of cultivars, to quantify the variability and to estimate the genetic distances of 66 wine grape accessions in the Grape Germplasm Bank of the EMBRAPA Semi-Arid, in Juazeiro, BA, Brazil, through the characterization of discrete and continuous phenotypic variables. Multivariate statistics, such as, principal components, Tocher's optimization procedure, and the graphic of the distance, were efficient in grouping more similar genotypes, according to their phenotypic characteristics. There was no agreement in the formation of groups between continuous and discrete morpho-agronomic traits, when Tocher's optimization procedure was used. Discrete variables allowed the separation of Vitis vinifera and hybrids in different groups. Significant positive correlations were observed between weight, length and width of bunches, and a negative correlation between titratable acidity and TSS/TTA. The major part (84.12% of the total variation present in the original data was explained by the four principal components. The results revealed little variability between wine grape accessions in the Grape Germplasm Bank of Embrapa Semi-Arid.

  16. Inbreeding and genetic diversity analysis in a hatchery release population and clones of Rhopilema esculentum based on microsatellite markers

    Science.gov (United States)

    Tian, Tao; Chen, Zaizhong; Wang, Mosang; Hu, Yulong; Wang, Weiji

    2016-07-01

    Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye (Scyphozoa: Rhizostomatidae). A total of 85 alleles were detected in 600 individuals. Within-population levels of observed (H o) and expected (H e) heterozygosity ranged from 0.152 to 0.839 (mean=0.464) and from 0.235 to 0.821 (mean=0.618), respectively. The polymorphism information content (PIC) of each marker ranged from 0.207 to 0.795 with an average of 0.580, indicating that the hatchery population maintained a high level of genetic diversity. Inbreeding levels were estimated in the hatchery population and the inbreeding coefficient was 0.203. This result revealed that a certain level of inbreeding occurred within the population. Meanwhile, we also determined genetic diversity at the clone level. Several polyps from the same scyphistomae were genotyped at the ten microsatellite loci and there was virtually no difference in their genotypes. Furthermore, we calculated the probabilities of exclusion. When both parents were known, the average exclusion probability of ten loci was 99.99%. Our data suggest that the ten microsatellite markers can not only be used to analyze the identity of individuals but they can also be applied to parentage identification. Our research provides a theoretical basis and technical support for genetic diversity detection and reasonable selection of R. esculentum hatchery populations. These findings support the use of releasing studies and conservation of R. esculentum germplasm resources.

  17. Genetic diversity of Plasmodium vivax over time and space: a community-based study in rural Amazonia.

    Science.gov (United States)

    Batista, Camilla L; Barbosa, Susana; Da Silva Bastos, Melissa; Viana, Susana Ariane S; Ferreira, Marcelo U

    2015-02-01

    To examine how community-level genetic diversity of the malaria parasite Plasmodium vivax varies across time and space, we investigated the dynamics of parasite polymorphisms during the early phases of occupation of a frontier settlement in the Amazon Basin of Brazil. Microsatellite characterization of 84 isolates of P. vivax sampled over 3 years revealed a moderate-to-high genetic diversity (mean expected heterozygosity, 0.699), with a large proportion (78.5%) of multiple-clone infections (MCI), but also a strong multilocus linkage disequilibrium (LD) consistent with rare outcrossing. Little temporal and no spatial clustering was observed in the distribution of parasite haplotypes. A single microsatellite haplotype was shared by 3 parasites collected during an outbreak; all other 81 haplotypes were recovered only once. The lowest parasite diversity, with the smallest proportion of MCI and the strongest LD, was observed at the time of the outbreak, providing a clear example of epidemic population structure in a human pathogen. Population genetic parameters returned to pre-outbreak values during last 2 years of study, despite the concomitant decline in malaria incidence. We suggest that parasite genotyping can be useful for tracking the spread of new parasite strains associated with outbreaks in areas approaching malaria elimination.

  18. Genetic Diversity of Cowpea (Vigna unguiculata (L.) Walp.) Accession in Kenya Gene Bank Based on Simple Sequence Repeat Markers.

    Science.gov (United States)

    Wamalwa, Emily N; Muoma, John; Wekesa, Clabe

    2016-01-01

    Increased agricultural production is an urgent issue. Projected global population is 9 million people by mid of this century. Estimation projects death of 1 million people for lack of food quality (micronutrient deficit) and quantity (protein deficit). Majority of these people will be living in developing countries. Other global challenges include shrinking cultivable lands, salinity, and flooding due to climate changes, new emerging pathogens, and pests. These affect crop production. Furthermore, they are major threats to crop genetic resources and food security. Genetic diversity in cultivated crops indicates gene pool richness. It is the greatest resource for plant breeders to select lines that enhance food security. This study was conducted by Masinde Muliro University to evaluate genetic diversity in 19 cowpea accessions from Kenya national gene bank. Accessions clustered into two major groups. High divergence was observed between accessions from Ethiopia and Australia and those from Western Kenya. Upper Volta accessions were closely related to those from Western Kenya. Low variation was observed between accessions from Eastern and Rift Valley than those from Western and Coastal regions of Kenya. Diversity obtained in this study can further be exploited for the improvement of cowpea in Kenya as a measure of food security.

  19. Genetic diversity of native chicken based on analysis of D-Loop mtDNA marker

    Directory of Open Access Journals (Sweden)

    Tike Sartika

    2000-06-01

    Full Text Available Production was carried out using control region/D-loop mtDNA marker. The base population of native chicken was selected from subpopulation at Cianjur, Jatiwangi, Depok, Bogor I, and Bogor 2. Samples from each population was 10 heads and 2 samples Green Jungle Fowl (Gallus various from East Java as out Group samples. Two primers binding conserved tRNA Phenylalanine gene and tRNA Glutamine gene were DNA Heavy stranded HI255 (5'-CATCTTGGCATCTTCAGTGCC-3' and DNA Light stranded Ll6750 (5'-AGGACTACGGCTTGAAAAGC-3' was used to amplify D-Ioop mtDNA chicken. PCR-RFLP methods with 6 restriction enzymes 4 cutter such as, Alul (AG↓CT, Hpall (C↓CGG, Mbol (↓GATC, Rsal (GT↓AC, NlaIII (CATG↓ and HaeIII (GG↓CC were used to detect polymorphism within and between subpopulation. Result of experiment show that mtDNA which was amplified by PCR was 1320 bp, consist of 1227 bp control region/D-loop, 45 bp tRNA Glutamine gene and 48 bp tRNA Phenylalananine gene. PCR product which were digested from 6 endonucleases enzyme show that native chicken within and between population was monomorphic and if its compare with Green Jungle Fowl was polymorphic.

  20. Genetic diversity of Ehrlichia canis in Brazil.

    Science.gov (United States)

    Aguiar, D M; Zhang, X; Melo, A L T; Pacheco, T A; Meneses, A M C; Zanutto, M S; Horta, M C; Santarém, V A; Camargo, L M A; McBride, J W; Labruna, M B

    2013-06-28

    Canine monocytic ehrlichiosis is a highly prevalent disease in Brazil, where the genetic diversity of Ehrlichia canis remains undefined. In this study, we used the TRP36 gene to examine the genetic diversity of E. canis strains from naturally infected dogs residing in five distinct geographic regions in Brazil. E. canis DNA was detected in 82/126 (65%) dogs by dsb-specific PCR and E. canis was isolated in cell culture from 13 dogs. Sequences obtained from dsb genes amplified from the isolates were identical to the US E. canis strain. An extended molecular characterization based on the TRP36 gene identified two major genogroups based on differences among eight isolates. Isolates with tandem repeat amino acid sequence (TEDSVSAPA) identical to the previously reported TRP36 sequence were found in the midwest, northeast and southeast regions of Brazil, and classified into the US genogroup. A novel Brazilian genotype with a different tandem repeat sequence (ASVVPEAE) was also identified in midwest, northern and southern regions. Similarity in the N-terminal sequence of a US genogroup member with the Brazilian genogroup suggested that genomic recombination between the two genogroups may have occurred. Other subtypes within the Brazilian genogroup were also identified using C-terminal amino acid divergence. We identified two distinct major Brazilian genogroups and several subtypes based on analysis of TRP36, and such information will be useful for further genotyping and possible associations with disease severity, understanding of the genetic and antigenic variability of E. canis, and for developing strain-specific vaccines and diagnostic methods based on TRP36.

  1. [Genetic diversity based on swine leukocyte antigen complex mi-crosatellites(SLA-MS) in five pig populations].

    Science.gov (United States)

    Yu, Hui; Liu, Rong-Hui; Li, Hua; Zuo, Qi-Zhen; Li, Yan; Wu, Zhen-Fang

    2012-11-01

    The genetic diversity of swine leukocyte antigen complex (SLA) was studied among Guangdong local pigs, Huanan wild boars (S.s. chirodontus) and introduced pigs, which aimed at providing a theoretical foundation for further pig anti-disease resistance breeding. Pietrain pigs, Duroc pigs, Large black-white pigs, Lantang pigs, and Huanan wild boars were genotyped by employing 18 microsatellites in swine leukocyte antigen complex (SLA-MS). The result showed that the average diversity in SLA II was higher (He=0.628, PIC=0.581) than that in SLA I (He=0.530, PIC=0.474) and in SLA III (He=0.526, PIC=0.458). The molecular diversity indices (MDI) of Huanan wild boars was the highest(0.716), followed by Lantang pigs (0.614), Large black-white pigs (0.559), Pietrain pigs (0.550) and Duroc pigs (0.507). As a whole, the genetic diversity of Huanan wild boars was the highest over Guangdong native pigs and introduced pigs. Large black-white pigs and Duroc pigs had ever happened a severe bottleneck by comparison with the Garza-Williamson index (GWI) in Huanan wild boar. From the genetic distance, one clade was that Lantang pigs were first clustered with Huanan wild boar, and then grouped together with Large black-white pigs; another clade was that Pietrain pigs were independently clustered with Duroc pigs in the NJ tree. The results would establish the foundation for pig conservation of germplasm resource, disease resistance breeding, and multiplicative strains.

  2. AFLP-Based Analysis of Genetic Diversity, Population Structure, and Relationships with Agronomic Traits in Rice Germplasm from North Region of Iran and World Core Germplasm Set.

    Science.gov (United States)

    Sorkheh, Karim; Masaeli, Mohammad; Chaleshtori, Maryam Hosseini; Adugna, Asfaw; Ercisli, Sezai

    2016-04-01

    Analysis of the genetic diversity and population structure of crops is very important for use in breeding programs and for genetic resources conservation. We analyzed the genetic diversity and population structure of 47 rice genotypes from diverse origins using amplified fragment length polymorphism (AFLP) markers and morphological characters. The 47 genotypes, which were composed of four populations: Iranian native varieties, Iranian improved varieties, International Rice Research Institute (IRRI) rice varieties, and world rice collections, were analyzed using ten primer combinations. A total of 221 scorable bands were produced with an average of 22.1 alleles per pair of primers, of which 120 (54.30%) were polymorphic. The polymorphism information content (PIC) values varied from 0.32 to 0.41 with an average of 0.35. The high percentage of polymorphic bands (%PB) was found to be 64.71 and the resolving power (R p) collections were 63.36. UPGMA clustering based on numerical data from AFLP patterns clustered all 47 genotypes into three large groups. The genetic similarity between individuals ranged from 0.54 to 0.94 with an average of 0.74. Population genetic tree showed that Iranian native cultivars formed far distant cluster from the other populations, which may indicate that these varieties had minimal genetic change over time. Analysis of molecular variance (AMOVA) revealed that the largest proportion of the variation (84%) to be within populations showing the inbreeding nature of rice. Therefore, Iranian native varieties (landraces) may have unique genes, which can be used for future breeding programs and there is a need to conserve this unique diversity. Furthermore, crossing of Iranian genotypes with the genetically distant genotypes in the other three populations may result in useful combinations, which can be used as varieties and/or lines for future rice breeding programs.

  3. Analysis of genetic diversity and population structure of oil palm (Elaeis guineensis) from China and Malaysia based on species-specific simple sequence repeat markers.

    Science.gov (United States)

    Zhou, L X; Xiao, Y; Xia, W; Yang, Y D

    2015-12-08

    Genetic diversity and patterns of population structure of the 94 oil palm lines were investigated using species-specific simple sequence repeat (SSR) markers. We designed primers for 63 SSR loci based on their flanking sequences and conducted amplification in 94 oil palm DNA samples. The amplification result showed that a relatively high level of genetic diversity was observed between oil palm individuals according a set of 21 polymorphic microsatellite loci. The observed heterozygosity (Ho) was 0.3683 and 0.4035, with an average of 0.3859. The Ho value was a reliable determinant of the discriminatory power of the SSR primer combinations. The principal component analysis and unweighted pair-group method with arithmetic averaging cluster analysis showed the 94 oil palm lines were grouped into one cluster. These results demonstrated that the oil palm in Hainan Province of China and the germplasm introduced from Malaysia may be from the same source. The SSR protocol was effective and reliable for assessing the genetic diversity of oil palm. Knowledge of the genetic diversity and population structure will be crucial for establishing appropriate management stocks for this species.

  4. Genetic diversity in soybean genotypes with resistance to Heterodera glycines

    Directory of Open Access Journals (Sweden)

    Ana Paula Oliveira Nogueira

    2011-01-01

    Full Text Available The purpose of this study was to analyze the genetic diversity among soybean genotypes inoculated with Heteroderaglycines race 3. The experiments were conducted in a greenhouse. In two performance tests of morphological characteristics andresistance to the pathogen, 27 soybean genotypes were assessed. The coefficient of genotypic determination was estimated by themethod of analysis of variance and the genetic diversity analyzed based on dendrograms and optimization method. The estimatedcoefficients of determination indicated a predominantly genetic origin of the genotypic differences in the traits. The genetic variabilitywas maintained in the superior genotypes, which can be used in breeding programs for resistance to soybean cyst nematode

  5. Genetic diversity of 11 European pig breeds

    NARCIS (Netherlands)

    Lavall, G.; Iannuccelli, N.; Legault, C.; Milan, D.; Groenen, M.A.M.; Andersson, L.; Fredholm, M.; Geldermann, H.; Foulley, J.L.; Chevalet, C.; Ollivier, L.

    2000-01-01

    A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosi

  6. Characterization of Capsicum annuum genetic diversity and population structure based on parallel polymorphism discovery with a 30K unigene Pepper GeneChip.

    Directory of Open Access Journals (Sweden)

    Theresa A Hill

    Full Text Available The widely cultivated pepper, Capsicum spp., important as a vegetable and spice crop world-wide, is one of the most diverse crops. To enhance breeding programs, a detailed characterization of Capsicum diversity including morphological, geographical and molecular data is required. Currently, molecular data characterizing Capsicum genetic diversity is limited. The development and application of high-throughput genome-wide markers in Capsicum will facilitate more detailed molecular characterization of germplasm collections, genetic relationships, and the generation of ultra-high density maps. We have developed the Pepper GeneChip® array from Affymetrix for polymorphism detection and expression analysis in Capsicum. Probes on the array were designed from 30,815 unigenes assembled from expressed sequence tags (ESTs. Our array design provides a maximum redundancy of 13 probes per base pair position allowing integration of multiple hybridization values per position to detect single position polymorphism (SPP. Hybridization of genomic DNA from 40 diverse C. annuum lines, used in breeding and research programs, and a representative from three additional cultivated species (C. frutescens, C. chinense and C. pubescens detected 33,401 SPP markers within 13,323 unigenes. Among the C. annuum lines, 6,426 SPPs covering 3,818 unigenes were identified. An estimated three-fold reduction in diversity was detected in non-pungent compared with pungent lines, however, we were able to detect 251 highly informative markers across these C. annuum lines. In addition, an 8.7 cM region without polymorphism was detected around Pun1 in non-pungent C. annuum. An analysis of genetic relatedness and diversity using the software Structure revealed clustering of the germplasm which was confirmed with statistical support by principle components analysis (PCA and phylogenetic analysis. This research demonstrates the effectiveness of parallel high-throughput discovery and

  7. Characterization of Capsicum annuum genetic diversity and population structure based on parallel polymorphism discovery with a 30K unigene Pepper GeneChip.

    Science.gov (United States)

    Hill, Theresa A; Ashrafi, Hamid; Reyes-Chin-Wo, Sebastian; Yao, JiQiang; Stoffel, Kevin; Truco, Maria-Jose; Kozik, Alexander; Michelmore, Richard W; Van Deynze, Allen

    2013-01-01

    The widely cultivated pepper, Capsicum spp., important as a vegetable and spice crop world-wide, is one of the most diverse crops. To enhance breeding programs, a detailed characterization of Capsicum diversity including morphological, geographical and molecular data is required. Currently, molecular data characterizing Capsicum genetic diversity is limited. The development and application of high-throughput genome-wide markers in Capsicum will facilitate more detailed molecular characterization of germplasm collections, genetic relationships, and the generation of ultra-high density maps. We have developed the Pepper GeneChip® array from Affymetrix for polymorphism detection and expression analysis in Capsicum. Probes on the array were designed from 30,815 unigenes assembled from expressed sequence tags (ESTs). Our array design provides a maximum redundancy of 13 probes per base pair position allowing integration of multiple hybridization values per position to detect single position polymorphism (SPP). Hybridization of genomic DNA from 40 diverse C. annuum lines, used in breeding and research programs, and a representative from three additional cultivated species (C. frutescens, C. chinense and C. pubescens) detected 33,401 SPP markers within 13,323 unigenes. Among the C. annuum lines, 6,426 SPPs covering 3,818 unigenes were identified. An estimated three-fold reduction in diversity was detected in non-pungent compared with pungent lines, however, we were able to detect 251 highly informative markers across these C. annuum lines. In addition, an 8.7 cM region without polymorphism was detected around Pun1 in non-pungent C. annuum. An analysis of genetic relatedness and diversity using the software Structure revealed clustering of the germplasm which was confirmed with statistical support by principle components analysis (PCA) and phylogenetic analysis. This research demonstrates the effectiveness of parallel high-throughput discovery and application of genome

  8. Genetic diversity of wild Cymbidium goeringii (Orchidaceae)populations from Hubei based on Inter-simple sequence repeats analysis

    Institute of Scientific and Technical Information of China (English)

    YAO Xiaohong; GAO Li; YANG Bo

    2007-01-01

    Cymbidium goeringii is a diploid and nonrewarding,bumblebee-pollinated species,which is distributed in China,Japan and Korea Peninsula.This species is now highly endangered due to the mass collection and forest clearance in China.In the present study,we investigated the distribution of genetic variation within and between eleven populations of Cymbidium goeringii in central China by using Inter-simple sequence repeats (ISSR) markers.Eleven primers produced a total of 127 clear and reproducible bands of which 112 were polymorphic.High genetic diversity was detected in Cymbidium goeringii for both population level (P = 63.1%;He = 0.194 5) and species level (P = 88.2%;He = 0.262 8).A higher level of genetic differentiation was detected among populations (GST = 0.244 0,FST = 0.220 7)with Nei's Gsr analysis and analysis of molecular variance (AMOVA),and no correlation was found between geographical and genetic distance.Genetic drift rather than gene flow played an important role in forming the present population structure of Cymbidium goeringii.Limited gene flow among populations and gene drift increase the extinction risk of local populations.Some conservation concerns are therefore discussed together with possible strategies for implementing in situ and ex situ conservation.

  9. Genetic diversity increases insect herbivory on oak saplings.

    Directory of Open Access Journals (Sweden)

    Bastien Castagneyrol

    Full Text Available A growing body of evidence from community genetics studies suggests that ecosystem functions supported by plant species richness can also be provided by genetic diversity within plant species. This is not yet true for the diversity-resistance relationship as it is still unclear whether damage by insect herbivores responds to genetic diversity in host plant populations. We developed a manipulative field experiment based on a synthetic community approach, with 15 mixtures of one to four oak (Quercus robur half-sib families. We quantified genetic diversity at the plot level by genotyping all oak saplings and assessed overall damage caused by ectophagous and endophagous herbivores along a gradient of increasing genetic diversity. Damage due to ectophagous herbivores increased with the genetic diversity in oak sapling populations as a result of higher levels of damage in mixtures than in monocultures for all families (complementarity effect rather than because of the presence of more susceptible oak genotypes in mixtures (selection effect. Assemblages of different oak genotypes would benefit polyphagous herbivores via improved host patch location, spill over among neighbouring saplings and diet mixing. By contrast, genetic diversity was a poor predictor of the abundance of endophagous herbivores, which increased with individual sapling apparency. Plant genetic diversity may not provide sufficient functional contrast to prevent tree sapling colonization by specialist herbivores while enhancing the foraging of generalist herbivores. Long term studies are nevertheless required to test whether the effect of genetic diversity on herbivory change with the ontogeny of trees and local adaptation of specialist herbivores.

  10. Genetic diversity within and among four South European native horse breeds based on microsatellite DNA analysis: implications for conservation.

    Science.gov (United States)

    Solis, A; Jugo, B M; Mériaux, J C; Iriondo, M; Mazón, L I; Aguirre, A I; Vicario, A; Estomba, A

    2005-01-01

    In the present study, genetic analyses of diversity and differentiation were performed on four Basque-Navarrese semiferal native horse breeds. In total, 417 animals were genotyped for 12 microsatellite markers. Mean heterozygosity was higher than in other horse breeds, surely as a consequence of management. Although the population size of some of these breeds has declined appreciably in the past century, no genetic bottleneck was detected in any of the breeds, possibly because it was not narrow enough to be detectable. In the phylogenetic tree, the Jaca Navarra breed was very similar to the Pottoka, but appeared to stand in an intermediate position between this and the meat breeds. Assuming that Pottoka is the breed less affected by admixture, the others gradually distanced themselves from it through varying influences from outside breeds, among other factors. In a comparative study with other breeds, the French breeds Ardanais, Comtois, and Breton were the closest to the four native breeds. Three different approaches for evaluating the distribution of genetic diversity were applied. The high intrabreed variability of Euskal Herriko Mendiko Zaldia (EHMZ) was pointed out in these analyses. In our opinion, cultural, economic, and scientific factors should also be considered in the management of these horse breeds.

  11. Structural and genetic diversity in antibody repertoires from diverse species.

    Science.gov (United States)

    de los Rios, Miguel; Criscitiello, Michael F; Smider, Vaughn V

    2015-08-01

    The antibody repertoire is the fundamental unit that enables development of antigen specific adaptive immune responses against pathogens. Different species have developed diverse genetic and structural strategies to create their respective antibody repertoires. Here we review the shark, chicken, camel, and cow repertoires as unique examples of structural and genetic diversity. Given the enormous importance of antibodies in medicine and biological research, the novel properties of these antibody repertoires may enable discovery or engineering of antibodies from these non-human species against difficult or important epitopes.

  12. Microbial diversity--insights from population genetics.

    Science.gov (United States)

    Mes, Ted H M

    2008-01-01

    Although many environmental microbial populations are large and genetically diverse, both the level of diversity and the extent to which it is ecologically relevant remain enigmatic. Because the effective (or long-term) population size, N(e), is one of the parameters that determines population genetic diversity, tests and simulations that assume selectively neutral mutations may help to identify the processes that have shaped microbial diversity. Using ecologically important genes, tests of selective neutrality suggest that adaptive as well as non-adaptive types of selection act and that departure from neutrality may be widespread or restricted to small groups of genotypes. Population genetic simulations using population sizes between 10(3) and 10(7) suggest extremely high levels of microbial diversity in environments that sustain large populations. However, census and effective population sizes may differ considerably, and because we know nothing of the evolutionary history of environmental microbial populations, we also have no idea what N(e) of environmental populations is. On the one hand, this reflects our ignorance of the microbial world. On the other hand, the tests and simulations illustrate interactions between microbial diversity and microbial population genetics that should inform our thinking in microbial ecology. Because of the different views on microbial diversity across these disciplines, such interactions are crucial if we are to understand the role of genes in microbial communities.

  13. Pyrosequencing and genetic diversity of microeukaryotes

    DEFF Research Database (Denmark)

    Harder, Christoffer Bugge

    Free-living, heterotrophic protozoa have an important ecological role in most terrestrial ecosystems by their grazing of bacteria as one of the first links in food chains and webs. Furthermore, some of them serve as reservoirs for disease-causing bacteria and /or as occasional opportunistic...... pathogens themselves. Protozoa is a morphological group which occurs in many different eukaryotic phyla, and many apparently morphologically similar types are very different from each others genetically. This complicates the development of good primers for analysis of their diversity with modern DNA based...... methods. Compared to other microorganisms such as fungi, algae and bacteria, much less is known about protozoa. It has been an essential element of this thesis to to advance our knowledge of protozoa by developing new primers for DNA-based studies of protozoa impact on ecosystems or as indicators...

  14. Arenavirus genetic diversity and its biological implications.

    Science.gov (United States)

    Emonet, Sebastien F; de la Torre, Juan C; Domingo, Esteban; Sevilla, Noemí

    2009-07-01

    The Arenaviridae family currently comprises 22 viral species, each of them associated with a rodent species. This viral family is important both as tractable experimental model systems to study acute and persistent infections and as clinically important human pathogens. Arenaviruses are enveloped viruses with a bi-segmented negative-strand RNA genome. The interaction with the cellular receptor and subsequent entry into the host cell differs between Old World and New World arenavirus that use alpha-dystoglycan or human transferring receptor 1, respectively, as main receptors. The recent development of reverse genetic systems for several arenaviruses has facilitated progress in understanding the molecular biology and cell biology of this viral family, as well as opening new approaches for the development of novel strategies to combat human pathogenic arenaviruses. On the other hand, increased availability of genetic data has allowed more detailed studies on the phylogeny and evolution of arenaviruses. As with other riboviruses, arenaviruses exist as viral quasispecies, which allow virus adaptation to rapidly changing environments. The large number of different arenavirus host reservoirs and great genetic diversity among virus species provide the bases for the emergence of new arenaviruses potentially pathogenic for humans.

  15. Biodiversity assessment in forests - from genetic diversity to landscape diversity

    Directory of Open Access Journals (Sweden)

    Granke O

    2009-01-01

    Full Text Available Assessing biodiversity in forests requires a reliable and sustainable monitoring concept, which must include all levels of diversity, the genetic, the species and the landscape level. Diversity studies should not be reduced to quantitative analysis, but qualitative interpretations are an important part for the understanding of the results. Also, the linkage of terrestrial data and remote sensing data as well the implementation of abiotic and biotic data collected on existing monitoring systems are useful sources to analyse cause-effect relationships and interactions between the different aspects of diversity.

  16. A call for tiger management using "reserves" of genetic diversity.

    Science.gov (United States)

    Bay, Rachael A; Ramakrishnan, Uma; Hadly, Elizabeth A

    2014-01-01

    Tigers (Panthera tigris), like many large carnivores, are threatened by anthropogenic impacts, primarily habitat loss and poaching. Current conservation plans for tigers focus on population expansion, with the goal of doubling census size in the next 10 years. Previous studies have shown that because the demographic decline was recent, tiger populations still retain a large amount of genetic diversity. Although maintaining this diversity is extremely important to avoid deleterious effects of inbreeding, management plans have yet to consider predictive genetic models. We used coalescent simulations based on previously sequenced mitochondrial fragments (n = 125) from 5 of 6 extant subspecies to predict the population growth needed to maintain current genetic diversity over the next 150 years. We found that the level of gene flow between populations has a large effect on the local population growth necessary to maintain genetic diversity, without which tigers may face decreases in fitness. In the absence of gene flow, we demonstrate that maintaining genetic diversity is impossible based on known demographic parameters for the species. Thus, managing for the genetic diversity of the species should be prioritized over the riskier preservation of distinct subspecies. These predictive simulations provide unique management insights, hitherto not possible using existing analytical methods.

  17. Conservation of Genetic Diversity in Culture Plants

    Directory of Open Access Journals (Sweden)

    MAXIM A.

    2010-08-01

    Full Text Available The most important international document relating to the conservation of biodiversity is one adopted by theUN in Rio de Janeiro (1992 that "Convention on Biodiversity". Based on this agreement, the EU has taken a series ofmeasures to reduce genetic erosion in agriculture, which grew with the expansion of industrialized agriculture.Throughout its existence, mankind has used some 10,000 growing plant species. According to FAO statistics, today,90% of food production is ensured by some 120 growing plant species. In addition to drastic reduction in specificdiversity, the advent of industrialized agriculture has generated a process of strong genetic erosion. Old varieties andlocal varieties of crops have mostly been affected, in favour of "modern" varieties. Landraces are characterized by highheterogenity. They have the advantage of being much better adapted to biotic and abiotic stress conditions (diseases,pests, drought, low in nutrients, etc. and have excellent taste qualities, which can justify a higher price recovery thancommercial varieties. Thanks to these features, these crops need small inputs, which correspond to the concept ofsustainable development. Landraces are an invaluable genetic potential for obtaining new varieties of plants and are bestsuited for crop cultivation in ecological systems, becoming more common. Also, for long term food security in thecontext of global warming, rich genetic diversity will be require. “In situ” and “ex situ” conservation are the two majorstrategies used in the conservation of plant genetic resources. There is a fundamental difference between these twostrategies: “ex situ” conservation involves sampling, transfer and storage of a particular species population away fromthe original location, while “in situ” conservation (in their natural habitat implies that the varieties of interest,management and monitoring their place of origin takes place in the community to which they belong. These

  18. Investigating Genetic Diversity of Foeniculum Vulgare Mill using Molecular Markers

    Directory of Open Access Journals (Sweden)

    Omid Jadidi

    2016-06-01

    Full Text Available Medicinal plants are considered valuable genetic resources in Iran. One of these medicinal as well as spice plants is Foeniculum Vulgare Mill from Umbellifetae family used in different industries such as food, medicine, and cosmetics. It seems that due to different climate conditions in Iran this plant represents a high and valuable genetic diversity; therefore, management of genetic resources protection and obtaining information about genetic diversity will help awareness of evolution processes as well as genetic erosion of this valuable plant. Genetic diversity in local masses of Foeniculum Vulgare Mill can be investigated using molecule markers such as AFLP, RAPD, ISSR, SRAP, RFLP, and so on. In investigation of over 30 ecotype of local Foeniculum Vulgare Mill, different markers have shown that mean polymorphic content (PIC is about 36% and mean genetic diversity is estimated about 40% in different samples. Data obtained from molecule software analyses help to categorize Foeniculum Vulgare Mill genotype in different groups based on climate and geographical conditions. Principle components analysis (PCOA has also confirmed the results of cluster analysis. Dendrogram obtained by cluster analysis based on similarity coefficient of simple matching (SM and UPGMA algorithm can also categorize population of Foeniculum Vulgare Mill in different groups. Results of molecular variance analysis (AMOVA have shown that most genetic variance between geographical groups can be seen in populations. In general, according to investigations, there is a significant genetic diversity regarding agronomic and molecular traits of Foeniculum Vulgare Mill masses in Iran and knowing this genetic diversity will help in breeding programs, complementary studies, categorization, and so on.

  19. Nephronophthisis: A Genetically Diverse Ciliopathy

    Directory of Open Access Journals (Sweden)

    Roslyn J. Simms

    2011-01-01

    Full Text Available Nephronophthisis (NPHP is an autosomal recessive cystic kidney disease and a leading genetic cause of established renal failure (ERF in children and young adults. Early presenting symptoms in children with NPHP include polyuria, nocturia, or secondary enuresis, pointing to a urinary concentrating defect. Renal ultrasound typically shows normal kidney size with increased echogenicity and corticomedullary cysts. Importantly, NPHP is associated with extra renal manifestations in 10–15% of patients. The most frequent extrarenal association is retinal degeneration, leading to blindness. Increasingly, molecular genetic testing is being utilised to diagnose NPHP and avoid the need for a renal biopsy. In this paper, we discuss the latest understanding in the molecular and cellular pathogenesis of NPHP. We suggest an appropriate clinical management plan and screening programme for individuals with NPHP and their families.

  20. Bamboo: an overview on its genetic diversity and characterization.

    Science.gov (United States)

    Yeasmin, Lucina; Ali, Md Nasim; Gantait, Saikat; Chakraborty, Somsubhra

    2015-02-01

    Genetic diversity represents the heritable variation both within and among populations of organisms, and in the context of this paper, among bamboo species. Bamboo is an economically important member of the grass family Poaceae, under the subfamily Bambusoideae. India has the second largest bamboo reserve in Asia after China. It is commonly known as "poor man's timber", keeping in mind the variety of its end use from cradle to coffin. There is a wide genetic diversity of bamboo around the globe and this pool of genetic variation serves as the base for selection as well as for plant improvement. Thus, the identification, characterization and documentation of genetic diversity of bamboo are essential for this purpose. During recent years, multiple endeavors have been undertaken for characterization of bamboo species with the aid of molecular markers for sustainable utilization of genetic diversity, its conservation and future studies. Genetic diversity assessments among the identified bamboo species, carried out based on the DNA fingerprinting profiles, either independently or in combination with morphological traits by several researchers, are documented in the present review. This review will pave the way to prepare the database of prevalent bamboo species based on their molecular characterization.

  1. Genetic diversity in somatic mutants of grape (Vitis vinifera) cultivar Italia based on random amplified polymorphic DNA.

    Science.gov (United States)

    Maia, S H Z; Mangolin, C A; Collet, S A O; Machado, M F P S

    2009-01-13

    Random amplified polymorphic DNA (RAPD) markers were used to detect polymorphism and to examine relationships among four table grape clones from northwestern Paraná, in southern Brazil. The 10 primers used for RAPD fingerprints generated 126 reproducible fragments, of which 63, 68, 76, and 72 were polymorphic in cultivars Italia, Rubi, Benitaka, and Brasil, respectively. Among the primers, OPP-08 generated the highest number of fragments, whereas OPE-15 was the most efficient for discriminating polymorphic fragments. The distribution of the clones by cluster analysis indicated that there were no differences in RAPD markers between the colored mutant and the original clone (cultivar Italia), supporting the hypothesis that the non-colored and the colored mutant are the same cultivar. However, we found high levels of polymorphism within and between the cultivars Italia, Rubi, Benitaka, and Brasil (65.1%), contrary to a previous hypothesis that the four clones are genetically uniform. This confirmed our expectation of genetic variation among the clones and within each clone. We conclude that the primers are useful for analyzing the development of the genetic diversity within each of these clones.

  2. Genetic diversity of cultured and wild populations of the freshwater prawn Macrobrachium rosenbergii based on microsatellite analysis

    Science.gov (United States)

    Freshwater prawn Macrobrachium rosenbergii culture in the Western Hemisphere is primarily, if not entirely, based on thirty-six individual prawn introduced to Hawaii from Malaysia in 1965 and 1966. Little information is available regarding the genetic background or current population status of cult...

  3. Genetic diversity and association mapping in a collection of selected Chinese soybean accessions based on SSR marker analysis

    NARCIS (Netherlands)

    Li, Y.H.; Smulders, M.J.M.; Chang, R.Z.; Qiu, L.J.

    2011-01-01

    For broadening the narrow genetic base of modern soybean cultivars, 159 accessions were selected from the Chinese soybean collection which contained at least one of seven important agronomic traits: resistance to soybean cyst nematode (SCN) or soybean mosaic virus (SMV), tolerance to salt, cold, or

  4. Comparison of PCR-RFLP Based on Ribosomal Regions and SSR Markers in Genetic Diversity of Pistachio Die-Back Caused by Paecilomyces variotii

    Directory of Open Access Journals (Sweden)

    Rostami

    2015-01-01

    Full Text Available Background In recent years, die-back of pistachio has become one of the most important diseases in Kerman gardens. With regard to the importance of this disease and the lack of comprehensive information regarding the population genetic structure of the pathogen, it is necessary to set an appropriate indicator in the study of genetic diversity. Objectives In the present study, we examined simple sequence repeats (SSRs and restriction fragment length polymorphism (PCR-RFLPs (two PCR-based marker assays to determine Paecilomyces variotti genetic diversity. Materials and Methods The utility of SSRs and PCR-RFLPs was examined to determine genetic diversity using 20 isolates of Paecilomyces variotii. In order to determine the performance of indicators, effective multiplex ratio (EMR, polymorphism information content (PIC, and marker index (MI were calculated. Results Both systems discriminated 20 isolates of P. variotii successfully but were different in the amount of detectable polymorphism. Using cluster analysis of digestion reaction, SSR based on UPGMA algorithm, and Jaccard similarity coefficient, the isolates with 70% similarity level were divided into 7 and 3 groups, respectively. Reviewed indicators were at higher level for PCR-RFLPs marker. Four restriction endonucleases enzymes in RFLP produced 20 loci that 90% of them were polymorphic; and for SSR it was 32 loci that 37.5% were polymorphic. Conclusions This is the first research in comparing two genetic marker systems in P. variotti. We were prompted to explore polymorphisms utility in P. variotti with a look at using germplasm screening mapping of genome and strain improvement programs.

  5. Strategic Conservation of Orchard Germplasm Based on Indigenous Knowledge and Genetic Diversity: a Case Study of Sour Orange Populations in China

    Institute of Scientific and Technical Information of China (English)

    Feng Ming; Qi-Kun Liu; Jin-Lel Shi; Wei Wang; Bao-Rong Lu

    2009-01-01

    To effectively conserve sour orange (Citrus aurantium L.) germplasm on two Islands at the estuary of the Yangtze River In China, we estimated genetic variation and relationships of the known parental trees and their proposed descendents (young trees) using the fingerprinta of random amplified polymorphic DHA (RAPD). Results based on RAPD analyses showed considerable genetic diversity In the parental populations (H = 0.202). The overall populations including the parental and young trees showed slightly higher genetic diversity (H = 0.298) than the parents, with about 10% variation between populations. An unweighted pair group method with arithmetic mean analysis dendrogram based on cluster analysis of the Jaccard similarity among individuals demonstrated a more complicated relationship of the parental and young trees from the two islands, although the young trees showed a clear association with parental trees. This indicates a slgnificant contribution of parental trees in establishing the sour orange populations on the two islands. According to farmers' knowledge, conservation of only one or two parental trees would be sufficient because they believed that the whole populations were generated from a single mother tree. However, this study suggests that preserving most parental trees and some selected young trees with distant genetic relationships should be an effective conservation strategy for sour orange germplasm on the two islands.

  6. Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

    Science.gov (United States)

    Melito, Sara; Sias, Angela; Petretto, Giacomo L.; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

    2013-01-01

    Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil. PMID:24260149

  7. Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum.

    Directory of Open Access Journals (Sweden)

    Sara Melito

    Full Text Available BACKGROUND: Helichrysum italicum (Asteraceae is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. METHODS: H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. KEY RESULTS: The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. CONCLUSIONS: The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

  8. Phylogenetic and genetic diversity analysis in Leptospira species based on the sequence homology pattern of 16S rRNA gene

    Directory of Open Access Journals (Sweden)

    Pasupuleti Sreenivasa Rao

    2013-08-01

    Full Text Available Leptospirosis is a bacterial zoonosis, caused by pathogenic spirochete which belongs to the genus Leptospira. It exists in diverse ecological habitats and affects almost all the mammals including humans. Several online databases like NCBI etc will provide the complete genomic sequence data of various Leptospira species. However, the Phylogenetic and genetic diversity Analysis in Leptospira species based on 16S rRNA gene has not studied in detail. Therefore the present study was conducted. Sequences of various species related to genus Leptospira obtained from the NCBI database etc and aligned (CLUSTAL_X. Two Phylogenetic trees were constructed (MEGA-5 in which the first one is related to various serovars of L. interrogans and the other is related to various species of Leptospira. The Phylogenetic trees revealed the relationship and genetic diversity of various serovars of L. interrogans and the other Leptospira species, with their nearest phylogenetic relatives. In the first tree, two major clades were observed which were named as A and B, whereas in the second tree, three major clades were observed and named as A, B and C respectively. Aquifex pyrophilus strain has been used for out grouping in both the trees. The genetic distance between the species in the phylogenetic tree is presented by a bar which represents 0.5 nucleotide substitutions per alignment position in the 16S rRNA gene sequence among the various serovars of L. interrogans while 0.05 nucleotide substitutions in case of various species related to the genus Leptospira. Thus, the findings from the above study confirm that the genus Leptospira exhibits genetic diversity in the 16S rRNA gene. [Int J Res Med Sci 2013; 1(4.000: 369-377

  9. The impact of HIV-1 genetic diversity on the efficacy of a combinatorial RNAi-based gene therapy.

    Science.gov (United States)

    Herrera-Carrillo, E; Berkhout, B

    2015-06-01

    A hurdle for human immunodeficiency virus (HIV-1) therapy is the genomic diversity of circulating viruses and the possibility that drug-resistant virus variants are selected. Although RNA interference (RNAi) is a powerful tool to stably inhibit HIV-1 replication by the expression of antiviral short hairpin RNAs (shRNAs) in transduced T cells, this approach is also vulnerable to pre-existing genetic variation and the development of viral resistance through mutation. To prevent viral escape, we proposed to combine multiple shRNAs against important regions of the HIV-1 RNA genome, which should ideally be conserved in all HIV-1 subtypes. The vulnerability of RNAi therapy to viral escape has been studied for a single subtype B strain, but it is unclear whether the antiviral shRNAs can inhibit diverse virus isolates and subtypes, including drug-resistant variants that could be present in treated patients. To determine the breadth of the RNAi gene therapy approach, we studied the susceptibility of HIV-1 subtypes A-E and drug-resistant variants. In addition, we monitored the evolution of HIV-1 escape variants. We demonstrate that the combinatorial RNAi therapy is highly effective against most isolates, supporting the future testing of this gene therapy in appropriate in vivo models.

  10. Genetic diversity in Populus nigra plantations from west of Iran

    Directory of Open Access Journals (Sweden)

    Afrooz Alimohamadi

    2012-11-01

    Full Text Available In order to adopt strategies for forest conservation and development,it is necessary to estimate the amount and distribution of genetic diversity in existing populations of poplar in Iran. In this study, the genetic diversity between eight stands of Populus nigra established in Kermanshah province was evaluated on the basis of molecular and morphological markers. To amplify microsatellite loci (WPMS09, WPMS16 and WPMS18, DNA extraction from young and fresh leaveswas done. Various conditions of the PCR assay were examined and to evaluate the morphological variation of the morphological characters leaves (consist of 19 traits were measured. In addition, height growth was measured, to evaluate the growth function of the stands in homogeneous conditions. Genetic diversity in termof polymorphic loci was 0%, because three investigated microsatellite loci were monomorphic. The total number of alleles for 3 microsatellite loci was 6 (na = 2, ne = 2, heo = 1, hee = 0.51. Genetic identity based on Nei was 100%, so genetic distance was 0%. The whole sampled trees represented the same thus the genotype. No significant differences between the mean values of all morphological characters and height growth were revealed. Observed genetic similarity gave indication that same ramets had been selected to plant in poplar plantation established in Kermanshah province.These results suggest the need for an initial evaluation of the genetic diversity in selected ramets for planting in plantation to avoid repetition.

  11. [Evolutionary process unveiled by the maximum genetic diversity hypothesis].

    Science.gov (United States)

    Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi

    2013-05-01

    As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.

  12. Limited Genetic Diversity Preceded Extinction of the Tasmanian Tiger

    OpenAIRE

    Menzies, Brandon R; Renfree, Marilyn B.; Thomas Heider; Frieder Mayer; Thomas B. Hildebrandt; Pask, Andrew J

    2012-01-01

    The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived...

  13. Genetic diversity analysis of fruit characteristics of hawthorn germplasm.

    Science.gov (United States)

    Su, K; Guo, Y S; Wang, G; Zhao, Y H; Dong, W X

    2015-12-07

    One hundred and six accessions of hawthorn intraspecific resources, from the National Germplasm Repository at Shenyang, were subjected to genetic diversity and principal component analysis based on evaluation data of 15 fruit traits. Results showed that the genetic diversity of hawthorn fruit traits varied. Among the 15 traits, the fruit shape variable coefficient had the most obvious evaluation, followed by fruit surface state, dot color, taste, weight of single fruit, sepal posture, peduncle form, and metula traits. These are the primary traits by which hawthorn could be classified in the future. The principal component demonstrated that these traits are the most influential factors of hawthorn fruit characteristics.

  14. Genetic diversity of Tricholoma matsutake in Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    SHA Tao; ZHANG HanBo; DING HuaSun; LI ZongJu; CHENG LiZhong; ZHAO ZhiWei; ZHANG YaPing

    2007-01-01

    To investigate the genetic diversity of Tricholoma matsutake, we studied ITS and IGS1 sequences and PCR polymorphism of a retrotransposon in 56 fruit bodies collected from 13 counties of 9 regions in Yunnan Province. We found one and three haplotypes based on ITS and IGS1 sequences, respectively.Moreover, there was no significant difference in PCR polymorphism of the retrotransposon among different populations. Compared with Jilin Province (China) and Japanese populations, although Yunnan was highly homogenous to Japanese populations, Iow genetic diversity of T. matsutake in Yunnan did not support the view that this species originated from Yunnan.

  15. Assessment of genetic diversity and variation of Robinia pseudoacacia seeds induced by short-term spaceflight based on two molecular marker systems and morphological traits.

    Science.gov (United States)

    Yuan, C Q; Li, Y F; Sun, P; Sun, Y H; Zhang, G J; Yang, M S; Zhang, Y Y; Li, Y; Wang, L

    2012-12-17

    The black locust (Robinia pseudoacacia) is a forest legume that is highly valued as a honey plant and for its wood. We explored the effect of short-term spaceflight on development of R. pseudoacacia seedlings derived from seeds that endured a 15-day flight; the genetic diversity and variation of plants sampled from space-mutagenized seeds were compared to plants from parallel ground-based control seeds using molecular markers and morphological traits. In the morphology analysis, the space-mutagenized group had apparent variation compared with the control group in morphological traits, including plant height, basal diameter, number of branches, branch stipular thorn length, branch stipular thorn middle width, leaflet vertex angle, and tippy leaf vertex angle. Simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) molecular marker analyses showed a slightly higher levels of genetic diversity in the space-mutagenized group compared to the control group. In the SRAP analysis, the space-mutagenized group had 115 polymorphic bands vs 98 in the controls; 91.27% polymorphic loci vs 77.78% in the controls; 1.9127 ± 0.2834 alleles vs 1.7778 ± 0.4174 in the controls; Nei's genetic diversity (h) was 0.2930 ± 0.1631 vs 0.2688 ± 0.1862 in the controls, and the Shannon's information index (I) was 0.4452 ± 0.2177 vs 0.4031 ± 0.2596 in the controls. The number of alleles was significantly higher in the space-mutagenized group. In the SSR analysis, the space-mutagenized group also had more polymorphic bands (51 vs 46), a greater percentage of polymorphic loci (89.47% vs 80.70%); h was also higher (0.2534 ± 0.1533 vs 0.2240 ± 0.1743), as was I (0.3980 ± 0.2069 vs 0.3501 ± 0.2412). These results demonstrated that the range of genetic variation in the populations of R. pseudoacacia increased after spaceflight. It also suggested that the SSR and SRAP markers are effective markers for studying mutations and genetic diversity in R. pseudoacacia. The data

  16. Genetic structure and diversity of Shorea obtusa (Dipterocarpaceae) in Thailand

    Institute of Scientific and Technical Information of China (English)

    Chadaporn SENAKUN; Suchitra CHANGTRAGOON; Pairot PRAMUAL; Preecha PRATHEPHA

    2011-01-01

    Shorea obtusa is a keystone species of the dry deciduous dipterocarp forest in Thailand. In this study,the genetic structure and diversity of this species were evaluated by means of five microsatellite markers. A total of 146 trees were collected from five populations encompassing major forest regions of Thailand. High levels of genetic diversity were found among the five populations with the average He of 0.664. Genetic differentiations between populations, although significant, were low with approximately 3% of genetic variation partitioned among populations. This may indicate that the populations sampled were recently part of a continuous population. A tree constructed using the unweighted pair group method with arithmetic average, based on Nei's genetic distance, divided the populations into three groups. This separation was consistent with the altitudinal zonation of the populations,thus indicating that altitude might play a significant role in the genetic structure of S. obtusa. Areas of high genetic diversity were identified which could be considered priorities for conservation.

  17. The loss of genetic diversity during captive breeding of the endangered sculpin, Trachidermus fasciatus, based on ISSR markers: implications for its conservation

    Institute of Scientific and Technical Information of China (English)

    BI Xiaoxiao; YANG Qiaoli; GAO Tianxiang; LI Chuangju

    2011-01-01

    Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus,an endangered catadromous fish species in China.Six selected primers were used to amplify DNA samples from 85 individuals,and 353 loci were detected.Relatively low genetic diversity was detected in the cultured population (the percentage of polymorphic loci PPL=73.80%,Nei's gene diversity h=0.178 2,Shannon information index I=0.276 9).However,the genetic diversity at the species level was relatively high (PPL=91.78%; h=0.258 3,I=0.398 6).The UPGMA tree grouped together the genotypes almost according to their cultured and wild origin,showing distinct differences in genetic structure between wild and cultured populations.The pairwise Fst values confirmed significant genetic differentiation between wild and cultured samples.The cultivated population seems to be low in genetic diversity as a result of detrimental genetic effects in the captive population.The results suggest that ISSR markers are effective for rapid assessment of the degree of diversity of a population,thus giving important topical information relevant to preserving endangered species.

  18. Managing genetic diversity and society needs

    Directory of Open Access Journals (Sweden)

    Arthur da Silva Mariante

    2008-07-01

    Full Text Available Most livestock are not indigenous to Brazil. Several animal species were considered domesticated in the pre-colonial period, since the indigenous people manage them as would be typical of European livestock production. For over 500 years there have been periodic introductions resulting in the wide range of genetic diversity that for centuries supported domestic animal production in the country. Even though these naturalized breeds have acquired adaptive traits after centuries of natural selection, they have been gradually replaced by exotic breeds, to such an extent, that today they are in danger of extinction To avoid further loss of this important genetic material, in 1983 Embrapa Genetic Resources and Biotechnology decided to include conservation of animal genetic resources among its priorities. In this paper we describe the effort to genetically characterize these populations, as a tool to ensure their genetic variability. To effectively save the threatened local breeds of livestock it is important to find a niche market for each one, reinserting them in production systems. They have to be utilized in order to be conserved. And there is no doubt that due to their adaptive traits, the Brazilian local breeds of livestock can play an important role in animal production, to meet society needs.

  19. Great ape genetic diversity and population history

    DEFF Research Database (Denmark)

    Prado-Martinez, Javier; Sudmant, Peter H; Kidd, Jeffrey M

    2013-01-01

    Most great ape genetic variation remains uncharacterized; however, its study is critical for understanding population history, recombination, selection and susceptibility to disease. Here we sequence to high coverage a total of 79 wild- and captive-born individuals representing all six great ape...... species and seven subspecies and report 88.8 million single nucleotide polymorphisms. Our analysis provides support for genetically distinct populations within each species, signals of gene flow, and the split of common chimpanzees into two distinct groups: Nigeria-Cameroon/western and central....../eastern populations. We find extensive inbreeding in almost all wild populations, with eastern gorillas being the most extreme. Inferred effective population sizes have varied radically over time in different lineages and this appears to have a profound effect on the genetic diversity at, or close to, genes in almost...

  20. Gene diversity and genetic variation in lung flukes (genus Paragonimus).

    Science.gov (United States)

    Blair, David; Nawa, Yukifumi; Mitreva, Makedonka; Doanh, Pham Ngoc

    2016-01-01

    Paragonimiasis caused by lung flukes (genus Paragonimus) is a neglected disease occurring in Asia, Africa and the Americas. The genus is species-rich, ancient and widespread. Genetic diversity is likely to be considerable, but investigation of this remains confined to a few populations of a few species. In recent years, studies of genetic diversity have moved from isoenzyme analysis to molecular phylogenetic analysis based on selected DNA sequences. The former offered better resolution of questions relating to allelic diversity and gene flow, whereas the latter is more suitable for questions relating to molecular taxonomy and phylogeny. A picture is emerging of a highly diverse taxon of parasites, with the greatest diversity found in eastern and southern Asia where ongoing speciation might be indicated by the presence of several species complexes. Diversity of lung flukes in Africa and the Americas is very poorly sampled. Functional molecules that might be of value for immunodiagnosis, or as targets for medical intervention, are of great interest. Characterisation of these from Paragonimus species has been ongoing for a number of years. However, the imminent release of genomic and transcriptomic data for several species of Paragonimus will dramatically increase the rate of discovery of such molecules, and illuminate their diversity within and between species.

  1. Genetic diversity in aspen and its relation to arthropod abundance.

    Science.gov (United States)

    Zhang, Chunxia; Vornam, Barbara; Volmer, Katharina; Prinz, Kathleen; Kleemann, Frauke; Köhler, Lars; Polle, Andrea; Finkeldey, Reiner

    2014-01-01

    The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen.

  2. Genetic diversity analysis based on molecular marker and quantitative traits of the response of different tomato (Lycopersicon esculentum Mill. cultivars to drought stress

    Directory of Open Access Journals (Sweden)

    Metwali Ehab M.R.

    2016-01-01

    Full Text Available The drought tolerance of tomato (Lycopersicon esculentum Mill. is a trait needing urgent improvement due to recent climate changes and limited water availability. We therefore conducted a greenhouse screening experiment to identify tomato cultivars with improved drought tolerance. Several sensitivity and tolerance indices were computed based on morphological markers. With the aim of establishing a correlation to these markers, a total of 16 inter-simple sequence repeat (ISSR primers were used, the genetic diversity among cultivars was elucidated and clustering the cultivars into groups based on their molecular profiles was performed. The obtained results indicated that selection indices, such as geometric mean productivity (GMP, mean productivity (MP, tolerance index (TOL,and stress tolerance index (STI, represented suitable indices for screening the drought tolerance of tomato cultivars. An interesting correlation of the ISSR analyses to these morphological findings was established according to 83 detectable fragments derived from 10 primers. The highest value of the effective multiplex ratio (EMR and marker index (MI was detected for primer INC7 followed by INC1. Based on Jaccard's similarity coefficients, the genetic distance of the genotypes varied from 0.702 to 0.942 with a mean value of 0.882. The results showed a clear-cut separation of the 15 tomato cultivars due to their genetic variability, making them a valuable genetic source for their incorporation into potential breeding programs. Molecular data were in good agreement with the results as regards selection indices, and both of them will be useful tools for improvement of the tomato germplasm.

  3. Genetic diversity in a germplasm bank of Oenocarpus mapora (Arecaceae).

    Science.gov (United States)

    Moura, E F; de Oliveira, M S P

    2012-11-26

    Oenocarpus mapora is an Amazonian palm species commonly used by native populations for food and in folk medicine. We measured genetic variability, using RAPD markers, of material kept in a germplasm bank composed of accessions sampled from the Brazilian Amazon. These included 74 individuals from 23 accessions sampled from 9 localities in three States of the Brazilian Amazon. Jaccard genetic similarities were calculated based on 137 polymorphic bands, amplified by 15 primers. Dendrograms constructed based on the genetic similarities among individuals and sample localities demonstrated genetic separation of Acre State from the States of Amazonas and Pará. Two models in three hierarchical levels were considered for AMOVA: one considering the grouping of sampling sites in each state, and the other considering sampling sites in each subgroup formed by the dendrograms. The first model showed no significant genetic variation among states. On the other hand, genetic variation among subgroups was significant. In this model, the within-sample-site genetic diversity was 47.15%, which is considered to be low, since O. mapora is allogamous. By means of Bayesian analysis, the sample sites were clustered into five groups, and their distribution was similar to what we found in the dendrograms based on genetic similarity.

  4. Genetic diversity and molecular genealogy of local silkworm varieties

    Directory of Open Access Journals (Sweden)

    Zhouhe Du

    2013-03-01

    Full Text Available In order to explore the genetic diversity and systematic differentiation pattern among silkworm varieties, aiming to guide hybridization breeding, we sequenced a total of 72 Bmamy2 gene fragments from local silkworm varieties. The analysis of nucleotide sequence diversity and systematic differentiation indicated that there was rich genovariation in the sequencing region of Bmamy2 gene, and the base mutation rate is 5.6–8.2%, the haplotype diversity is 0.8294, and the nucleotide diversity is 0.0236±0.00122, suggesting Bmamy2 being a better marking gene with rich nucleotide sequence diversity, based on which the genetic diversity among different local silkworm varieties can be identified. The same heredity population structure is proclaimed by several analysis methods that every clade consisting of varieties from different geosystems and ecological types, while the varieties from the same geosystem and ecotype belong to different clades in the phylogeny. There is no population structure pattern that different varieties claded together according to geosystem or ecotype. It can be speculated that the silkworm origins from mixture of kinds of several voltinism mulberry silkworm, Bombyx mandarina, while the domestication events took place in several regions, from which the domesticated mulberry silkworms are all devoting to the domesticated silkworm population of today.

  5. Diversity evaluation based on morphological, physiological and isozyme variation in genetic resources of garlic (Allium sativum L.) collected worldwide.

    Science.gov (United States)

    Hirata, Sho; Abdelrahman, Mostafa; Yamauchi, Naoki; Shigyo, Masayoshi

    2016-11-26

    The aim of this study was to obtain primary information about the global diversity of garlic (Allium sativum L.) by evaluating morphological, physiological and isozyme variation. A total of 107 garlic accessions collected worldwide were grown in Yamaguchi, Japan. Five morphological traits (bulb weight, bulb diameter, number of cloves per bulb, number of bulbils and scape length) and one physiological trait (bolting period) of the collected garlic showed wide variation. Meanwhile, a total of 140 garlic accessions, including the 107 mentioned above, were characterized by leucine aminopeptidase (LAP) and phosphoglucoisomerase (PGI) isozyme analyses; they clearly showed polymorphisms in putative isozyme loci (Lap-1, Lap-2 and Pgi-1). Allelic frequencies were estimated in each group of accessions categorized by their geographical origin, and the observed (Ho) and expected (He) heterozygosities were calculated. The allelic frequencies differed between groups. A principal component analysis based on morpho-physiological data indicated a grouping of the garlic accessions into Central Asian and Northern Mediterranean groups as well as others. We discuss the roles of artificial and natural selection that may have caused differentiation in these traits, on the assumption that ancestral domesticated garlic populations have adapted in various regions using standing variation or mutations that accumulated during expansion, and have evolved along with human-preferred traits over a long history of cultivation.

  6. Multiple paternity does not depend on male genetic diversity

    OpenAIRE

    Thonhauser, Kerstin E.; Raveh, Shirley; Penn, Dustin J.

    2014-01-01

    Polyandry is common in many species and it has been suggested that females engage in multiple mating to increase the genetic diversity of their offspring (genetic diversity hypothesis). Multiple paternity occurs in 30% of litters in wild populations of house mice, Mus musculus musculus, and multiple-sired litters are genetically more diverse than single-sired ones. Here, we aimed to test whether female house mice produce multiple-sired litters when they have the opportunity to produce genetic...

  7. Molecular Diversity and Genetic Structure of Durum Wheat Landraces

    Directory of Open Access Journals (Sweden)

    GULNAR SHIKHSEYIDOVA

    2015-06-01

    Full Text Available To determine the genetic diversity of durum wheat, 41 accessions from Morocco, Ethiopia, Turkey, Lebanon, Kazakhstan, China, and Mongolia were analyzed through Inter-Simple Sequence Repeats (ISSR molecular markers. Out of the used twenty primers, 15 primers that included a considerable polymorphism were selected for the analyses. Among the genotypes under study, 163 fragments (73.7% were polymorph. Several indexes were used to determine the most appropriate primers. While UBC812, UBC864, UBC840, and UBC808 primers were among those markers which produced the highest number of bands and polymorphic bands, they also dedicated the highest rate of polymorphic index content (PIC. These primers also possessed the highest amounts of effective multiplex ratio (EMR and marker index (MI. Therefore, these primers can be recommended for genetic evaluation of the durum wheat. The results of cluster analysis and principle component analysis indicated that the observed genetic diversity in wheat materials under study is geographically structured. The results also indicated that the genetic diversity index based on ISSR markers was higher for Turkey, Lebanon, Morocco, and Ethiopia accessions than for other countries. The high level of polymorphism in this collections durum wheat would agree with the suggestion that Fertile Crescent and parts of Africa are first possible diversity center of this crop.

  8. Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L. Genotypes Based on Quantitative Traits

    Directory of Open Access Journals (Sweden)

    Mst. Tuhina-Khatun

    2015-01-01

    Full Text Available Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g. The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2, and number of filled grains/panicle and yields/plant (g. Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g, which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future.

  9. Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits.

    Science.gov (United States)

    Tuhina-Khatun, Mst; Hanafi, Mohamed M; Rafii Yusop, Mohd; Wong, M Y; Salleh, Faezah M; Ferdous, Jannatul

    2015-01-01

    Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO₂, and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future.

  10. Genetic diversity of arginine catabolic mobile element in Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Maria Miragaia

    Full Text Available BACKGROUND: The methicillin-resistant Staphylococcus aureus clone USA300 contains a novel mobile genetic element, arginine catabolic mobile element (ACME, that contributes to its enhanced capacity to grow and survive within the host. Although ACME appears to have been transferred into USA300 from S. epidermidis, the genetic diversity of ACME in the latter species remains poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS: To assess the prevalence and genetic diversity of ACME, 127 geographically diverse S. epidermidis isolates representing 86 different multilocus sequence types (STs were characterized. ACME was found in 51% (65/127 of S. epidermidis isolates. The vast majority (57/65 of ACME-containing isolates belonged to the predominant S. epidermidis clonal complex CC2. ACME was often found in association with different allotypes of staphylococcal chromosome cassette mec (SCCmec which also encodes the recombinase function that facilities mobilization ACME from the S. epidermidis chromosome. Restriction fragment length polymorphism, PCR scanning and DNA sequencing allowed for identification of 39 distinct ACME genetic variants that differ from one another in gene content, thereby revealing a hitherto uncharacterized genetic diversity within ACME. All but one ACME variants were represented by a single S. epidermidis isolate; the singular variant, termed ACME-I.02, was found in 27 isolates, all of which belonged to the CC2 lineage. An evolutionary model constructed based on the eBURST algorithm revealed that ACME-I.02 was acquired at least on 15 different occasions by strains belonging to the CC2 lineage. CONCLUSIONS/SIGNIFICANCE: ACME-I.02 in diverse S. epidermidis isolates were nearly identical in sequence to the prototypical ACME found in USA300 MRSA clone, providing further evidence for the interspecies transfer of ACME from S. epidermidis into USA300.

  11. The influence of recombination on human genetic diversity.

    Directory of Open Access Journals (Sweden)

    Chris C A Spencer

    2006-09-01

    Full Text Available In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution.

  12. Allozymes Genetic Diversity of Quercus mongolica Fisch in China

    Institute of Scientific and Technical Information of China (English)

    LI Wenying; GU Wanchun

    2006-01-01

    A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China.Eleven of 21 loci from 13 enzymes assayed were polymorphic.Q.mongolica maintained low level of genetic variation compared with the average Quercus species.At the species level,: the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (He) was 0.092 and the expected heterozygosity (He) was 0.099.At the population level, the estimates were A =1.421, P =28.976%, Ho= 0.088, He =0.085.Genetic differentiation (Gst was high among populations, it was 0.107.According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations.The low level of genetic diversity of Q.mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.

  13. Molecular diversity and genetic relationships in Secale

    Indian Academy of Sciences (India)

    E. SANTOS; M. MATOS; P. SILVA; A. M. FIGUEIRAS; C. BENITO; O. PINTO-CARNIDE

    2016-06-01

    The objective of this study was to quantify the molecular diversity and to determine the genetic relationships amongSecalespp. and among cultivars ofSecale cerealeusing RAPDs, ISSRs and sequence analysis of six exons ofScMATE1gene.Thirteen ryes (cultivated and wild) were genotyped using 21 RAPD and 16 ISSR primers. A total of 435 markers (242 RAPDsand 193 ISSRs) were obtained, with 293 being polymorphic (146 RAPDs and 147 ISSRs). Two RAPD and nine ISSR primersgenerated more than 80% of polymorphism. The ISSR markers were more polymorphic and informative than RAPDs. Further,69% of the ISSR primers selected achieved at least 70% of DNA polymorphism. The study of six exons of theScMATE1gene also demonstrated a high genetic variability that subsists inSecalegenus. One difference observed in exon 1 sequencesfromS. vaviloviiseems to be correlated with Al sensitivity in this species. The genetic relationships obtained using RAPDs,ISSRs and exons ofScMATE1gene were similar.S. ancestrale ,S. kuprijanoviiandS. cerealewere grouped in the same clusterandS. segetalewas in another cluster.S. vaviloviishowed evidences of not being clearly an isolate species and having greatintraspecific difference

  14. The silent threat of low genetic diversity

    Science.gov (United States)

    Hunter, Margaret E.

    2013-01-01

    Across the Caribbean, protected coastal waters have served as primary feeding and breeding grounds for the endangered Antillean manatee. Unfortunately, these same coastal waters are also a popular “habitat” for humans. In the past, the overlap between human and manatee habitat allowed for manatee hunting and threatened the survival of these gentle marine mammals. Today, however, threats are much more inadvertent and are often related to coastal development, degraded habitats and boat strikes. In the state of Florida, decades of research on the species’ biological needs have helped conservationists address threats to its survival. For example, low wake zones and boater education have protected manatees from boat strikes, and many of their critical winter refuges are now protected. The Florida population has grown steadily, thus increasing from approximately 1,200 in 1991 to more than 5,000 in 2010. It is conceivable that in Florida manatees may one day be reclassified as “threatened” rather than “endangered.” Yet, in other parts of the Caribbean, threats still loom. This includes small, isolated manatee populations found on islands that can be more susceptible to extinction and lack of genetic diversity. To ensure the species’ long-term viability, scientists have turned their sights to the overall population dynamics of manatees throughout the Caribbean. Molecular genetics has provided new insights into long-term threats the species faces. Fortunately, the emerging field of conservation genetics provides managers with tools and strategies for protecting the species’ long-term viability.

  15. A comparison of parallel pyrosequencing and sanger clone-based sequencing and its impact on the characterization of the genetic diversity of HIV-1.

    Directory of Open Access Journals (Sweden)

    Binhua Liang

    Full Text Available BACKGROUND: Pyrosequencing technology has the potential to rapidly sequence HIV-1 viral quasispecies without requiring the traditional approach of cloning. In this study, we investigated the utility of ultra-deep pyrosequencing to characterize genetic diversity of the HIV-1 gag quasispecies and assessed the possible contribution of pyrosequencing technology in studying HIV-1 biology and evolution. METHODOLOGY/PRINCIPAL FINDINGS: HIV-1 gag gene was amplified from 96 patients using nested PCR. The PCR products were cloned and sequenced using capillary based Sanger fluorescent dideoxy termination sequencing. The same PCR products were also directly sequenced using the 454 pyrosequencing technology. The two sequencing methods were evaluated for their ability to characterize quasispecies variation, and to reveal sites under host immune pressure for their putative functional significance. A total of 14,034 variations were identified by 454 pyrosequencing versus 3,632 variations by Sanger clone-based (SCB sequencing. 11,050 of these variations were detected only by pyrosequencing. These undetected variations were located in the HIV-1 Gag region which is known to contain putative cytotoxic T lymphocyte (CTL and neutralizing antibody epitopes, and sites related to virus assembly and packaging. Analysis of the positively selected sites derived by the two sequencing methods identified several differences. All of them were located within the CTL epitope regions. CONCLUSIONS/SIGNIFICANCE: Ultra-deep pyrosequencing has proven to be a powerful tool for characterization of HIV-1 genetic diversity with enhanced sensitivity, efficiency, and accuracy. It also improved reliability of downstream evolutionary and functional analysis of HIV-1 quasispecies.

  16. Morphological and genetic diversity of symbiotic cyanobacteria from cycads.

    Science.gov (United States)

    Thajuddin, Nooruddin; Muralitharan, Gangatharan; Sundaramoorthy, Mariappan; Ramamoorthy, Rengasamy; Ramachandran, Srinivasan; Akbarsha, Mohamed Abdulkadar; Gunasekaran, Muthukumaran

    2010-06-01

    The morphological and genetic diversity of cyanobacteria associated with cycads was examined using PCR amplification techniques and 16S rRNA gene sequence analysis. Eighteen symbiotic cyanobacteria were isolated from different cycad species. One of the symbiotic isolates was a species of Calothrix, a genus not previously reported to form symbioses with Cycadaceae family, and the remainder were Nostoc spp. Axenic cyanobacterial strains were compared by DNA amplification using PCR with either short arbitrary primers or primers specific for the repetitive sequences. Based on fingerprint patterns and phenograms, it was revealed that cyanobacterial symbionts exhibit important genetic diversity among host plants, both within and between cycad populations. A phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that most of the symbiotic cyanobacterial isolates fell into well-separated clades.

  17. [Analysis of genetic diversity of Russian regional populations based on common STR markers used in DNA identification].

    Science.gov (United States)

    Pesik, V Yu; Fedunin, A A; Agdzhoyan, A T; Utevska, O M; Chukhraeva, M I; Evseeva, I V; Churnosov, M I; Lependina, I N; Bogunov, Yu V; Bogunova, A A; Ignashkin, M A; Yankovsky, N K; Balanovska, E V; Orekhov, V A; Balanovsky, O P

    2014-06-01

    We conducted the first genetic analysis of a wide a range of rural Russian populations in European Russia with a panel of common DNA markers commonly used in criminalistics genetic identification. We examined a total of 647 samples from indigenous ethnic Russian populations in Arkhangelsk, Belgorod, Voronezh, Kursk, Rostov, Ryazan, and Orel regions. We employed a multiplex genotyping kit, COrDIS Plus, to genotype Short Tandem Repeat (STR) loci, which included the genetic marker panel officially recommended for DNA identification in the Russian Federation, the United States, and the European Union. In the course of our study, we created a database of allelic frequencies, examined the distribution of alleles and genotypes in seven rural Russian populations, and defined the genetic relationships between these populations. We found that, although multidimensional analysis indicated a difference between the Northern gene pool and the rest of the Russian European populations, a pairwise comparison using 19 STR markers among all populations did not reveal significant differences. This is in concordance with previous studies, which examined up to 12 STR markers of urban Russian populations. Therefore, the database of allelic frequencies created in this study can be applied for forensic examinations and DNA identification among the ethnic Russian population over European Russia. We also noted a decrease in the levels of heterozygosity in the northern Russian population compared to ethnic populations in southern and central Russia, which is consistent with trends identified previously using classical gene markers and analysis of mitochondrial DNA.

  18. Assessment of genetic diversity of Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Bacterial blight of rice, caused by Xanthomonas oryzae pv. Oryzae(Xoo. ), is one of the major rice diseases in China. Making clear the shift of genetic diversity of the pathogen will provide important information for rice breeding. Strains collected from 11 provinces located in Southern region of the Changjiang River in China were assessed by using inoculation method and IS-PCR(Insertion Sequence-Based Polymerase Chain Reaction) analysis.

  19. Diversity array technology markers: genetic diversity analyses and linkage map construction in rapeseed (Brassica napus L.).

    Science.gov (United States)

    Raman, Harsh; Raman, Rosy; Nelson, Matthew N; Aslam, M N; Rajasekaran, Ravikesavan; Wratten, Neil; Cowling, Wallace A; Kilian, A; Sharpe, Andrew G; Schondelmaier, Joerg

    2012-01-01

    We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines 'Lynx-037DH' and 'Monty-028DH'. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

  20. Assessment of genetic diversity in the Russian olive (Elaeagnus angustifolia based on ISSR genetic markers Avaliação da diversidade genética em Oliva Russa (Elaeagnus angustifolia com base em marcadores genéticos ISSR

    Directory of Open Access Journals (Sweden)

    Leila Sadat Asadiar

    2013-06-01

    Full Text Available Elaeagnus is a Eurasian tree with 77 species worldwide. In this study, ISSR markers were used to establish the level of genetic relationships and polymorphism across nine genotypes of Elaeagnus angustifolia collected from 9 different regions of West Azarbaijan province. The ISSR analysis with 11 anchored primers also generated 116 scorable loci, of which 92 were polymorphic (79.3%. The estimated Jaccard similarity coefficient ranged from 0.44 to 0.76 for the ISSR markers. Cluster analysis was carried out, based on the Unweighted Pair Group Method with Arithmetic Averages (UPGMA and the dendrogram drawn with the help of the NTSYSpc 2.02 software. The analysis revealed 5 main clusters for the ISSR data. According to our results, there is a relatively high genetic distance across E. angustifolia genotypes in the West Azarbaijan province of Iran. Furthermore, it could be inferred that ISSR markers are suitable tools for the evaluation of genetic diversity and relationships within the Elaeagnus genus.A Elaeagnus é uma árvore da Eurásia com 77 espécies em todo o mundo. Neste estudo, marcadores ISSR foram usados para estabelecer o nível de relações genéticas e polimorfismo entre nove genótipos de Elaeagnus angustifolia, coletados em 9 diferentes regiões da província do Azerbaijão Ocidental. A análise ISSR, com 11 primers ancorados, também gerou 116 loci contáveis, dos quais 92 polimórficos (79,3%. O coeficiente de similaridade de Jaccard estimado, variou de 0,44 a 0,76 para os marcadores ISSR. A análise de agrupamento foi realizada com base no Método não-ponderado de pares não-agrupados, com médias aritméticas (UPGMA, e a dendrograma elaborada com a ajuda do software NTSYSpc 2.02. A análise revelou cinco grupos principais para os dados ISSR. De acordo com nossos resultados, há uma distância genética relativamente alta entre genótipos de E. angustifolia na província de Azarbaijan Ocidental no Iran. Além disso, pode

  1. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  2. No apparent reduction in schistosome burden or genetic diversity following four years of school-based mass drug administration in mwea, central kenya, a heavy transmission area.

    Directory of Open Access Journals (Sweden)

    Agola E Lelo

    2014-10-01

    Full Text Available Schistosomiasis is a debilitating neglected tropical disease that infects over 200 million people worldwide. To combat this disease, in 2012, the World Health Organization announced a goal of reducing and eliminating transmission of schistosomes. Current control focuses primarily on mass drug administration (MDA. Therefore, we monitored transmission of Schistosoma mansoni via fecal egg counts and genetic markers in a typical school based MDA setting to ascertain the actual impacts of MDA on the targeted schistosome population.For 4 years, we followed 67 children enrolled in a MDA program in Kenya. Infection status and egg counts were measured each year prior to treatment. For 15 of these children, for which there was no evidence of acquired resistance, meaning they became re-infected following each treatment, we collected microsatellite genotype data from schistosomes passed in fecal samples as a representation of the force of transmission between drug treatments. We genotyped a total of 4938 parasites from these children, with an average of 329.2 parasites per child for the entire study, and an average of 82.3 parasites per child per annual examination. We compared prevalence, egg counts, and genetic measures including allelic richness, gene diversity (expected heterozygosity, adult worm burdens and effective number of breeders among time points to search for evidence for a change in transmission or schistosome populations during the MDA program.We found no evidence of reduced transmission or schistosome population decline over the course of the program. Although prevalence declined in the 67 children as it did in the overall program, reinfection rates were high, and for the 15 children studied in detail, schistosome egg counts and estimated adult worm burdens did not decline between years 1 and 4, and genetic diversity increased over the course of drug treatment.School based control programs undoubtedly improve the health of individuals

  3. [Research Progress on Genetic Diversity in Animal Parasitic Nematodes].

    Science.gov (United States)

    YIN, Fang-yuan; LI, Fa-cai; ZHAO, Jun-long; HU, Min

    2015-10-01

    The development of molecular genetic markers for parasitic nematodes has significant implications in fundamental and applied research in Veterinary Parasitology. Knowledge on genetic diversity of nematodes would not only provide a theoretical basis for understanding the spread of drug-resistance alleles, but also have implications in the development of nematode control strategies. This review discusses the applications of molecular genetic markers (RFLP, RAPD, PCR-SSCP, AFLP, SSR and mitochondrial DNA) in research on the genetic diversity of parasitic nematodes.

  4. Genetic diversity in the Yangtze finless porpoise by RAPD analysis

    Institute of Scientific and Technical Information of China (English)

    He Shunping; Wang Ding; Wang Wei; Chen Daoquan; Zhao Qingzhong; Gong Weiming

    2005-01-01

    To estimate the genetic diversity in the Yangtze finless porpoise (Neophocaenaphocaenoides asiaeorientalis), the randomly amplified polymorphic DNA techniquewas applied to examine ten animals captured from the Yangtze River. Out of 20 arbitrary primers used in the experiment, seventeen produced clearly reproducible bged from 0.0986 to 0.5634. Compared with other cetacean populations, this genetic distance is quite low. Such a low genetic diversity suggests that this population may be suffering from reduced genetic variation, and be very fragile. More studiesare needed for understanding the basis for this apparent low genetic diversity and to help protect this endangered, unique population.

  5. Isolation of genetically diverse Marburg viruses from Egyptian fruit bats.

    Directory of Open Access Journals (Sweden)

    Jonathan S Towner

    2009-07-01

    Full Text Available In July and September 2007, miners working in Kitaka Cave, Uganda, were diagnosed with Marburg hemorrhagic fever. The likely source of infection in the cave was Egyptian fruit bats (Rousettus aegyptiacus based on detection of Marburg virus RNA in 31/611 (5.1% bats, virus-specific antibody in bat sera, and isolation of genetically diverse virus from bat tissues. The virus isolates were collected nine months apart, demonstrating long-term virus circulation. The bat colony was estimated to be over 100,000 animals using mark and re-capture methods, predicting the presence of over 5,000 virus-infected bats. The genetically diverse virus genome sequences from bats and miners closely matched. These data indicate common Egyptian fruit bats can represent a major natural reservoir and source of Marburg virus with potential for spillover into humans.

  6. Isolation of genetically diverse Marburg viruses from Egyptian fruit bats.

    Science.gov (United States)

    Towner, Jonathan S; Amman, Brian R; Sealy, Tara K; Carroll, Serena A Reeder; Comer, James A; Kemp, Alan; Swanepoel, Robert; Paddock, Christopher D; Balinandi, Stephen; Khristova, Marina L; Formenty, Pierre B H; Albarino, Cesar G; Miller, David M; Reed, Zachary D; Kayiwa, John T; Mills, James N; Cannon, Deborah L; Greer, Patricia W; Byaruhanga, Emmanuel; Farnon, Eileen C; Atimnedi, Patrick; Okware, Samuel; Katongole-Mbidde, Edward; Downing, Robert; Tappero, Jordan W; Zaki, Sherif R; Ksiazek, Thomas G; Nichol, Stuart T; Rollin, Pierre E

    2009-07-01

    In July and September 2007, miners working in Kitaka Cave, Uganda, were diagnosed with Marburg hemorrhagic fever. The likely source of infection in the cave was Egyptian fruit bats (Rousettus aegyptiacus) based on detection of Marburg virus RNA in 31/611 (5.1%) bats, virus-specific antibody in bat sera, and isolation of genetically diverse virus from bat tissues. The virus isolates were collected nine months apart, demonstrating long-term virus circulation. The bat colony was estimated to be over 100,000 animals using mark and re-capture methods, predicting the presence of over 5,000 virus-infected bats. The genetically diverse virus genome sequences from bats and miners closely matched. These data indicate common Egyptian fruit bats can represent a major natural reservoir and source of Marburg virus with potential for spillover into humans.

  7. Genetic diversity of Cuban pineapple germplasm assessed by AFLP Markers

    Directory of Open Access Journals (Sweden)

    Ermis Yanes Paz

    2012-01-01

    Full Text Available The Cuban pineapple germplasm collection represents the genetic diversity of pineapple cultivated in that country and includes other important genotypes obtained from the germplasm collections in Brazil and Martinique. The collection has previously been characterized with morphological descriptors but a molecular characterization has been lacking. With this aim, 56 six genotypes of A. comosus and one of Bromelia pinguin were analyzed with a total of 191 AFLP markers. A dendrogram that represents the genetic relationships between these samples based on the AFLP results showed a low level of diversity in the Cuban pineapple collection. All Ananas comosus accessions, being the majority obtained from farmers in different regions in Cuba, are grouped at distances lower than 0.20. Molecular characterization was in line with morphological characterization. These results are useful for breeding and conservation purposes.

  8. Genetic diversity and population structure: implications for conservation of wild soybean (Glycine soja Sieb. et Zucc) based on nuclear and chloroplast microsatellite variation.

    Science.gov (United States)

    He, Shuilian; Wang, Yunsheng; Volis, Sergei; Li, Dezhu; Yi, Tingshuang

    2012-10-03

    Wild soybean (Glycine soja Sieb. et Zucc) is the most important germplasm resource for soybean breeding, and is currently subject to habitat loss, fragmentation and population decline. In order to develop successful conservation strategies, a total of 604 wild soybean accessions from 43 locations sampled across its range in China, Japan and Korea were analyzed using 20 nuclear (nSSRs) and five chloroplast microsatellite markers (cpSSRs) to reveal its genetic diversity and population structure. Relatively high nSSR diversity was found in wild soybean compared with other self-pollinated species, and the region of middle and lower reaches of Yangtze River (MDRY) was revealed to have the highest genetic diversity. However, cpSSRs suggested that Korea is a center of diversity. High genetic differentiation and low gene flow among populations were detected, which is consistent with the predominant self-pollination of wild soybean. Two main clusters were revealed by MCMC structure reconstruction and phylogenetic dendrogram, one formed by a group of populations from northwestern China (NWC) and north China (NC), and the other including northeastern China (NEC), Japan, Korea, MDRY, south China (SC) and southwestern China (SWC). Contrib analyses showed that southwestern China makes the greatest contribution to the total diversity and allelic richness, and is worthy of being given conservation priority.

  9. Patterns of genetic diversity in the polymorphic ground snake (Sonora semiannulata).

    Science.gov (United States)

    Cox, Christian L; Chippindale, Paul T

    2014-08-01

    We evaluated the genetic diversity of a snake species with color polymorphism to understand the evolutionary processes that drive genetic structure across a large geographic region. Specifically, we analyzed genetic structure of the highly polymorphic ground snake, Sonora semiannulata, (1) among populations, (2) among color morphs (3) at regional and local spatial scales, using an amplified fragment length polymorphism dataset and multiple population genetic analyses, including FST-based and clustering analytical techniques. Based upon these methods, we found that there was moderate to low genetic structure among populations. However, this diversity was not associated with geographic locality at either spatial scale. Similarly, we found no evidence for genetic divergence among color morphs at either spatial scale. These results suggest that despite dramatic color polymorphism, this phenotypic diversity is not a major driver of genetic diversity within or among populations of ground snakes. We suggest that there are two mechanisms that could explain existing genetic diversity in ground snakes: recent range expansion from a genetically diverse founder population and current or recent gene flow among populations. Our findings have further implications for the types of color polymorphism that may generate genetic diversity in snakes.

  10. Population genetic diversity and fitness in multiple environments

    Directory of Open Access Journals (Sweden)

    McGreevy Thomas J

    2010-07-01

    Full Text Available Abstract Background When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of populations to adapt to altered environments. However, it is not clear how much genetic diversity within populations may be lost before populations are put at significant risk. Development of tools to evaluate this relationship would be a valuable contribution to conservation biology. To address these issues, we have created an experimental system that uses laboratory populations of an estuarine crustacean, Americamysis bahia with experimentally manipulated levels of genetic diversity. We created replicate cultures with five distinct levels of genetic diversity and monitored them for 16 weeks in both permissive (ambient seawater and stressful conditions (diluted seawater. The relationship between molecular genetic diversity at presumptive neutral loci and population vulnerability was assessed by AFLP analysis. Results Populations with very low genetic diversity demonstrated reduced fitness relative to high diversity populations even under permissive conditions. Population performance decreased in the stressful environment for all levels of genetic diversity relative to performance in the permissive environment. Twenty percent of the lowest diversity populations went extinct before the end of the study in permissive conditions, whereas 73% of the low diversity lines went extinct in the stressful environment. All high genetic diversity populations persisted for the duration of the study, although population sizes and reproduction were reduced under stressful environmental conditions. Levels of fitness varied more among replicate low diversity populations than among replicate populations with high genetic diversity. There was a significant correlation

  11. Genetic Diversity of Cannabis sativa L. Based on AFLP Analysis%大麻品种遗传多样性的AFLP分析

    Institute of Scientific and Technical Information of China (English)

    胡尊红; 杨明; 郭鸿彦; 胡学礼; 陈璇; 刘旭云; 郭孟壁; 张庆滢; 许艳萍; 郭丽芬

    2012-01-01

    Genetic diversity of 13 Cannabis populations from different sources was analyzed by POPGENE 3.2 Software. AFLP analysis showed that the Yunnan population had the highest level of genetic diversity (PPB = 88.82% ,He = 0.3011,/ = 0.4571) ,and then the Heilongjiang population (PPB = 75. 66% ,He = 0. 2572, / = 0. 3897). The percentage of polymorphic loci (PPB) of 13 Cannabis populations was 92. 11% . Nei's total genetic diversity (Ht) was 0. 3837,the genetic diversity (Hs) was 0. 1640. Coefficient of genetic differentiation among populations (Gst) was 0. 5725 ,it means that 57. 25% of the total genetic variation occurred among populations, and 42.75% genetic variation in different populations. To further analyze the genetic differentiation among populations, the genetic distance and genetic identity of Cannabis were calculated according to Nei's (1978) method. The results showed that the genetic identity among populations was from 0. 6556 to 0.9258 ,the highest degree of consensus between Guangxi population and Sichuan population was 0. 9258. Genetic identity between Yunnan population and Guizhou population or Sichuan population were 0.9196 and 0.9173. Gansu and Shanxi population with lowest genetic identity in all populations was 0. 6556. The results indicated that rich genetic diversity among 13 cannabis populations. This study analyzed genetic diversity of cannabis populations in molecular level,provided scientific evidence for the protection of seeds, breeding, evolution study of industrial hemp.%利用POPGENE 3.2软件对13个不同来源的大麻群体进行遗传多样性分析.结果显示:云南地区的大麻群体具有最高的遗传多样性水平(PPB=88.82%,He=0.3000,I=0.4571),其次为黑龙江群体(PPB=75.66%,He=0.2572,I =0.3897).13个大麻群体的多态位点百分率(PPB)为92.11%,Nei's总遗传多样性(Ht)为0.3837,Shannon's信息指数I=0.5374.群体内遗传多样性(Hs)为0.1640,群体间的遗传分化系数(Gst)为0.5725,

  12. Phylogeography, genetic diversity and demographic history of the Iranian Kurdish groups based on mtDNA sequences

    Indian Academy of Sciences (India)

    FATAH ZAREI; HASSAN RAJABI-MAHAM

    2016-12-01

    Throughout the history of modern humans, the current Kurdish-inhabited area has served as part of a tricontinental crossroad for major human migrations. Also, a significant body of archaeological evidence points to this area as the site of Neolithic transition. To investigate the phylogeography, origins and demographic history, mtDNA D-loop region of individuals representing four Kurdish groups from Iran were analysed. Our data indicated that most of the Kurds mtDNA lineages belong to branches of the haplogroups with the Western Eurasian origin; with small fractions of the Eastern Eurasian and sub-Saharan African lineages. The low level of mtDNA diversity observed in the Havrami group presented a bias towards isolation or increased drift due to small population size; while in the Kurmanji group it indicated a bias towards drift or mass migration events during the 5–18th century AD. The Mantel test showed strong isolation by distance, and AMOVA results for global and regional scales confirmed that the geography had acted as the main driving force in shaping the current pattern of mtDNA diversity, rather than linguistic similarity. The results of demographic analyses, in agreement with archaeological data, revealed a recent expansion of the Kurds (∼9,500 years before present) related to the Neolithic transition from hunting and gathering, to farmingand cattle breeding in the Near East. Further, the high frequencies of typical haplogroups for early farmers (H; 37.1%) and hunter-gatherers (U; 13.8%) in the Kurds may testify the earlier hunter-gatherers in the Kurdish-inhabited area that adopted and admixed the Kurds ancestors following the Neolithic transition.

  13. Genetic structure and diversity of Oryza sativa L.in Guizhou, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongLing; CAO YongSheng; WANG XiangKun; LI ZiChao; ZHANG HongLiang; WEI XingHua; QI YongWen; WANG MeiXing; SUN JunLi; DING Li; TANG ShengXiang; QIU Zong'En

    2007-01-01

    Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic diversity and structure of 537 accessions of cultivated rice from Guizhou were studied using 36 microsatellite markers and 39 phenotypic characters. The results showed that the model-based genetic structure was the same as genetic-distance-based one using SSRs but somewhat different from the documented classification (mainly based on phenotype) of two subspecies. The accessions being classified into indica by phenotype but japonica by genetic structure were much more than that being classified into japonica by phenotype but indica by genetic structure. Like Ding Ying's taxonomic system of cultivated rice, the subspecific differentiation was the most distinct differentiation within cultivated rice. But the differentiation within indica or japonica population was different: japonica presented clearer differentiation between soil-watery ecotypes than indica, and indica presented clearer differentiation between seasonal ecotypes than japonica. Cultivated rices in Guizhou revealed high genetic diversity at both DNA and phenotypic levels. Possessing the highest genetic diversity and all the necessary conditions as a center of genetic diversity, region Southwestern of Guizhou was suggested as the center of genetic diversity of O. sativa L. from Guizhou.

  14. Analysis of Genetic Diversity Among Sweetpotato Landraces in China

    Institute of Scientific and Technical Information of China (English)

    HE Xue-qin; LIU Qing-chang; WANG Yu-ping; ZHAI Hong

    2004-01-01

    Genetic diversity of 48 sweetpotato landraces randomly sampled from Anhui,Fujian, Henan and Guangdong provinces in China was analyzed using RAPD, ISSR and AFLP markers. Thirty RAPD primers, 14 ISSR primers and 9 AFLP primer pairs generated 227, 249 and 260 polymorphic bands, respectively. AFLP markers were better than RAPD and ISSR markers in terms of the number of polymorphic bands detected and the experimental stability. These three molecular markers revealed the similar results that Chinese landraces exhibited a high level of genetic diversity, and the genetic variation of Guangdong landraces was significantly higher than those of the landraces from the other three regions. These results supported the hypothesis that China was a secondary center of sweetpotato diversity. The present results also supported the view that sweetpotato was first introduced to Guangdong and from there spread to other regions of China. The dendrogram based on the combined RAPD, ISSR and AFLP dataset could separate the 48 landraces into two groups: One mainly including 8 landraces from Guangdong and the other consisting of the remaining landraces from Guangdong and landraces from the other three regions. Thus, the utilization of Guangdong landraces should be specially considered in sweetpotato breeding.

  15. Low genetic diversity and high genetic differentiation in the critically endangered Omphalogramma souliei (Primulaceae):implications for its conservation

    Institute of Scientific and Technical Information of China (English)

    Yuan HUANG; Chang-Qin ZHANG; De-Zhu LI

    2009-01-01

    Omphalogramma souliei Franch. Is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations of O. Souliei in NW Yunnan, China. The genetic diversity at the species level is low with P= 42.5% (percentage of polymorphic bands) and Hsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: Gst=0.6038; AMOVA analysis: Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenog-amy predominated and autogamy played an assistant role in O. Souliei. The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.

  16. Genetic landscapes GIS Toolbox: tools to map patterns of genetic divergence and diversity.

    Science.gov (United States)

    Vandergast, Amy G.; Perry, William M.; Lugo, Roberto V.; Hathaway, Stacie A.

    2011-01-01

    The Landscape Genetics GIS Toolbox contains tools that run in the Geographic Information System software, ArcGIS, to map genetic landscapes and to summarize multiple genetic landscapes as average and variance surfaces. These tools can be used to visualize the distribution of genetic diversity across geographic space and to study associations between patterns of genetic diversity and geographic features or other geo-referenced environmental data sets. Together, these tools create genetic landscape surfaces directly from tables containing genetic distance or diversity data and sample location coordinates, greatly reducing the complexity of building and analyzing these raster surfaces in a Geographic Information System.

  17. Comparative evaluation of genetic diversity using RAPD, SSR and cytochrome P450 gene based markers with respect to calcium content in finger millet (Eleusine coracana L. Gaertn.)

    Indian Academy of Sciences (India)

    Preety Panwar; Manoj Nath; Vijay Kumar Yadav; Anil Kumar

    2010-08-01

    Genetic relationships among 52 Eleusine coracana (finger millet) genotypes collected from different districts of Uttarakhand were investigated by using randomly amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and cytochrome P450 gene based markers. A total of 18 RAPD primers, 10 SSR primers, and 10 pairs of cytochrome P450 gene based markers, respectively, revealed 49.4%, 50.2% and 58.7% polymorphism in 52 genotypes of E. coracana. Mean polymorphic information content (PIC) for each of these marker systems (0.351 for RAPD, 0.505 for SSR and 0.406 for cyt P450 gene based markers) suggested that all the marker systems were effective in determining polymorphisms. Pair-wise similarity index values ranged from 0.011 to 0.999 (RAPD), 0.010 to 0.999 (SSR) and 0.001 to 0.998 (cyt P450 gene based markers) and mean similarity index value of 0.505, 0.504 and 0.499, respectively. The dendrogram developed by RAPD, SSR and cytochrome P450 gene based primers analyses revealed that the genotypes are grouped in different clusters according to high calcium (300–450 mg/100 g), medium calcium (200–300 mg/100 g) and low calcium (100–200 mg/100 g). Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.95 for all the three marker systems. The dendrograms and principal coordinate analysis (PCA) plots derived from the binary data matrices of the three marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. Comparison of RAPD, SSR and cytochrome P450 gene based markers, in terms of the quality of data output, indicated that SSRs and cyt P450 gene based markers are particularly promising for the analysis of plant genome diversity. The genotypes of finger millet collected from different districts of Uttarakhand constitute a wide genetic base and clustered according to calcium contents. The identified genotypes could be used in breeding programmes and

  18. Broad-Scale Genetic Diversity of Cannabis for Forensic Applications

    Science.gov (United States)

    Dufresnes, Christophe; Jan, Catherine; Bienert, Friederike; Goudet, Jérôme; Fumagalli, Luca

    2017-01-01

    Cannabis (hemp and marijuana) is an iconic yet controversial crop. On the one hand, it represents a growing market for pharmaceutical and agricultural sectors. On the other hand, plants synthesizing the psychoactive THC produce the most widespread illicit drug in the world. Yet, the difficulty to reliably distinguish between Cannabis varieties based on morphological or biochemical criteria impedes the development of promising industrial programs and hinders the fight against narcotrafficking. Genetics offers an appropriate alternative to characterize drug vs. non-drug Cannabis. However, forensic applications require rapid and affordable genotyping of informative and reliable molecular markers for which a broad-scale reference database, representing both intra- and inter-variety variation, is available. Here we provide such a resource for Cannabis, by genotyping 13 microsatellite loci (STRs) in 1 324 samples selected specifically for fibre (24 hemp varieties) and drug (15 marijuana varieties) production. We showed that these loci are sufficient to capture most of the genome-wide diversity patterns recently revealed by NGS data. We recovered strong genetic structure between marijuana and hemp and demonstrated that anonymous samples can be confidently assigned to either plant types. Fibres appear genetically homogeneous whereas drugs show low (often clonal) diversity within varieties, but very high genetic differentiation between them, likely resulting from breeding practices. Based on an additional test dataset including samples from 41 local police seizures, we showed that the genetic signature of marijuana cultivars could be used to trace crime scene evidence. To date, our study provides the most comprehensive genetic resource for Cannabis forensics worldwide. PMID:28107530

  19. Broad-Scale Genetic Diversity of Cannabis for Forensic Applications.

    Science.gov (United States)

    Dufresnes, Christophe; Jan, Catherine; Bienert, Friederike; Goudet, Jérôme; Fumagalli, Luca

    2017-01-01

    Cannabis (hemp and marijuana) is an iconic yet controversial crop. On the one hand, it represents a growing market for pharmaceutical and agricultural sectors. On the other hand, plants synthesizing the psychoactive THC produce the most widespread illicit drug in the world. Yet, the difficulty to reliably distinguish between Cannabis varieties based on morphological or biochemical criteria impedes the development of promising industrial programs and hinders the fight against narcotrafficking. Genetics offers an appropriate alternative to characterize drug vs. non-drug Cannabis. However, forensic applications require rapid and affordable genotyping of informative and reliable molecular markers for which a broad-scale reference database, representing both intra- and inter-variety variation, is available. Here we provide such a resource for Cannabis, by genotyping 13 microsatellite loci (STRs) in 1 324 samples selected specifically for fibre (24 hemp varieties) and drug (15 marijuana varieties) production. We showed that these loci are sufficient to capture most of the genome-wide diversity patterns recently revealed by NGS data. We recovered strong genetic structure between marijuana and hemp and demonstrated that anonymous samples can be confidently assigned to either plant types. Fibres appear genetically homogeneous whereas drugs show low (often clonal) diversity within varieties, but very high genetic differentiation between them, likely resulting from breeding practices. Based on an additional test dataset including samples from 41 local police seizures, we showed that the genetic signature of marijuana cultivars could be used to trace crime scene evidence. To date, our study provides the most comprehensive genetic resource for Cannabis forensics worldwide.

  20. A genomic scale map of genetic diversity in Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Ackermann Alejandro A

    2012-12-01

    Full Text Available Abstract Background Trypanosoma cruzi, the causal agent of Chagas Disease, affects more than 16 million people in Latin America. The clinical outcome of the disease results from a complex interplay between environmental factors and the genetic background of both the human host and the parasite. However, knowledge of the genetic diversity of the parasite, is currently limited to a number of highly studied loci. The availability of a number of genomes from different evolutionary lineages of T. cruzi provides an unprecedented opportunity to look at the genetic diversity of the parasite at a genomic scale. Results Using a bioinformatic strategy, we have clustered T. cruzi sequence data available in the public domain and obtained multiple sequence alignments in which one or two alleles from the reference CL-Brener were included. These data covers 4 major evolutionary lineages (DTUs: TcI, TcII, TcIII, and the hybrid TcVI. Using these set of alignments we have identified 288,957 high quality single nucleotide polymorphisms and 1,480 indels. In a reduced re-sequencing study we were able to validate ~ 97% of high-quality SNPs identified in 47 loci. Analysis of how these changes affect encoded protein products showed a 0.77 ratio of synonymous to non-synonymous changes in the T. cruzi genome. We observed 113 changes that introduce or remove a stop codon, some causing significant functional changes, and a number of tri-allelic and tetra-allelic SNPs that could be exploited in strain typing assays. Based on an analysis of the observed nucleotide diversity we show that the T. cruzi genome contains a core set of genes that are under apparent purifying selection. Interestingly, orthologs of known druggable targets show statistically significant lower nucleotide diversity values. Conclusions This study provides the first look at the genetic diversity of T. cruzi at a genomic scale. The analysis covers an estimated ~ 60% of the genetic diversity present in the

  1. Genetic diversity of human RNase 8

    Directory of Open Access Journals (Sweden)

    Chan Calvin C

    2012-01-01

    Full Text Available Abstract Background Ribonuclease 8 is a member of the RNase A family of secretory ribonucleases; orthologs of this gene have been found only in primate genomes. RNase 8 is a divergent paralog of RNase 7, which is lysine-enriched, highly conserved, has prominent antimicrobial activity, and is expressed in both normal and diseased skin; in contrast, the physiologic function of RNase 8 remains uncertain. Here, we examine the genetic diversity of human RNase 8, a subject of significant interest given the existence of functional pseudogenes (coding sequences that are otherwise intact but with mutations in elements crucial for ribonucleolytic activity in non-human primate genomes. Results RNase 8 expression was detected in adult human lung, spleen and testis tissue by quantitative reverse-transcription PCR. Only two single-nucleotide polymorphisms and four unique alleles were identified within the RNase 8 coding sequence; nucleotide sequence diversity (π = 0.00122 ± 0.00009 per site was unremarkable for a human nuclear gene. We isolated transcripts encoding RNase 8 via rapid amplification of cDNA ends (RACE and RT-PCR which included a distal potential translational start site followed by sequence encoding an additional 30 amino acids that are conserved in the genomes of several higher primates. The distal translational start site is functional and promotes RNase 8 synthesis in transfected COS-7 cells. Conclusions These results suggest that RNase 8 may diverge considerably from typical RNase A family ribonucleases and may likewise exhibit unique function. This finding prompts a reconsideration of what we have previously termed functional pseudogenes, as RNase 8 may be responding to constraints that promote significant functional divergence from the canonical structure and enzymatic activity characteristic of the RNase A family.

  2. Genetic diversity in Brassica species and Eruca sativa for yield associated parameters

    OpenAIRE

    Kanwal Mahwish; Farhatullah; Rabbani Ashiq M.; Iqbal Sidra; Fayyaz Laila; Afzal M.

    2014-01-01

    Brassica species are vulnerable to narrow genetic base due to the ignorance of their wild relatives which possess many superior characters. This study was aimed to explore the genetic diversity in five Brassica species from U triangle as well as in their wild relative Eruca sativa. For the complete insight of genetic diversity, four accessions, each from five species of genus Brassica along with one species of Eruca collected from different geographical loc...

  3. Endemic insular and coastal Tunisian date palm genetic diversity.

    Science.gov (United States)

    Zehdi-Azouzi, Salwa; Cherif, Emira; Guenni, Karim; Abdelkrim, Ahmed Ben; Bermil, Aymen; Rhouma, Soumaya; Salah, Mohamed Ben; Santoni, Sylvain; Pintaud, Jean Christophe; Aberlenc-Bertossi, Frédérique; Hannachi, Amel Salhi

    2016-04-01

    The breeding of crop species relies on the valorisation of ancestral or wild varieties to enrich the cultivated germplasm. The Tunisian date palm genetic patrimony is being threatened by diversity loss and global climate change. We have conducted a genetic study to evaluate the potential of spontaneous coastal resources to improve the currently exploited Tunisian date palm genetic pool. Eighteen microsatellite loci of Phoenix dactylifera L. were used to compare the genetic diversity of coastal accessions from Kerkennah, Djerba, Gabès and continental date palm accessions from Tozeur. A collection of 105 date palms from the four regions was analysed. This study has provided us with an extensive understanding of the local genetic diversity and its distribution. The coastal date palm genotypes exhibit a high and specific genetic diversity. These genotypes are certainly an untapped reservoir of agronomically important genes to improve cultivated germplasm in continental date palm.

  4. Beauveria bassiana: quercetinase production and genetic diversity

    Directory of Open Access Journals (Sweden)

    Eula Maria de M. B Costa

    2011-03-01

    Full Text Available Beauveria bassiana genetic diversity and ability to synthesize quercetin 2,3-dioxygenase (quercetinase were analyzed. B. bassiana isolates, obtained from Brazilian soil samples, produced quercetinase after induction using 0.5 g/L quercetin. B. bassiana ATCC 7159 (29.6 nmol/mL/min and isolate IP 11 (27.5 nmol/ml/min showed the best performances and IP 3a (9.5 nmol/mL/min presented the lowest level of quercetinase activity in the culture supernatant. A high level of polymorphism was detected by random amplified polymorphic DNA (RAPD analysis. The use of internal-transcribed-spacer ribosomal region restriction fragment length polymorphism (ITS-RFLP did not reveal characteristic markers to differentiate isolates. However, the ITS1-5.8S-ITS2 region sequence analysis provided more information on polymorphism among the isolates, allowing them to be clustered by relative similarity into three large groups. Correlation was tested according to the Person's correlation. Data of our studies showed, that lower associations among groups, level of quercetinase production, or geographical origin could be observed. This study presents the production of a novel biocatalyst by B. bassiana and suggests the possible industrial application of this fungal species in large-scale biotechnological manufacture of quercetinase.

  5. Genetic Diversity of Pectobacterium carotovorum subsp. brasiliensis Isolated in Korea

    Directory of Open Access Journals (Sweden)

    Dong Hwan Lee

    2014-06-01

    Full Text Available The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed.

  6. Multiple paternity does not depend on male genetic diversity.

    Science.gov (United States)

    Thonhauser, Kerstin E; Raveh, Shirley; Penn, Dustin J

    2014-07-01

    Polyandry is common in many species and it has been suggested that females engage in multiple mating to increase the genetic diversity of their offspring (genetic diversity hypothesis). Multiple paternity occurs in 30% of litters in wild populations of house mice, Mus musculus musculus, and multiple-sired litters are genetically more diverse than single-sired ones. Here, we aimed to test whether female house mice produce multiple-sired litters when they have the opportunity to produce genetically diverse litters. We assessed the rates of multiple paternity when females could choose to mate with two males that were genetically dissimilar to each other (i.e. nonsiblings and MHC dissimilar) compared with when females could choose to mate with two males that were genetically similar to each other (i.e. siblings and shared MHC alleles). Multiple mating may depend upon a female's own condition, and, therefore, we also tested whether inbred (from full-sibling matings) females were more likely to produce multiple-sired progeny than outbred controls. Overall we found that 29% of litters had multiple sires, but we found no evidence that females were more likely to produce multiple-sired litters when they had the opportunity to mate with genetically dissimilar males compared with controls, regardless of whether females were inbred or outbred. Thus, our findings do not support the idea that female mice increase multiple paternity when they have the opportunity to increase the genetic diversity of their offspring, as expected from the genetic diversity hypothesis.

  7. Genetic diversity and population structure of cucumber (Cucumis sativus L.)

    Science.gov (United States)

    Understanding genetic variation in germplasm collection is essential for the conservation and their efficient use in plant breeding. Cucumber is an important vegetable crop worldwide. Previous studies revealed a low genetic diversity in cucumber, but detailed insights into the crop’s genetic structu...

  8. Hidden genetic diversity in the green alga Spirogyra (Zygnematophyceae, Streptophyta

    Directory of Open Access Journals (Sweden)

    Chen Charlotte

    2012-06-01

    Full Text Available Abstract Background The unbranched filamentous green alga Spirogyra (Streptophyta, Zygnemataceae is easily recognizable based on its vegetative morphology, which shows one to several spiral chloroplasts. This simple structure falsely points to a low genetic diversity: Spirogyra is commonly excluded from phylogenetic analyses because the genus is known as a long-branch taxon caused by a high evolutionary rate. Results We focused on this genetic diversity and sequenced 130 Spirogyra small subunit nuclear ribosomal DNA (SSU rDNA strands of different origin. The resulting SSU rDNA sequences were used for phylogenetic analyses using complex evolutionary models (posterior probability, maximum likelihood, neighbor joining, and maximum parsimony methods. The sequences were between 1672 and 1779 nucleotides long. Sequence comparisons revealed 53 individual clones, but our results still support monophyly of the genus. Our data set did not contain a single slow-evolving taxon that would have been placed on a shorter branch compared to the remaining sequences. Out of 130 accessions analyzed, 72 showed a secondary loss of the 1506 group I intron, which formed a long-branched group within the genus. The phylogenetic relationship to the genus Spirotaenia was not resolved satisfactorily. The genetic distance within the genus Spirogyra exceeded the distances measured within any other genus of the remaining Zygnemataceae included in this study. Conclusion Overall, we define eight distinct clades of Spirogyra, one of them including the genus Sirogonium. A large number of non-homoplasious synapomorphies (NHS; 114 NHS in total was found for Spirogyra (41 NHS and for each clade (totaling 73 NHS. This emphasizes the high genetic diversity of this genus and the distance to the remaining Zygnematophyceae.

  9. The genetic diversity of strawberry (Fragaria ananassa Duch. hybrids based on ISSR markers - doi: 10.4025/actasciagron.v35i4.16737

    Directory of Open Access Journals (Sweden)

    Claudinéia Ferreira Nunes

    2013-05-01

    Full Text Available The strawberry is an important agricultural crop in Brazil. However, most of the commercial genotypes currently in cultivation in Brazil were developed in other countries with environmental adaptations often inadequate for the regional conditions. In this work, inter-simple sequence repeat markers were used to determine the genetic variability and the loci segregation profiles of 84 strawberry hybrids obtained from a genetic breeding program at the ‘Empresa de Pesquisa Agropecuária de Minas Gerais.’ The hybrids were produced from crosses involving the following progenitors: ‘Toyonoka’ x ‘Sweet Charlie’, ‘Camino Real’ x ‘Sweet Charlie’, ‘Oso Grande’ x ‘Sweet Charlie’, ‘Oso Grande’ x ‘Toyonoka’, ‘Dover’ x ‘Oso Grande’, and ‘Camino Real’ x ‘Toyonoka’. Fourteen genotypes were randomly sampled for each hybrid combination and evaluated. The results showed that the genetic profiles of the hybrids from each test cross were very diverse, most likely due to the high heterozygosity of the genome of each progenitor involved, which might indicate the presence of adequate genetic diversity among the hybrids to allow for the selection of new cultivars with agronomic traits that are more suitable to environmental conditions in Brazil.

  10. Extreme genetic diversity in asexual grass thrips populations.

    Science.gov (United States)

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations.

  11. Hierarchical clustering of genetic diversity associated to different levels of mutation and recombination in Escherichia coli: a study based on Mexican isolates.

    Science.gov (United States)

    González-González, Andrea; Sánchez-Reyes, Luna L; Delgado Sapien, Gabriela; Eguiarte, Luis E; Souza, Valeria

    2013-01-01

    Escherichia coli occur as either free-living microorganisms, or within the colons of mammals and birds as pathogenic or commensal bacteria. Although the Mexican population of intestinal E. coli maintains high levels of genetic diversity, the exact mechanisms by which this occurs remain unknown. We therefore investigated the role of homologous recombination and point mutation in the genetic diversification and population structure of Mexican strains of E. coli. This was explored using a multi locus sequence typing (MLST) approach in a non-outbreak related, host-wide sample of 128 isolates. Overall, genetic diversification in this sample appears to be driven primarily by homologous recombination, and to a lesser extent, by point mutation. Since genetic diversity is hierarchically organized according to the MLST genealogy, we observed that there is not a homogeneous recombination rate, but that different rates emerge at different clustering levels such as phylogenetic group, lineage and clonal complex (CC). Moreover, we detected clear signature of substructure among the A+B1 phylogenetic group, where the majority of isolates were differentiated into four discrete lineages. Substructure pattern is revealed by the presence of several CCs associated to a particular life style and host as well as to different genetic diversification mechanisms. We propose these findings as an alternative explanation for the maintenance of the clear phylogenetic signal of this species despite the prevalence of homologous recombination. Finally, we corroborate using both phylogenetic and genetic population approaches as an effective mean to establish epidemiological surveillance tailored to the ecological specificities of each geographic region.

  12. Molecular assessment of genetic diversity in mung bean germplasm

    Indian Academy of Sciences (India)

    G. Roopa Lavanya; Jyoti Srivastava; Shirish A. Ranade

    2008-04-01

    RAPD profiles were used to identify the extent of diversity among 54 accessions of mung bean that included both improved and local land races. Out of the 40 primers screened, seven primers generated 174 amplification products with an average of 24.85 bands per primer. The RAPD profiles were analysed for Jaccard’s similarity coefficients that was found to be in the range from 0 to 0.48, indicating the presence of wide range of genetic diversity at molecular level. Cluster analysis was carried out based on distances (1-similarity coefficient) using neighbour-joining method in Free Tree package. The dendrogram resolved all the accessions into two major clusters, I (with 11 accessions) and II (with 43 accessions). However, the cluster was further divided into four subclusters (II A with six, II B with nine, II C with 15 and II D with 13 accessions). The distribution of the accessions in different clusters and subclusters appeares to be related to their performance in field conditions for 10 morphological traits that were scored. This study indicated that the RAPD profiles provide an easy and simple technique for preliminary genetic diversity assessment of mung bean accessions that may reflect morphological trait differences among them.

  13. Limited genetic diversity preceded extinction of the Tasmanian tiger.

    Science.gov (United States)

    Menzies, Brandon R; Renfree, Marilyn B; Heider, Thomas; Mayer, Frieder; Hildebrandt, Thomas B; Pask, Andrew J

    2012-01-01

    The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived specimens collected between 102 and 159 years ago. We examined a portion of the mitochondrial DNA hyper-variable control region and determined that all sequences were on average 99.5% identical at the nucleotide level. As a measure of accuracy we also sequenced mitochondrial DNA from a mother and two offspring. As expected, these samples were found to be 100% identical, validating our methods. We also used 454 sequencing to reconstruct 2.1 kilobases of the mitochondrial genome, which shared 99.91% identity with the two complete thylacine mitochondrial genomes published previously. Our thylacine genomic data also contained three highly divergent putative nuclear mitochondrial sequences, which grouped phylogenetically with the published thylacine mitochondrial homologs but contained 100-fold more polymorphisms than the conserved fragments. Together, our data suggest that the thylacine population in Tasmania had limited genetic diversity prior to its extinction, possibly as a result of their geographic isolation from mainland Australia approximately 10,000 years ago.

  14. Limited genetic diversity preceded extinction of the Tasmanian tiger.

    Directory of Open Access Journals (Sweden)

    Brandon R Menzies

    Full Text Available The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived specimens collected between 102 and 159 years ago. We examined a portion of the mitochondrial DNA hyper-variable control region and determined that all sequences were on average 99.5% identical at the nucleotide level. As a measure of accuracy we also sequenced mitochondrial DNA from a mother and two offspring. As expected, these samples were found to be 100% identical, validating our methods. We also used 454 sequencing to reconstruct 2.1 kilobases of the mitochondrial genome, which shared 99.91% identity with the two complete thylacine mitochondrial genomes published previously. Our thylacine genomic data also contained three highly divergent putative nuclear mitochondrial sequences, which grouped phylogenetically with the published thylacine mitochondrial homologs but contained 100-fold more polymorphisms than the conserved fragments. Together, our data suggest that the thylacine population in Tasmania had limited genetic diversity prior to its extinction, possibly as a result of their geographic isolation from mainland Australia approximately 10,000 years ago.

  15. Genetic diversity in cattle of eight regions in Costa Rica.

    Directory of Open Access Journals (Sweden)

    Juan Miguel Cordero-Solórzano

    2015-06-01

    Full Text Available The aim of this study was to explore the extent of inter-regional genetic diversity present in the cattle of Costa Rica. 1498 DNA samples were collected (year 2013 from eight different regions within the country. Allelic frequencies and major population genetic parameters were determined for eighteen microsatellite markers. An analysis of molecular variance was also carried out and genetic distances were calculated between cattle from different regions. At the national level, a high allelic diversity was found, with an average of 14.6±1.01 observed alleles and 5.6+0.37 effective alleles per marker. Observed (Ho and expected (He heterozygosities were 0.76±0.01 and 0.81±01, respectively. Polymorphic Information Content (PIC and Coefficient of Inbreeding (FIS were 0.79±0.06 and 0.06±0.004, respectively. At the regional level, Ho ranged between 0.73±0.02 in the South Central region to 0.78±0.01 in the North Huetar region. The dendrogram showed three clearly distinct groups, Metropolitan Central and West Central regions in one group, Caribbean Huetar, South Central, Central Pacific and Chorotega regions in a second group; and North Huetar and Brunca regions in a third intermediate group. Estimates of genetic differentiation (RST were significant between regions from different groups and non-significant for regions within the same group. Genetic differences between regions are related to differential proliferation of breed groups based on their adaptability to the agro-ecological conditions and production systems prevailing in each region.

  16. Genetic Diversity in Upland Cotton(Gossypium hirsutum L. )Cultivars Based on RAPDs and SSRs%基于RAPD和SSR标记分析的陆地棉品种遗传多样性

    Institute of Scientific and Technical Information of China (English)

    Long-fu ZHU; Xian-long ZHANG; Yi-chun NIE

    2002-01-01

    @@ Quantification and classification of diversity in germplasm collection is important for both genetic researchers and plant breeders. Some advance was made in this area in the world ( Liu et al, 2000) based on SSRs and in China(Xu et al, 2001; 2002 ) based on RAPDs. In this research, 72 cultivars including 14 latest introduced and 30 Bt-transformed ones were evaluated by RAPDs and SSRs.

  17. Genetic diversity and population structure of endangered Aquilaria malaccensis revealed potential for future conservation.

    Science.gov (United States)

    Singh, Pradeep; Nag, Akshay; Parmar, Rajni; Ghosh, Sneha; Bhau, Brijmohan Singh; Sharma, Ram Kumar

    2015-12-01

    The endangered Aquilaria malaccensis,is an important plant with high economic values. Characterization of genetic diversity and population structure is receiving tremendous attention for effective conservation of genetic resources. Considering important repositories of biological diversity, the genetic relationships of 127 A. malaccensis accessions from 10 home gardens of three states of northeast India were assessed using amplified fragment length polymorphism (AFLP). Of the 1153 fragments amplified with four AFLP primer combinations, 916 (79.4%) were found to be polymorphic. Polymorphic information content (PIC) and marker index (MI) of each primer combination correlate significantly with the number of genotypes resolved. Overall, a high genetic diversity (avg. 71.85%) was recorded. Further, high gene flow (Nm: 3.37), low genetic differentiation (FST: 0.069) and high within population genetic variation (93%) suggests that most of the genetic diversity is restricted within population. Neighbour joining (NJ), principal coordinate analysis (PCoA) and Bayesian-based STRUCTURE grouped all the accessions in two clusters with significant intermixing between populations, therefore, revealed that two genetically distinct gene pools are operating in the A. malaccensis populations cultivated in home gardens. Based on the various diversity inferences, five diverse populations (JOH, FN, HLF, DHM and ITN) were identified, which can be potentially exploited to develop conservation strategies for A. malaccensis.

  18. Genetic diversity in introduced populations with an Allee effect.

    Science.gov (United States)

    Wittmann, Meike J; Gabriel, Wilfried; Metzler, Dirk

    2014-09-01

    A phenomenon that strongly influences the demography of small introduced populations and thereby potentially their genetic diversity is the demographic Allee effect, a reduction in population growth rates at small population sizes. We take a stochastic modeling approach to investigate levels of genetic diversity in populations that successfully overcame either a strong Allee effect, in which populations smaller than a certain critical size are expected to decline, or a weak Allee effect, in which the population growth rate is reduced at small sizes but not negative. Our results indicate that compared to successful populations without an Allee effect, successful populations with a strong Allee effect tend to (1) derive from larger founder population sizes and thus have a higher initial amount of genetic variation, (2) spend fewer generations at small population sizes where genetic drift is particularly strong, and (3) spend more time around the critical population size and thus experience more genetic drift there. In the case of multiple introduction events, there is an additional increase in diversity because Allee-effect populations tend to derive from a larger number of introduction events than other populations. Altogether, a strong Allee effect can either increase or decrease genetic diversity, depending on the average founder population size. By contrast, a weak Allee effect tends to decrease genetic diversity across the entire range of founder population sizes. Finally, we show that it is possible in principle to infer critical population sizes from genetic data, although this would require information from many independently introduced populations.

  19. Genetic diversity of Histoplasma and Sporothrix complexes based on sequences of their ITS1-5.8S-ITS2 regions from the BOLD System.

    Science.gov (United States)

    Estrada-Bárcenas, Daniel Alfonso; Vite-Garín, Tania; Navarro-Barranco, Hortensia; de la Torre-Arciniega, Raúl; Pérez-Mejía, Amelia; Rodríguez-Arellanes, Gabriela; Ramirez, Jose Antonio; Humberto Sahaza, Jorge; Taylor, Maria Lucia; Toriello, Conchita

    2014-01-01

    High sensitivity and specificity of molecular biology techniques have proven usefulness for the detection, identification and typing of different pathogens. The ITS (Internal Transcribed Spacer) regions of the ribosomal DNA are highly conserved non-coding regions, and have been widely used in different studies including the determination of the genetic diversity of human fungal pathogens. This article wants to contribute to the understanding of the intra- and interspecific genetic diversity of isolates of the Histoplasma capsulatum and Sporothrix schenckii species complexes by an analysis of the available sequences of the ITS regions from different sequence databases. ITS1-5.8S-ITS2 sequences of each fungus, either deposited in GenBank, or from our research groups (registered in the Fungi Barcode of Life Database), were analyzed using the maximum likelihood (ML) method. ML analysis of the ITS sequences discriminated isolates from distant geographic origins and particular wild hosts, depending on the fungal species analyzed. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

  20. Analysis on Genetic Diversity of Echinacea purpurea Moench Based on SRAP%紫锥菊遗传多样性的S RA P分析

    Institute of Scientific and Technical Information of China (English)

    韩琳娜

    2014-01-01

    采用SRAP分子标记技术,对14份引种紫锥菊材料的遗传多样性进行分析。结果显示,9对SRAP引物组合扩增出171条带,多态性比率为80.7%,说明SRAP可应用于紫锥菊种内遗传多样性分析;聚类分析表明紫锥菊样品间的亲缘关系与种质来源地存在一定的相关性。%The sequence-related amplified polymorphism (SRAP)molecular marker was used to detect the genetic diversity among 14 introduced Echinacea purpurea from different germplasm sources.The results showed that 171 bands were obtained by 9 pairs of SRAP primers.The percentage of polymorphic bands was 80.7%.It indicated that the SRAP markers could be used for intraspecific genetic diversity analysis of Echi-nacea purpurea.Cluster analysis showed that there was certain correlation between the genetic relationship and germplasm sources.

  1. Population genetic diversity of the northern snakehead (Channa argus) in China based on the mitochondrial DNA control region and adjacent regions sequences.

    Science.gov (United States)

    Zhou, Aiguo; Zhuo, Xiaolei; Zou, Qing; Chen, Jintao; Zou, Jixing

    2015-06-01

    Genetic variation and population structure of northern snakehead (Channa argus) from eight locations in China were investigated using mitochondrial DNA control region and adjacent regions sequences. Sequence analysis showed that there were 105 haplotypes in 260 individuals, 48 unique haplotypes and 57 shared haplotypes, but no common haplotype shared by all populations. As a whole, the haplotype diversity was high (h=0.989), while the nucleotide diversity was low (π=0.00482). AMOVA analysis detected significant genetic differentiation among all eight populations (FST=0.328, p<0.01) and 66.17% of the total variance was resulted from intra-population differentiation. UPGMA analysis indicated that the eight populations could be divided into four major clusters, which was consistent with that the eight sampled locations were belonged to four isolated river systems. The neutrality and mismatch distribution tests suggested that the eight populations of C. argus in the sampling locations underwent recent population expansion. Among the eight populations, the Erhai Lake population may represent a unique genetic resource and therefore needs to be conserved.

  2. Research of Genetic Diversity in Seven Kobresia by AFLP in Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hong-mei; HU Tian-ming; WANG Quan-zhen; ZHANG Guo-yun; SONG Jiang-hu

    2009-01-01

    This work analyzed the genetic diversity of Kobresia accessions at the molecular level, and further obtained the necessary information for breeding and germplasm evaluation. Genomic DNA of Kobresia was amplified with four E+3 and M+3 primer combinations with AFLP (amplified fragment length polymorphism). AFLP analysis produced 164 scorable bands,of which 154 (93.96%) were polymorphic. The mean Nei's gene diversity index (H) was 0.2430, and the Shannon's information index (I) was 0.4012, indicating the abundant genetic diversity of Kobresia. The 11 Kobresia accessions from Tibetan Plateau, China, can be classified into five groups after cluster analysis based on the UPGMA (unweighted pair group method arithmetic average) method. In general, there was abundant genetic diversity among Kobresia accessions resources, and the genetic coefficient was unrelated to their geographic latitude. Natural habitats influenced genetic differentiation of Kobresia.

  3. 板栗品种线粒体SSR遗传多样性分析%Genetic Diversity of Castanea mollissima Variety Based on Mitochondrial SSR Markers

    Institute of Scientific and Technical Information of China (English)

    张先启; 郭献平; 刘玉芬; 张国庆; 王珊珊; 刘妍; 秦岭; 曹庆芹

    2012-01-01

    本试验通过对来自水稻和马铃薯的16对具有多态性的线粒体SSR引物进行筛选,得到2对适用于板栗的具有多态性条带的线粒体SSR引物.利用这2对多态性引物对76个板栗品种进行遗传多样性分析.结果表明2个多态性SSR位点检测到4个等位基因,平均每个位点产生2.0个等位基因.应用NTSYS2.10软件中的UPGMA方法,对数据进行聚类分析,获得板栗资源线粒体SSR聚类图.结果表明:在相似系数0.15处可以将板栗种质资源按亲缘关系分成3组.%The genetic diversity of 76 Castanea mollissima accesions was analyzed by mitochondrial SSR. Two polymorphic mtSSR primers were obtained by testing universal 16 primers from rice and potato. Two polymorphic mtSSR primers generated 4 alleles with an average of 2. 0 alleles per primer among 76 C. mollissima accessions. Unweighted pair-group arithematic averages method (UPGMA) was applied to construct a cluster tree of C. mollissima resources based on mitochondrial SSR data by NTSYS2.10 software was. The results showed that 76 C. mollissima cultivars were classified into three groups at the level of similarity 0.15.

  4. Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

    Science.gov (United States)

    Garrido-Sanz, Daniel; Meier-Kolthoff, Jan P; Göker, Markus; Martín, Marta; Rivilla, Rafael; Redondo-Nieto, Miguel

    2016-01-01

    The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR) with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH) identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI) approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as PGPR.

  5. Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

    Directory of Open Access Journals (Sweden)

    Daniel Garrido-Sanz

    Full Text Available The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as

  6. Comparison of genetic diversity structure analyses of SSR molecular marker data within apple (Malus×domestica) genetic resources.

    Science.gov (United States)

    Patzak, Josef; Paprštein, František; Henychová, Alena; Sedlák, Jiří

    2012-09-01

    The aim of this study was to compare traditional hierarchical clustering techniques and principal coordinate analysis (PCoA) with the model-based Bayesian cluster analyses in relation to subpopulation differentiation based on breeding history and geographical origin of apple (Malus×domestica Borkh.) cultivars and landraces. We presented the use of a set of 10 microsatellite (SSR) loci for genetic diversity structure analyses of 273 apple accessions from national genetic resources. These SSR loci yielded a total of 113 polymorphic SSR alleles, with 5-18 alleles per locus. SSR molecular data were successfully used in binary and allelic input format for all genetic diversity analyses, but allelic molecular data did not reveal reliable results with the NTSYS-pc and BAPS softwares. A traditional cluster analysis still provided an easy and effective way for determining genetic diversity structure in the apple germplasm collection. A model-based Bayesian analysis also provided the clustering results in accordance to traditional cluster analysis, but the analyses were distorted by the presence of a dominant group of apple genetic resources owing to the narrow origin of the apple genome. PCoA confirmed that there were no noticeable differences in genetic diversity structure of apple genetic resources during the breeding history. The results of our analyses are useful in the context of enhancing apple collection management, sampling of core collections, and improving breeding processes.

  7. The characterization of goat genetic diversity : Towards a genomic approach

    NARCIS (Netherlands)

    Ajmone-Marsan, P.; Colli, L.; Han, J. L.; Achilli, A.; Lancioni, H.; Joost, S.; Crepaldi, P.; Pilla, F.; Stella, A.; Taberlet, P.; Boettcher, P.; Negrini, R.; Lenstra, J. A.

    2014-01-01

    The investigation of genetic diversity at molecular level has been proposed as a valuable complement and sometimes proxy to phenotypic diversity of local breeds and is presently considered as one of the FAO priorities for breed characterization. By recommending a set of selected molecular markers fo

  8. Assessment of genetic diversity within sour cherry clones

    DEFF Research Database (Denmark)

    Clausen, S. K.; Andersen, S. B.; Henriksen, K.;

    2013-01-01

    of improved breeding material. However, no differences in allele profile were found between or within the clones, calling into question the extent of the available genetic diversity and indicating that the observed variance in yield may have to be explained by other genetic mechanisms, including epigenetic...

  9. Genetic diversity of Toxoplama gondii isolates from Ethiopian feral cats

    Science.gov (United States)

    Recent studies indicate greater genetic variability among isolates of Toxoplasma gondii worldwide than previously thought. However, there is no information on genetic diversity of T. gondii from any host in Ethiopia. In the present study, genotyping was performed on viable T. gondii isolates by bioa...

  10. Genetic diversity revealed by AFLP markers in Albanian goat breeds

    Directory of Open Access Journals (Sweden)

    Hoda Anila

    2012-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP technique with three EcoRI/TaqI primer combinations was used in 185 unrelated individuals, representative of 6 local goat breeds of Albania, and 107 markers were generated. The mean Nei’s expected heterozygosity value for the whole population was 0.199 and the mean Shannon index was 0.249, indicating a high level of within-breed diversity. Wright’s FST index, Nei’s unbiased genetic distance and Reynolds’ genetic distance were calculated. Pairwise Fst values among the populations ranged from 0.019 to 0.047. A highly significant average FST of 0.031 was estimated, showing a low level of breed subdivision. Most of the variation is accounted for by differences among individuals. Cluster analysis based on Reynolds’ genetic distance between breeds and PCA were performed. An individual UPGMA tree based on Jaccard’s similarity index showed clusters with individuals from all goat breeds. Analysis of population structure points to a high level of admixture among breeds.

  11. Genetic diversity in farm animals - A review

    NARCIS (Netherlands)

    Groeneveld, L. F.; Lenstra, J. A.; Eding, H.; Toro, M. A.; Scherf, B.; Pilling, D.; Negrini, R.; Finlay, E. K.; Jianlin, H.; Groeneveld, E.; Weigend, S.

    2010-01-01

    Domestication of livestock species and a long history of migrations, selection and adaptation have created an enormous variety of breeds. Conservation of these genetic resources relies on demographic characterization, recording of production environments and effective data management. In addition, m

  12. Genetic diversity in Chinese modern wheat varieties revealed by microsatellite markers

    Institute of Scientific and Technical Information of China (English)

    HAO; Chenyang; WANG; Lanfen; ZHANG; Xueyong; YOU; Guangxia; DONG; Yushen; JIA; Jizeng; LIU; Xu; SHANG; Xunwu; LIU; Sancai; CAO; Yongsheng

    2006-01-01

    Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers.

  13. Genetic diversity and phylogeography of highly zoonotic Echinococcus granulosus genotype G1 in the Americas (Argentina, Brazil, Chile and Mexico) based on 8279bp of mtDNA.

    Science.gov (United States)

    Laurimäe, Teivi; Kinkar, Liina; Andresiuk, Vanessa; Haag, Karen Luisa; Ponce-Gordo, Francisco; Acosta-Jamett, Gerardo; Garate, Teresa; Gonzàlez, Luis Miguel; Saarma, Urmas

    2016-11-01

    Echinococcus granulosus is a taeniid cestode and the etiological agent of an infectious zoonotic disease known as cystic echinococcosis (CE) or hydatid disease. CE is a serious public health concern in many parts of the world, including the Americas, where it is highly endemic in many regions. Echinococcus granulosus displays high intraspecific genetic variability and is divided into multiple genotypes (G1-G8, G10) with differences in their biology and etiology. Of these, genotype G1 is responsible for the majority of human and livestock infections and has the broadest host spectrum. However, despite the high significance to the public and livestock health, the data on genetic variability and regional genetic differences of genotype G1 in America are scarce. The aim of this study was to evaluate the genetic variability and phylogeography of G1 in several countries in America by sequencing a large portion of the mitochondrial genome. We analysed 8279bp of mtDNA for 52 E. granulosus G1 samples from sheep, cattle and pigs collected in Argentina, Brazil, Chile and Mexico, covering majority of countries in the Americas where G1 has been reported. The phylogenetic network revealed 29 haplotypes and a high haplotype diversity (Hd=0.903). The absence of phylogeographic segregation between different regions in America suggests the importance of animal transportation in shaping the genetic structure of E. granulosus G1. In addition, our study revealed many highly divergent haplotypes, indicating a long and complex evolutionary history of E. granulosus G1 in the Americas.

  14. Assessment of genetic diversity on a sample of cocoa accessions resistant to witches' broom disease based on RAPD and pedigree data Avaliação da diversidade genética em uma amostra de acessos de cacau resistentes à doença vassoura-de-bruxa, com base em dados de RAPD e pedigree

    OpenAIRE

    Ronaldo Carvalho dos Santos; José Luís Pires; Uilson Vanderley Lopes; Karina Peres G. Gramacho; Acassi Batista Flores; Rita de Cássia S. Bahia; Helaine C. Cristine Ramos; Ronan Xavier Corrêa; Dario Ahnert

    2005-01-01

    Genetic diversity in cocoa (Theobroma cacao L.) has been assessed based on morphological and molecular markers for germplasm management and breeding purposes. Pedigree data is available in cocoa but it has not been used for assessing genetic relatedness. The geneitic diversity of 30 clonal cocoa accessions resistant to witche´ broom disease, from the CEPEC series, were studied on the basis of RAPD data and pedigree information. Twenty of these accessions descend from the TSA-644 clone, ...

  15. Genetic diversity analysis of spawner and recaptured populations of Chinese shrimp (Fenneropenaeus chinensis) during stock enhancement in the Bohai Bay based on an SSR marker

    Institute of Scientific and Technical Information of China (English)

    WANG Mosang; WANG Weiji; XIAO Guangxia; LIU Kefeng; HU Yulong; TIAN Tao; KONG Jie; JIN Xianshi

    2016-01-01

    Eight microsatellite markers were used to analyze genetic diversity, level of inbreeding, and effective population size of spawner and recaptured populations of Chinese shrimp (Fenneropenaeus chinensis) during stock enhancement in the Bohai Bay in 2013. A total of 254 and 238 alleles were identified in the spawner and recaptured populations, respectively, and the numbers of alleles (Na) were 8–63 and 6–60, respectively. The numbers of effective alleles (Ne) were 2.52–21.60 and 2.67–20.72, respectively. The polymorphism information content ranged from 0.529 to 0.952. The observed heterozygosity (Ho) values (0.638–0.910 and 0.712–0.927) were lower than the expected heterozygosity (He) values (0.603–0.954 and 0.625–0.952), which indicated that the two populations possessed a rich genetic diversity. In 16 tests (2 populations×8 loci), 13 tests deviated from the Hardy-Weinberg equilibrium.Fis values were positive at seven loci and the inbreeding coefficients (F) of the two populations estimated by trioML were 13.234% and 11.603%, suggesting that there was a relatively high degree of inbreeding. A certain level of inbreeding depression had occurred in the Chinese shrimp population.Fst values ranged from 0 to 0.059, with a mean of 0.028, displaying a low level of genetic differentiation in the two populations. Effective population sizes (3 060.2 and 3 842.8) were higher than the minimum number suggested for retaining the evolutionary potential to adapt to new environmental conditions. For enhancement activity in 2014, the ideal number of captured shrimp spawners should have ranged from 7 686 to 19 214 to maintain genetic diversity and effective population size. Further strategies to adjust the balance of economic cost, fishing effort and ideal number of shrimp spawners to maintain a satisfactory effective population size for ensuring the sustainability of Chinese shrimp are proposed.

  16. Hitchhiker's guide to genetic diversity in socially structured populations

    Institute of Scientific and Technical Information of China (English)

    L.S.PREMO

    2012-01-01

    When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking.A model built to investigate reduced genetic diversity in Pleistocene hominins shows that genetic hitchhiking can have a strong effect on neutral diversity in the presence of culturally mediated migration.Under conditions in which genetic and cultural variants are transmitted symmetrically,neutral genes may also hitchhike to higher frequencies on the coattails of adaptive cultural traits through a process called cultural hitchhiking.Cultural hitchhiking has been proposed to explain why some species of matrilineal whales display relatively low levels of mitochondrial DNA diversity,and it may be applicable to humans as well.This paper provides a critical review of recent models of both types of hitchhiking in socially structured populations.The models' assumptions and predictions are compared and discussed in the hope that studies of reduced genetic diversity in humans might improve our understanding of reduced genetic diversity in other species,and vice versa [Current Zoology 58 (1):287-297,2012].

  17. Genetic diversity and population structure of a diverse set of rice germplasm for association mapping.

    Science.gov (United States)

    Jin, Liang; Lu, Yan; Xiao, Peng; Sun, Mei; Corke, Harold; Bao, Jinsong

    2010-08-01

    Germplasm diversity is the mainstay for crop improvement and genetic dissection of complex traits. Understanding genetic diversity, population structure, and the level and distribution of linkage disequilibrium (LD) in target populations is of great importance and a prerequisite for association mapping. In this study, 100 genome-wide simple sequence repeat (SSR) markers were used to assess genetic diversity, population structure, and LD of 416 rice accessions including landraces, cultivars and breeding lines collected mostly in China. A model-based population structure analysis divided the rice materials into seven subpopulations. 63% of the SSR pairs in these accessions were in LD, which was mostly due to an overall population structure, since the number of locus pairs in LD was reduced sharply within each subpopulation, with the SSR pairs in LD ranging from 5.9 to 22.9%. Among those SSR pairs showing significant LD, the intrachromosomal LD had an average of 25-50 cM in different subpopulations. Analysis of the phenotypic diversity of 25 traits showed that the population structure accounted for an average of 22.4% of phenotypic variation. An example association mapping for starch quality traits using both the candidate gene mapping and genome-wide mapping strategies based on the estimated population structure was conducted. Candidate gene mapping confirmed that the Wx and starch synthase IIa (SSIIa) genes could be identified as strongly associated with apparent amylose content (AAC) and pasting temperature (PT), respectively. More importantly, we revealed that the Wx gene was also strongly associated with PT. In addition to the major genes, we found five and seven SSRs were associated with AAC and PT, respectively, some of which have not been detected in previous linkage mapping studies. The results suggested that the population may be useful for the genome-wide marker-trait association mapping. This new association population has the potential to identify

  18. Genetic diversity of rhizobia nodulating native Vicia spp. in Sweden.

    Science.gov (United States)

    Ampomah, Osei Yaw; Huss-Danell, Kerstin

    2016-05-01

    Despite the recognition that Rhizobium leguminosarum sv. viciae is the most common symbiont of Vicia species worldwide, there is no available information on rhizobia nodulating native Vicia species in Sweden. We have therefore studied the genetic diversity and phylogeny of root nodule bacteria isolated from V. cracca, V. hirsuta, V. sepium, V. tetrasperma and V. sylvatica growing in different locations in Sweden as well as an isolate each from V. cracca in Tromsø, Norway, and V. multicaulis in Siberia, Russia. Out of 25 isolates sampled from the six Vicia species in 12 different locations, there were 14 different genotypes based on the atpD, recA and nodA gene phylogenies. All isolates were classified into Rhizobium leguminosarum sv. viciae group based on the concatenated atpD and recA phylogeny and the nodA phylogeny.

  19. Genetic diversity and elite gene introgression reveal the japonica rice breeding in northern China

    Institute of Scientific and Technical Information of China (English)

    LIU Dan; WANG Jia-yu; WANG Xiao-xue; YANG Xian-li; SUN Jian; CHEN Wen-fu

    2015-01-01

    Abundant genetic diversity and rational population structure of germplasm beneift crop breeding greatly. To investigate genetic variation among geographical y diverse set of japonica germplasm, we analyzed 233 japonica rice cultivars col-lected from Liaoning, Jilin and Heilongjiang provinces of China, which were released from 1970 to 2011 by using 62 simple sequence repeat (SSR) markers and 8 functional gene tags related to yield. A total of 195 al eles (Na) were detected with an average of 3.61 per locus, indicating a low level of genetic diversity level among al individuals. The genetic diversity of the cultivars from Jilin Province was the highest among the three geographic distribution zones. Moreover, the genetic diversity was increased slightly with the released period of cultivars from 1970 to 2011. The analysis of molecular variance (AMOVA) revealed that genetic differentiation was more diverse within the populations than that among the populations. The neighbor-joining (NJ) tree indicated that cultivar clusters based on geographic distribution represented three independent groups, among which the cluster of cultivars from Heilongjiang is distinctly different to the cluster of cultivars from Liaoning. For the examined functional genes, two or three al elic variations for each were detected, except for IPA1 and GW2, and most of elite genes had been introgressed in modern japonica rice varieties. These results provide a valuable evaluation for genetic backgrounds of current japonica rice and wil be used directly for japonica rice breeding in future.

  20. Tetraploid wheat landraces in the Mediterranean basin: taxonomy, evolution and genetic diversity.

    Directory of Open Access Journals (Sweden)

    Hugo R Oliveira

    Full Text Available The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population structure in tetraploid wheats (wild emmer, emmer, rivet and durum using nuclear and chloroplast simple sequence repeats, functional variations and insertion site-based polymorphisms. Emmer and wild emmer constitute a genetically distinct population from durum and rivet, the latter seeming to share a common gene pool. Our population structure and genetic diversity data suggest a dynamic history of introduction and extinction of genotypes in the Mediterranean fields.

  1. Genetic Diversity among Ancient Nordic Populations

    DEFF Research Database (Denmark)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R;

    2010-01-01

    , the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two...

  2. Ensuring the genetic diversity of potatoes

    Science.gov (United States)

    Opportunities for advances in the potato crop through genetics are great, since potato has many needs for improvement, and many related species with the traits required are available. Genebanks provide a centralized and specialized resource for providing the services of acquisition, classification, ...

  3. 基于 SSR 分子标记的芥蓝遗传多样性分析%Genetic Diversity of Chinese Kale Based on SSR Markers

    Institute of Scientific and Technical Information of China (English)

    张德双; 卢桂香; 张娜; 于拴仓; 张凤兰; 隋光磊; 余阳俊; 赵岫云; 汪维红; 苏同兵

    2014-01-01

    Classification and genetic diversity of local varieties in Chinese kale were studied before .With the extending of Chinese kale hybrids ,they can show higher heterosis and better benefit .Therefore study on genetic di-versity of inbred lines is important now .In this research ,98 Chinese kale inbred lines were analyzed by 15 polymor-phic SSR markers which were selected from 55 pairs of primers locating on 9 chromosomes of cabbage .65 polymor-phic bands were detected by these 15 pairs of primers .UPGMA method was used to determine genetic diversities of 98 Chinese kale inbred lines .They were initially clustered intoⅠ,Ⅱ,Ⅲ,Ⅳ,Ⅴ groups with coefficient 0.71.Re-sults can be used to breed Chinese kale including selection and match of parents ,identification of hybrids and pro-tection of resources .%芥蓝的研究多集中在分类、常规种资源遗传多样性等方面。随着芥蓝杂交种的问世,杂交种的优势越来越突出,市场效果明显,因此,对芥蓝自交系的遗传多样性等研究尤为重要。选取分布在甘蓝9条染色体上的55对SSR引物,从中筛选出多态性好、分布均匀的15条SSR引物对98份芥蓝自交系进行分析,共得到65个多态性带型。采用UPGMA方法构建了一张聚类图,在相似系数为0.71时,将98份芥蓝自交系初步分为1,2,3,4,5组。研究结果为芥蓝育种中的亲本选配、杂交种鉴定和资源保护等提供了依据。在试配芥蓝新组合时,应选择遗传距离较远的自交系作为重点材料,后代的杂种优势会更显著。

  4. High Genetic Diversity in a Rare, Narrowly Endemic Primrose Species: Primula interjacens by ISSR Analysis

    Institute of Scientific and Technical Information of China (English)

    XUEDa-Wei; GEXue-Jun; HAOGang; ZHANGChang-Qin

    2004-01-01

    Prirnula interjacens Chen (Primulaceae) is a rare and narrow endemic species of centralsouth of Yunnan Province in China. This species consists of two varieties: P.interjacens var. interjacens known with only one population, and P.interjacens var. epilosa with two populations. Intersimple sequence repeat (ISSR) marker was used to detect the genetic diversity of the three extant populations. We expected a low genetic diversity level, but our results revealed a high level of intraspecific genetic diversity (at population level: P=59.75%, HE=0.2368, and Hpop=0.3459; at species level: P=75.47%, HT= 0.320 5, and Hsp = 0.4618), probably resulting from floral heteromorphism and preferring outcrossing. A moderate level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (26.13%) and Shannon's diversity index (25.09%). Although P./ntedacens var. intedacens and P. interjacens var. epilosa were morphologically distinct, UPGMA cluster analysis showed that the two varieties had no distinct genetic differentiation and may be treated as a single taxon. Conservation measures are suggested, including in situ and ex situ strategies, based on the observed population genetic information.

  5. Genetic diversity and structure of Brazilian ginger germplasm (Zingiber officinale) revealed by AFLP markers.

    Science.gov (United States)

    Blanco, Eleonora Zambrano; Bajay, Miklos Maximiliano; Siqueira, Marcos Vinícius Bohrer Monteiro; Zucchi, Maria Imaculada; Pinheiro, José Baldin

    2016-12-01

    Ginger is a vegetable with medicinal and culinary properties widely cultivated in the Southern and Southeastern Brazil. The knowledge of ginger species' genetic variability is essential to direct correctly future studies of conservation and genetic improvement, but in Brazil, little is known about this species' genetic variability. In this study, we analyzed the genetic diversity and structure of 55 Brazilian accessions and 6 Colombian accessions of ginger, using AFLP (Amplified Fragment Length Polymorphism) molecular markers. The molecular characterization was based on 13 primers combinations, which generated an average of 113.5 polymorphic loci. The genetic diversity estimates of Nei (Hj), Shannon-Weiner index (I) and an effective number of alleles (n e ) were greater in the Colombian accessions in relation to the Brazilian accessions. The analysis of molecular variance showed that most of the genetic variation occurred between the two countries while in the Brazilian populations there is no genetic structure and probably each region harbors 100 % of genetic variation found in the samples. The bayesian model-based clustering and the dendrogram using the dissimilarity's coefficient of Jaccard were congruent with each other and showed that the Brazilian accessions are highly similar between themselves, regardless of the geographic region of origin. We suggested that the exploration of the interspecific variability and the introduction of new varieties of Z.officinale are viable alternatives for generating diversity in breeding programs in Brazil. The introduction of new genetic materials will certainly contribute to a higher genetic basis of such crop.

  6. Genetic diversity among ancient Nordic populations.

    Science.gov (United States)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R; Kivisild, Toomas; Dissing, Jørgen

    2010-01-01

    Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13%) than among extant Danes and Scandinavians (approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  7. Analysis of genetic diversity and population structure in a tomato (Solanum lycopersicum L.) germplasm collection based on single nucleotide polymorphism markers.

    Science.gov (United States)

    Wang, T; Zou, Q D; Qi, S Y; Wang, X F; Wu, Y Y; Liu, N; Zhang, Y M; Zhang, Z J; Li, H T

    2016-07-29

    Knowledge of genetic diversity is important to assist breeders in the selection of parental materials and in the design of breeding programs. In this study, we genotyped 348 inbred tomato lines, representing vintage and contemporary fresh-market varieties, by using 52 single nucleotide polymorphisms (SNPs); 45 of these were found to be polymorphic. The average minor allele frequency and unbiased expected heterozygosity were 0.315 and 0.356, respectively. Population structure analysis revealed that contemporary germplasm could be distinctly divided into six subpopulations representing three market classes and breeding programs (pink, green, and red). Vintage germplasm could be separated into at least two subpopulations, and more admixtures were found in vintage lines than in contemporary lines. These findings indicate that contemporary inbred lines are more diversified than vintage inbred lines. AMOVA of vintage and contemporary lines was performed. A significant difference was found (P tomato lines and to select elite inbred lines, which will accelerate the breeding process.

  8. Genetic diversity of Chlamydia pecorum strains in wild koala locations across Australia and the implications for a recombinant C. pecorum major outer membrane protein based vaccine.

    Science.gov (United States)

    Kollipara, Avinash; Polkinghorne, Adam; Wan, Charles; Kanyoka, Pride; Hanger, Jon; Loader, Joanne; Callaghan, John; Bell, Alicia; Ellis, William; Fitzgibbon, Sean; Melzer, Alistar; Beagley, Kenneth; Timms, Peter

    2013-12-27

    The long term survival of the koala (Phascolarctos cinereus) is at risk due to a range of threatening processes. A major contributing factor is disease caused by infection with Chlamydia pecorum, which has been detected in most mainland koala populations and is associated with ocular and genital tract infections. A critical aspect for the development of vaccines against koala chlamydial infections is a thorough understanding of the prevalence and strain diversity of C. pecorum infections across wild populations. In this study, we describe the largest survey (403 koalas from eight wild populations and three wildlife hospitals) examining the diversity of C. pecorum infections. 181 of the 403 koalas tested (45%) positive for C. pecorum by species-specific quantitative PCR with infection rates ranging from 20% to 61% in the eight wild populations sampled. The ompA gene, which encodes the chlamydial major outer membrane protein (MOMP), has been the major target of several chlamydial vaccines. Based on our analysis of the diversity of MOMP amino types in the infected koalas, we conclude that, (a) there exists significant diversity of C. pecorum strains in koalas, with 10 distinct, full length C. pecorum MOMP amino types identified in the 11 koala locations sampled, (b) despite this diversity, there are predicted T and B cell epitopes in both conserved as well as variable domains of MOMP which suggest cross-amino type immune responses, and (c) a recombinant MOMP-based vaccine consisting of MOMP "F" could potentially induce heterotypic protection against a range of C. pecorum strains.

  9. Genetic diversity of Leishmania infantum field populations from Brazil

    Directory of Open Access Journals (Sweden)

    Marcela Segatto

    2012-02-01

    Full Text Available Leishmania infantum (syn. Leishmania chagasi is the etiological agent of visceral leishmaniasis (VL in Brazil. The epidemiology of VL is poorly understood. Therefore, a more detailed molecular characterization at an intraspecific level is certainly needed. Herein, three independent molecular methods, multilocus microsatellite typing (MLMT, random amplification of polymorphic DNA (RAPD and simple sequence repeats-polymerase chain reaction (SSR-PCR, were used to evaluate the genetic diversity of 53 L. infantum isolates from five different endemic areas in Brazil. Population structures were inferred by distance-based and Bayesian-based approaches. Eighteen very similar genotypes were detected by MLMT, most of them differed in only one locus and no correlation was found between MLMT profiles, geographical origin or the estimated population structure. However, complex profiles composed of 182 bands obtained by both RAPD and SSR-PCR assays gave different results. Unweighted pair group method with arithmetic mean trees built from these data revealed a high degree of homogeneity within isolates of L. infantum. Interestingly, despite this genetic homogeneity, most of the isolates clustered according to their geographical origin.

  10. Genetic diversity among ancient Nordic populations.

    Directory of Open Access Journals (Sweden)

    Linea Melchior

    Full Text Available Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13% than among extant Danes and Scandinavians (approximately 2.5% as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  11. New data on sterlet (Acipenser ruthenus L. genetic diversity in the middle and Lower Danube sections, based on mitochondrial DNA analyses

    Directory of Open Access Journals (Sweden)

    Cvijanović Gorčin

    2015-01-01

    Full Text Available Poor regulated fishery, pollution, fragmentation and loss of habitat are most important factors influencing decline of sterlet population worldwide. In Middle and Lower Danube region, this species still have significant economic importance since wilde populations are commercially exploited, while Upper Danube populations are dependent on stocking efforts in order to maintain their presence in open waters. Aim of present study is to analyze genetic diversity of sterlet populations from the Middle and Lower Danube and Lower Tisza rivers, as a prerequisite for their effective conservation and management. Analysis of a highly variable D-loop fragment of mitochondrial DNA detected five new haplotypes, while the eight previously identified haplotypes had extended their previous range. Genetic variability could be attributed almost entirely to individuals, with observed lack of population structure. Negative values of neutrality test indicate recent expansion on some sampling locations. Adittionaly, gene flow analysis between Lower and Middle Danube region showed intensive exchange of speciemens. At the same time analysis showed some influence of Tisza dam on gene flow between samples from Tisza and Middle Danube section.Our study indicated the need for a careful planning of sterlet stocking programmes and inclusion of demographic data or catch time-series. [Projekat Ministarstva nauke Republike Srbije, br. 173045

  12. High genetic diversity and population structure in the endangered Canarian endemic Ruta oreojasme (Rutaceae).

    Science.gov (United States)

    Meloni, Marilena; Reid, Andrea; Caujapé-Castells, Juli; Soto, Moisés; Fernández-Palacios, José María; Conti, Elena

    2015-10-01

    Insular species are expected to have low genetic diversity, for their populations are often small and isolated, and characterized by restricted gene flow and increased incidence of inbreeding. However, empirical results do not always match this expectation. For example, population genetic analyses of several Canarian endemics, based mainly on allozymes, show levels of genetic diversity exceptionally high for insular species. To investigate whether genetic variation in rare species endemic to Canary Islands is low, as predicted by theoretical expectations, or high, as documented in some previous studies, we analysed genetic diversity of the endangered Ruta oreojasme, a rare endemic of the island of Gran Canaria, using microsatellite markers, which are more variable than allozymes. Our analyses identified very high levels of genetic diversity (A = 7.625, P = 0.984, H o = 0.558, H e = 0.687) for R. oreojasme. Even though the distribution of the species is restricted to the South of Gran Canaria, only one population shows low genetic diversity, isolation and signs of a recent bottleneck/founder event. Some intrinsic characteristics of R. oreojasme (hermaphroditism, proterandry and polyploidy), the relative climatic stability of the Canarian archipelago during Quaternary glacials/interglacials, the size of most populations (thousands of individuals), its age, and the relative proximity of the archipelago to the mainland might have contributed to the high diversity that characterises this endemic. As expected, given the marked topographic complexity of Gran Canaria, we found marked genetic structure in R. oreojasme populations. Our results support the observation that Canarian endemics are characterised by unexpectedly high genetic diversity and provides important insights for potential applications to the conservation of R. oreojasme.

  13. Genetic diversity of indigenous soybean-nodulating rhizobia in response to locally-based long term fertilization in a Mollisol of Northeast China.

    Science.gov (United States)

    Yan, Jun; Chen, WenFeng; Han, XiaoZeng; Wang, EnTao; Zou, WenXiu; Zhang, ZhiMing

    2017-01-01

    The influences of five different fertilizer treatments on diversity of rhizobia in soybean nodule were investigated in a long-term experiment with with four replicates: (1) control (without fertilization), (2) balanced NPK fertilizer (NPK), and (3-5) unbalanced chemical fertilizers without one of the major elements (NP, PK, and NK) in Mollisol in Northeast China. The highest soybean yield was observed in the NPK treatment. Total of 200 isolates were isolated and grouped into four Bradyrhizobium genospecies corresponding to B. japonicum, B. diazoefficiens, B. ottawaense and Bradyrhizobium sp. I, based upon the multilocus sequence analysis of 6 housekeeping genes. The Bradyrhizobium sp. I was extensively distributed throughout the study site and was recorded as the dominant soybean rhizobia (82.5-87.5%). Except the NK treatment, the other fertilizer treatments had no effect on rhizobial species composition. Compared with the CK treatment, all the fertilizer treatments decreased species richness, diversity and evenness. The soil organic carbon contents, available N content and pH were the key soil factors to rhizobial community structure. Results suggest that long-term fertilization can decrease rhizobial species diversity, while balanced fertilization with NPK is the most suitable fertilization regime if taking both soybean yields and rhizobial diversity into account.

  14. Diversity-Oriented Synthesis as a Tool for Chemical Genetics

    Directory of Open Access Journals (Sweden)

    Elena Lenci

    2014-10-01

    Full Text Available Chemical genetics is an approach for identifying small molecules with the ability to induce a biological phenotype or to interact with a particular gene product, and it is an emerging tool for lead generation in drug discovery. Accordingly, there is a need for efficient and versatile synthetic processes capable of generating complex and diverse molecular libraries, and Diversity-Oriented Synthesis (DOS of small molecules is the concept of choice to give access to new chemotypes with high chemical diversity. In this review, the combination of chemical genetics and diversity-oriented synthesis to identify new chemotypes as hit compounds in chemical biology and drug discovery is reported, giving an overview of basic concepts and selected case studies.

  15. Genetic diversity of Plasmodium vivax and Plasmodium falciparum in Honduras

    Directory of Open Access Journals (Sweden)

    Lopez Ana

    2012-11-01

    Full Text Available Abstract Background Understanding the population structure of Plasmodium species through genetic diversity studies can assist in the design of more effective malaria control strategies, particularly in vaccine development. Central America is an area where malaria is a public health problem, but little is known about the genetic diversity of the parasite’s circulating species. This study aimed to investigate the allelic frequency and molecular diversity of five surface antigens in field isolates from Honduras. Methods Five molecular markers were analysed to determine the genotypes of Plasmodium vivax and Plasmodium falciparum from endemic areas in Honduras. Genetic diversity of ama-1, msp-1 and csp was investigated for P. vivax, and msp-1 and msp-2 for P. falciparum. Allelic frequencies were calculated and sequence analysis performed. Results and conclusion A high genetic diversity was observed within Plasmodium isolates from Honduras. A different number of genotypes were elucidated: 41 (n = 77 for pvama-1; 23 (n = 84 for pvcsp; and 23 (n = 35 for pfmsp-1. Pvcsp sequences showed VK210 as the only subtype present in Honduran isolates. Pvmsp-1 (F2 was the most polymorphic marker for P. vivax isolates while pvama-1 was least variable. All three allelic families described for pfmsp-1 (n = 30 block 2 (K1, MAD20, and RO33, and both allelic families described for the central domain of pfmsp-2 (n = 11 (3D7 and FC27 were detected. However, K1 and 3D7 allelic families were predominant. All markers were randomly distributed across the country and no geographic correlation was found. To date, this is the most complete report on molecular characterization of P. vivax and P. falciparum field isolates in Honduras with regards to genetic diversity. These results indicate that P. vivax and P. falciparum parasite populations are highly diverse in Honduras despite the low level of transmission.

  16. Conservation priorities for Ethiopian sheep breeds combining threat status, breed merits and contributions to genetic diversity

    Directory of Open Access Journals (Sweden)

    Windig Jack J

    2008-07-01

    Full Text Available Abstract Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding's marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers and current merits (economic, ecological and cultural merits. Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04 as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83. We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan.

  17. Does genetic diversity hinder parasite evolution in social insect colonies?

    DEFF Research Database (Denmark)

    Hughes, William Owen Hamar; Boomsma, Jacobus Jan

    2006-01-01

    Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impac...... hinder the ability of parasites to adapt while cycling within social insect colonies.......Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impact...

  18. Entropy and Information Approaches to Genetic Diversity and its Expression: Genomic Geography

    Directory of Open Access Journals (Sweden)

    William B. Sherwin

    2010-07-01

    Full Text Available This article highlights advantages of entropy-based genetic diversity measures, at levels from gene expression to landscapes. Shannon’s entropy-based diversity is the standard for ecological communities. The exponentials of Shannon’s and the related “mutual information” excel in their ability to express diversity intuitively, and provide a generalised method of considering microscopic behaviour to make macroscopic predictions, under given conditions. The hierarchical nature of entropy and information allows integrated modeling of diversity along one DNA sequence, and between different sequences within and among populations, species, etc. The aim is to identify the formal connections between genetic diversity and the flow of information to and from the environment.

  19. Castor bean organelle genome sequencing and worldwide genetic diversity analysis.

    Directory of Open Access Journals (Sweden)

    Maximo Rivarola

    Full Text Available Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade.

  20. Castor bean organelle genome sequencing and worldwide genetic diversity analysis.

    Science.gov (United States)

    Rivarola, Maximo; Foster, Jeffrey T; Chan, Agnes P; Williams, Amber L; Rice, Danny W; Liu, Xinyue; Melake-Berhan, Admasu; Huot Creasy, Heather; Puiu, Daniela; Rosovitz, M J; Khouri, Hoda M; Beckstrom-Sternberg, Stephen M; Allan, Gerard J; Keim, Paul; Ravel, Jacques; Rabinowicz, Pablo D

    2011-01-01

    Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade.

  1. Castor Bean Organelle Genome Sequencing and Worldwide Genetic Diversity Analysis

    Science.gov (United States)

    Chan, Agnes P.; Williams, Amber L.; Rice, Danny W.; Liu, Xinyue; Melake-Berhan, Admasu; Huot Creasy, Heather; Puiu, Daniela; Rosovitz, M. J.; Khouri, Hoda M.; Beckstrom-Sternberg, Stephen M.; Allan, Gerard J.; Keim, Paul; Ravel, Jacques; Rabinowicz, Pablo D.

    2011-01-01

    Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade. PMID:21750729

  2. Genetic diversity among ancient Nordic populations

    DEFF Research Database (Denmark)

    Melchior, Linea Cecilie; Lynnerup, Niels; Siegismund, Hans Redlef

    2010-01-01

    the ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic...... samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least...... for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture....

  3. Genetic diversity in wild populations of Paulownia fortune.

    Science.gov (United States)

    Li, H Y; Ru, G X; Zhang, J; Lu, Y Y

    2014-11-01

    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.

  4. Genetic diversity and population structure of cucumber (Cucumis sativus L..

    Directory of Open Access Journals (Sweden)

    Jing Lv

    Full Text Available Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop's genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber.

  5. GENETIC DIVERSITY OF THE WILD AND REARED PSEUDOSCIAENA CROCEA

    Institute of Scientific and Technical Information of China (English)

    王军; 苏永全; 全成干; 丁少雄; 张纹

    2001-01-01

    The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) col-lected from Guan-Jing-Yang in Ningde, China in May 1999 was investigated by random amplified poly-morphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild popula-tion as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were rel-atively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance be-tween the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overilshing, small number of parents as broodstocks and the debatable arti-ficial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan-Jing-Yang still potentially wide genetic variability. It is sug-gested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population.

  6. GENETIC DIVERSITY OF THE WILD AND REARED PSEUDOSCIAENA CROCEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) collected from Guan-Jing-Yang in Ningde, China in May 1999 was investigated by random amplified polymorphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild population as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were relatively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance between the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overfishing, small number of parents as broodstocks and the debatable artificial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan-Jing-Yang still potentially wide genetic variability. It is suggested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population.

  7. Feasible Initial Population with Genetic Diversity for a Population-Based Algorithm Applied to the Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Marco Antonio Cruz-Chávez

    2016-01-01

    Full Text Available A stochastic algorithm for obtaining feasible initial populations to the Vehicle Routing Problem with Time Windows is presented. The theoretical formulation for the Vehicle Routing Problem with Time Windows is explained. The proposed method is primarily divided into a clustering algorithm and a two-phase algorithm. The first step is the application of a modified k-means clustering algorithm which is proposed in this paper. The two-phase algorithm evaluates a partial solution to transform it into a feasible individual. The two-phase algorithm consists of a hybridization of four kinds of insertions which interact randomly to obtain feasible individuals. It has been proven that different kinds of insertions impact the diversity among individuals in initial populations, which is crucial for population-based algorithm behavior. A modification to the Hamming distance method is applied to the populations generated for the Vehicle Routing Problem with Time Windows to evaluate their diversity. Experimental tests were performed based on the Solomon benchmarking. Experimental results show that the proposed method facilitates generation of highly diverse populations, which vary according to the type and distribution of the instances.

  8. Dynamic Change of Genetic Diversity in Conserved Populations with Different Initial Genetic Architectures

    Institute of Scientific and Technical Information of China (English)

    LU Yun-feng; LI Hong-wei; WU Ke-liang; WU Chang-xin

    2013-01-01

    Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is the retention of genetic diversity of conserved populations in a long-term perspective. However, numerous factors may affect evolution of genetic diversity of a conserved population. Among those factors, the genetic architecture of conserved populations is little considered in current conservation strategies. In this study, we investigated the dynamic changes of genetic diversity of conserved populations with two scenarios on initial genetic architectures by computer simulation in which thirty polymorphic microsatellite loci were chosen to represent genetic architecture of the populations with observed heterozygosity (Ho) and expected heterozygosity (He), observed and mean effective number of alleles (Ao and Ae), number of polymorphic loci (NP) and the percentage of polymorphic loci (PP), number of rare alleles (RA) and number of non-rich polymorphic loci (NRP) as the estimates of genetic diversity. The two scenarios on genetic architecture were taken into account, namely, one conserved population with same allele frequency (AS) and another one with actual allele frequency (AA). The results showed that the magnitude of loss of genetic diversity is associated with genetic architecture of initial conserved population, the amplitude of genetic diversity decline in the context AS was more narrow extent than those in context AA, the ranges of decline of Ho and Ao were about 4 and 2 times in AA compared with that in AS, respectively, the occurrence of first monomorphic locus and the time of change of measure NP in scenario AA is 20 generations and 23 generations earlier than that in scenario AS, respectively. Additionally, we found that NRP, a novel measure proposed by our research group, was a proper estimate for monitoring the evolution of genetic diversity

  9. [Genetic Diversity of Vitis vinifera L. in Azerbaijan].

    Science.gov (United States)

    Salayeva, S J; Ojaghi, J M; Pashayeva, A N; Izzatullayeva, V I; Akhundova, E M; Akperov, Z I

    2016-04-01

    To examine the genetic diversity of Vitis vinifera L., growing in the Republic of Azerbaijan in the region near the Caspian Sea, nuclear genomes of 31 cultivated and 34 wild grapevine accessions were studied at population and individual levels using five ISSR primers. In total, 51 fragments were amplified, of which 45 were found to be polymorphic. A high level of polymorphism was revealed (the mean PPF and PIC values constituted 87.69% and 0.94, respectively). High values of the EMR, MI, and RP indices showed the effectiveness of the application of ISSR primers and the possibility of their use in further investigations in this direction. Cluster analysis based on Nei's genetic distance values showed that all genotypes could be grouped into seven main clusters. Furthermore, no differences between the wild and cultivated grape wine accessions were revealed. For instance, there was no distinct distribution of the accessions according to their geographical localization. On the basis of the PIC values, the group of cultivars from Absheron Peninsula--was distinguished by the highest polymorphism level (PIC = 0.36). Natural populations from the Guba and Shabran regions were characterized by a relatively low polymorphism level (PIC = 0.31 and PIC = 0.28, respectively); and a wild population from Nabran demonstrated the lowest polymorphism level (PIC = 0.25). The data obtained confirmed paleontological and historical data of different periods, provide the supposition that Azerbaijan is the center of diversity of V. vinifera L. In addition, our data indicate that Azerbaijan grape landraces originated from local wild forms.

  10. Genetic diversity of Echinococcus granulosus in center of Iran.

    Science.gov (United States)

    Pestechian, Nader; Hosseini Safa, Ahmad; Tajedini, Mohammadhasan; Rostami-Nejad, Mohammad; Mousavi, Mohammad; Yousofi, Hosseinali; Haghjooy Javanmard, Shaghayegh

    2014-08-01

    Hydatid cyst caused by Echinococcus granulosus is one of the most important parasitic diseases around the world and many countries in Asia, including Iran, are involved with this infection. This disease can cause high mortality in humans as well as economic losses in livestock. To date, several molecular methods have been used to determine the genetic diversity of E. granulosus. So far, identification of E. granulosus using real-time PCR fluorescence-based quantitative assays has not been studied worldwide, also in Iran. Therefore, the aim of this study was to investigate the genetic diversity of E. granulosus from center of Iran using real-time PCR method. A total of 71 hydatid cysts were collected from infected sheep, goat, and cattle slaughtered in Isfahan, Iran during 2013. DNA was extracted from protoscolices and/or germinal layers from each individual cyst and used as template to amplify the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) (420 bp). Five cattle isolates out of 71 isolates were sterile and excluded from further investigation. Overall, of 66 isolates, partial sequences of the cox1 gene of E. granulosus indicated the presence of genotypes G1 in 49 isolates (74.2%), G3 in 15 isolates (22.7%), and G6 in 2 isolates (3.0%) in infected intermediate hosts. Sixteen sequences of G1 genotype had microgenetic variants, and they were compared to the original sequence of cox1. However, isolates identified as G3 and G6 genotypes were completely consistent with original sequences. G1 genotype in livestock was the dominant genotype in Isfahan region, Iran.

  11. Genetic diversity of natural Hepatacodium miconioides populations in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    LI Junmin; JIN Zexin

    2006-01-01

    Hepatacodium miconioides is the Class Ⅱ protected plant species in China.This paper studies the genetic diversity and differentiation of its nine natural populations in Zhejiang Province by using random amplified polymorphic DNA (RAPD) technique.Twelve random primers were selected in the amplification,and 164 repetitive loci were produced.The percentage of polymorphic loci in each H.miconioides population ranged from 14.60% to 27.44%,with an average of 20.73%.Among the test populations,Kuochangshan had the highest percentage of polymorphic loci,Simingshan took the second place,and Guanyinping had the lowest percentage.As estimated by Shannon index,the genetic diversity within H.miconioides populations accounted for 27.28% of the total genetic diversity,while that among H.miconioides populations accounted for 72.72%.The genetic differentiation among H.miconioides populations as estimated by Nei index was 0.715,7.This figure was generally consistent with that estimated by Shannon index,i.e.,the genetic differentiation among populations was relatively high,but that within populations was relatively low.The gene flow among H.miconioides populations was relatively low (0.198,7),and the genetic similarity ranged from 0.655,7 to 0.811,9,with an average of 0.730,6.The highest genetic distance among populations was 0.422,9,while the lowest was 0.208,3.All the results showed that there was a distinct genetic differentiation among H.miconioides populations.The genetic distance matrix of nine test populations was calculated using this method,and the clustering analysis was made using the unweighted pair group method with arithmetic mean (UPGMA).The cluster analysis suggested that the ninepopulations of H.miconioides in Zhejiang Province could be divided into two groups,the eastern Zhejiang group and the western Zhejiang group.

  12. Sequence variation and genetic diversity in the giant panda

    Institute of Scientific and Technical Information of China (English)

    张亚平; Oliver A.Ryder; 范志勇; 张和明; 何廷美; 何光昕; 张安居; 费立松; 钟顺隆; 陈红; 张成林; 杨明海; 朱飞兵; 彭真信; 普天春; 陈玉村; 姚敏达; 郭伟

    1997-01-01

    About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottle-neck attacks. Afterwards, its genetic diversity seemed to recover to some extent.

  13. A comparison of the genetic diversity in Dipteronia sinensis Oliv.and Dipteronia dyeriana Henry

    Institute of Scientific and Technical Information of China (English)

    LI Shan; QIAN Zengqiang; CAI Yuliang; ZHAO Guifang

    2006-01-01

    Dipteronia is an endemic genus to China and includes only two species, Dipteronia sinensis and D.dyeriana.Based on random amplified polymorphic DNA (RAPD) markers,a comparative study of the genetic diversity and genetic structure of Dipteronia was performed.In total,128 and 103 loci were detected in 17 D.sinensis populations and 4 D.dyeriana populations,respectively,using 18 random primers.These results showed that the proportions of polymorphic loci for the two species were 92.97% and 81.55%,respectively,indicating that the genetic diversity of D.sinensis was higher than that of D.dyeriana.Analysis,based on similarity coefficients,Shannon diversity index and Nei gene diversity index,also confirmed this result.AMOVA analysis demonstrated that the genetic variation of D.sinensis within and among populations accounted for 56.89% and 43.11% of the total variation,respectively,and that of D.dyeriana was 57.86% and 42.14%,respectively.The Shannon diversity index and Nei gene diversity index showed similar results.The abovementioned characteristics indicated that the genetic diversity levels of these two species were extremely similar and that the interpopulational genetic differentiation within both species was relatively high.Analysis of the genetic distance among populations also supported this conclusion.Low levels of interpopulational gene flow within both species were believed to be among the leading causes for the above-mentioned phenomenon.The correlation analysis between genetic and geographical distances showed the existence of a remarkably significant correlation between the genetic distance and the longitudinal difference among populations of D.sinensis (p<0.01),while no significant correlation was found between genetic and geographical distances among populations of D.dyeriana.This indicated that genetic distance was correlated with geographical distances on a large scale rather than on a small scale.This result may be related to differences in the

  14. Genetic Diversity and Population Structure of Mesoamerican Jaguars (Panthera onca): Implications for Conservation and Management

    Science.gov (United States)

    Wultsch, Claudia; Caragiulo, Anthony; Dias-Freedman, Isabela; Quigley, Howard; Rabinowitz, Salisa; Amato, George

    2016-01-01

    Mesoamerican jaguars (Panthera onca) have been extirpated from over 77% of their historic range, inhabiting fragmented landscapes at potentially reduced population sizes. Maintaining and restoring genetic diversity and connectivity across human-altered landscapes has become a major conservation priority; nonetheless large-scale genetic monitoring of natural populations is rare. This is the first regional conservation genetic study of jaguars to primarily use fecal samples collected in the wild across five Mesoamerican countries: Belize, Costa Rica, Guatemala, Honduras, and Mexico. We genotyped 445 jaguar fecal samples and examined patterns of genetic diversity and connectivity among 115 individual jaguars using data from 12 microsatellite loci. Overall, moderate levels of genetic variation were detected (NA = 4.50 ± 1.05, AR = 3.43 ± 0.22, HE = 0.59 ± 0.04), with Mexico having the lowest genetic diversity, followed by Honduras, Guatemala, Belize, and Costa Rica. Population-based gene flow measures (FST = 0.09 to 0.15, Dest = 0.09 to 0.21), principal component analysis, and Bayesian clustering applied in a hierarchical framework revealed significant genetic structure in Mesoamerican jaguars, roughly grouping individuals into four genetic clusters with varying levels of admixture. Gene flow was highest among Selva Maya jaguars (northern Guatemala and central Belize), whereas genetic differentiation among all other sampling sites was moderate. Genetic subdivision was most pronounced between Selva Maya and Honduran jaguars, suggesting limited jaguar movement between these close geographic regions and ultimately refuting the hypothesis of contemporary panmixia. To maintain a critical linkage for jaguars dispersing through the Mesoamerican landscape and ensure long-term viability of this near threatened species, we recommend continued management and maintenance of jaguar corridors. The baseline genetic data provided by this study underscores the importance of

  15. Landscape genetics, adaptive diversity and population structure in Phaseolus vulgaris.

    Science.gov (United States)

    Rodriguez, Monica; Rau, Domenico; Bitocchi, Elena; Bellucci, Elisa; Biagetti, Eleonora; Carboni, Andrea; Gepts, Paul; Nanni, Laura; Papa, Roberto; Attene, Giovanna

    2016-03-01

    Here we studied the organization of genetic variation of the common bean (Phaseolus vulgaris) in its centres of domestication. We used 131 single nucleotide polymorphisms to investigate 417 wild common bean accessions and a representative sample of 160 domesticated genotypes, including Mesoamerican and Andean genotypes, for a total of 577 accessions. By analysing the genetic spatial patterns of the wild common bean, we documented the existence of several genetic groups and the occurrence of variable degrees of diversity in Mesoamerica and the Andes. Moreover, using a landscape genetics approach, we demonstrated that both demographic processes and selection for adaptation were responsible for the observed genetic structure. We showed that the study of correlations between markers and ecological variables at a continental scale can help in identifying local adaptation genes. We also located putative areas of common bean domestication in Mesoamerica, in the Oaxaca Valley, and the Andes, in southern Bolivia-northern Argentina. These observations are of paramount importance for the conservation and exploitation of the genetic diversity preserved within this species and other plant genetic resources.

  16. 花生表型及SSR遗传多样性的研究%Phenotype and SSR-Based Genetic Diversity Assessment in Peanut

    Institute of Scientific and Technical Information of China (English)

    康红梅; 李保云; 孙毅

    2012-01-01

    The study had analyzed the Shannon-Weaver and Simpson indexes of phenotypic traits including plant type,presence or absence of hair,grain color,grain shape,leaf shape,habit of growth,flowering habit,particle size, particle color on 75 peanut cultivars(28 identified cultivars and 47 local cultivars) from Institute of Industrial Crops,Shanxi Academy of Agricultral Science. The results showed that genetic diversity index of 75 peanut cultivars were SWI =0. 924,SI =0.500 respectively,flowering habit was the lowest(SWI = 0. 139,SI =0. 014) .while Shannon-Weaver index of grain color was the highest with value of 1.841 ,and Simpson index was 0. 712. 48 pairs SSR markers of peanut were used to analyse genetic diversity of the tested materials, the results were as follows: (1) 35 pairs SSR markers(72. 9% )were polymorphic,and 215 polymorphic bands had been detected,6 polymorphic bands could be detected by each marker averagely. (2) On the basis of the results, the genetic similarity(GS) among 75 peanut cultivars were in a range from 0. 25 to 0. 85, with the mean of 0. 55 , and the average genetic similarity among the 28 identified cultivars were 0. 6 at a range of 0. 39 -0. 85.%对山西省农业科学院经济作物研究所保存的75份花生材料(包括28个已审定的花生品种和47个地方品种)进行了包括株型、茸毛的有无、叶色、粒形、叶形、生长习性、开花习性、粒大小、粒色等表型性状的Shannon-Weaver遗传多样性指数(简称SWI)和Simpson遗传多样性指数(简称SI)分析.结果表明:参试的75份花生品种遗传多样性指数分别为SWI=0.924,SI=0.500,其中以开花习性最低(SWI=0.139,SI =0.014),而Shannon-Weaver指数以粒色最高为1.841,Simpson指数为0.712.利用48对SSR引物对这些材料进行了遗传多样性分析,结果如下:(1)在48对花生的SSR引物中,有35对(占所用引物总数的72.9%)具有多态性,共检测到215条多态性条带,平均每对引物可扩增6

  17. Effect of domestication on the genetic diversity and structure of Saccharina japonica populations in China

    Science.gov (United States)

    Zhang, Jie; Wang, Xiuliang; Yao, Jianting; Li, Qiuying; Liu, Fuli; Yotsukura, Norishige; Krupnova, Tatiana N.; Duan, Delin

    2017-01-01

    Saccharina japonica is a commercially and ecologically important seaweed and is an excellent system for understanding the effects of domestication on marine crops. In this study, we used 19 selected simple sequence repeat (SSR) markers to investigate the influence of domestication on the genetic diversity and structure of S. japonica populations. Wild kelp populations exhibited higher genetic diversity than cultivated populations based on total NA, HE, HO, NP and AR. Discriminant analysis of principal components (DAPC), a neighbour-joining (NJ) tree and STRUCTURE analyses indicated that S. japonica populations could be divided into two groups (a cultivated/introduced group and a wild indigenous group) with significant genetic differentiation (P < 0.0001). Divergent selection, continuous inbreeding and inter-specific hybridization have caused the divergence of these two genetically separate gene pools. The significant genetic differentiation between northern and southern cultivated populations appears to be due to inter-specific hybridization and wild germplasm introduction during the domestication process. In addition, the cultivation of S. japonica has not resulted in any serious genetic disturbance of wild introduced S. japonica populations. An understanding of the genetic diversity and genetic structure of domesticated S. japonica will be necessary for further genetic improvement and effective use of germplasm. PMID:28176848

  18. Genetic diversity of Kenyan native oyster mushroom (Pleurotus).

    Science.gov (United States)

    Otieno, Ojwang D; Onyango, Calvin; Onguso, Justus Mungare; Matasyoh, Lexa G; Wanjala, Bramwel W; Wamalwa, Mark; Harvey, Jagger J W

    2015-01-01

    Members of the genus Pleurotus, also commonly known as oyster mushroom, are well known for their socioeconomic and biotechnological potentials. Despite being one of the most important edible fungi, the scarce information about the genetic diversity of the species in natural populations has limited their sustainable utilization. A total of 71 isolates of Pleurotus species were collected from three natural populations: 25 isolates were obtained from Kakamega forest, 34 isolates from Arabuko Sokoke forest and 12 isolates from Mount Kenya forest. Amplified fragment length polymorphism (AFLP) was applied to thirteen isolates of locally grown Pleurotus species obtained from laboratory samples using five primer pair combinations. AFLP markers and internal transcribed spacer (ITS) sequences of the ribosomal DNA were used to estimate the genetic diversity and evaluate phylogenetic relationships, respectively, among and within populations. The five primer pair combinations generated 293 polymorphic loci across the 84 isolates. The mean genetic diversity among the populations was 0.25 with the population from Arabuko Sokoke having higher (0.27) diversity estimates compared to Mount Kenya population (0.24). Diversity between the isolates from the natural population (0.25) and commercial cultivars (0.24) did not differ significantly. However, diversity was greater within (89%; P > 0.001) populations than among populations. Homology search analysis against the GenBank database using 16 rDNA ITS sequences randomly selected from the two clades of AFLP dendrogram revealed three mushroom species: P. djamor, P. floridanus and P. sapidus; the three mushrooms form part of the diversity of Pleurotus species in Kenya. The broad diversity within the Kenyan Pleurotus species suggests the possibility of obtaining native strains suitable for commercial cultivation.

  19. 中国大豆疫霉菌群体遗传结构的RFLP分析%Genetic Diversity of Phytophthora sojae in China Based on RFLP

    Institute of Scientific and Technical Information of China (English)

    肖江涛; 苗苗; 高坤; 向桂林; 杨帅; 董莎萌; 王源超; 王克荣

    2011-01-01

    [目的]分析中国大豆疫霉菌的群体遗传结构,探索不同地区大豆疫霉菌群体间的亲缘关系.[方法]采用RFLP(restriction fragment length polymorphism)技术,对大豆疫霉菌进行群体遗传结构的分析;利用Popgene V1.32软件计算大豆疫霉菌群体间的遗传相似度;利用NTSYSpc V2.10软件估算菌株间的遗传距离,并依据遗传距离构建UPGMA(unweighted pair-group method with arithmetic averages)系统树状图谱.[结果]采用探针PS127558对来自黑龙江、新疆和内蒙古等5个大豆疫霉菌地理群体的133个菌株的遗传多样性进行了分析,共得到25条杂交带,其中多态性条带为24个,占96%.黑龙江分别和新疆、内蒙古群体间遗传相似度较高.相对于黑龙江群体遗传结构的高度复杂性,新疆和内蒙古菌株的群体遗传结构则比较简单,分别有88.2%和100%的菌株分属于同一聚类组,且均有超过58%的菌株和部分黑龙江菌株指纹图谱完全相同.Shannon's多样性指数也表明黑龙江群体的遗传多样性最为丰富.福建和其它群体之间的遗传相似度较低,且分别有45.5%和54.5%的福建群体都属于聚类组E和F,遗传背景较为单一.福建群体的Shannon's多样性指数低于黑龙江和美国.美国和黑龙江群体之间的遗传相似度较高,且部分美国菌株和黑龙江菌株指纹图谱相同.[结论]新疆、内蒙古的大豆疫霉菌起源于黑龙江,福建的大豆疫霉菌可能为一个独立的进化分支或起源于其它地区.此外,中国和美国的大豆疫霉菌群体间存在菌源交流.%[ Objective ] The objective of this study is to explore the genetic diversity among Phytophthora sojae strains from soybean-growing regions in China and America. [Method] Restriction fragment length polymorphism (RFLP) was used to examine the genetic relationships among strains of P. sojae collected from 5 different regions. Nei's genetic distances among the strains of P

  20. Genetic diversity in the Paramecium aurelia species complex.

    Science.gov (United States)

    Catania, Francesco; Wurmser, François; Potekhin, Alexey A; Przybos, Ewa; Lynch, Michael

    2009-02-01

    Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized-reproductively and genetically-worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.

  1. Assessment of genetic diversity in Cattleya intermedia Lindl. (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Nelson Barbosa Machado Neto

    2011-10-01

    Full Text Available Orchids are valuable pot plants and Cattleya intermedia is a promising species underused in breeding programs. Recently, breeding work with this species produced superior plants that are believed to be not the true species owing to the morphological differences from wild plants. The aim of this study was to estimate the level of genetic diversity and interrelationships between wild and bred Cattleya intermedia collected at three different Brazilian states and from commercial breeders with RAPD markers. A total of 65 polymorphic bands were used to generate a genetic distance matrix. No specific groupings were revealed by the cluster analysis as bred materials were not different from wild plants. The genetic differentiation (F ST = 0.01626 was very low indicating a high gene flow in C. intermedia due to artificial crosses and a high differentiation between populations. The genetic variability available within this species is high enough to allow genetic progress in flower shape and size.

  2. Genetic diversity and population structure of begomoviruses infecting sweet potato

    Science.gov (United States)

    Begomoviruses infecting sweet potatoes (Ipomoea batatas) exhibit high genetic diversity, and approximately eight species including Sweet potato leaf curl virus (SPLCV) have been described from different regions around the world. In this study, the complete genomic sequences of 17 geographically dist...

  3. Assessment of genetic diversity of sweet potato in Puerto Rico

    Science.gov (United States)

    Sweet potato (Ipomoea batatas L.) is the seventh most important food crop due to its distinct advantages, such as adaptability to different environmental conditions and high nutritional value. Assessing the genetic diversity of this important crop is necessary due to the constant increase of demand ...

  4. Genetic diversity and differentiation of Pseudophoenix (Arecaceae) in Hispaniola

    Science.gov (United States)

    Technical Abstract Pseudophoenix ekmanii Burret, P. lediniana Read, and P. vinifera (Mart.) Becc. (Arecaceae) are endemic to Hispaniola. The more wide-ranging P. sargentii H.Wendl. ex Sarg. occurs on this island as well. The population genetic diversity and structure of Pseudophoenix was investigate...

  5. Ortholog identification in genera of high genetic diversity and evolution

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo; Vesth, Tammi Camilla; Frisvad, Jens Christian;

    In the era of high-throughput sequencing, comparative genomics is vastly used in the discovery of genetic diversity between species, but also in defining the core and pan genome of single species to whole genera. Current comparative approaches are implementing ortholog identification to establish...... genome annotations, gene or protein evolutions or defining functional features in individual species and groups....

  6. Genetic diversity in diploid vs. tetraploid Rorippa amphibia (Brassicaceae)

    NARCIS (Netherlands)

    Luttikhuizen, P.C.; Stift, M.; Kuperus, P.; van Tienderen, P.H.

    2007-01-01

    The frequency of polyploidy increases with latitude in the Northern Hemisphere, especially in deglaciated, recently colonized areas. The cause or causes of this pattern are largely unknown, but a greater genetic diversity of individual polyploid plants due to a doubled genome and/or a hybrid origin

  7. Genetic diversity of Ascaris in southwestern Uganda

    DEFF Research Database (Denmark)

    Betson, Martha; Nejsum, Peter; Llewellyn-Hughes, Julia

    2012-01-01

    Despite the common occurrence of ascariasis in southwestern Uganda, helminth control in the region has been limited. To gain further insights into the genetic diversity of Ascaris in this area, a parasitological survey in mothers (n=41) and children (n=74) living in two villages, Habutobere and M...

  8. Genetic diversity of Actinobacillus lignieresii isolates from different hosts

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Angen, Øystein; Bisgaard, Magne

    2011-01-01

    Genetic diversity detected by analysis of amplified fragment length polymorphisms (AFLPs) of 54 Actinobacilus lignieresii isolates from different hosts and geographic localities is described. On the basis of variances in AFLP profiles, the strains were grouped in two major clusters; one comprisin...

  9. Utilization of Genetic Diversity on Establishing Chinese Soybean (G.max0 Core Collection

    Institute of Scientific and Technical Information of China (English)

    QiuLijuan; XieHua; ChangRuzhen; LiWei; WangWenhui; ZhangBo; ZhangMinghui; FengZhongfu

    2002-01-01

    Genetic diversity plays a very important role in establishing core collection.In this study,A total of 405 Chinese soybean accessions was selected from the preliminary core collection,which had 5 different ecotypes from three cultivation regions,including northeastern spring sowing soybean(NSpSS),huanghuai summer sowing soybean(HSuSS),southern spring sowing soybean(SSpSS),southern summer sowing soybean(SSuSS),southern autumn sowing soybean(SAuSS).The genetic diversities and genetic relationship of five ecotypes were analyzed at DNA level by using SSR markers in order to provide information for establishemnt of Chinese soybean core collection.A set of 67 SSR primers were used to analyze these accessions,and detected 502 alleles with averaged 7.49 alleles per locus.SAuSS appeared to be the highest number of alleles,HSuSS had the biggest genetic diversity indexes and NSpSS were lowest for both numbers of alleles and genetic diversity indexes among 5 ecotypes.Since five ecotypes differentiated obviously,various sampling strategy for establishing core collection should be adaped for different ecotypes based on the number of alleles and genetic diversity indexes.

  10. Population structure and genetic diversity of black redhorse (Moxostoma duquesnei) in a highly fragmented watershed

    Science.gov (United States)

    Reid, S.M.; Wilson, C.C.; Mandrak, N.E.; Carl, L.M.

    2008-01-01

    Dams have the potential to affect population size and connectivity, reduce genetic diversity, and increase genetic differences among isolated riverine fish populations. Previous research has reported adverse effects on the distribution and demographics of black redhorse (Moxostoma duquesnei), a threatened fish species in Canada. However, effects on genetic diversity and population structure are unknown. We used microsatellite DNA markers to assess the number of genetic populations in the Grand River (Ontario) and to test whether dams have resulted in a loss of genetic diversity and increased genetic differentiation among populations. Three hundred and seventy-seven individuals from eight Grand River sites were genotyped at eight microsatellite loci. Measures of genetic diversity were moderately high and not significantly different among populations; strong evidence of recent population bottlenecks was not detected. Pairwise FST and exact tests identified weak (global FST = 0.011) but statistically significant population structure, although little population structuring was detected using either genetic distances or an individual-based clustering method. Neither geographic distance nor the number of intervening dams were correlated with pairwise differences among populations. Tests for regional equilibrium indicate that Grand River populations were either in equilibrium between gene flow and genetic drift or that gene flow is more influential than drift. While studies on other species have identified strong dam-related effects on genetic diversity and population structure, this study suggests that barrier permeability, river fragment length and the ecological characteristics of affected species can counterbalance dam-related effects. ?? 2007 Springer Science+Business Media B.V.

  11. Genetic diversity analysis in Piper species (Piperaceae) using RAPD markers.

    Science.gov (United States)

    Sen, Sandeep; Skaria, Reby; Abdul Muneer, P M

    2010-09-01

    The genetic diversity of eight species of Piper (Piperaceae) viz., P. nigrum, P. longum, P. betle, P. chaba, P. argyrophyllum, P. trichostachyon, P. galeatum, and P. hymenophyllum from Kerala state, India were analyzed by Random amplified polymorphic DNA (RAPD). Out of 22 10-mer RAPD primers screened, 11 were selected for comparative analysis of different species of Piper. High genetic variations were found among different Piper species studied. Among the total of 149 RAPD fragments amplified, 12 bands (8.05%) were found monomorphic in eight species. The remaining 137 fragments were found polymorphic (91.95%). Species-specific bands were found in all eight species studied. The average gene diversity or heterozygosity (H) was 0.33 across all the species, genetic distances ranged from 0.21 to 0.69. The results of this study will facilitate germplasm identification, management, and conservation.

  12. Assessment of genetic diversity among different indigenous Xanthomonas isolates via RAPD and ISSR

    Directory of Open Access Journals (Sweden)

    Fatima Sabin

    2012-01-01

    Full Text Available The genetic diversity among seven Xanthomonas isolates representing four species was assessed using RAPD and ISSR PCR-based techniques. Both techniques revealed high degrees of polymorphisms among the studied isolates. A cluster dendrogram based on the combined data of RAPD and ISSR showed that genetic diversity exists in local isolates of Xanthomonas. In terms of percentage similarity values, the genomic variation was found to be in the range of 29.29% - 100% among the isolates. X. campestris (Mangifera indica remained unclustered in cluster dendrogram and revealed a unique genomic profile compared to other isolates used in this study.

  13. Thai pigs and cattle production, genetic diversity of livestock and strategies for preserving animal genetic resources

    Directory of Open Access Journals (Sweden)

    Kesinee Gatphayak

    2013-03-01

    Full Text Available This paper reviews the current situation of livestock production in Thailand, genetic diversity and evaluation, as well as management strategies for animal genetic resources focusing on pigs and cattle. Sustainable conservation of indigenous livestock as a genetic resource and vital components within the agricultural biodiversity domain is a great challenge as well as an asset for the future development of livestock production in Thailand.

  14. Transferability of Cucurbita SSR markers for genetic diversity assessment of Turkish bottle gourd (Lagenaria siceraria) genetic resources

    Science.gov (United States)

    The genetic diversity present in crop landraces represents a valuable genetic resource for breeding and genetic studies. Bottle gourd (Lagenaria siceraria) landraces in Turkey are highly genetically diverse. However, the limited genomic resources available for this crop hinder the molecular characte...

  15. Assessing and Broadening Genetic Diversity of Elymus sibiricus Germplasm for the Improvement of Seed Shattering

    Directory of Open Access Journals (Sweden)

    Zongyu Zhang

    2016-07-01

    Full Text Available Siberian wild rye (Elymus sibiricus L. is an important native grass in the Qinghai-Tibet Plateau of China. It is difficult to grow for commercial seed production, since seed shattering causes yield losses during harvest. Assessing the genetic diversity and relationships among germplasm from its primary distribution area contributes to evaluating the potential for its utilization as a gene pool to improve the desired agronomic traits. In the study, 40 EST-SSR primers were used to assess the genetic diversity and population structure of 36 E. sibiricus accessions with variation of seed shattering. A total of 380 bands were generated, with an average of 9.5 bands per primer. The polymorphic information content (PIC ranged from 0.23 to 0.50. The percentage of polymorphic bands (P for the species was 87.11%, suggesting a high degree of genetic diversity. Based on population structure analysis, four groups were formed, similar to results of principal coordinate analysis (PCoA. The molecular variance analysis (AMOVA revealed the majority of genetic variation occurred within geographical regions (83.40%. Two genotypes from Y1005 and ZhN06 were used to generate seven F1 hybrids. The molecular and morphological diversity analysis of F1 population revealed rich genetic variation and high level of seed shattering variation in F1 population, resulting in significant improvement of the genetic base and desired agronomic traits.

  16. Genetic diversity of Hungarian Maize dwarf mosaic virus isolates.

    Science.gov (United States)

    Gell, Gyöngyvér; Balázs, Ervin; Petrik, Kathrin

    2010-04-01

    The genetic diversity of the coat-protein (CP) region and the untranslated C-terminal region (3'UTR) of Maize dwarf mosaic virus (MDMV) was analyzed to evaluate the variability between isolates (inter-isolate sequence diversity). The results of inter-isolate sequence diversity analysis showed that the diversity of the MDMV CP gene is fairly high (p-distance: up to 0.136). During sequence analysis, a 13 amino-acid residue insertion and an 8 amino-acid residue deletion were found within the N-terminal region of the CP gene. The phylogenetic analysis showed that-unlike other potyvirus species in this subgroup-the MDMV isolates could not be distinguished on the basis of their host plants or geographic origins.

  17. Acrocomia emensis (Arecaceae) genetic structure and diversity using SSR molecular markers.

    Science.gov (United States)

    Neiva, D S; Melo Júnior, A F; Oliveira, D A; Royo, V A; Brandão, M M; Menezes, E V

    2016-03-24

    Acrocomia emensis, popularly known as the creeping tucum, belongs to the family Arecaceae, and is an oilseed specie of the Brazilian Savannah. The expansion of agricultural activity has rapidly destroyed its natural habitat, leading to a decrease in its population size. Genetic studies can be used to investigate the genetic variability, and may assist with the charting future conservation strategies. In this study the genetic diversity and structure of 150 individuals sampled in three locations in Minas Gerais were analysed, based on the transferability of six microsatellite markers, previously developed for A. aculeata. The results indicate that the populations studied have low levels of genetic variability (Ho = 0.148) and high, positive and significant inbreeding coefficient, indicating an excess of homozygotes. The average heterozygosity within the population (Hs = 0.700) accounted for 95.03% of the total genetic diversity, indicating that there is greater variability within population than between them, consistent with low genetic differentiation between population (GST = 0.046). Bayesian analysis identified three distinct groups; however, populations shared large numbers of alleles, which can be explained by the reduced distance between populations. These results reveal the need to implement genetic conservation programs for the maintenance of this species and to prioritize population from Bonito and Brasília, which showed the lowest values of genetic diversity.

  18. Evaluation of genetic diversity in Piper spp using RAPD and SRAP markers.

    Science.gov (United States)

    Jiang, Y; Liu, J-P

    2011-11-29

    Random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analysis were applied to 74 individual plants of Piper spp in Hainan Island. The results showed that the SRAP technique may be more informative and more efficient and effective for studying genetic diversity of Piper spp than the RAPD technique. The overall level of genetic diversity among Piper spp in Hainan was relatively high, with the mean Shannon diversity index being 0.2822 and 0.2909, and the mean Nei's genetic diversity being 0.1880 and 0.1947, calculated with RAPD and SRAP data, respectively. The ranges of the genetic similarity coefficient were 0.486-0.991 and 0.520-1.000 for 74 individual plants of Piper spp (the mean genetic distance was 0.505 and 0.480) and the within-species genetic distance ranged from 0.063 to 0.291 and from 0.096 to 0.234, estimated with RAPD and SRAP data, respectively. These genetic indices indicated that these species are closely related genetically. The dendrogram generated with the RAPD markers was topologically different from the dendrogram based on SRAP markers, but the SRAP technique clearly distinguished all Piper spp from each other. Evaluation of genetic variation levels of six populations showed that the effective number of alleles, Nei's gene diversity and the Shannon information index within Jianfengling and Diaoluoshan populations are higher than those elsewhere; consequently conservation of wild resources of Piper in these two regions should have priority.

  19. Determinants of Genetic Diversity of Spontaneous Drug Resistance in Bacteria.

    Science.gov (United States)

    Couce, Alejandro; Rodríguez-Rojas, Alexandro; Blázquez, Jesús

    2016-07-01

    Any pathogen population sufficiently large is expected to harbor spontaneous drug-resistant mutants, often responsible for disease relapse after antibiotic therapy. It is seldom appreciated, however, that while larger populations harbor more mutants, the abundance distribution of these mutants is expected to be markedly uneven. This is because a larger population size allows early mutants to expand for longer, exacerbating their predominance in the final mutant subpopulation. Here, we investigate the extent to which this reduction in evenness can constrain the genetic diversity of spontaneous drug resistance in bacteria. Combining theory and experiments, we show that even small variations in growth rate between resistant mutants and the wild type result in orders-of-magnitude differences in genetic diversity. Indeed, only a slight fitness advantage for the mutant is enough to keep diversity low and independent of population size. These results have important clinical implications. Genetic diversity at antibiotic resistance loci can determine a population's capacity to cope with future challenges (i.e., second-line therapy). We thus revealed an unanticipated way in which the fitness effects of antibiotic resistance can affect the evolvability of pathogens surviving a drug-induced bottleneck. This insight will assist in the fight against multidrug-resistant microbes, as well as contribute to theories aimed at predicting cancer evolution.

  20. Genetic Diversity and Population Structure of Theileria annulata in Oman.

    Directory of Open Access Journals (Sweden)

    Salama Al-Hamidhi

    Full Text Available Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle.Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman.We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia. A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075,

  1. Growth stage-based modulation in physiological and biochemical attributes of two genetically diverse wheat (Triticum aestivum L.) cultivars grown in salinized hydroponic culture.

    Science.gov (United States)

    Ashraf, Muhammad Arslan; Ashraf, Muhammad

    2016-04-01

    Hydroponic experiment was conducted to appraise variation in the salt tolerance potential of two wheat cultivars (salt tolerant, S-24, and moderately salt sensitive, MH-97) at different growth stages. These two wheat cultivars are not genetically related as evident from randomized polymorphic DNA analysis (random amplified polymorphic DNA (RAPD)) which revealed 28% genetic diversity. Salinity stress caused a marked reduction in grain yield of both wheat cultivars. However, cv. S-24 was superior to cv. MH-97 in maintaining grain yield under saline stress. Furthermore, salinity caused a significant variation in different physiological attributes measured at different growth stages. Salt stress caused considerable reduction in different water relation attributes of wheat plants. A significant reduction in leaf water, osmotic, and turgor potentials was recorded in both wheat cultivars at different growth stages. Maximal reduction in leaf water potential was recorded at the reproductive stage in both wheat cultivars. In contrast, maximal turgor potential was observed at the boot stage. Salt-induced adverse effects of salinity on different water relation attributes were more prominent in cv. MH-97 as compared to those in cv. S-24. Salt stress caused a substantial decrease in glycine betaine and alpha tocopherols. These biochemical attributes exhibited significant salt-induced variation at different growth stages in both wheat cultivars. For example, maximal accumulation of glycine betaine was evident at the early growth stages (vegetative and boot). However, cv. S-24 showed higher accumulation of this organic osmolyte, and this could be the reason for maintenance of higher turgor than that of cv. MH-97 under stress conditions. Salt stress significantly increased the endogenous levels of toxic ions (Na(+) and Cl(-)) and decreased essential cations (K(+) and Ca(2+)) in both wheat cultivars at different growth stages. Furthermore, K(+)/Na(+) and Ca(2+)/Na(+) ratios

  2. Genetic diversity of different accessions of Thymus kotschyanus using RAPD marker

    Directory of Open Access Journals (Sweden)

    Ahmad Ismaili

    2014-11-01

    Full Text Available Analysis of genetic diversity is a major step for understanding evolution and breeding applications. Recent advances in the application of the polymerase chain reaction make it possible to score individuals at a large number of loci. The RAPD technique has been successfully used in a variety of taxonomic and genetic diversity studies. The genetic diversity of 18 accessions of Thymus kotschyanus collected from different districts of Iran has been reported in this study, using 30 random amplified polymorphic DNA primers. Multivariate statistical analyses including principal coordinate analysis (PCOA and cluster analysis were used to group the accessions. From 29 primers, 385 bands were scored corresponding to an average of 13.27 bands per primer with 298 bands showing polymorphism (77.40%. A dendrogram constructed based on the UPGMA clustering method revealed three major clusters. The obtained results from grouping 18 accessions of T. kotschyanus with two studied methods indicated that in the most cases the applied methods produced similar grouping results. This study revealed nearly rich genetic diversity among T. kotschyanus accessions from different regions of Iran. The results showed RAPD marker was a useful marker for genetic diversity studies of T. kotschyanus and it was indicative of geographica variations.

  3. Genetic Diversity of Parkia biglobosa from Different Agroecological Zones of Nigeria Using RAPD Markers

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    Oluwafemi Amusa

    2014-01-01

    Full Text Available Parkia biglobosa (Jacq. is an important leguminous tree crop in the African Savannahs useful to the natives where it is found, for domestic use. Previous diversity studies on this tree crop had been majorly on morphological and biochemical analysis. In order to capture the maximum diversity not obtained by previous research, the study aimed at evaluating the genetic diversity of accessions of this crop in the different agroecological zones in Nigeria using RAPD markers. A total of 81 scorable bands with an average of 8.1 bands per primer were amplified among the accessions studied. Intrazonal genetic diversity analysis showed a percentage polymorphism with a range of 11.11% to 65.43% among the agroecological zones studied. Although, gene diversity was highest within Humid forest agroecological zone, a low genetic distance and high genetic similarity between the agroecological zones were observed. Cluster analysis indicated six main groups of which four groups had single accessions while the two groups clustered the remaining accessions, indicating a narrowed genetic base from the 23 accessions studied.

  4. Genetic diversity and population structure in Polygonum cespitosum: insights to an ongoing plant invasion.

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    Silvia Matesanz

    Full Text Available Molecular markers can help elucidate how neutral evolutionary forces and introduction history contribute to genetic variation in invaders. We examined genetic diversity, population structure and colonization patterns in the invasive Polygonum cespitosum, a highly selfing, tetraploid Asian annual introduced to North America. We used nine diploidized polymorphic microsatellite markers to study 16 populations in the introduced range (northeastern North America, via the analyses of 516 individuals, and asked the following questions: 1 Do populations have differing levels of within-population genetic diversity? 2 Do populations form distinct genetic clusters? 3 Does population structure reflect either geographic distances or habitat similarities? We found low heterozygosity in all populations, consistent with the selfing mating system of P. cespitosum. Despite the high selfing levels, we found substantial genetic variation within and among P. cespitosum populations, based on the percentage of polymorphic loci, allelic richness, and expected heterozygosity. Inferences from individual assignment tests (Bayesian clustering and pairwise FST values indicated high among-population differentiation, which indicates that the effects of gene flow are limited relative to those of genetic drift, probably due to the high selfing rates and the limited seed dispersal ability of P. cespitosum. Population structure did not reflect a pattern of isolation by distance nor was it related to habitat similarities. Rather, population structure appears to be the result of the random movement of propagules across the introduced range, possibly associated with human dispersal. Furthermore, the high population differentiation, genetic diversity, and fine-scale genetic structure (populations founded by individuals from different genetic sources in the introduced range suggest that multiple introductions to this region may have occurred. High genetic diversity may further

  5. Analysis of genetic diversity in Bolivian llama populations using microsatellites.

    Science.gov (United States)

    Barreta, J; Gutiérrez-Gil, B; Iñiguez, V; Romero, F; Saavedra, V; Chiri, R; Rodríguez, T; Arranz, J J

    2013-08-01

    South American camelids (SACs) have a major role in the maintenance and potential future of rural Andean human populations. More than 60% of the 3.7 million llamas living worldwide are found in Bolivia. Due to the lack of studies focusing on genetic diversity in Bolivian llamas, this analysis investigates both the genetic diversity and structure of 12 regional groups of llamas that span the greater part of the range of distribution for this species in Bolivia. The analysis of 42 microsatellite markers in the considered regional groups showed that, in general, there were high levels of polymorphism (a total of 506 detected alleles; average PIC across per marker: 0.66), which are comparable with those reported for other populations of domestic SACs. The estimated diversity parameters indicated that there was high intrapopulational genetic variation (average number of alleles and average expected heterozygosity per marker: 12.04 and 0.68, respectively) and weak genetic differentiation among populations (FST range: 0.003-0.052). In agreement with these estimates, Bolivian llamas showed a weak genetic structure and an intense gene flow between all the studied regional groups, which is due to the exchange of reproductive males between the different flocks. Interestingly, the groups for which the largest pairwise FST estimates were observed, Sud Lípez and Nor Lípez, showed a certain level of genetic differentiation that is probably due to the pattern of geographic isolation and limited communication infrastructures of these southern localities. Overall, the population parameters reported here may serve as a reference when establishing conservation policies that address Bolivian llama populations.

  6. GENETIC DIVERSITY AND THE ORIGINS OF CULTURAL FRAGMENTATION

    Science.gov (United States)

    Ashraf, Quamrul; Galor, Oded

    2013-01-01

    Despite the importance attributed to the effects of diversity on the stability and prosperity of nations, the origins of the uneven distribution of ethnic and cultural fragmentation across countries have been underexplored. Building on the role of deeply-rooted biogeographical forces in comparative development, this research empirically demonstrates that genetic diversity, predominantly determined during the prehistoric “out of Africa” migration of humans, is an underlying cause of various existing manifestations of ethnolinguistic heterogeneity. Further exploration of this uncharted territory may revolutionize the understanding of the effects of deeply-rooted factors on economic development and the composition of human capital across the globe. PMID:25506084

  7. Genetic diversity and selection regulates evolution of infectious bronchitis virus.

    Science.gov (United States)

    Toro, Haroldo; van Santen, Vicky L; Jackwood, Mark W

    2012-09-01

    Conventional and molecular epidemiologic studies have confirmed the ability of infectious bronchitis virus (IBV) to rapidly evolve and successfully circumvent extensive vaccination programs implemented since the early 1950s. IBV evolution has often been explained as variation in gene frequencies as if evolution were driven by genetic drift alone. However, the mechanisms regulating the evolution of IBV include both the generation of genetic diversity and the selection process. IBV's generation of genetic diversity has been extensively investigated and ultimately involves mutations and recombination events occurring during viral replication. The relevance of the selection process has been further understood more recently by identifying genetic and phenotypic differences between IBV populations prior to, and during, replication in the natural host. Accumulating evidence suggests that multiple environmental forces within the host, including immune responses (or lack thereof) and affinity for cell receptors, as well as physical and biochemical conditions, are responsible for the selection process. Some scientists have used or adopted the related quasispecies frame to explain IBV evolution. The quasispecies frame, while providing a distinct explanation of the dynamics of populations in which mutation is a frequent event, exhibits relevant limitations which are discussed herein. Instead, it seems that IBV populations evolving by the generation of genetic variability and selection on replicons follow the evolutionary mechanisms originally proposed by Darwin. Understanding the mechanisms underlying the evolution of IBV is of basic relevance and, without doubt, essential to appropriately control and prevent the disease.

  8. Turtle carapace anomalies: the roles of genetic diversity and environment.

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    Guillermo Velo-Antón

    Full Text Available BACKGROUND: Phenotypic anomalies are common in wild populations and multiple genetic, biotic and abiotic factors might contribute to their formation. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we integrated field observations, manipulative experiments, and climatic and genetic approaches to investigate the origin of carapace scute anomalies across Iberian populations of the European pond turtle, Emys orbicularis. The proportion of anomalous individuals varied from 3% to 69% in local populations, with increasing frequency of anomalies in northern regions. We found no significant effect of climatic and soil moisture, or climatic temperature on the occurrence of anomalies. However, lower genetic diversity and inbreeding were good predictors of the prevalence of scute anomalies among populations. Both decreasing genetic diversity and increasing proportion of anomalous individuals in northern parts of the Iberian distribution may be linked to recolonization events from the Southern Pleistocene refugium. CONCLUSIONS/SIGNIFICANCE: Overall, our results suggest that developmental instability in turtle carapace formation might be caused, at least in part, by genetic factors, although the influence of environmental factors affecting the developmental stability of turtle carapace cannot be ruled out. Further studies of the effects of environmental factors, pollutants and heritability of anomalies would be useful to better understand the complex origin of anomalies in natural populations.

  9. Genetic Diversity of Dalmatian Sage (Salvia officinalis L. as Assessed by RAPD Markers

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    Zlatko Liber

    2014-09-01

    Full Text Available Dalmatian or common sage (Salvia officinalis L. is an outcrossing plant species native to East Adriatic coast. Random Amplified Polymorphic DNA markers (RAPD were used to analyze genetic diversity and structure of ten natural populations from the East-Adriatic coastal region. The highest genetic diversity was found in populations from the central and south Dalmatia, while the highest frequency down-weighted marker values were found in the northernmost populations and the southern most inland population. Although analysis of molecular variance (AMOVA revealed that most of the genetic diversity was attributable to differences among individuals within populations, highly significant φST values suggested the existence of genetic differentiation among populations. By assuming Hardy-Weinberg equilibrium within populations, the calculated FST value among population was moderate. Bayesian model-based clustering method revealed that at K = 2 all individuals belonging to two northern populations were assigned to a separate cluster from the individuals belonging to the rest of the population. At K = 3, the newly formed cluster grouped the majority of individuals belonging to populations from central Dalmatia. The high correlation between matrices of genetic and geographical distances showed that isolation by distance may play a considerable role in overall structuring of the genetic diversity.

  10. Genetic Diversity of Dalmatian Sage (Salvia offi cinalis L. as Assessed by RAPD Markers

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    Zlatko Liber

    2014-10-01

    Full Text Available Dalmatian or common sage (Salvia officinalis L. is an outcrossing plant species native to East Adriatic coast. Random Amplified Polymorphic DNA markers (RAPD were used to analyze genetic diversity and structure of ten natural populations from the East-Adriatic coastal region. The highest genetic diversity was found in populations from the central and south Dalmatia, while the highest frequency down-weighted marker values were found in the northernmost populations and the southern most inland population. Although analysis of molecular variance (AMOVA revealed that most of the genetic diversity was attributable to differences among individuals within populations, highly significant φST values suggested the existence of genetic differentiation among populations. By assuming Hardy-Weinberg equilibrium within populations, the calculated FST value among population was moderate. Bayesian model-based clustering method revealed that at K = 2 all individuals belonging to two northern populations were assigned to a separate cluster from the individuals belonging to the rest of the population. At K = 3, the newly formed cluster grouped the majority of individuals belonging to populations from central Dalmatia. The high correlation between matrices of genetic and geographical distances showed that isolation by distance may play a considerable role in overall structuring of the genetic diversity.

  11. Correlation analysis of genetic diversity and population structure of Houttuynia cordata Thunb with regard to environment.

    Science.gov (United States)

    Zhong, J; Wu, F-C; Qiu, P; Dai, L-J

    2016-01-01

    To study the levels of genetic diversity, and population structure, of Houttuynia cordata Thunb, the genetic background and relationships of populations were analyzed in terms of environmental factors. The genetic diversity and population structure of H. cordata were investigated using sequence-related amplified polymorphisms and correlation with environmental factors was analyzed using the SPSS software. Two thousand one hundred sixty-three sites were amplified from 41 pairs of primers, 1825 of which were polymorphic, and the percentage of polymorphic loci was 84.37%; the percentage of polymorphic sites was 72.14 and 67.77% at the species and population level, respectively. The observed number of alleles was 1.52 and 1.30 at species and population level, respectively. The effective number of alleles was 1.38 and 1.24 at species and population level, respectively. The Nei's diversity was 0.26 and 0.15 at species and population level, respectively. The Shannon's information index was 0.87 and 0.63 at species and population level, respectively. The genetic differentiation coefficient of populations was 0.51, and 12 populations were divided into three classes based on D = 0.20; the genetic diversities of different populations are correlated at different significance levels (P Genetic differentiation existed among populations and the populations exhibited heteroplasmy.

  12. Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata

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    Andrea C. Aplasca

    2016-03-01

    Full Text Available The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each. However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations.

  13. Assessing genetic diversity of wild populations of Japanese flounder using AFLP markers

    Institute of Scientific and Technical Information of China (English)

    XU Xiaofei; ZHANG Quanqi; WANG Zhigang; QI Jie; ZHANG Zhifeng; BAO Zhenmin; Heisuke Nakagawa

    2006-01-01

    Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic diversity of four wild geographical populations of Japanese flounder (Paralichthys olivaceus). A total of 775 loci (58.32% of which was polymorphic) in the range between 100 and 1 300 base pairs were detected from 110 individuals using seven primer combinations. The percentage of polymorphic loci detected by single primer combination for each population was calculated, ranging from 19.59% to 53.33%. Genetic similarities within and among the populations were calculated from the binary matrices of presence - absence. Phylogenetic tree of four populations was constructed by using the UPGMA method using PHYLIP Version 3.5. According to intrapopulation genetic similarities, CW population displayed the highest genetic diversity value and KY population had the lowest genetic diversity value.The distance between CW and CF populations was the farthest, which was possibly resulted from the farthest distance of Weihai of Shandong and Fujian of China compared with the geographical distance between other locations of populations. The subpopulation differentiation value ( Gst ) is 0.356 5, showing a certain extent of differentiation among the four geographical populations. AFLP technology was confirmed to be an effective tool to assess within- and among-population genetic diversity of Japanese flounder. The present survey provided significant insights for research in the Japanese flounder breeding program.

  14. Analysis of population structure and genetic diversity of Egyptian and exotic rice (Oryza sativa L.) genotypes.

    Science.gov (United States)

    Salem, Khaled F M; Sallam, Ahmed

    2016-01-01

    Understanding the population structure and genetic diversity is a very important goal to improve the economic value of crops. In rice, a loss of genetic diversity in the last few centuries is observed. To address this challenge, a set of 22 lines from three different regions - India (two), and Philippines (six), and Egypt (14) - were used to assess the genetic diversity and the features of population structure. These genotypes were analyzed using 106 SSR alleles that showed a clear polymorphism among the lines. Genetic diversity was estimated based on the number of different alleles, polymorphism information content (PIC), and gene diversity. A total of 106 SSR alleles was identified from the 23 SSR loci and used to study the population structure and carry out a cluster analysis. All SSR loci showed a wide range of the number of different alleles extended from two (one loci) to seven alleles (three loci). Five and eight loci showed high PIC and gene diversity (≥0.70), respectively. The results of population structure are in agreement with cluster analysis results. Both analyses revealed two different subpopulations (G1 and G2) with different genetic properties in number of private alleles, number of different alleles (Na), number of effective alleles (Ne), expected heterozygosity (He), and Shannon's Information Index (SII). Our findings indicate that five SSR loci (RM 111, RM 307, RM 22, RM 19, and RM 271) could be used in breeding programs to enhance the marker-assisted selection through QTL mapping and association studies. A high genetic diversity found between genotypes which can be exploited to improve and produce rice cultivars for important traits (e.g. high agronomic features and tolerance to biotic or/and abiotic stresses).

  15. Genetic diversity analysis of Gossypium arboreum germplasm accessions using genotyping-by-sequencing.

    Science.gov (United States)

    Li, Ruijuan; Erpelding, John E

    2016-10-01

    The diploid cotton species Gossypium arboreum possesses many favorable agronomic traits such as drought tolerance and disease resistance, which can be utilized in the development of improved upland cotton cultivars. The USDA National Plant Germplasm System maintains more than 1600 G. arboreum accessions. Little information is available on the genetic diversity of the collection thereby limiting the utilization of this cotton species. The genetic diversity and population structure of the G. arboreum germplasm collection were assessed by genotyping-by-sequencing of 375 accessions. Using genome-wide single nucleotide polymorphism sequence data, two major clusters were inferred with 302 accessions in Cluster 1, 64 accessions in Cluster 2, and nine accessions unassigned due to their nearly equal membership to each cluster. These two clusters were further evaluated independently resulting in the identification of two sub-clusters for the 302 Cluster 1 accessions and three sub-clusters for the 64 Cluster 2 accessions. Low to moderate genetic diversity between clusters and sub-clusters were observed indicating a narrow genetic base. Cluster 2 accessions were more genetically diverse and the majority of the accessions in this cluster were landraces. In contrast, Cluster 1 is composed of varieties or breeding lines more recently added to the collection. The majority of the accessions had kinship values ranging from 0.6 to 0.8. Eight pairs of accessions were identified as potential redundancies due to their high kinship relatedness. The genetic diversity and genotype data from this study are essential to enhance germplasm utilization to identify genetically diverse accessions for the detection of quantitative trait loci associated with important traits that would benefit upland cotton improvement.

  16. Bartonella Prevalence and Genetic Diversity in Small Mammals from Ethiopia

    DEFF Research Database (Denmark)

    Meheretu, Yonas; Leirs, Herwig E.l.; Welegerima, Kiros;

    2013-01-01

    More than 500 small mammals were trapped at 3 localities in northern Ethiopia to investigate Bartonella infection prevalence and the genetic diversity of the Bartonella spp. We extracted total DNA from liver samples and performed PCR using the primers 1400F and 2300R targeting 852 bp of the Barto......More than 500 small mammals were trapped at 3 localities in northern Ethiopia to investigate Bartonella infection prevalence and the genetic diversity of the Bartonella spp. We extracted total DNA from liver samples and performed PCR using the primers 1400F and 2300R targeting 852 bp...... of the Bartonella RNA polymerase beta subunit (rpoB) gene. We used a generalized linear mixed model to relate the probability of Bartonella infection to species, season, locality, habitat, sex, sexual condition, weight, and ectoparasite infestation. Overall, Bartonella infection prevalence among the small mammals...

  17. Single nucleotide polymorphisms for assessing genetic diversity in castor bean (Ricinus communis

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    Rabinowicz Pablo D

    2010-01-01

    Full Text Available Abstract Background Castor bean (Ricinus communis is an agricultural crop and garden ornamental that is widely cultivated and has been introduced worldwide. Understanding population structure and the distribution of castor bean cultivars has been challenging because of limited genetic variability. We analyzed the population genetics of R. communis in a worldwide collection of plants from germplasm and from naturalized populations in Florida, U.S. To assess genetic diversity we conducted survey sequencing of the genomes of seven diverse cultivars and compared the data to a reference genome assembly of a widespread cultivar (Hale. We determined the population genetic structure of 676 samples using single nucleotide polymorphisms (SNPs at 48 loci. Results Bayesian clustering indicated five main groups worldwide and a repeated pattern of mixed genotypes in most countries. High levels of population differentiation occurred between most populations but this structure was not geographically based. Most molecular variance occurred within populations (74% followed by 22% among populations, and 4% among continents. Samples from naturalized populations in Florida indicated significant population structuring consistent with local demes. There was significant population differentiation for 56 of 78 comparisons in Florida (pairwise population ϕPT values, p Conclusion Low levels of genetic diversity and mixing of genotypes have led to minimal geographic structuring of castor bean populations worldwide. Relatively few lineages occur and these are widely distributed. Our approach of determining population genetic structure using SNPs from genome-wide comparisons constitutes a framework for high-throughput analyses of genetic diversity in plants, particularly in species with limited genetic diversity.

  18. Genetic Diversity of the Two Commercial Tetraploid Cotton Species in the Gossypium Diversity Reference Set.

    Science.gov (United States)

    Hinze, Lori L; Gazave, Elodie; Gore, Michael A; Fang, David D; Scheffler, Brian E; Yu, John Z; Jones, Don C; Frelichowski, James; Percy, Richard G

    2016-05-01

    A diversity reference set has been constructed for the Gossypium accessions in the US National Cotton Germplasm Collection to facilitate more extensive evaluation and utilization of accessions held in the Collection. A set of 105 mapped simple sequence repeat markers was used to study the allelic diversity of 1933 tetraploid Gossypium accessions representative of the range of diversity of the improved and wild accessions of G. hirsutum and G. barbadense. The reference set contained 410 G. barbadense accessions and 1523 G. hirsutum accessions. Observed numbers of polymorphic and private bands indicated a greater diversity in G. hirsutum as compared to G. barbadense as well as in wild-type accessions as compared to improved accessions in both species. The markers clearly differentiated the 2 species. Patterns of diversity within species were observed but not clearly delineated, with much overlap occurring between races and regions of origin for wild accessions and between historical and geographic breeding pools for cultivated accessions. Although the percentage of accessions showing introgression was higher among wild accessions than cultivars in both species, the average level of introgression within individual accessions, as indicated by species-specific bands, was much higher in wild accessions of G. hirsutum than in wild accessions of G. barbadense. The average level of introgression within individual accessions was higher in improved G. barbadense cultivars than in G. hirsutum cultivars. This molecular characterization reveals the levels and distributions of genetic diversity that will allow for better exploration and utilization of cotton genetic resources.

  19. Social Organization of Crop Genetic Diversity. The G × E × S Interaction Model

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    Geo Coppens d’Eeckenbrugge

    2011-12-01

    Full Text Available A better knowledge of factors organizing crop genetic diversity in situ increases the efficiency of diversity analyses and conservation strategies, and requires collaboration between social and biological disciplines. Four areas of anthropology may contribute to our understanding of the impact of social factors on crop diversity: ethnobotany, cultural, cognitive and social anthropology. So far, most collaborative studies have been based on ethnobotanical methods, focusing on farmers’ individual motivations and actions, and overlooking the effects of farmer’s social organization per se. After reviewing common shortcomings in studies on sorghum and maize, this article analyzes how social anthropology, through the analysis of intermarriage, residence and seed inheritance practices, can contribute to studies on crop genetic diversity in situ. Crop varieties are thus considered social objects and socially based sampling strategies can be developed. Such an approach is justified because seed exchange is built upon trust and as such seed systems are embedded in a pre-existing social structure and centripetally oriented as a function of farmers’ social identity. The strong analogy between farmers’ cultural differentiation and crop genetic differentiation, both submitted to the same vertical transmission processes, allows proposing a common methodological framework for social anthropology and crop population genetics, where the classical interaction between genetic and environmental factors, G × E, is replaced by a three-way interaction G × E × S, where “S” stands for the social differentiation factors.

  20. Genetic diversity and maternal origin of Bangladeshi chicken.

    Science.gov (United States)

    Bhuiyan, M S A; Chen, Shanyuan; Faruque, S; Bhuiyan, A K F H; Beja-Pereira, Albano

    2013-06-01

    Local domestic chicken populations are of paramount importance as a source of protein in developing countries. Bangladesh possesses a large number of native chicken populations which display a broad range of phenotypes well adapted to the extreme wet and hot environments of this region. This and the fact that wild jungle fowls (JFs) are still available in some regions of the country, it urges to study the present genetic diversity and relationships between Bangladeshi autochthonous chicken populations. Here, we report the results of the mitochondrial DNA (mtDNA) sequence polymorphisms analyses to assess the genetic diversity and possible maternal origin of Bangladeshi indigenous chickens. A 648-bp fragment of mtDNA control region (D-loop) was analyzed in 96 samples from four different chicken populations and one red JF population. Sequence analysis revealed 39 variable sites that defined 25 haplotypes. Estimates of haplotype and nucleotide diversities ranged from 0.745 to 0.901 and from 0.011 to 0.016, respectively. The pairwise differences between populations ranged from 0.091 to 1.459 while most of the PhiST (ΦST) values were significant. Furthermore, AMOVA analysis revealed 89.16 % of the total genetic diversity was accounted for within population variation, indicating little genetic differentiation among the studied populations. The median network analysis from haplotypes of Bangladeshi chickens illustrated five distinct mitochondrial haplogroups (A, D, E, F and I). Individuals from all Bangladeshi chicken populations were represented in the major clades D and E; those maternal origins are presumed to be from Indian Subcontinent and Southeast Asian countries, more particularly from South China, Vietnam, Myanmar and Thailand. Further, phylogenetic analysis between indigenous chicken populations and sub-species of red JFs showed G. g. gallus and G. g. spadiceus shared with almost all haplogroups and had major influence than G. g. murghi in the origin of

  1. Genetic diversity among monoconidial and polyconidial isolates of Bipolaris sorokiniana.

    Science.gov (United States)

    Mann, Michele B; Minotto, Elisandra; Feltrin, Thaisa; Milagre, Luciana P; Spadari, Cristina; Van Der Sand, Sueli T

    2014-12-01

    Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat-growing regions of the world. This fungus shows a high genetic diversity and morphological and physiologic variability. In this study, 19 polysporic and 57 monosporic isolates of B. sorokiniana were characterized using universal rice primers-URP-PCR. The results obtained when the dendrogram was constructed with all the data produced with the amplification products showed very distinct clusters. However, the similarity among the isolates was low where 37 and 26.3 % of the monosporic and polysporic isolates, respectively, showed similarity above 70 %. All primers amplified multiple DNA fragments of polysporic as well as the monosporic isolates. Isolates fingerprints were constructed based on binary characters revealed by the three primers. An amplified fragment of approximately 750 bp was observed among 40 % of the isolates, when primer URP-1F was used. When primers URP-4R and URP-2R were used, a fragment of 450 and 400 bp was present in 31.5 and 29 % of the isolates, respectively. It was expected a higher similarity among the isolates since the monosporic cultures were originated from the polysporic. The dendrogram did not enable the separation of B. sorokiniana isolates by their geographic origin. This low correlation suggests that gene transfer may have occurred by parasexual combination in this fungus population. However, in spite of the research efforts for that end, it has not been possible to establish patterns that characterize the profile of B. sorokiniana.

  2. Genetic diversity of Chlamydia among captive birds from central Argentina.

    Science.gov (United States)

    Frutos, María C; Monetti, Marina S; Vaulet, Lucia Gallo; Cadario, María E; Fermepin, Marcelo Rodríguez; Ré, Viviana E; Cuffini, Cecilia G

    2015-01-01

    To study the occurrence of Chlamydia spp. and their genetic diversity, we analysed 793 cloacal swabs from 12 avian orders, including 76 genera, obtained from 80 species of asymptomatic wild and captive birds that were examined with conventional nested polymerase chain reaction and quantitative polymerase chain reaction. Chlamydia spp. were not detected in wild birds; however, four species (Chlamydia psittaci, Chlamydia pecorum, Chlamydia pneumoniae and Chlamydia gallinacea) were identified among captive birds (Passeriformes, n = 20; Psittaciformes, n = 15; Rheiformes, n = 8; Falconiformes n = 2; Piciformes n = 2; Anseriformes n = 1; Galliformes n = 1; Strigiformes n = 1). Two pathogens (C. pneumoniae and C. pecorum) were identified simultaneously in samples obtained from captive birds. Based on nucleotide-sequence variations of the ompA gene, three C. psittaci-positive samples detected were grouped into a cluster with the genotype WC derived from mammalian hosts. A single positive sample was phylogenetically related to a new strain of C. gallinacea. This report contributes to our increasing understanding of the abundance of Chlamydia in the animal kingdom.

  3. Identifying Genetic Hotspots by Mapping Molecular Diversity of Widespread Trees: When Commonness Matters.

    Science.gov (United States)

    Souto, Cintia P; Mathiasen, Paula; Acosta, María Cristina; Quiroga, María Paula; Vidal-Russell, Romina; Echeverría, Cristian; Premoli, Andrea C

    2015-01-01

    Conservation planning requires setting priorities at the same spatial scale at which decision-making processes are undertaken considering all levels of biodiversity, but current methods for identifying biodiversity hotspots ignore its genetic component. We developed a fine-scale approach based on the definition of genetic hotspots, which have high genetic diversity and unique variants that represent their evolutionary potential and evolutionary novelties. Our hypothesis is that wide-ranging taxa with similar ecological tolerances, yet of phylogenetically independent lineages, have been and currently are shaped by ecological and evolutionary forces that result in geographically concordant genetic patterns. We mapped previously published genetic diversity and unique variants of biparentally inherited markers and chloroplast sequences for 9 species from 188 and 275 populations, respectively, of the 4 woody dominant families of the austral temperate forest, an area considered a biodiversity hotspot. Spatial distribution patterns of genetic polymorphisms differed among taxa according to their ecological tolerances. Eight genetic hotspots were detected and we recommend conservation actions for some in the southern Coastal Range in Chile. Existing spatially explicit genetic data from multiple populations and species can help to identify biodiversity hotspots and guide conservation actions to establish science-based protected areas that will preserve the evolutionary potential of key habitats and species.

  4. Glacial refugia and modern genetic diversity of 22 western North American tree species.

    Science.gov (United States)

    Roberts, David R; Hamann, Andreas

    2015-04-07

    North American tree species, subspecies and genetic varieties have primarily evolved in a landscape of extensive continental ice and restricted temperate climate environments. Here, we reconstruct the refugial history of western North American trees since the last glacial maximum using species distribution models, validated against 3571 palaeoecological records. We investigate how modern subspecies structure and genetic diversity corresponds to modelled glacial refugia, based on a meta-analysis of allelic richness and expected heterozygosity for 473 populations of 22 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r(2) = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles.

  5. Diversity-Based Boosting Algorithm

    Directory of Open Access Journals (Sweden)

    Jafar A. Alzubi

    2016-05-01

    Full Text Available Boosting is a well known and efficient technique for constructing a classifier ensemble. An ensemble is built incrementally by altering the distribution of training data set and forcing learners to focus on misclassification errors. In this paper, an improvement to Boosting algorithm called DivBoosting algorithm is proposed and studied. Experiments on several data sets are conducted on both Boosting and DivBoosting. The experimental results show that DivBoosting is a promising method for ensemble pruning. We believe that it has many advantages over traditional boosting method because its mechanism is not solely based on selecting the most accurate base classifiers but also based on selecting the most diverse set of classifiers.

  6. Comparative analysis of genetic diversity in sacred lotus (Nelumbo nucifera Gaertn.) using AFLP and SSR markers.

    Science.gov (United States)

    Hu, Jihong; Pan, Lei; Liu, Honggao; Wang, Shuzhen; Wu, Zhihua; Ke, Weidong; Ding, Yi

    2012-04-01

    The sacred lotus (Nelumbo nucifera Gaertn.) is an aquatic plant of economic and ornamental importance in China. In this study, we developed twenty novel sacred lotus SSR markers, and used AFLP and SSR markers to investigate the genetic diversity and genetic relationships among 58 accessions of N. nucifera including 15 seed lotus, 12 rhizome lotus, 24 flower lotus and 7 wild lotus. Our results showed that sacred lotus exhibited a low level of genetic diversity, which may attribute to asexual reproduction and long-term artificial selection. A dendrogram based on both AFLP and SSR clustering data showed that: (1) the seed lotus accessions and rhizome lotus accessions were distinctly clustered into different groups, which indicated the significant genetic differentiation between them. This may be attributed to the two modes of reproduction and lack of genetic exchange; (2) the accessions of Thailand wild lotus were separated from other wild lotus accessions. This implied that the Thailand lotus might be genetically differentiated from other wild lotuses. In addition, Mantel test conducted gave highly significant correlation between AFLP-SSR data and each of the AFLP and SSR ones, with the values of r = 0.941 and r = 0.879, respectively, indicating the higher efficiency of the combination of these techniques (AFLP and SSR) in estimation and validation of the genetic diversity among the accession of sacred lotus. This knowledge of the genetic diversity and genetic relatedness of N. nucifera is potentially useful to improve the current strategies in breeding and germplasm conservation to enhance the ornamental and economic value of sacred lotus.

  7. Genetic diversity in introduced golden mussel populations corresponds to vector activity.

    Directory of Open Access Journals (Sweden)

    Sara Ghabooli

    Full Text Available We explored possible links between vector activity and genetic diversity in introduced populations of Limnoperna fortunei by characterizing the genetic structure in native and introduced ranges in Asia and South America. We surveyed 24 populations: ten in Asia and 14 in South America using the mitochondrial cytochrome c oxidase subunit I (COI gene, as well as eight polymorphic microsatellite markers. We performed population genetics and phylogenetic analyses to investigate population genetic structure across native and introduced regions. Introduced populations in Asia exhibit higher genetic diversity (H(E = 0.667-0.746 than those in South America (H(E =  0.519-0.575, suggesting higher introduction effort for the former populations. We observed pronounced geographical structuring in introduced regions, as indicated by both mitochondrial and nuclear markers based on multiple genetic analyses including pairwise Ф(ST, F(ST, bayesian clustering method, and three-dimensional factorial correspondence analyses. Pairwise F(ST values within both Asia (F(ST = 0.017-0.126, P = 0.000-0.009 and South America (F(ST =0.004-0.107, P = 0.000-0.721 were lower than those between continents (F(ST = 0.180-0.319, P = 0.000. Fine-scale genetic structuring was also apparent among introduced populations in both Asia and South America, suggesting either multiple introductions of distinct propagules or strong post-introduction selection and demographic stochasticity. Higher genetic diversity in Asia as compared to South America is likely due to more frequent propagule transfers associated with higher shipping activities between source and donor regions within Asia. This study suggests that the intensity of human-mediated introduction vectors influences patterns of genetic diversity in non-indigenous species.

  8. Genetic diversity in Penaeus chinensis shrimp as revealed by RAPD technique

    Institute of Scientific and Technical Information of China (English)

    庄志猛; 石拓; 孔杰; 刘萍; 刘振辉; 孟宪红; 邓景耀

    2001-01-01

    The random amplified polymorphic DNA analysis was used to estimate genetic diversity in one successively cultivated stock and three wild stocks of Penaeus chinensis shrimp, two of which were collected from the spawning and wintering grounds in the west coast of Korean Peninsula, and one from the feeding ground in the China coast of the Yellow Sea. A random primer kit was employed to scan the genomic DNA in 20 individuals of each index stock. A total of 110 reproducible RAPD markers were obtained, 68.2 % of which showed a sound eonformability within all the individuals detected, implying that the genetic variability in P. chinensis is relatively low. The proportions of polymorphic loci among these four stocks ranged from 20% to 33.3%, while the degrees of genetic polymorphisms varied from 0.0093 to 0.0307. The genetic variability of inter-stocks was higher than that of intra-stock. The genetic diversity in different stocks differed from each other; that is, a less genetic differentiation in the spawning and wintering stocks from the west coast of Korean Peninsula was revealed and their genetic diversities were higher than that of the spawning stock in the Bohai Sea and the China coast of the Yellow Sea. As detected, the genetic diversity in the successively cultivated stock was the lowest among these four stocks. Through genetic distance analysis between a random pair of individuals, a dendrogram of the above-mentioned four stocks was constructed by unweighted pair group method with arithmetic mean. The results based on cluster analysis well fitted with the geographical distribution of P. chinensis in the Bohai and Yellow Seas.

  9. Genetic and Functional Diversity of Propagating Cells in Glioblastoma

    Directory of Open Access Journals (Sweden)

    Sara G.M. Piccirillo

    2015-01-01

    Full Text Available Glioblastoma (GBM is a lethal malignancy whose clinical intransigence has been linked to extensive intraclonal genetic and phenotypic diversity and the common emergence of therapeutic resistance. This interpretation embodies the implicit assumption that cancer stem cells or tumor-propagating cells are themselves genetically and functionally diverse. To test this, we screened primary GBM tumors by SNP array to identify copy number alterations (a minimum of three that could be visualized in single cells by multicolor fluorescence in situ hybridization. Interrogation of neurosphere-derived cells (from four patients and cells derived from secondary transplants of these same cells in NOD-SCID mice allowed us to infer the clonal and phylogenetic architectures. Whole-exome sequencing and single-cell genetic analysis in one case revealed a more complex clonal structure. This proof-of-principle experiment revealed that subclones in each GBM had variable regenerative or stem cell activity, and highlighted genetic alterations associated with more competitive propagating activity in vivo.

  10. Development of Pineapple Microsatellite Markers and Germplasm Genetic Diversity Analysis

    Directory of Open Access Journals (Sweden)

    Suping Feng

    2013-01-01

    Full Text Available Two methods were used to develop pineapple microsatellite markers. Genomic library-based SSR development: using selectively amplified microsatellite assay, 86 sequences were generated from pineapple genomic library. 91 (96.8% of the 94 Simple Sequence Repeat (SSR loci were dinucleotide repeats (39 AC/GT repeats and 52 GA/TC repeats, accounting for 42.9% and 57.1%, resp., and the other three were mononucleotide repeats. Thirty-six pairs of SSR primers were designed; 24 of them generated clear bands of expected sizes, and 13 of them showed polymorphism. EST-based SSR development: 5659 pineapple EST sequences obtained from NCBI were analyzed; among 1397 nonredundant EST sequences, 843 were found containing 1110 SSR loci (217 of them contained more than one SSR locus. Frequency of SSRs in pineapple EST sequences is 1SSR/3.73 kb, and 44 types were found. Mononucleotide, dinucleotide, and trinucleotide repeats dominate, accounting for 95.6% in total. AG/CT and AGC/GCT were the dominant type of dinucleotide and trinucleotide repeats, accounting for 83.5% and 24.1%, respectively. Thirty pairs of primers were designed for each of randomly selected 30 sequences; 26 of them generated clear and reproducible bands, and 22 of them showed polymorphism. Eighteen pairs of primers obtained by the one or the other of the two methods above that showed polymorphism were selected to carry out germplasm genetic diversity analysis for 48 breeds of pineapple; similarity coefficients of these breeds were between 0.59 and 1.00, and they can be divided into four groups accordingly. Amplification products of five SSR markers were extracted and sequenced, corresponding repeat loci were found and locus mutations are mainly in copy number of repeats and base mutations in the flanking region.

  11. Promoting utilization of Saccharum spp. genetic resources through genetic diversity analysis and core collection construction.

    Directory of Open Access Journals (Sweden)

    Spurthi N Nayak

    Full Text Available Sugarcane (Saccharum spp. and other members of Saccharum spp. are attractive biofuel feedstocks. One of the two World Collections of Sugarcane and Related Grasses (WCSRG is in Miami, FL. This WCSRG has 1002 accessions, presumably with valuable alleles for biomass, other important agronomic traits, and stress resistance. However, the WCSRG has not been fully exploited by breeders due to its lack of characterization and unmanageable population. In order to optimize the use of this genetic resource, we aim to 1 genotypically evaluate all the 1002 accessions to understand its genetic diversity and population structure and 2 form a core collection, which captures most of the genetic diversity in the WCSRG. We screened 36 microsatellite markers on 1002 genotypes and recorded 209 alleles. Genetic diversity of the WCSRG ranged from 0 to 0.5 with an average of 0.304. The population structure analysis and principal coordinate analysis revealed three clusters with all S. spontaneum in one cluster, S. officinarum and S. hybrids in the second cluster and mostly non-Saccharum spp. in the third cluster. A core collection of 300 accessions was identified which captured the maximum genetic diversity of the entire WCSRG which can be further exploited for sugarcane and energy cane breeding. Sugarcane and energy cane breeders can effectively utilize this core collection for cultivar improvement. Further, the core collection can provide resources for forming an association panel to evaluate the traits of agronomic and commercial importance.

  12. Promoting utilization of Saccharum spp. genetic resources through genetic diversity analysis and core collection construction.

    Science.gov (United States)

    Nayak, Spurthi N; Song, Jian; Villa, Andrea; Pathak, Bhuvan; Ayala-Silva, Tomas; Yang, Xiping; Todd, James; Glynn, Neil C; Kuhn, David N; Glaz, Barry; Gilbert, Robert A; Comstock, Jack C; Wang, Jianping

    2014-01-01

    Sugarcane (Saccharum spp.) and other members of Saccharum spp. are attractive biofuel feedstocks. One of the two World Collections of Sugarcane and Related Grasses (WCSRG) is in Miami, FL. This WCSRG has 1002 accessions, presumably with valuable alleles for biomass, other important agronomic traits, and stress resistance. However, the WCSRG has not been fully exploited by breeders due to its lack of characterization and unmanageable population. In order to optimize the use of this genetic resource, we aim to 1) genotypically evaluate all the 1002 accessions to understand its genetic diversity and population structure and 2) form a core collection, which captures most of the genetic diversity in the WCSRG. We screened 36 microsatellite markers on 1002 genotypes and recorded 209 alleles. Genetic diversity of the WCSRG ranged from 0 to 0.5 with an average of 0.304. The population structure analysis and principal coordinate analysis revealed three clusters with all S. spontaneum in one cluster, S. officinarum and S. hybrids in the second cluster and mostly non-Saccharum spp. in the third cluster. A core collection of 300 accessions was identified which captured the maximum genetic diversity of the entire WCSRG which can be further exploited for sugarcane and energy cane breeding. Sugarcane and energy cane breeders can effectively utilize this core collection for cultivar improvement. Further, the core collection can provide resources for forming an association panel to evaluate the traits of agronomic and commercial importance.

  13. Assessment of genetic diversity and population structure of Vietnamese indigenous cattle populations by microsatellites

    DEFF Research Database (Denmark)

    Pham, Lan Doan; Do, Duy Ngoc; Binh, Nguyen Trong;

    2013-01-01

    geographic distances. Structure analysis indicated five homogeneous clusters. The Brahman, Lang Son, Ha Giang and U Dau Riu cattle were assigned to independent clusters while Nghe An, Thanh Hoa and Phu Yen cattle were grouped in a single cluster. We conclude that Vietnamese indigenous cattle have high levels...... of genetic diversity and distinct genetic structures. Based on these results, we recommend that for conservation homogenous populations (Nghe An, Thanh Hoa and Phu Yen) can be grouped to reduce costs and U Dau Riu, Lang Son and Ha Giang populations should be conserved separately to avoid loss of genetic...

  14. Initial genetic diversity enhances population establishment and alters genetic structuring of a newly established Daphnia metapopulation.

    Science.gov (United States)

    Holmes, Christopher J; Pantel, Jelena H; Schulz, Kimberly L; Cáceres, Carla E

    2016-07-01

    When newly created habitats are initially colonized by genotypes with rapid population growth rates, later arriving colonists may be prevented from establishing. Although these priority effects have been documented in multiple systems, their duration may be influenced by the diversity of the founding population. We conducted a large-scale field manipulation to investigate how initial clonal diversity influences temporal and landscape patterns of genetic structure in a developing metapopulation. Six genotypes of obligately asexual Daphnia pulex were stocked alone (no clonal diversity) or in combination ('high' clonal diversity) into newly created experimental woodland ponds. We also measured the population growth rate of all clones in the laboratory when raised on higher-quality and lower-quality resources. Our predictions were that in the 3 years following stocking, clonally diverse populations would be more likely to persist than nonclonally diverse populations and exhibit evidence for persistent founder effects. We expected that faster growing clones would be found in more pools and comprise a greater proportion of individuals genotyped from the landscape. Genetic composition, both locally and regionally, changed significantly following stocking. Six of 27 populations exhibited evidence for persistent founder effects, and populations stocked with 'high' clonal diversity were more likely to exhibit these effects than nonclonally diverse populations. Performance in the laboratory was not predictive of clonal persistence or overall dominance in the field. Hence, we conclude that although laboratory estimates of fitness did not fully explain metapopulation genetic structure, initial clonal diversity did enhance D. pulex population establishment and persistence in this system.

  15. Genetic diversity of Poa pratensis L. depending on geographical origin and compared with genetic markers

    Directory of Open Access Journals (Sweden)

    Magdalena Szenejko

    2016-09-01

    Full Text Available Background Poa pratensis is one of the most common species of meadow grass in Europe. Most cultivars of the species found in Poland were originally derived from its ecotypes. We compared the effectiveness of the RAPD and ISSR methods in assessing the genetic diversity of the selected populations of P. pratensis. We examined whether these methods could be useful for detecting a possible link between the geographical origin of a given population and its assessed genetic variation. Methods The molecular markers RAPD and ISSR were used and their efficiency compared using, inter alia, statistical multivariate methods (UPGMA and PCA. Results The low value of Dice’s coefficient (0.369 along with the significantly high percentage of polymorphic products indicates a substantial degree of genetic diversity among the studied populations. Our results found a correlation between the geographical origin of the studied populations and their genetic variations. For ISSR, which proved to be the more effective method in that respect, we selected primers with the greatest differentiating powers correlating to geographical origin. Discussion The populations evaluated in this study were characterized by a high genetic diversity. This seems to confirm the hypothesis that ecotypes of P. pratensis originating from different regions of Central Europe with different terrain structures and habitat conditions can be a source of great genetic variability.

  16. Characterisation of the genetic diversity of Brucella by multilocus sequencing

    Directory of Open Access Journals (Sweden)

    MacMillan Alastair P

    2007-04-01

    Full Text Available Abstract Background Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus. Results Nine discrete genomic loci corresponding to 4,396 bp of sequence were examined from 160 Brucella isolates. By assigning each distinct allele at a locus an arbitrary numerical designation the population was found to represent 27 distinct sequence types (STs. Diversity at each locus ranged from 1.03–2.45% while overall genetic diversity equated to 1.5%. Most loci examined represent housekeeping gene loci and, in all but one case, the ratio of non-synonymous to synonymous change was substantially Brucella species, B. abortus, B. melitensis, B. ovis and B. neotomae correspond to well-separated clusters. With the exception of biovar 5, B. suis isolates cluster together, although they form a more diverse group than other classical species with a number of distinct STs corresponding to the remaining four biovars. B. canis isolates are located on the same branch very closely related to, but distinguishable from, B. suis biovar 3 and 4 isolates. Marine mammal isolates represent a distinct, though rather weakly supported, cluster within which individual STs display one of three clear host preferences. Conclusion The sequence database provides a powerful dataset for addressing ongoing controversies in Brucella taxonomy and a tool for unambiguously placing atypical, phenotypically discordant or newly emerging Brucella isolates. Furthermore, by using the phylogenetic backbone described here, robust and rationally selected markers for use in

  17. Challenges and opportunities in estimating viral genetic diversity from next-generation sequencing data

    Directory of Open Access Journals (Sweden)

    Niko eBeerenwinkel

    2012-09-01

    Full Text Available Many viruses, including the clinically relevant RNA viruses HIV and HCV, exist in large populations and display high genetic heterogeneity within and between infected hosts. Assessing intra-patient viral genetic diversity is essential for understanding the evolutionary dynamics of viruses, for designing effective vaccines, and for the success of antiviral therapy. Next-generation sequencing technologies allow the rapid and cost-effective acquisition of thousands to millions of short DNA sequences from a single sample. However, this approach entails several challenges in experimental design and computational data analysis. Here, we review the entire process of inferring viral diversity from sample collection to computing measures of genetic diversity. We discuss sample preparation, including reverse transcription and amplification, and the effect of experimental conditions on diversity estimates due to in vitro base substitutions, insertions, deletions, and recombination. The use of different next-generation sequencing platforms and their sequencing error profiles are compared in the context of various applications of diversity estimation, ranging from the detection of single nucleotide variants to the reconstruction of whole-genome haplotypes. We describe the statistical and computational challenges arising from these technical artifacts, and we review existing approaches, including available software, for their solution. Finally, we discuss open problems, and highlight successful biomedical applications and potential future clinical use of next-generation sequencing to estimate viral diversity.

  18. Genetic diversity and bottleneck studies in the Marwari horse breed

    Indian Academy of Sciences (India)

    A. K. Gupta; M. Chauhan; S. N. Tandon; Sonia

    2005-12-01

    Genetic diversity within the Marwari breed of horses was evaluated using 26 different microsatellite pairs with 48 DNA samples from unrelated horses. This molecular characterisation was undertaken to evaluate the problem of genetic bottlenecks also, if any, in this breed. The estimated mean (± s.e.) allelic diversity was 5.9 (± 2.24), with a total of 133 alleles. A high level of genetic variability within this breed was observed in terms of high values of mean (± s.e.) effective number of alleles (3.3 ± 1.27), observed heterozygosity (0.5306 ± 0.22), expected Levene’s heterozygosity (0.6612 ± 0.15), expected Nei’s heterozygosity (0.6535 ± 0.14), and polymorphism information content (0.6120 ± 0.03). Low values of Wright’s fixation index, $F_{\\text{IS}}$ (0.2433 ± 0.05) indicated low levels of inbreeding. This basic study indicated the existence of substantial genetic diversity in the Marwari horse population. No significant genotypic linkage disequilibrium was detected across the population, suggesting no evidence of linkage between loci. A normal ‘L’ shaped distribution of mode–shift test, non-significant heterozygote excess on the basis of different models, as revealed from Sign, Standardized differences and Wilcoxon sign rank tests as well as non-significant ratio value suggested that there was no recent bottleneck in the existing Marwari breed population, which is important information for equine breeders. This study also revealed that the Marwari breed can be differentiated from some other exotic breeds of horses on the basis of three microsatellite primers.

  19. Detection of Genetic Diversity in Synthetic Hexaploid Wheats Using Microsatellite Markers

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-yue; LI Li-hui

    2007-01-01

    Ninety-five synthetic hexaploid wheats(2n=6x=42,AABBDD)were analyzed using 45 microsatellite markers to investigate the potential genetic diversity in wheat breeding programs.A total of 326 alleles were detected by these microsatellite primer pairs,with an average of 6.65 alleles per locus.The polymorphic information content(PIC),Simpson index(SI),and genetic similarity(GS)coefficient showed that the D genome is of the highest genetic diversity among the A,B,and D genomes in the synthetic hexaploid wheats.The results also indicated that the synthetic hexaploid wheat is an efficient way to enrich wheat genetic backgrounds,especially to use the genetic variations of the D genome from Aegilops squarrosa for wheat improvement.The UPGMA dendogram,based on a similarity matrix by a simple matching coefficient algorithm,delineated the above accessions into 5 major clusters and was in accordance with the available pedigree information.The results demonstrated the utility of microsatellite markers in detecting DNA polymorphism and estimating genetic diversity.

  20. Final Report DE-SC0006634. Quantifying phenotypic and genetic diversity of Miscanthus sinensis as a resource for knowledge-based improvement of M. ×giganteus (M. sinensis × M. sacchariflorus)

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, Erik [Univ. of Illinois, Urbana, IL (United States)

    2016-02-08

    Miscanthus is especially attractive as a bioenergy crop for temperate environments because it produces high yields, needs few inputs, and grows well during the cool weather of early spring and late fall when few warm-season grasses can. However, Miscanthus feedstock production for the emerging U.S. bioenergy industry and for existing demand in Europe is based on a single sterile, vegetatively propagated variety of M. ×giganteus. M. ×giganteus is an interspecific hybrid of the parental species M. sinensis and M. sacchariflorus. Prior to the current study, little information existed about the genetic diversity and breeding potential of either M. ×giganteus parental species. In the current project, we studied more than 600 accessions of M. sinensis from throughout its native range in China, Japan, and Korea, in addition to ornamental cultivars and U.S. naturalized populations. Using thousands of DNA markers, we identified seven geographically distinct genetic groups of M. sinensis. Notably, we found that the ornamental cultivars and U.S. naturalized populations were derived from only a subset of the Southern Japan group, indicating that our study greatly increased the genetic diversity available for breeding new biomass cultivars. Additionally, this new understanding of M. sinensis population structure could be used to predict which crosses may produce progeny with the greatest hybrid vigor. Replicated field trials were also established at multiple locations in North America and Asia. Data on traits of importance for biomass productivity, such as flowering time, yield and height, were taken. Analyses of the phenotypic data from the field trials along with the DNA markers allowed us to identify many marker-trait associations. These results will enable marker-assisted breeding, which will allow selection at the seedling stage rather than waiting two to three years to obtain phenotypic data. Thus, this study is expected to greatly increase the efficiency of breeding

  1. Genetic diversity of Salsola passerina populations in northwestern China based on inter-simple sequence repeat(ISSR)%基于ISSR西北地区珍珠猪毛菜(Salsola passerina)的遗传多样性

    Institute of Scientific and Technical Information of China (English)

    高天鹏; 高海宁; 张勇; 徐世健; 安黎哲

    2009-01-01

    Genetic diversity and differentiation among seven populations of Salsola passerina in north-western China were investigated using ISSR markers.15 ISSR primers gave rise to 196 discernible DNA fragments,of which 153(78.06%)were polymorphic.However,the polymorphism at the population level was relatively low,with an average of 45.60%.The mean expected heterozygosity and Shannon,s infor-mation index were 0.1759 and 0.281 1 at the species level,0.125l and 0.1977 at the population level,respectively.Based on Nei's Gst value,a large proportion of genetic variance(70.96%)resided among individuals within populations;however,only 29.04%genetic variance resided among populations.Pair-wise genetic identity values among populations had a mean of 0.932 0.AMOVA analysis also indicated a similar genetic structure.UPGMA cluster analysis based on Nei's genetic distance divided the popula-tions into three main groups:QHDLH,LZXJS and the rest five populations(NXZN,NMWH,MQHLY,JTDX,and AXTS).The mantel test showed that genetic distance was significantly correlated with verti-cal geographical distribution(P<0.001).A means of preserving genetic variation of this endemic species in those regions is to stop deforestation and to protect its suitable habitats in view of the lower genetic diversity within populations.%运片JSSR分子标记的方法,对分布于中国北方7个居群的137个珍珠猪毛菜个体筛选出了15条引物,产生了196条带,其中153条为多态性条带,总的基因多态率为78.06%,多态性在种群水平上较低,平均多态率为45.60%.平均期望杂合度和Shannon信息指数在种间水平上分别为0.1759和0.2811,在居群水平上为0.125l和0.1977,种群内个体间的遗传分化较大,为70.96%,而种群间遗传分化较小,为29.04%,种群间的遗传一致度平均为0.9320.AMOVA分析得到了相似结果.基于Nei's遗传距离的UPGMA聚类分析将7个居群分为3组:德令哈、兰州和其余5个居群(中宁,乌海,民勤,金塔和

  2. Genetic Diversity and Molecular Evolution of Chinese Waxy Maize Germplasm

    Science.gov (United States)

    Zheng, Hongjian; Wang, Hui; Yang, Hua; Wu, Jinhong; Shi, Biao; Cai, Run; Xu, Yunbi; Wu, Aizhong; Luo, Lijun

    2013-01-01

    Waxy maize (Zea mays L. var. certaina Kulesh), with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection. PMID:23818949

  3. Genetic diversity and molecular evolution of Chinese waxy maize germplasm.

    Directory of Open Access Journals (Sweden)

    Hongjian Zheng

    Full Text Available Waxy maize (Zea mays L. var. certaina Kulesh, with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima's D and Fu and Li's F* were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection.

  4. Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations

    DEFF Research Database (Denmark)

    Pham, L. D.; Do, Duy Ngoc; Nam, L. Q.

    2014-01-01

    in 236 samples. All estimated loci were very polymorphic indicated by high values of polymorphism information content (from 0.76 in S0225 to 0.92 in Sw2410). Indigenous populations had very high level of genetic diversity (mean He = 0.75); of all indigenous breeds, Lung Pu showed highest mean number...

  5. Molecular markers: a potential resource for ginger genetic diversity studies.

    Science.gov (United States)

    Ismail, Nor Asiah; Rafii, M Y; Mahmud, T M M; Hanafi, M M; Miah, Gous

    2016-12-01

    Ginger is an economically important and valuable plant around the world. Ginger is used as a food, spice, condiment, medicine and ornament. There is available information on biochemical aspects of ginger, but few studies have been reported on its molecular aspects. The main objective of this review is to accumulate the available molecular marker information and its application in diverse ginger studies. This review article was prepared by combing material from published articles and our own research. Molecular markers allow the identification and characterization of plant genotypes through direct access to hereditary material. In crop species, molecular markers are applied in different aspects and are useful in breeding programs. In ginger, molecular markers are commonly used to identify genetic variation and classify the relatedness among varieties, accessions, and species. Consequently, it provides important input in determining resourceful management strategies for ginger improvement programs. Alternatively, a molecular marker could function as a harmonizing tool for documenting species. This review highlights the application of molecular markers (isozyme, RAPD, AFLP, SSR, ISSR and others such as RFLP, SCAR, NBS and SNP) in genetic diversity studies of ginger species. Some insights on the advantages of the markers are discussed. The detection of genetic variation among promising cultivars of ginger has significance for ginger improvement programs. This update of recent literature will help researchers and students select the appropriate molecular markers for ginger-related research.

  6. Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco from five lakes in the middle and lower reaches of the Yangtze River, China, based on mitochondrial DNA control region.

    Science.gov (United States)

    Zhong, Liqiang; Song, Chao; Wang, Minghua; Chen, Youming; Qin, Qin; Pan, Jianlin; Chen, Xiaohui

    2013-10-01

    Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco were examined by using mitochondrial DNA control region sequences in 143 specimens sampled from five lakes in the middle and lower reaches of the Yangtze River, China; 151 polymorphic sites defined 72 distinct haplotypes. Haplotype diversity indices (0.903-0.953) and nucleotide diversity indices (0.00378-0.00970) demonstrated low genetic diversity of the yellow catfish populations in the five lakes. The analysis of molecular variance and the fixation index (F(st) = 0.0896) revealed insignificant genetic difference between samples from different lakes. In addition, neutral tests and analysis of mismatch distribution suggested that yellow catfish might have undergone a population expansion. Neighbor-joining tree indicated a correlation between these population genetic differences and geographic distance. This study revealed the extant population genetic diversity and structure of the yellow catfish and was in favor of the related fishery management issues including fishery stock identification, conservation, and artificial breeding.

  7. Assessment of Genetic Diversity and Population Genetic Structure of Corylus mandshurica in China Using SSR Markers.

    Directory of Open Access Journals (Sweden)

    Jian-Wei Zong

    Full Text Available Corylus mandshurica, also known as pilose hazelnut, is an economically and ecologically important species in China. In this study, ten polymorphic simple sequence repeat (SSR markers were applied to evaluate the genetic diversity and population structure of 348 C. mandshurica individuals among 12 populations in China. The SSR markers expressed a relatively high level of genetic diversity (Na = 15.3, Ne = 5.6604, I = 1.8853, Ho = 0.6668, and He = 0.7777. According to the coefficient of genetic differentiation (Fst = 0.1215, genetic variation within the populations (87.85% were remarkably higher than among populations (12.15%. The average gene flow (Nm = 1.8080 significantly impacts the genetic structure of C. mandshurica populations. The relatively high gene flow (Nm = 1.8080 among wild C. mandshurica may be caused by wind-pollinated flowers, highly nutritious seeds and self-incompatible mating system. The UPGMA (unweighted pair group method of arithmetic averages dendrogram was divided into two main clusters. Moreover, the results of STRUCTURE analysis suggested that C. mandshurica populations fell into two main clusters. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population subdivisions and the genetic relationships among populations of C. mandshurica. Group I accessions were located in Northeast China, while Group II accessions were in North China. It is worth noting that a number of genetically similar populations were located in the same geographic region. The results further showed that there was obvious genetic differentiation among populations from Northeast China to North China. Results from the Mantel test showed a weak but still significant positive correlation between Nei's genetic distance and geographic distance (km among populations (r = 0.419, P = 0.005, suggesting that genetic differentiation in the 12 C. mandshurica populations might be related to geographic

  8. Genetic Diversity Evaluation of Maize Recurrent Selection Population with RAPD Marker

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The genetic diversity of maize populations Wuxi (W) from Southwest China, BSSS9(B) from America, Mohuangjiu (M) from Mexico, WBMC0 synthesized by W, B, M as main parents,WBMC1 one cycle selected from WBMC0 were evaluated by RAPD molecular marker. The results showed that :(1) Totally 89 fragments (loci) were amplified by 15 10-mar random primers, the proportion of polymorphic loci were W 76. 4%, B 75. 3%, M 79. 8%,WBMC0 85. 4% and WBMC1 92. 1% respectively; (2) The mean gene heterozygosity based on 89 loci was W 0. 285, B 0. 252, M 0. 296, WBMC0 0. 327 and WBMC1 0. 346; (3) The mean genetic distance based on 89 loci were W 0. 2533, B 0. 2246, M 0. 2481, WBMC0 0. 3006 and WBMC1 0. 3119; (4) The genotypic mean numbers amplified by 15 primers were W 9.1, B 7.8, M 8.5, WBMC0 10. 1 and WBMC1 10. All indexes indicated that the synthesized maize population were more polymorphic than the parent populations in DNA level. One cycle selection did not reduce the variation. The new conception of "genotypic diversity" (the number of genotypes in a population) was provided to describe the genetic diversity for any population being equilibrium or unequilibrium in genetics. The principle and technical system were discussed for evaluating genetic variation of recurrent selection population using RAPD molecular marker.

  9. Genetic Diversity of Tropical Hybrid Rice Germplasm Measured by Molecular Markers

    Institute of Scientific and Technical Information of China (English)

    HE Zhi-zhou; XIE Fang-ming; CHEN Li-yun; Madonna Angelita DELA PAZ

    2012-01-01

    Investigation of genetic diversity and relationships among breeding lines is of great importance to facilitate parent selection in hybrid rice breeding programs.In this study,we characterized 168 hybrid rice parents from International Rice Research Institute with 207 simple sequence repeat (SSR) and 353 single nucleotide polymorphism (SNP) markers.A total of 1 267 SSR and 706 SNP alleles were detected with the averages of 6.1 (SSR) and 2.0 (SNP) alleles per locus respectively across all lines.Based on the genetic distances estimated from the SSR and SNP markers separately and combined,the unrooted neighbor-joining cluster and STRUCTURE analyses consistently separated the 168 hybrid rice parents into two major groups:B-line and R-line,which is consistent with known parent pedigree information.The genetic distance matrices derived from the SSR and SNP genotyping were highly correlated (r=0.81,P 0.001),indicating that both of the SSR and SNP markers have distinguishable power to detect polymorphism and are appropriate for genetic diversity analysis among tropical hybrid rice parents.A subset of 60 SSR markers were also chosen by the Core Hunter with 368 alleles,and the cluster analysis based on the total and subset of SSR markers highly corresponded at r =0.91 (P < 0.001 ),suggesting that fewer SSR markers can be used to classify and evaluate genetic diversity among parental lines.

  10. Loss and recovery of genetic diversity in adapting populations of HIV.

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    Pleuni S Pennings

    2014-01-01

    Full Text Available The evolution of drug resistance in HIV occurs by the fixation of specific, well-known, drug-resistance mutations, but the underlying population genetic processes are not well understood. By analyzing within-patient longitudinal sequence data, we make four observations that shed a light on the underlying processes and allow us to infer the short-term effective population size of the viral population in a patient. Our first observation is that the evolution of drug resistance usually occurs by the fixation of one drug-resistance mutation at a time, as opposed to several changes simultaneously. Second, we find that these fixation events are accompanied by a reduction in genetic diversity in the region surrounding the fixed drug-resistance mutation, due to the hitchhiking effect. Third, we observe that the fixation of drug-resistance mutations involves both hard and soft selective sweeps. In a hard sweep, a resistance mutation arises in a single viral particle and drives all linked mutations with it when it spreads in the viral population, which dramatically reduces genetic diversity. On the other hand, in a soft sweep, a resistance mutation occurs multiple times on different genetic backgrounds, and the reduction of diversity is weak. Using the frequency of occurrence of hard and soft sweeps we estimate the effective population size of HIV to be 1.5 x 10(5 (95% confidence interval [0.8 x 10(5,4.8 x 10(5]. This number is much lower than the actual number of infected cells, but much larger than previous population size estimates based on synonymous diversity. We propose several explanations for the observed discrepancies. Finally, our fourth observation is that genetic diversity at non-synonymous sites recovers to its pre-fixation value within 18 months, whereas diversity at synonymous sites remains depressed after this time period. These results improve our understanding of HIV evolution and have potential implications for treatment strategies.

  11. Influence of ethnolinguistic diversity on the sorghum genetic patterns in subsistence farming systems in eastern Kenya.

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    Vanesse Labeyrie

    Full Text Available Understanding the effects of actions undertaken by human societies on crop evolution processes is a major challenge for the conservation of genetic resources. This study investigated the mechanisms whereby social boundaries associated with patterns of ethnolinguistic diversity have influenced the on-farm distribution of sorghum diversity. Social boundaries limit the diffusion of planting material, practices and knowledge, thus shaping crop diversity in situ. To assess the effect of social boundaries, this study was conducted in the contact zone between the Chuka, Mbeere and Tharaka ethnolinguistic groups in eastern Kenya. Sorghum varieties were inventoried and samples collected in 130 households. In all, 297 individual plants derived from seeds collected under sixteen variety names were characterized using a set of 18 SSR molecular markers and 15 morphological descriptors. The genetic structure was investigated using both a Bayesian assignment method and distance-based clustering. Principal Coordinates Analysis was used to describe the structure of the morphological diversity of the panicles. The distribution of the varieties and the main genetic clusters across ethnolinguistic groups was described using a non-parametric MANOVA and pairwise Fisher tests. The spatial distribution of landrace names and the overall genetic spatial patterns were significantly correlated with ethnolinguistic partition. However, the genetic structure inferred from molecular makers did not discriminate the short-cycle landraces despite their morphological distinctness. The cases of two improved varieties highlighted possible fates of improved materials. The most recent one was often given the name of local landraces. The second one, that was introduced a dozen years ago, displays traces of admixture with local landraces with differential intensity among ethnic groups. The patterns of congruence or discordance between the nomenclature of farmers' varieties and the

  12. Genetic diversity analysis of highly incomplete SNP genotype data with imputations: an empirical assessment.

    Science.gov (United States)

    Fu, Yong-Bi

    2014-03-13

    Genotyping by sequencing (GBS) recently has emerged as a promising genomic approach for assessing genetic diversity on a genome-wide scale. However, concerns are not lacking about the uniquely large unbalance in GBS genotype data. Although some genotype imputation has been proposed to infer missing observations, little is known about the reliability of a genetic diversity analysis of GBS data, with up to 90% of observations missing. Here we performed an empirical assessment of accuracy in genetic diversity analysis of highly incomplete single nucleotide polymorphism genotypes with imputations. Three large single-nucleotide polymorphism genotype data sets for corn, wheat, and rice were acquired, and missing data with up to 90% of missing observations were randomly generated and then imputed for missing genotypes with three map-independent imputation methods. Estimating heterozygosity and inbreeding coefficient from original, missing, and imputed data revealed variable patterns of bias from assessed levels of missingness and genotype imputation, but the estimation biases were smaller for missing data without genotype imputation. The estimates of genetic differentiation were rather robust up to 90% of missing observations but became substantially biased when missing genotypes were imputed. The estimates of topology accuracy for four representative samples of interested groups generally were reduced with increased levels of missing genotypes. Probabilistic principal component analysis based imputation performed better in terms of topology accuracy than those analyses of missing data without genotype imputation. These findings are not only significant for understanding the reliability of the genetic diversity analysis with respect to large missing data and genotype imputation but also are instructive for performing a proper genetic diversity analysis of highly incomplete GBS or other genotype data.

  13. Origin and genetic diversity of diploid parthenogenetic Artemia in Eurasia.

    Science.gov (United States)

    Maccari, Marta; Amat, Francisco; Gómez, Africa

    2013-01-01

    There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia). Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca) are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages.

  14. Origin and Genetic Diversity of Diploid Parthenogenetic Artemia in Eurasia

    Science.gov (United States)

    Maccari, Marta; Amat, Francisco; Gómez, Africa

    2013-01-01

    There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia). Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca) are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages. PMID:24376692

  15. Origin and genetic diversity of diploid parthenogenetic Artemia in Eurasia.

    Directory of Open Access Journals (Sweden)

    Marta Maccari

    Full Text Available There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia. Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages.

  16. Diversity Controlling Genetic Algorithm for Order Acceptance and Scheduling Problem

    Directory of Open Access Journals (Sweden)

    Cheng Chen

    2014-01-01

    Full Text Available Selection and scheduling are an important topic in production systems. To tackle the order acceptance and scheduling problem on a single machine with release dates, tardiness penalty, and sequence-dependent setup times, in this paper a diversity controlling genetic algorithm (DCGA is proposed, in which a diversified population is maintained during the whole search process through survival selection considering both the fitness and the diversity of individuals. To measure the similarity between individuals, a modified Hamming distance without considering the unaccepted orders in the chromosome is adopted. The proposed DCGA was validated on 1500 benchmark instances with up to 100 orders. Compared with the state-of-the-art algorithms, the experimental results show that DCGA improves the solution quality obtained significantly, in terms of the deviation from upper bound.

  17. Identification and Preliminary Analysis of the Genetic Diversity of Cenococcum geophilum Fr.

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-hong; YAN Wei; XU Yan

    2007-01-01

    To identify Cenococcum geophilum Fr., estimate their genetic diversity and study the effects on their genetic variation,27 Chinese C. geophilum isolates from 6 host plant species and 5 French C. geophilum isolates were analyzed using morphological and molecular methods. The universal primers ITS1/ITS4 were used in PCR-RFLP to amplify the rDNA internal transcribed spacer (ITS) of tested C. geophilum isolates. The amplified products were digested with EcoR Ⅰ,Hinf Ⅰ, and Mbo Ⅰ, and the digested fragments of PCR products showed that there were obvious differences. A random primer (5'-CGCACCGCAC-3') was employed in RAPD to amplify the genomic DNA of C. geophilum, and 19 detectable and reliable DNA bands of 300-2 000 bp size were observed. According to the number, position, and strength of the DNA bands in agarose gel, the genetic distance and the genetic similarity among C. geophilum isolates were calculated using the PopGen Ver. 1.31 dendrogram analysis software. A phylogenetic tree was constructed based on the genetic distance by the Neighbor-Joining/UPGMA in PHYLIP. The results suggest the high level of genetic diversity among C. geophilum isolates from the same or different hosts. The effects of geographical factors or host plant species on C. geophilum genetic variation are not obvious.

  18. The impact of recent events on human genetic diversity.

    Science.gov (United States)

    Jobling, Mark A

    2012-03-19

    The historical record tells us stories of migrations, population expansions and colonization events in the last few thousand years, but what was their demographic impact? Genetics can throw light on this issue, and has mostly done so through the maternally inherited mitochondrial DNA (mtDNA) and the male-specific Y chromosome. However, there are a number of problems, including marker ascertainment bias, possible influences of natural selection, and the obscuring layers of the palimpsest of historical and prehistorical events. Y-chromosomal lineages are particularly affected by genetic drift, which can be accentuated by recent social selection. A diversity of approaches to expansions in Europe is yielding insights into the histories of Phoenicians, Roma, Anglo-Saxons and Vikings, and new methods for producing and analysing genome-wide data hold much promise. The field would benefit from more consensus on appropriate methods, and better communication between geneticists and experts in other disciplines, such as history, archaeology and linguistics.

  19. Human impact on genetic diversity of Toxoplasma gondii: example of the anthropized environment from French Guiana.

    Science.gov (United States)

    Mercier, A; Ajzenberg, D; Devillard, S; Demar, M P; de Thoisy, B; Bonnabau, H; Collinet, F; Boukhari, R; Blanchet, D; Simon, S; Carme, B; Dardé, M-L

    2011-08-01

    In French Guiana, severe cases of toxoplasmosis in immunocompetent patients are associated with atypical strains of Toxoplasma gondii linked to a wild neotropical rainforest cycle and a higher genetic diversity than usually observed for T. gondii isolates from anthropized environment. This raises the question of the impact of anthropization of the natural environment, on genetic diversity and on the population structure of T. gondii. However, few data are available on strains circulating in the anthropized areas from French Guiana. Seropositive animals originating mainly from anthropized sub-urban areas and punctually from wild environment in French Guiana were analyzed for T. gondii isolation and genotyping. Thirty-three strains were obtained by bioassay in mice and compared with 18 previously reported isolates chiefly originating from the Amazon rainforest. The genotyping analysis performed with 15 microsatellite markers located on 12 different chromosomes revealed a lower genetic diversity in the anthropized environment. Results were analyzed in terms of population structure by clustering methods, Neighbor-joining trees reconstruction based on genetic distances, F(ST,) Mantel's tests and linkage disequilibrium. They clearly showed a genetic differentiation between strains associated to the anthropized environment and those associated to the wild, but with some inbreeding between them. The majority of strains from the anthropized environment were clustered into additional lineages of T. gondii that are common in the Caribbean. In conclusion the two environmental populations "wild" and "anthropized" were genetically well differentiated. The anthropization of the environment seems to be accompanied with a decreased diversity of T. gondii associated with a greater structure of the populations. We detected potential interpenetration and genetic exchanges between these two environmental populations. As a higher pathogenicity in human of "wild" genotypes has been

  20. Genetic diversity among Juglans regia L. genotypes assessed by morphological traits and microsatellite markers

    Directory of Open Access Journals (Sweden)

    R. Mahmoodi

    2013-05-01

    Full Text Available In this study, genetic diversity was assayed among 16 accessions and five cultivars of Persian walnut (Juglans regia L. using morphological traits and nine simple sequence repeat (SSR markers. Samples were collected from Agriculture Research Center of Urmia city (North West Iran. Study on important morphological traits revealed genetic similarity of -0.6 to 0.99 based on CORR coefficient. The microsatellite marker system produced 34 alleles in range of 160-290 bp. The minimum (2 and maximum (7 number of alleles were obtained from WGA71 and WGA202 genetic loci, respectively. The mean number of alleles per locus was 4.25. Jaccard’s similarity coefficient ranged from 0.13 to 0.76. The results of this paper indicate high diversity among these genotypes which could be used for breeding management.

  1. The genetic diversity of triticale genotypes involved in Polish breeding programs.

    Science.gov (United States)

    Niedziela, Agnieszka; Orłowska, Renata; Machczyńska, Joanna; Bednarek, Piotr T

    2016-01-01

    Genetic diversity analysis of triticale populations is useful for breeding programs, as it helps to select appropriate genetic material for classifying the parental lines, heterotic groups and predicting hybrid performance. In our study 232 breeding forms were analyzed using diversity arrays technology markers. Principal coordinate analysis followed by model-based Bayesian analysis of population structure revealed the presence of weak data structuring with three groups of data. In the first group, 17 spring and 17 winter forms were clustered. The second and the third groups were represented by 101 and 26 winter forms, respectively. Polymorphic information content values, as well as Shannon's Information Index, were higher for the first (0.319) and second (0.309) than for third (0.234) group. AMOVA analysis demonstrated a higher level of within variation (86 %) than among populations (14 %). This study provides the basic information on the presence of structure within a genetic pool of triticale breeding forms.

  2. Genetic diversity among Juglans regia L. genotypes assessed by morphological traits and microsatellite markers

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoodi, R.; Rahmani, F.; Rezaee, R.

    2013-06-01

    In this study, genetic diversity was assayed among 16 accessions and five cultivars of Persian walnut (Juglans regia L.) using morphological traits and nine simple sequence repeat (SSR) markers. Samples were collected from Agriculture Research Center of Urmia city (North West Iran). Study on important morphological traits revealed genetic similarity of -0.6 to 0.99 based on CORR coefficient. The microsatellite marker system produced 34 alleles in range of 160-290 bp. The minimum (2) and maximum (7) number of alleles were obtained from WGA71 and WGA202 genetic loci, respectively. The mean number of alleles per locus was 4.25. Jaccards similarity coefficient ranged from 0.13 to 0.76. The results of this paper indicate high diversity among these genotypes which could be used for breeding management. (Author) 28 refs.

  3. Centennial olive trees as a reservoir of genetic diversity

    Science.gov (United States)

    Díez, Concepción M.; Trujillo, Isabel; Barrio, Eladio; Belaj, Angjelina; Barranco, Diego; Rallo, Luis

    2011-01-01

    Background and Aims Genetic characterization and phylogenetic analysis of the oldest trees could be a powerful tool both for germplasm collection and for understanding the earliest origins of clonally propagated fruit crops. The olive tree (Olea europaea L.) is a suitable model to study the origin of cultivars due to its long lifespan, resulting in the existence of both centennial and millennial trees across the Mediterranean Basin. Methods The genetic identity and diversity as well as the phylogenetic relationships among the oldest wild and cultivated olives of southern Spain were evaluated by analysing simple sequence repeat markers. Samples from both the canopy and the roots of each tree were analysed to distinguish which trees were self-rooted and which were grafted. The ancient olives were also put into chronological order to infer the antiquity of traditional olive cultivars. Key Results Only 9·6 % out of 104 a priori cultivated ancient genotypes matched current olive cultivars. The percentage of unidentified genotypes was higher among the oldest olives, which could be because they belong to ancient unknown cultivars or because of possible intra-cultivar variability. Comparing the observed patterns of genetic variation made it possible to distinguish which trees were grafted onto putative wild olives. Conclusions This study of ancient olives has been fruitful both for germplasm collection and for enlarging our knowledge about olive domestication. The findings suggest that grafting pre-existing wild olives with olive cultivars was linked to the beginnings of olive growing. Additionally, the low number of genotypes identified in current cultivars points out that the ancient olives from southern Spain constitute a priceless reservoir of genetic diversity. PMID:21852276

  4. Genetic Diversity of Some Tomato Cultivars and Breeding Lines Commonly Used in Pakistani Breeding Program

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    Muhammad Azhar Shah

    2014-10-01

    Full Text Available Genetic diversity present in gene pool is an important determination for breeding programs, and characterization is useful of building crop plant collections primarily based on the knowledge of the presence of valuable genes and traits. Developing successful varieties for increasing the future yield and quality of tomato depend mainly on the genetic diversity of parents used in the breeding program. Molecular characterization of 21 tomato genotypes used in in Pakistani breeding program was studied using random amplified polymorphic DNA (RAPD markers. Total 102 bands were amplified among 21 genotypes using 20 RAPD primers. Overall 73.5% polymorphism was shown as 75 out of 102 loci were polymorphic. High degree of divergence between varieties was indicated by low level of monomorphic bands. The number of PCR products per primer varied from 2-8 with an average of 5.1 bands per primer. Primer GL J-20 and GL C-09 produced maximum number of bands whereas the primers GL A-09 produced the lowest. The polymorphism per RAPD primer ranged from 50% to 100% with an average of 73.5%. The accumulative analysis of amplified products generated by RAPD’s was enough to assess the genetic diversity among the genotypes. The information would be helpful for formulating future breeding and genome mapping programs. This study will also work as an indicator for tomato breeders to evolve varieties with genetic diverse back ground to achieve sustainability in tomato production in the country.

  5. Genetic diversity and matrilineal structure in Chinese tree shrews inhabiting Kunming, China.

    Science.gov (United States)

    Chen, Shi-Yi; Xu, Ling; Lü, Long-Bao; Yao, Yong-Gang

    2011-02-01

    Due to their special phylogenetic position in the Euarchontoglires and close affinity to primates, tree shrews have been proposed as an alternative experimental animal to primates in biomedical research. However, the population genetic structure of tree shrews has largely remained unknown and this has hindered the development of tree shrew breeding and selection. Here we sampled 80 Chinese tree shrews (Tupaia belangeri chinensis) in Kunming, China, and analyzed partial mtDNA control region sequence variation. Based on our samples and two published sequences from northern tree shrews (T. belangeri), we identified 29 substitutions in the mtDNA control region fragment (~604 bp) across 82 individuals and defined 13 haplotypes. Seventeen samples were selected for sequencing of the cytochrome b (Cyt b; 1134 bp) gene based on control region sequence variation and were analyzed in combination with 34 published sequences to solidify the phylogenetic pattern obtained from control region data. Overall, tree shrews from Kunming have high genetic diversity and present a remarkable long genetic distance to the two reported northern tree shrews outside China. Our results provide some caution when using tree shrews to establish animal models because of this apparent genetic difference. In addition, the high genetic diversity of Chinese tree shrews inhabiting Kunming suggests that systematic genetic investigations should be conducted before establishing an inbred strain for medical and biological research.

  6. Genetic diversity of the cestode Echinococcus multilocularis in red foxes at a continental scale in Europe.

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    Jenny Knapp

    Full Text Available BACKGROUND: Alveolar echinococcosis (AE is a severe helminth disease affecting humans, which is caused by the fox tapeworm Echinococcus multilocularis. AE represents a serious public health issue in larger regions of China, Siberia, and other regions in Asia. In Europe, a significant increase in prevalence since the 1990s is not only affecting the historically documented endemic area north of the Alps but more recently also neighbouring regions previously not known to be endemic. The genetic diversity of the parasite population and respective distribution in Europe have now been investigated in view of generating a fine-tuned map of parasite variants occurring in Europe. This approach may serve as a model to study the parasite at a worldwide level. METHODOLOGY/PRINCIPAL FINDINGS: The genetic diversity of E. multilocularis was assessed based upon the tandemly repeated microsatellite marker EmsB in association with matching fox host geographical positions. Our study demonstrated a higher genetic diversity in the endemic areas north of the Alps when compared to other areas. CONCLUSIONS/SIGNIFICANCE: The study of the spatial distribution of E. multilocularis in Europe, based on 32 genetic clusters, suggests that Europe can be considered as a unique global focus of E. multilocularis, which can be schematically drawn as a central core located in Switzerland and Jura Swabe flanked by neighbouring regions where the parasite exhibits a lower genetic diversity. The transmission of the parasite into peripheral regions is governed by a "mainland-island" system. Moreover, the presence of similar genetic profiles in both zones indicated a founder event.

  7. Molecular Insights into the Genetic Diversity of Garcinia cambogia Germplasm Accessions

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    C Tharachand

    2015-10-01

    Full Text Available ABSTRACTIn this work, the genetic relationship among twelveGarcinia cambogia (Gaertn. Desr. accessions were evaluated using Random Amplified Polymorphic DNA markers. The samples were part of the germplasm collected and maintained at NBPGR Regional station, Thrissur, India. Out of thirty RAPD primers used for screening, seven primers produced a total of 128 polymorphic markers in twelve accessions. The Polymorphic Information Content (PIC ranged from 0.28 (OPA18 to 0.37 (OPA9 and Marker Index (MI ranged between 3.61 (OPA12 and 5.93 (OPA3 among the primers used. Jaccard's coefficient of genetic similarity ranged between 0.07 and 0.64. The dendrogram constructed based on the similarity matrix generated from the molecular and morphological data showed the genetic relationship among the sampled accessions. Mantel matrix test showed a positive correlation (r = 0.49 between the cluster analysis of RAPD data and morphological data. The clustering pattern in the molecular dendrogram and Principle Coordinate Analysis (PCoA showed that the genotypes were diverse, which was in congruence with the similarity index values and morphological dendrogram. High frequency of similarity values in the range of 0.11 to 0.17 suggested the existence of high genetic diversity among the accessions. The high level of genetic diversity among the studied accessions ofG.cambogia was also supported by the large variation in the morphological characters observed in the flowers, leaves, fruits and seeds of these sampled accessions. This is the first report for the molecular based genetic diversity studies for these accessions.

  8. Reduced Genetic Diversity and Increased Dispersal in Guigna (Leopardus guigna) in Chilean Fragmented Landscapes.

    Science.gov (United States)

    Napolitano, Constanza; Díaz, Diego; Sanderson, Jim; Johnson, Warren E; Ritland, Kermit; Ritland, Carol E; Poulin, Elie

    2015-01-01

    Landscape fragmentation is often a major cause of species extinction as it can affect a wide variety of ecological processes. The impact of fragmentation varies among species depending on many factors, including their life-history traits and dispersal abilities. Felids are one of the groups most threatened by fragmented landscapes because of their large home ranges, territorial behavior, and low population densities. Here, we model the impacts of habitat fragmentation on patterns of genetic diversity in the guigna (Leopardus guigna), a small felid that is closely associated with the heavily human-impacted temperate rainforests of southern South America. We assessed genetic variation in 1798 base pairs of mitochondrial DNA sequences, 15 microsatellite loci, and 2 sex chromosome genes and estimated genetic diversity, kinship, inbreeding, and dispersal in 38 individuals from landscapes with differing degrees of fragmentation on Chiloé Island in southern Chile. Increased fragmentation was associated with reduced genetic diversity, but not with increased kinship or inbreeding. However, in fragmented landscapes, there was a weaker negative correlation between pairwise kinship and geographic distance, suggesting increased dispersal distances. These results highlight the importance of biological corridors to maximize connectivity in fragmented landscapes and contribute to our understanding of the broader genetic consequences of habitat fragmentation, especially for forest-specialist carnivores.

  9. Genetic diversity in maize dent landraces assessed by morphological and molecular markers

    Directory of Open Access Journals (Sweden)

    Ristić Danijela

    2013-01-01

    Full Text Available Maize Research Institute “Zemun Polje” genebank maintains a collection of landraces grouped into 18 agro-ecological collected from ex-Yugoslavia territories. The application and comparison of different marker systems are important for the characterization and use of maize landraces in breeding program, as potential sources of desirable traits. In this study, 15 morphological traits, 7 RAPD primers and 10 SSR primer pairs were applied to i to determine genetic distance between 21 maize dent landraces and ii compare results obtained on morphological and molecular markers. Phenotypic analysis showed high level of heterogeneity between landraces. Higher level of genetic diversity was obtained with SSR than with RAPD. Genetic distance mean value for RAPD data was 0.35 i.e. for SSR 0.48. Based on the morphological traits and molecular markers, unweighted pairgroup method (UPGMA analysis was applied for cluster analysis, using statistical NTSYSpc program package. Cluster analysis of morphological and molecular markers distances did not show the same population grouping. Better agreement with agro-ecological data was obtained with RAPD markers. Correlations between dissimilarity matrices for different types of markers were low. Data obtained in this work could be useful for further study of a larger number of landraces, and conservation of genetic resources and their genetic diversity. [Projekat Ministarstva nauke Republike Srbije, br. TR31028: Exploitation of maize diversity to improve grain quality and drought tolerance

  10. Evaluation of Genetic Diversity of Sichuan Common Wheat Landraces in China by SSR Markers

    Institute of Scientific and Technical Information of China (English)

    LI Wei; BIAN Chun-mei; WEI Yu-ming; LIU An-jun; CHEN Guo-yue; PU Zhi-en; LIU Ya-xi; ZHENG You-liang

    2013-01-01

    Genetic diversity of 62 Sichuan wheat landraces accessions of China was investigated by agronomic traits and SSR markers. The landrace population showed the characters of higher tiller capability and more kernels/spike, especially tiller no./plant of six accessions was over 40 and kernels/spike of three accessions was more than 70. A total of 547 alleles in 124 polymorphic loci were detected with an average of 4.76 alleles per locus by 114 SSR markers. Parameters analysis indicated that the genetic diversity ranked as genome A>genome B>genome D, and the homoeologous groups ranked as 5>4>3>1>2>7>6 based on genetic richness (Ri). Furthermore, chromosomes 2A, 1B and 3D had more diversity than that of chromosomes 4A, 7A and 6B. The variation of SSR loci on chromosomes 1B, 2A, 2D, 3B, and 4B implied that, in the past, different selective pressures might have acted on different chromosome regions of these landraces. Our results suggested that Sichuan common wheat landraces is a useful genetic resource for genetic research and wheat improvement.

  11. Genetic diversity of Cosmos species revealed by RAPD and ISSR markers.

    Science.gov (United States)

    Rodríguez-Bernal, A; Piña-Escutia, J L; Vázquez-García, L M; Arzate-Fernández, A M

    2013-12-04

    The genus Cosmos is native of America and is constituted by 34 species; 28 of them are endemic of Mexico. The cosmos are used as a nematicide, antimalarial, and antioxidative agent. The aim of this study was to estimate the genetic diversity among 7 cosmos species based on random amplified polymorphic DNA (RAPD) and inter-simple sequences repeats (ISSR) markers. With RAPD markers, the obtained polymorphism was 91.7 % and the genetic diversity was 0.33, whereas these values were 65.6%, and 0.22 from ISSR markers, respectively, indicating the presence of high genetic diversity among the Cosmos species that were analyzed. The unweighted pair group method with arithmetic mean dendrograms that were obtained with both markers were notably similar, revealing 2 clusters and indicating a clear genetic differentiation among the Cosmos species that were assessed. The first cluster comprised the species Cosmos sulphureus, Cosmos pacificus, and Cosmos diversifolius, while the second cluster included the species Cosmos purpureus, Cosmos crithmifolius, Cosmos bipinnatus, and Cosmos parviflorus. Besides this, the Cosmos species were clustered according to their collection sites. The Mantel test corroborates the correlation between the genetic distance and the geographic altitude of each Cosmos species. The results suggest that it is necessary to preserve the Cosmos species in their natural habitat in addition to the germoplasm collection for ex situ conservation.

  12. Assessment of genetic diversity in the sorghum reference set using EST-SSR markers.

    Science.gov (United States)

    Ramu, P; Billot, C; Rami, J-F; Senthilvel, S; Upadhyaya, H D; Ananda Reddy, L; Hash, C T

    2013-08-01

    Selection and use of genetically diverse genotypes are key factors in any crop breeding program to develop cultivars with a broad genetic base. Molecular markers play a major role in selecting diverse genotypes. In the present study, a reference set representing a wide range of sorghum genetic diversity was screened with 40 EST-SSR markers to validate both the use of these markers for genetic structure analyses and the population structure of this set. Grouping of accessions is identical in distance-based and model-based clustering methods. Genotypes were grouped primarily based on race within the geographic origins. Accessions derived from the African continent contributed 88.6 % of alleles confirming the African origin of sorghum. In total, 360 alleles were detected in the reference set with an average of 9 alleles per marker. The average PIC value was 0.5230 with a range of 0.1379-0.9483. Sub-race, guinea margaritiferum (Gma) from West Africa formed a separate cluster in close proximity to wild accessions suggesting that the Gma group represents an independent domestication event. Guineas from India and Western Africa formed two distinct clusters. Accessions belongs to the kafir race formed the most homogeneous group as observed in earlier studies. This analysis suggests that the EST-SSR markers used in the present study have greater discriminating power than the genomic SSRs. Genetic variance within the subpopulations was very high (71.7 %) suggesting that the germplasm lines included in the set are more diverse. Thus, this reference set representing the global germplasm is an ideal material for the breeding community, serving as a community resource for trait-specific allele mining as well as genome-wide association mapping.

  13. Genetic Diversity of Chinese Soybean mosaic virus Strains and Their Relationships with Other Plant Potyviruses Based on P3 Gene Sequences

    Institute of Scientific and Technical Information of China (English)

    YANG Qing-hua; LI Kai; ZHI Hai-jian; GAI Jun-yi

    2014-01-01

    Soybean mosaic virus (SMV), a member of the genus Potyvirus, is a major pathogen of soybean plants in China, and 16 SMV strains have been identiifed nationwide based on a former detailed SMV classiifcation system. As the P3 gene is thought to be involved in viral replication, systemic infection, pathogenicity, and overcoming resistance, knowledge of the P3 gene sequences of SMV and other potyviruses would be useful in efforts to know the genetic relationships among them and control the disease. P3 gene sequences were obtained from representative isolates of the above-mentioned 16 SMV strains and were compared with other SMV strains and 16 Potyvirus species from the National Center for Biotechnology GenBank database. The P3 genes from the 16 SMV isolates are composed of 1 041 nucleotides, encoding 347 amino acids, and share 90.7-100%nucleotide (NT) sequence identities and 95.1-100%amino acid (AA) sequence identities. The P3 coding regions of the 16 SMV isolates share high identities (92.4-98.9%NT and 96.0-100%AA) with the reported Korean isolates, followed by the USA isolates (88.5-97.9%NT and 91.4-98.6%AA), and share low identities (80.5-85.2%NT and 82.1-84.7%AA) with the reported HZ1 and P isolates from Pinellia ternata. The sequence identities of the P3 genes between SMV and the 16 potyviruses varied from 44.4 to 81.9%in the NT sequences and from 21.4 to 85.3%in the AA sequences, respectively. Among them, SMV was closely related to Watermelon mosaic virus (WMV), with 76.0-81.9%NT and 77.5-85.3%AA identities. In addition, the SMV isolates and potyvirus species were clustered into six distinct groups. All the SMV strains isolated from soybean were clustered in Group I, and the remaining species were clustered in other groups. A multiple sequence alignment analysis of the C-terminal regions indicated that the P3 genes within a species were highly conserved, whereas those among species were relatively variable.

  14. Genetic diversity of Ulva prolifera population in Qingdao coastal water during the green algal blooms revealed by microsatellite.

    Science.gov (United States)

    Li, Yue; Huang, Hong-Jia; Li, Hongye; Liu, Jiesheng; Yang, Weidong

    2016-10-15

    Green tides have occurred in Qingdao coast in China for seven consecutive years from 2007 to 2013. To provide information on the genetic structure of these blooms, 210 free-floating green algae samples isolated from the green tide in Qingdao coast on June 19, 2013 were identified based on the ITS, rbcL and 5S sequence, and genetic diversity was investigated by microsatellite markers. According to ITS, rbcL and 5S sequence, all the 210 samples belonged to Ulva prolifera. Nei's genetic diversity and Shannon index estimated using eight microsatellite markers indicated that the genetic diversity of U. prolifera population within Qingdao's green bloom in 2013 was low. Taking into account previous reports about life history and physiology of U. prolifera, we proposed that the limited origin area of the free-floating biomass and asexual reproduction of U. prolifera might be responsible for the lower diversity of free floating U. prolifera.

  15. Genetic diversity in the SIR model of pathogen evolution.

    Science.gov (United States)

    Gordo, Isabel; Gomes, M Gabriela M; Reis, Daniel G; Campos, Paulo R A

    2009-01-01

    We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR). We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts), where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is well predicted by analytical expressions, such that pathogen neutral molecular variation is bounded by the level of infection and increases with the duration of infection. We then introduce selection in the model and study the invasion probability of a new pathogenic strain whose fitness (R(0)(1+s)) is higher than the fitness of the resident strain (R(0)). We show that this invasion probability is given by the relative increment in R(0) of the new pathogen (s). By analyzing the patterns of genetic diversity in this framework, we identify the molecular signatures during the replacement and compare these with those observed in sequences of influenza A.

  16. Genetic diversity in the SIR model of pathogen evolution.

    Directory of Open Access Journals (Sweden)

    Isabel Gordo

    Full Text Available We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR. We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts, where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is well predicted by analytical expressions, such that pathogen neutral molecular variation is bounded by the level of infection and increases with the duration of infection. We then introduce selection in the model and study the invasion probability of a new pathogenic strain whose fitness (R(0(1+s is higher than the fitness of the resident strain (R(0. We show that this invasion probability is given by the relative increment in R(0 of the new pathogen (s. By analyzing the patterns of genetic diversity in this framework, we identify the molecular signatures during the replacement and compare these with those observed in sequences of influenza A.

  17. Human KIR repertoires: shaped by genetic diversity and evolution.

    Science.gov (United States)

    Manser, Angela R; Weinhold, Sandra; Uhrberg, Markus

    2015-09-01

    Killer cell immunoglobulin-like receptors (KIRs) on natural killer (NK) cells are crucially involved in the control of cancer development and virus infection by probing cells for proper expression of HLA class I. The clonally distributed expression of KIRs leads to great combinatorial diversity that develops in the presence of the evolutionary older CD94/NKG2A receptor to create highly stochastic but tolerant repertoires of NK cells. These repertoires are present at birth and are subsequently shaped by an individuals' immunological history toward recognition of self. The single most important factor that shapes functional NK cell repertoires is the genetic diversity of KIR, which is characterized by the presence of group A and B haplotypes with complementary gene content that are present in all human populations. Group A haplotypes constitute the minimal genetic entity that provides high affinity recognition of all major human leukocyte antigen class I-encoded ligands, whereas group B haplotypes contribute to the diversification of NK cell repertoires by providing sets of stimulatory KIR genes that modify NK cell responses. We suggest a cooperative model for the balancing selection of A and B haplotypes, which is driven by the need to provide a suitable corridor of repertoire complexity in which A/A individuals with only 16 different KIR combinations coexist with A/B and B/B donors expressing up to 2048 different clone types.

  18. Whole mitochondrial genome genetic diversity in an Estonian population sample.

    Science.gov (United States)

    Stoljarova, Monika; King, Jonathan L; Takahashi, Maiko; Aaspõllu, Anu; Budowle, Bruce

    2016-01-01

    Mitochondrial DNA is a useful marker for population studies, human identification, and forensic analysis. Commonly used hypervariable regions I and II (HVI/HVII) were reported to contain as little as 25% of mitochondrial DNA variants and therefore the majority of power of discrimination of mitochondrial DNA resides in the coding region. Massively parallel sequencing technology enables entire mitochondrial genome sequencing. In this study, buccal swabs were collected from 114 unrelated Estonians and whole mitochondrial genome sequences were generated using the Illumina MiSeq system. The results are concordant with previous mtDNA control region reports of high haplogroup HV and U frequencies (47.4 and 23.7% in this study, respectively) in the Estonian population. One sample with the Northern Asian haplogroup D was detected. The genetic diversity of the Estonian population sample was estimated to be 99.67 and 95.85%, for mtGenome and HVI/HVII data, respectively. The random match probability for mtGenome data was 1.20 versus 4.99% for HVI/HVII. The nucleotide mean pairwise difference was 27 ± 11 for mtGenome and 7 ± 3 for HVI/HVII data. These data describe the genetic diversity of the Estonian population sample and emphasize the power of discrimination of the entire mitochondrial genome over the hypervariable regions.

  19. On the Biological and Genetic Diversity in Neospora caninum

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    John T. Ellis

    2010-03-01

    Full Text Available Neospora caninum is a parasite regarded a major cause of foetal loss in cattle. A key requirement to an understanding of the epidemiology and pathogenicity of N. caninum is knowledge of the biological characteristics of the species and the genetic diversity within it. Due to the broad intermediate host range of the species, worldwide geographical distribution and its capacity for sexual reproduction, significant biological and genetic differences might be expected to exist. N. caninum has now been isolated from a variety of different host species including dogs and cattle. Although isolates of this parasite show only minor differences in ultrastructure, considerable differences have been reported in pathogenicity using mainly mouse models. At the DNA level, marked levels of polymorphism between isolates were detected in mini- and microsatellites found in the genome of N. caninum. Knowledge of what drives the biological differences that have been observed between the various isolates at the molecular level is crucial in aiding our understanding of the epidemiology of this parasite and, in turn, the development of efficacious strategies, such as live vaccines, for controlling its impact. The purpose of this review is to document and discuss for the first time, the nature of the diversity found within the species Neospora caninum.

  20. Genetic diversity in Spanish donkey breeds using microsatellite DNA markers

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    Jordana Jordi

    2001-07-01

    Full Text Available Abstract Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (HE over all the populations varied between 0.637 and 0.684 in this study. The low GST value showed that only 3.6% of the diversity was between breeds (P A distance matrix showed little differentiation between Spanish breeds, but great differentiation between them and the Moroccan ass and also with the horse, used as an outgroup. These results confirm the potential use of equine microsatellite loci as a tool for genetic studies in domestic donkey populations, which could also be useful for conservation plans.

  1. The evolutionary history of Plasmodium vivax as inferred from mitochondrial genomes: parasite genetic diversity in the Americas.

    Science.gov (United States)

    Taylor, Jesse E; Pacheco, M Andreína; Bacon, David J; Beg, Mohammad A; Machado, Ricardo Luiz; Fairhurst, Rick M; Herrera, Socrates; Kim, Jung-Yeon; Menard, Didier; Póvoa, Marinete Marins; Villegas, Leopoldo; Mulyanto; Snounou, Georges; Cui, Liwang; Zeyrek, Fadile Yildiz; Escalante, Ananias A

    2013-09-01

    Plasmodium vivax is the most prevalent human malaria parasite in the Americas. Previous studies have contrasted the genetic diversity of parasite populations in the Americas with those in Asia and Oceania, concluding that New World populations exhibit low genetic diversity consistent with a recent introduction. Here we used an expanded sample of complete mitochondrial genome sequences to investigate the diversity of P. vivax in the Americas as well as in other continental populations. We show that the diversity of P. vivax in the Americas is comparable to that in Asia and Oceania, and we identify several divergent clades circulating in South America that may have resulted from independent introductions. In particular, we show that several haplotypes sampled in Venezuela and northeastern Brazil belong to a clade that diverged from the other P. vivax lineages at least 30,000 years ago, albeit not necessarily in the Americas. We propose that, unlike in Asia where human migration increases local genetic diversity, the combined effects of the geographical structure and the low incidence of vivax malaria in the Americas has resulted in patterns of low local but high regional genetic diversity. This could explain previous views that P. vivax in the Americas has low genetic diversity because these were based on studies carried out in limited areas. Further elucidation of the complex geographical pattern of P. vivax variation will be important both for diversity assessments of genes encoding candidate vaccine antigens and in the formulation of control and surveillance measures aimed at malaria elimination.

  2. Genetic diversity among five T4-like bacteriophages

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    Bertrand Claire

    2006-05-01

    Full Text Available Abstract Background Bacteriophages are an important repository of genetic diversity. As one of the major constituents of terrestrial biomass, they exert profound effects on the earth's ecology and microbial evolution by mediating horizontal gene transfer between bacteria and controlling their growth. Only limited genomic sequence data are currently available for phages but even this reveals an overwhelming diversity in their gene sequences and genomes. The contribution of the T4-like phages to this overall phage diversity is difficult to assess, since only a few examples of complete genome sequence exist for these phages. Our analysis of five T4-like genomes represents half of the known T4-like genomes in GenBank. Results Here, we have examined in detail the genetic diversity of the genomes of five relatives of bacteriophage T4: the Escherichia coli phages RB43, RB49 and RB69, the Aeromonas salmonicida phage 44RR2.8t (or 44RR and the Aeromonas hydrophila phage Aeh1. Our data define a core set of conserved genes common to these genomes as well as hundreds of additional open reading frames (ORFs that are nonconserved. Although some of these ORFs resemble known genes from bacterial hosts or other phages, most show no significant similarity to any known sequence in the databases. The five genomes analyzed here all have similarities in gene regulation to T4. Sequence motifs resembling T4 early and late consensus promoters were observed in all five genomes. In contrast, only two of these genomes, RB69 and 44RR, showed similarities to T4 middle-mode promoter sequences and to the T4 motA gene product required for their recognition. In addition, we observed that each phage differed in the number and assortment of putative genes encoding host-like metabolic enzymes, tRNA species, and homing endonucleases. Conclusion Our observations suggest that evolution of the T4-like phages has drawn on a highly diverged pool of genes in the microbial world. The T4

  3. Genetic Diversity Assessment of Acid Lime (Citrus Aurantifolia Swingle Landraces of Eastern Nepal Using RAPD Markers

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    NN Munankarmi

    2014-09-01

    Full Text Available Acid lime (Citrus aurantifolia Swingle is an important commercial fruit crop, cultivated from terai to high hill landscapes of Nepal. However, production and productivity is very low due to various reasons including infestations by various diseases and pests, lack of diseases and pests resistant and high yielding varieties. In this context, determination of genetic variation at molecular level is fundamental to citrus breeders for the development of elite cultivars with desirable traits. In the present study, Random Amplified Polymorphic DNA (RAPD marker technique has been employed to assess genetic diversity in 60 acid lime landraces representing different agro-ecological zones of eastern Nepal. Nine selected arbitrary primers generated 79 RAPD fragments of which 75 were polymorphic (94.94%. Phenogram was constructed by NTSYSPC ver. 2.21i using UPGMA cluster analysis based on Jaccard’s similarity coefficient to deduce overall genetic diversity and relationships of the acidlime genotypes under study. Sixty acid lime landraces formed seven clusters and similarity value ranged from 38% to 98% with an average of 72%. Genetic variation at different agro-ecological zones was assessed using Popgene ver. 1.32 and found 47% to 69.6% polymorphism. Shannon’s index and Nei’s gene diversity showed highest level of acid lime diversity in Terai zone (PPB, 69.62%; H, 0.213; I, 0.325 followed by mid-hill zone (PPB, 67.09%; H, 0.208; I, 0.317. The results obtained will be useful to citrus breeders for elite cultivar development. The RAPD-PCR technique is found to be the rapid and effective tool for genetic diversity assessment in acid lime landraces of Nepal.

  4. Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population

    Institute of Scientific and Technical Information of China (English)

    Jiandong YANG; Zhihe ZHANG; Fujun SHEN; Xuyu YANG; Liang ZHANG; Limin CHEN; Wenping ZHANG; Qing ZHU; Rong HOU

    2011-01-01

    Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species.Tangjiahe Nature Reserve (NR) is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China.Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation.Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population.The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve.Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations.All individuals from the same subpopulation were assigned to one cluster.This indicates high gene flow between subpopulations.F statistic analyses revealed a low Fls-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR.Additionally,our data show a high level of genetic diversity for the Tangjiahe population.Mean allele number (A),Allelic richness (AR) and mean expected heterozygosity (HE) for the Tangiiahe population was 5.9,5.173 and 0.703,respectively.This wild giant panda population can be restored through concerted effort [Current Zoology 57 (6):717-724,2011].

  5. Genetic diversity, morphological uniformity and polyketide production in dinoflagellates (Amphidinium, Dinoflagellata.

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    Shauna A Murray

    Full Text Available Dinoflagellates are an intriguing group of eukaryotes, showing many unusual morphological and genetic features. Some groups of dinoflagellates are morphologically highly uniform, despite indications of genetic diversity. The species Amphidinium carterae is abundant and cosmopolitan in marine environments, grows easily in culture, and has therefore been used as a 'model' dinoflagellate in research into dinoflagellate genetics, polyketide production and photosynthesis. We have investigated the diversity of 'cryptic' species of Amphidinium that are morphologically similar to A. carterae, including the very similar species Amphidinium massartii, based on light and electron microscopy, two nuclear gene regions (LSU rDNA and ITS rDNA and one mitochondrial gene region (cytochrome b. We found that six genetically distinct cryptic species (clades exist within the species A. massartii and four within A. carterae, and that these clades differ from one another in molecular sequences at levels comparable to other dinoflagellate species, genera or even families. Using primers based on an alignment of alveolate ketosynthase sequences, we isolated partial ketosynthase genes from several Amphidinium species. We compared these genes to known dinoflagellate ketosynthase genes and investigated the evolution and diversity of the strains of Amphidinium that produce them.

  6. Genetic diversity, morphological uniformity and polyketide production in dinoflagellates (Amphidinium, Dinoflagellata).

    Science.gov (United States)

    Murray, Shauna A; Garby, Tamsyn; Hoppenrath, Mona; Neilan, Brett A

    2012-01-01

    Dinoflagellates are an intriguing group of eukaryotes, showing many unusual morphological and genetic features. Some groups of dinoflagellates are morphologically highly uniform, despite indications of genetic diversity. The species Amphidinium carterae is abundant and cosmopolitan in marine environments, grows easily in culture, and has therefore been used as a 'model' dinoflagellate in research into dinoflagellate genetics, polyketide production and photosynthesis. We have investigated the diversity of 'cryptic' species of Amphidinium that are morphologically similar to A. carterae, including the very similar species Amphidinium massartii, based on light and electron microscopy, two nuclear gene regions (LSU rDNA and ITS rDNA) and one mitochondrial gene region (cytochrome b). We found that six genetically distinct cryptic species (clades) exist within the species A. massartii and four within A. carterae, and that these clades differ from one another in molecular sequences at levels comparable to other dinoflagellate species, genera or even families. Using primers based on an alignment of alveolate ketosynthase sequences, we isolated partial ketosynthase genes from several Amphidinium species. We compared these genes to known dinoflagellate ketosynthase genes and investigated the evolution and diversity of the strains of Amphidinium that produce them.

  7. Genetic Diversity and Population Structure of Cowpea (Vigna unguiculata L. Walp).

    Science.gov (United States)

    Xiong, Haizheng; Shi, Ainong; Mou, Beiquan; Qin, Jun; Motes, Dennis; Lu, Weiguo; Ma, Jianbing; Weng, Yuejin; Yang, Wei; Wu, Dianxing

    2016-01-01

    The genetic diversity of cowpea was analyzed, and the population structure was estimated in a diverse set of 768 cultivated cowpea genotypes from the USDA GRIN cowpea collection, originally collected from 56 countries. Genotyping by sequencing was used to discover single nucleotide polymorphism (SNP) in cowpea and the identified SNP alleles were used to estimate the level of genetic diversity, population structure, and phylogenetic relationships. The aim of this study was to detect the gene pool structure of cowpea and to determine its relationship between different regions and countries. Based on the model-based ancestry analysis, the phylogenetic tree, and the principal component analysis, three well-differentiated genetic populations were postulated from 768 worldwide cowpea genotypes. According to the phylogenetic analyses between each individual, region, and country, we may trace the accession from off-original, back to the two candidate original areas (West and East of Africa) to predict the migration and domestication history during the cowpea dispersal and development. To our knowledge, this is the first report of the analysis of the genetic variation and relationship between globally cultivated cowpea genotypes. The results will help curators, researchers, and breeders to understand, utilize, conserve, and manage the collection for more efficient contribution to international cowpea research.

  8. THE EFFECT OF INDIVIDUAL SELECTION FOR GENETIC DIVERSITY OF Acacia mangium SEEDLING SEED ORCHARD USING AFLP MARKERS

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    A. Y.P.B.C. Widyatmoko

    2006-07-01

    Full Text Available Establishment of seed orchard is aimed at producing good quality seeds which is an important activity for breeding program. Seed orchard is also a base population, thus its genetic diversity is depending on its design and composition (provenance, family and individual tree. Selection of an individual tree in seed orchard is needed for the enhancement of  retaining good-character trees. However, selection of individual tree can change the genetic diversity of seed orchard, and the degrees to which the genetic diversity will change depend on the used selection methods. In order to investigate the effects of selection methods, 4 simulations of selection methods based on height, diameter and stem performance of individual trees were used. The differences among the 4 methods were the ranking of individual trees those selected, and families and provenances those have been represented. Seedling seed orchard of Acacia mangium in Wonogiri, Central Java was used as materials. Analysis of genetic diversity was carried out using AFLP markers. Nine primer combinations were used to produce 1025 AFLP banding patterns. Among those banding patterns, only 109 were polymorphic markers. No significant effect of individual tree selection was revealed in this study. Even though the selection was done intensively, only 7.1% of genetic diversity was reduced. In other words, the selection activity did not reduce the genetic diversity of seed orchard significantly. The result is important for developing future tree improvement of A. mangium, including development of hybrid between A. mangium and A. auriculiformis.

  9. [Genetic bases of diversity of the repertoire of immunoglobulins in application to diagnostics of clonality of B-cell lymphoid populations].

    Science.gov (United States)

    Zakharova, E S; Kazilo, N A; Stefanov, D N; Sinitsina, M N; Kovrigina, A M

    2011-06-01

    Molecular mechanisms underlying the formation of B-cell lymphomas in connection with processes associated with the maturation of B lymphocytes are reviewed. The currently used diagnostic methods do not always distinguish lymphomas from reactive changes of the lymphoid tissue. The principle of the molecular genetic method ofclonality detection in lymphocyte populations, technical problems, and the strategy of its application in clinical diagnostics of lymphomas are described in detail.

  10. Genetic diversity and variability in two Italian autochthonous donkey genetic types assessed by microsatellite markers

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    Donato Matassino

    2014-01-01

    Full Text Available Since 13rd century, Italian domestic autochthonous donkey population has been characterised by Mediterranean grey mousy cruciate ancestral phenotype, currently typical of Amiata donkey (AD genetic type. This phenotype persisted up to the 16th century when a marked introduction of Hispanic and French big sized and dark bay or darkish coloured sires occurred. In the context of a safeguard programme of Latial Equide resources, the aim of this research was to evaluate the genetic diversity and similarity between the AD breed and an autochthonous donkey population native from Lazio, the Viterbese donkey (VD, using molecular markers. A total of 135 animals (50 AD and 85 VD were genetically characterised by using 16 short tandem repeat markers. A high genetic differentiation between populations (FST=0.158; P<0.01 and a low betweenbreeds genetic similarity (0.233±0.085 were observed. Correspondence analysis, the result of STRUCTURE software analysis and analysis of molecular variance would seem to indicate genetically different entities as well. It would be desirable to increase the number of comparison with other breeds to better understand the origin of VD. Moreover, results obtained in this study suggest that the loss of genetic variation observed in VD could mainly derive from unnoticed sub-population structuring (Wahlund effect, rather than to other factors such as inbreeding, null alleles or selection influence.

  11. Elevated Genetic Diversity in the Emerging Blueberry Pathogen Exobasidium maculosum.

    Directory of Open Access Journals (Sweden)

    Jane E Stewart

    Full Text Available Emerging diseases caused by fungi are increasing at an alarming rate. Exobasidium leaf and fruit spot of blueberry, caused by the fungus Exobasidium maculosum, is an emerging disease that has rapidly increased in prevalence throughout the southeastern USA, severely reducing fruit quality in some plantings. The objectives of this study were to determine the genetic diversity of E. maculosum in the southeastern USA to elucidate the basis of disease emergence and to investigate if populations of E. maculosum are structured by geography, host species, or tissue type. We sequenced three conserved loci from 82 isolates collected from leaves and fruit of rabbiteye blueberry (Vaccinium virgatum, highbush blueberry (V. corymbosum, and southern highbush blueberry (V. corymbosum hybrids from commercial fields in Georgia and North Carolina, USA, and 6 isolates from lowbush blueberry (V. angustifolium from Maine, USA, and Nova Scotia, Canada. Populations of E. maculosum from the southeastern USA and from lowbush blueberry in Maine and Nova Scotia are distinct, but do not represent unique species. No difference in genetic structure was detected between different host tissues or among different host species within the southeastern USA; however, differentiation was detected between populations in Georgia and North Carolina. Overall, E. maculosum showed extreme genetic diversity within the conserved loci with 286 segregating sites among the 1,775 sequenced nucleotides and each isolate representing a unique multilocus haplotype. However, 94% of the nucleotide substitutions were silent, so despite the high number of mutations, selective constraints have limited changes to the amino acid sequences of the housekeeping genes. Overall, these results suggest that the emergence of Exobasidium leaf and fruit spot is not due to a recent introduction or host shift, or the recent evolution of aggressive genotypes of E. maculosum, but more likely as a result of an increasing

  12. Late Quaternary loss of genetic diversity in muskox (Ovibos

    Directory of Open Access Journals (Sweden)

    Mol Dick

    2005-10-01

    Full Text Available Abstract Background The modern wildherd of the tundra muskox (Ovibos moschatus is native only to the New World (northern North America and Greenland, and its genetic diversity is notably low. However, like several other megafaunal mammals, muskoxen enjoyed a holarctic distribution during the late Pleistocene. To investigate whether collapse in range and loss of diversity might be correlated, we collected mitochondrial sequence data (hypervariable region and cytochrome b from muskox fossil material recovered from localities in northeastern Asia and the Arctic Archipelago of northern North America, dating from late Pleistocene to late Holocene, and compared our results to existing databases for modern muskoxen. Results Two classes of haplotypes were detected in the fossil material. "Surviving haplotypes" (SHs, closely similar or identical to haplotypes found in modern muskoxen and ranging in age from ~22,000 to ~160 yrbp, were found in all New World samples as well as some samples from northeastern Asia. "Extinct haplotypes" (EHs, dating between ~44,000 and ~18,000 yrbp, were found only in material from the Taimyr Peninsula and New Siberian Islands in northeastern Asia. EHs were not found in the Holocene muskoxen specimens available for this study, nor have they been found in other studies of extant muskox populations. Conclusion We provisionally interpret this evidence as showing that genetic variability was reduced in muskoxen after the Last Glacial Maximum but before the mid-Holocene, or roughly within the interval 18,000-4,000 yrbp. Narrowing this gap further will require the recovery of more fossils and additional genetic information from this interval.

  13. Genetic diversity within and between European pig breeds using microsatellite markers

    NARCIS (Netherlands)

    SanCristobal, M.; Chevalet, C.; Haley, C.S.; Joosten, R.; Rattink, A.P.; Harlizius, B.; Groenen, M.A.M.

    2006-01-01

    An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole co

  14. Population size and time since island isolation determine genetic diversity loss in insular frog populations.

    Science.gov (United States)

    Wang, Supen; Zhu, Wei; Gao, Xu; Li, Xianping; Yan, Shaofei; Liu, Xuan; Yang, Ji; Gao, Zengxiang; Li, Yiming

    2014-02-01

    Understanding the factors that contribute to loss of genetic diversity in fragmented populations is crucial for conservation measurements. Land-bridge archipelagoes offer ideal model systems for identifying the long-term effects of these factors on genetic variations in wild populations. In this study, we used nine microsatellite markers to quantify genetic diversity and differentiation of 810 pond frogs (Pelophylax nigromaculatus) from 24 islands of the Zhoushan Archipelago and three sites on nearby mainland China and estimated the effects of the island area, population size, time since island isolation, distance to the mainland and distance to the nearest larger island on reduced genetic diversity of insular populations. The mainland populations displayed higher genetic diversity than insular populations. Genetic differentiations and no obvious gene flow were detected among the frog populations on the islands. Hierarchical partitioning analysis showed that only time since island isolation (square-root-transformed) and population size (log-transformed) significantly contributed to insular genetic diversity. These results suggest that decreased genetic diversity and genetic differentiations among insular populations may have been caused by random genetic drift following isolation by rising sea levels during the Holocene. The results provide strong evidence for a relationship between retained genetic diversity and population size and time since island isolation for pond frogs on the islands, consistent with the prediction of the neutral theory for finite populations. Our study highlights the importance of the size and estimated isolation time of populations in understanding the mechanisms of genetic diversity loss and differentiation in fragmented wild populations.

  15. Genetic diversity of Plasmodium vivax isolates from Azerbaijan

    Directory of Open Access Journals (Sweden)

    Majori Giancarlo

    2004-11-01

    Full Text Available Abstract Background Plasmodium vivax, although causing a less serious disease than Plasmodium falciparum, is the most widespread of the four human malarial species. Further to the recent recrudescence of P. vivax cases in the Newly Independent States (NIS of central Asia, a survey on the genetic diversity and dissemination in Azerbaijan was undertaken. Azerbaijan is at the crossroads of Asia and, as such, could see a rise in the number of cases, although an effective malaria control programme has been established in the country. Methods Thirty-six P. vivax isolates from Central Azerbaijan were characterized by analysing the genetic polymorphism of the circumsporozoite protein (CSP and the merozoite surface protein 1 (MSP-1 genes, using PCR amplifications and amplicons sequencing. Results Analysis of CSP sequences showed that all the processed isolates belong to the VK 210 type, with variations in the alternation of alanine residue (A or aspartic acid residue (D in the repeat motif GDRA(A/DGQPA along the sequence. As far as MSP-1 genotyping is concerned, it was found that the majority of isolates analysed belong to Belem and Sal I types. Five recombinant isolates were also identified. Combined analysis with the two genetic markers allowed the identification of 19 plasmodial sub-types. Conclusion The results obtained in the present study indicate that there are several P. vivax clones circulating in Azerbaijan and, consequently, a careful malaria surveillance could be of paramount importance to identify, at early stage, the occurrence of possible P. vivax malaria outbreaks.

  16. Comparative analysis of genetic diversity of Synechogobius ommaturus based on the mitochondrial DNA control region%斑尾复虾虎鱼群体遗传多样性比较分析

    Institute of Scientific and Technical Information of China (English)

    宋娜; 宋林; 高天翔; 孙希福

    2011-01-01

    The spottedtail goby, Synechogobius ommaturus (Richardson)is a large, commercially important,benthic fish in the family Gobiidae,which inhabits Asian inshore waters of the Northwestern Pacific,from Japan and China to Indonesia.With the development of fishery resource,S.ommaturus is becoming an important marine food and will face higher fishing pressure.It is,therefore,very important to investigate the genetic variance and population structure of this species in order to provide the background information for the management of the species.Until now studies on S.ommaturus mainly focused on the biology and chromosome, and there are no genetic investigations for this fish.In the present study, genetic diversity of S.ommaturus and genetic differentiation between two geographical populations were analyzed.A 478 base pair (bp)fragment of the hypervariable portion of the mtDNA control region was sequenced and sequences were edited and aligned by DNA Star software.Genetic diversity indices such as number of haplotypes,polymorphic sites,transitions,transversions,indels,haplotype diversity,nucleotide diversity and the mean number of pair-wise differences were obtained using the program Arlequin version 3.0.A Neighbour-Joining(NJ)tree of the control region haplotypes was constructed using MEGA 3.0 and evaluated with 1 000 bootstrap replicates,and Acantogobius flavimanus was served as the out-group.Genetic differentiation between two populations was evaluated with the pairwise fixation index Fsr by Arlequin version 3.0.Historical demography of S.ommaturus was examined by neutrality tests and mismatch distribution analysis.The results of present study showed that haplotype diversity(0.006 3 ±0.003 8) ,nucleotidediversity (0.889 5 ± 0.050 8) and the mean number of pairwise differences (3.000 0 ± 1.634 3 ) of Dandong population were higher than those of Tianjin population.The topology of the NJ tree rooted with the out-group A.flavimanus was shallow,and there were no

  17. Genetic diversity of alfalfa domesticated varietal populations from Libyan genbank revealed by RAPD markers

    Directory of Open Access Journals (Sweden)

    Ahsyee Salem R.

    2013-01-01

    Full Text Available Alfalfa (Medicago sativa L. is an important forage legume in Libya. The genetic diversity of nine alfalfa domesticated varietal populations was studied using thirteen RAPD primer combinations. The number of polymorphic fragments detected per primer combination ranged from 8 to 46 bands with an average of 24 bands. The number of polymorphic bands detected was from 6 (Atalia population to 37 (Gabsia population. The lowest genetic distance was 0.058 and the highest was 0.655. The average genetic distance was (0.356. The dendrogram based on Ward’s minimum variance clustering method grouped the nine populations into the two main clusters. The first group included Fazania, Atalia, Masratia, Zawia, Denamo Ferade and Arezona. The second group was composed of Tagoria, Gabsia and Wade Alrabeh. The simplicity of RAPD assays for detection of genetic polymorphisms is confirmed in our study, and results can be utilized in breeding practice.

  18. Genetic bases for glaucoma.

    Science.gov (United States)

    Fuse, Nobuo

    2010-05-01

    Glaucoma is the leading cause of visual impairment and blindness throughout the world. Primary open angle glaucoma (POAG; MIM 137760) is the main type of glaucoma in most populations, and more than 20 genetic loci for POAG have been reported. Only three causative genes have been identified in these loci, viz. myocilin (MYOC), optineurin (OPTN), and WD repeat domain 36 (WDR36). However, mutations in these genes account for only a small percentage of the patients with POAG. Some of these glaucoma cases have a Mendelian inheritance pattern, and a considerable fraction of the cases result from a large number of variants in several genes each contributing small effects. Glaucoma is considered to be a common disease such as diabetes mellitus, coronary disease, Crohn disease, and several( )common cancers. The main technological approaches used to identify the genes associated with glaucoma are the candidate gene approach, linkage analysis, case-control association study, and genome-wide association study. Association studies have found about 27 genes related to POAG, but the glaucoma-causing effects of these genes need to be investigated in more detail. The current trend is to use case-control association studies or genome-wide association studies to map the genes associated with glaucoma. Such studies are expected to greatly advance our understanding of the genetic basis of glaucoma, and to provide information on the effectiveness of glaucoma therapy. This review gives an overview on the genetic aspects of glaucoma.

  19. Interpreting genetics in the context of eating disorders: evidence of disease, not diversity.

    Science.gov (United States)

    Easter, Michele

    2014-07-01

    How is genetic involvement interpreted for disorders whose medicalisation is contested? Framing psychiatric and behavioural disorders in terms of genetics is expected to make them seem more medical. Yet a genetic aetiology can also be used to frame behaviour as acceptable human variation, rather than a medical problem (for example, sexual orientation). I analyse responses to the idea that there is a genetic component in anorexia and bulimia nervosa (AN or BN) via semi-structured interviews with a sample of 50 women diagnosed with an eating disorder (25 had recovered). All but three volunteered that genetics would medicalise AN or BN by (i) making eating disorders seem more like 'real diseases'; implying that these disorders need (ii) professional treatment or (iii) a biologically based treatment. The results also indicate there are several counter-logics by which genetic framing could support non-medical definitions of AN or BN. I argue that genetic framing reduces perceived individual responsibility, which can support definitions of behaviour as either a reflection of disease (which entails intervention) or a reflection of normal human diversity (which does not). In the context of public scepticism as to the 'reality' of AN or BN, genetic involvement was taken as evidence of disease in ongoing negotiations about the medical and moral status of people with eating disorders.

  20. Application of various statistical methods to analyze genetic diversity of Austrian (Pinus nigra Arn. and Scots pine (Pinus sylvestris L. based on protein markers

    Directory of Open Access Journals (Sweden)

    Lučić Aleksandar

    2011-01-01

    Full Text Available This paper presents the results of studies on protein polymorphism in seeds of Scots pine (Pinus sylvestris L. and Austrian pine (Pinus nigra Arn. as the most important economic species of the genus Pinus in Serbia. Polymorphism of protein markers was determined in selected genotypes originating from seven populations (Scots pine and six populations (Austrian pine. Analysis of protein markers was performed using two statistical methods, NTSYS and correspondence analysis. Both methods give the same arrangement of the analyzed populations, whereby, because of a different view of genetic distances, they can and should be combined, enabling easier and more precise understanding of mutual relationships of the observation units.

  1. Genetic Diversity and Relationship of Bougainvillea Germplasm Resources Based on SRAP Markers%基于SRAP的叶子花种质资源遗传多样性及遗传关系分析

    Institute of Scientific and Technical Information of China (English)

    唐源江; 武晓燕; 曹雯静

    2014-01-01

    In order to understand the genetic relationship of Bougainvillea germplasms, the SRAP (sequence-related amplified polymorphism) markers were firstly applied on analysis of genetic diversity and relationship among 48 Bougainvillea cultivars. The results showed that twenty-five primer pairs screened from 208 primer pairs ampliifed a total of 773 bands, of which 750 were polymorphic bands, and the percentage of polymorphic bands was 97.02%. The genetic similar coefficient of Bougainvillea germplasms ranged from 0.4058 to 0.8568, and UPGMA (Unweighted pair-group method arithmetic average) analysis showed that 48 cultivars could clustered into 4 groups with the genetic similarity coefifcient of 0.558. However, the cultivar B. glabra‘Formosa’ and B. spectabilis‘Spectabilis’ were clustered into a separate cluster, respectively, the other cultivars were clustered into two groups. The genetic relationships of all cultivars examined would be made clear based on SRAP molecular markers. The results could provide scientific foundation for using germplasm resource appropriately and improving the efifciency of screening new cultivars.%为探讨叶子花(Bougainvillea sp.)品种间的遗传关系,应用SRAP (Sequence-related ampliifed polymorphism)标记技术对48个叶子花品种的遗传多样性及遗传关系进行了分析。结果表明,从208对引物中筛选出25对多态性较高的引物组合,共扩增出773条清晰条带,其中多态性条带750条,平均多态性条带百分率达97.02%。UPGMA聚类分析结果表明,48个叶子花品种的遗传相似性系数为0.4058~0.8568,在遗传相似性系数0.558水平上,可分为4个类群,福摩萨叶子花与毛叶紫花叶子花各自成一类,其它品种分为两大类群。SRAP标记可较好地反映叶子花种质间的遗传关系,为合理利用叶子花种质资源及提高育种效率提供了科学基础。

  2. THE USE OF MICROSATELLITE MARKERS TO STUDY GENETIC DIVERSITY IN INDONESIAN SHEEP

    OpenAIRE

    Jakaria; M.S.A. Zein; S. Sulandari; Subandriyo,; Muladno

    2014-01-01

    The purpose of this research was to study genetic diversity in Indonesian sheep population using microsatellite markers. A total of 18 microsatellite loci have been used for genotyping Indonesian sheep. Total sheep blood 200 samples were extracted from garut sheep of fighting and meat types, purbalingga sheep, batur sheep and jember sheep populations by using a salting out method. Microsatellite loci data were analyzed using POPGENE 3.2 software. Based on this study obtained 180 alleles from ...

  3. PRODUCTIVITY AND GENETIC DIVERSITY OF LOCAL CATTLE IN CIAMIS-WEST JAVA

    OpenAIRE

    N. Hilmia; R. R. Noor; C. Sumantri; R.E. Gurnadi; R. Priyanto

    2014-01-01

    The objectives of this study were to identify the productivity and genetic diversity of local cattle inCiamis West Java based on DNA microsatellite, in order to provide the basic information for its rearing,conservation and development. Eighteen of local cattle were kept for 58 days by feeding concentratesand rice straw. The measured parameters were weekly body weight as well as carcass percentage. Thepercentage of comparing carcass was taken from PO, Bali and crossbred cattle from local catt...

  4. PRODUCTIVITY AND GENETIC DIVERSITY OF LOCAL CATTLE IN CIAMIS-WEST JAVA

    OpenAIRE

    N. Hilmia; R. R. Noor; C. Sumantri; R.E. Gurnadi; R. Priyanto

    2013-01-01

    The objectives of this study were to identify the productivity and genetic diversity of local cattle in Ciamis West Java based on DNA microsatellite, in order to provide the basic information for its rearing, conservation and development. Eighteen of local cattle were kept for 58 days by feeding concentrates and rice straw. The measured parameters were weekly body weight as well as carcass percentage. The percentage of comparing carcass was taken from PO, Bali and crossbred cattle from local ...

  5. Genetic Diversity and Phylogenetic Analysis of South-East Asian Duck Populations Based on the mtDNA D-loop Sequences

    Science.gov (United States)

    Sultana, H.; Seo, D. W.; Bhuiyan, M. S. A.; Choi, N. R.; Hoque, M. R.; Heo, K. N.; Lee, J. H.

    2016-01-01

    The maternally inherited mitochondrial DNA (mtDNA) D–loop region is widely used for exploring genetic relationships and for investigating the origin of various animal species. Currently, domestic ducks play an important role in animal protein supply. In this study, partial mtDNA D–loop sequences were obtained from 145 samples belonging to six South-East Asian duck populations and commercial duck population. All these populations were closely related to the mallard duck (Anas platyrhynchos), as indicated by their mean overall genetic distance. Sixteen nucleotide substitutions were identified in sequence analyses allowing the distinction of 28 haplotypes. Around 42.76% of the duck sequences were classified as Hap_02, which completely matched with Anas platyrhynchos duck species. The neighbor-joining phylogenetic tree also revealed that South-East Asian duck populations were closely related to Anas platyrhynchos. Network profiles were also traced using the 28 haplotypes. Overall, results showed that those duck populations D-loop haplotypes were shared between several duck breeds from Korea and Bangladesh sub continental regions. Therefore, these results confirmed that South-East Asian domestic duck populations have been domesticated from Anas platyrhynchos duck as the maternal origins. PMID:27004808

  6. Genetic diversity of Metarhizium anisopliae var. anisopliae in southwestern British Columbia.

    Science.gov (United States)

    Inglis, G Douglas; Duke, Grant M; Goettel, Mark S; Kabaluk, J Todd

    2008-05-01

    The abundance and genetic diversity of the entomopathogenic fungus, Metarhizium anisopliae var. anisopliae, in southwestern British Columbia (BC) and southern Alberta was examined. The fungus was found to be widespread in soil throughout southwestern BC, and was recovered from 56% of 85 sample sites. In contrast to southwestern BC, no M. anisopliae isolates were recovered in southern Alberta. An automated fluorescent amplified fragment length polymorphism (AFLP) method was used to examine genetic diversity. In excess of 200 isolates were characterized. The method identified 211 polymorphic amplicons, ranging in size from approximately 92 to 400 base pairs, and it was found to be reproducible with a resolution limit of 86.2% similarity. The AFLP method distinguished Metarhizium from other entomopathogenic fungal genera, and demonstrated considerable genetic diversity (25 genotypes) among the reference strains of M. anisopliae isolates examined (i.e. recovered from various substrates and geographical locations). Although 13 genotypes of M. anisopliae var. anisopliae were recovered from southwestern BC soils, the vast majority of isolates (91%) belonged to one of two closely-related genotypes. Furthermore, these two genotypes predominated in urban, agricultural and forest soils. The reasons for the limited diversity of M. anisopliae var. anisopliae in southwestern BC are uncertain. However, findings of this study are consistent with island biogeography theory, and have significant implications for the development of this fungus for microbial control of pest insects.

  7. Utilization of Genetic Diversity on Establishing Chinese Soybean (G.max) Core Collection

    Institute of Scientific and Technical Information of China (English)

    Qiu Lijuan; Xie Hua; Chang Ruzhen; Li Wei; Wang Wenhui; Zhang Bo; Zhang Minghui; Feng Zhongfu

    2002-01-01

    Genetic diversity plays a veryimportant role in establishing core collation. Inthis study, A total of 405 Chinese soybeanaccessions was selected from the preliminarycore collection, which had 5 different ecotypesfrom three cultivation regions, includingnortheastern spring sowing soybean (NSpSS),huanghuai summer sowing soybean (HSuSS),southern spring sowing soybean (SSpSS),southern summer sowing soybean (SSuSS),southern autumn sowing soybean (SAuSS). Thegenetic diversities and genetic relationship offive ecotypes were analyzed at DNA level byusing SSR markers in order to provideinformation for establishment of Chinesesoybean core collection. A set of 67 SSRprimers were used to analyze these accessions,and detected 502 alleles with averaged 7.49alleles per locus. SAuSS appeared to be thehighest number of alleles, HSuSS had thebiggest genetic diversity indexes and NSpSSwere lowest for both numbers of alleles andgenetic d versity indexes among 5 ecotypes.Since five ecotypes differentiated obviously,various sampling strategy for establishing corecollection should be adapted for differentecotypes based on the number of alleles andgenetic diversity indexes.

  8. Genetic diversity for gliadin patterns of durum wheat landraces in the Northwest of Iran and Azerbaijan

    Directory of Open Access Journals (Sweden)

    Mohammad Zaefizadeh

    2010-12-01

    Full Text Available The objective of this study was to identify gliadin band patterns and the extent of genetic diversity in durum wheat genotypes from Northwestern Iran and the Republic of Azerbaijan. Gliadins from 46 landraces and four cultivars were evaluated through acid PAGE analyses. Sixty-six polymorphic bands and 81 patterns were identified. Twenty-four different motility bands and 22 patterns were found in the ω gliadin region with 14 polymorph bands and 20 patterns for α and γ gliadins, and 14 bands and 19 different patterns for β gliadins. The combination of these patterns generated 38 and 39 combinations for Gli-1 and Gli-2 loci, respectively. The genetic diversity index (H was higher for α gliadins (0.924, followed by ω and γ gliadins (0.899 and 0.878, respectively, and for β gliadin patterns (0.866. Extensive polymorphism (H = 0.875 was observed in four gliadin pattern regions, with higher genetic diversity in the Iranian landraces than in the Azerbaijani ones. Each genotype had special identifying patterns in the gliadin acid PAGE analysis, and cluster analysis based on Jaccard's similarity coefficients formed six groups. Gliadin has a simple, repeatable and economic analysis, and can be used in genetic studies

  9. Genetic Diversity and Population Structure of Two Tomato Species from the Galapagos Islands

    KAUST Repository

    Pailles, Yveline

    2017-02-15

    Endemic flora of the Galapagos Islands has adapted to thrive in harsh environmental conditions. The wild tomato species from the Galapagos Islands, Solanum cheesmaniae and S. galapagense, are tolerant to various stresses, and can be crossed with cultivated tomato. However, information about genetic diversity and relationships within and between populations is necessary to use these resources efficiently in plant breeding. In this study, we analyzed 3,974 polymorphic SNP markers, obtained through the genotyping-by-sequencing technique, DArTseq, to elucidate the genetic diversity and population structure of 67 accessions of Galapagos tomatoes (compared to two S. lycopersicum varieties and one S. pimpinellifolium accession). Two clustering methods, Principal Component Analysis and STRUCTURE, showed clear distinction between the two species and a subdivision in the S. cheesmaniae group corresponding to geographical origin and age of the islands. High genetic variation among the accessions within each species was suggested by the AMOVA. High diversity in the S. cheesmaniae group and its correlation with the islands of origin were also suggested. This indicates a possible influence of the movement of the islands, from west to east, on the gene flow. Additionally, the absence of S. galapagense populations in the eastern islands points to the species divergence occurring after the eastern islands became isolated. Based on these results, it can be concluded that the population structure of the Galapagos tomatoes collection partially explains the evolutionary history of both species, knowledge that facilitates exploitation of their genetic potential for the identification of novel alleles contributing to stress tolerance.

  10. The Mediterranean fruit fly (Ceratitis capitata in Iran: genetic diversity and comparison with other countries

    Directory of Open Access Journals (Sweden)

    M. Rajabiyan

    2015-04-01

    Full Text Available The Mediterranean fruit fly, Ceratitis capitata (Wiedemann is an economically important pest on fruits all over the world. The origin of this fly is thought to be from Africa, but it has recently expanded its distribution in many geographic regions including Iran. Due to the wide spread of this pest in Iran and its serious damage to fruit on trees, including citrus orchards of northern Iran, the present study was conducted firstly to investigate genetic diversity within populations of C. capitata based on the sequences of three mitochondrial DNA (mtDNA genes including cytochrome C oxidase I (COI, NAHD dehydrogenase subunits 4 and 5 (ND4 and ND5 and secondly to compare the Iranian haplotypes with those found in other countries. Results of this study indicated low levels of genetic diversity (four, four and three haplotypes among different populations of this pest, respectively for the COI, ND4 and ND5 genes in northern Iranian populations. The genetic similarity and very low levels of genetic diversity of northern Iranian populations suggest that the pest colonisation occurred relatively recently. In addition, haplotypes of Mazandaran province are similar to haplotypes of those countries that have recently been infected by this pest.

  11. The study of genetic diversity of Daemonorops draco (Palmae using ISSR markers

    Directory of Open Access Journals (Sweden)

    REVIS ASRA

    2014-10-01

    Full Text Available Asra R, Syamsuardi, Mansyurdin, Witono JR. 2014. The study of genetic diversity of Daemonorops draco (Palmae using ISSR markers. Biodiversitas 15: 109-114. The genetic diversity in five populations of Daemonorops draco(Willd. Blume (Jernang: in Bahasa Indonesia was analyzed using Inter Simple Sequence Repeat (ISSR markers. The screening results from using 15 ISSR primers showed that only 5 of ISSR primers had clear and reproducible bands. Based on the data from the matrix binary analyzed using POPGENE version 3.2, the highest genetic diversity was found in the Sepintun population at 0.0969 average heterozygosis (H and 0.146 average Shannon Index (I. The heterozygosis calculation of the total population (HT was 0.2571. The heterozygosis value within a population (HS=0.0704 was smaller than that between populations (DST=0.1867. Using the clustering analysis program Past version 32 on 43 individuals of D. draco, we found that there were three groups of D. draco. Group A consisted of 8 individuals in the Bengayoan population, group B consisted of 9 units in the Nunusan population and group C consisted of three populations; Tebo, Sepintun and Mandiangin consisted of 10, 8 and 8 individuals. The genetic similarity varied among all populations withthe values between 0.07-0.93.

  12. Function Optimization Based on Quantum Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Ying Sun

    2014-01-01

    Full Text Available Optimization method is important in engineering design and application. Quantum genetic algorithm has the characteristics of good population diversity, rapid convergence and good global search capability and so on. It combines quantum algorithm with genetic algorithm. A novel quantum genetic algorithm is proposed, which is called Variable-boundary-coded Quantum Genetic Algorithm (vbQGA in which qubit chromosomes are collapsed into variable-boundary-coded chromosomes instead of binary-coded chromosomes. Therefore much shorter chromosome strings can be gained. The method of encoding and decoding of chromosome is first described before a new adaptive selection scheme for angle parameters used for rotation gate is put forward based on the core ideas and principles of quantum computation. Eight typical functions are selected to optimize to evaluate the effectiveness and performance of vbQGA against standard Genetic Algorithm (sGA and Genetic Quantum Algorithm (GQA. The simulation results show that vbQGA is significantly superior to sGA in all aspects and outperforms GQA in robustness and solving velocity, especially for multidimensional and complicated functions.

  13. Status of the genetic diversity and population structure of the Pêga donkey.

    Science.gov (United States)

    Santana, Mário Luiz; Bignardi, Annaiza Braga

    2015-12-01

    Pedigree analysis was extended to the Pêga donkey population in order to evaluate the status of genetic diversity and population structure. All parameters were computed for three reference populations of animals born between 2004 and 2014: all animals, animals with mouse gray coat color, and animals with roan coat color. Although the average inbreeding coefficient observed was low (about 3 %), highly inbred animals are present in the current population. The effective population size based on the individual inbreeding rate was 35, while the effective population size based on the individual coancestry rate was about three times higher. The number of equivalent subpopulations was at around three, indicating that the Pêga donkey population is highly structured. There is no evidence of differentiation between subpopulations based on the coat color of the animals (Nei's minimum distance 0.10 %). The breeding policy of Pêga donkeys is predominantly intra-herd. The loss of genetic diversity since the founder generations can be considered small in Pêga donkeys (1.25 %). The excessive contribution of few ancestors to the gene pool may lead to narrower bottlenecks in the pedigree of this population in the future. The long generation interval in Pêga donkeys (10.7 years) may be considered an advantage to reduce the increase in inbreeding and to maintain the genetic diversity of these animals.

  14. Inter simple sequence repeat fingerprints for assess genetic diversity of tunisian garlic populations

    OpenAIRE

    Jabbes, Naouel; Geoffriau, Emmanuel; Le Clerc, Valérie; Dridi, Boutheina; Hannechi, Chérif

    2011-01-01

    Garlic (Allium sativum L.) that is cultivated in Tunisia is heterogeneous and unclassified with no registered local cultivars. At present, the level of genetic diversity in Tunisian garlic is almost unknown. Inter Simple Sequence Repeats (ISSR) genetic markers were therefore used to assess the genetic diversity and its distribution in 31 Tunisian garlic accessions with 4 French classified clones used as control. It was the first time that ISSR markers were used to detect diversity in garlic. ...

  15. Assessment of genetic diversity in Indian rice germplasm (Oryza sativa L.): use of random versus trait-linked microsatellite markers

    Indian Academy of Sciences (India)

    Sheel Yadav; Ashutosh Singh; M. R. Singh; Nitika Goel; K. K. Vinod; T. Mohapatra; A. K. Singh

    2013-12-01

    Assessment of genetic diversity in a crop germplasm is a vital part of plant breeding. DNA markers such as microsatellite or simple sequence repeat markers have been widely used to estimate the genetic diversity in rice. The present study was carried out to decipher the pattern of genetic diversity in terms of both phenotypic and genotypic variability, and to assess the efficiency of random vis-à-vis QTL linked/gene based simple sequence repeat markers in diversity estimation. A set of 88 rice accessions that included landraces, farmer’s varieties and popular Basmati lines were evaluated for agronomic traits and molecular diversity. The random set of SSR markers included 50 diversity panel markers developed under IRRI’s Generation Challenge Programme (GCP) and the trait-linked/gene based markers comprised of 50 SSR markers reportedly linked to yield and related components. For agronomic traits, significant variability was observed, ranging between the maximum for grains/panicle and the minimum for panicle length. The molecular diversity based grouping indicated that varieties from a common centre were genetically similar, with few exceptions. The trait-linked markers gave an average genetic dissimilarity of 0.45 as against that of 0.37 by random markers, along with an average polymorphic information constant value of 0.48 and 0.41 respectively. The correlation between the kinship matrix generated by trait-linked markers and the phenotype based distance matrix (0.29) was higher than that of random markers (0.19). This establishes the robustness of trait-linked markers over random markers in estimating genetic diversity of rice germplasm.

  16. Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality

    Directory of Open Access Journals (Sweden)

    Angela R. Piergiovanni

    2010-05-01

    Full Text Available The long tradition of common bean cultivation in Italy has allowed the evolution of many landraces adapted to restricted areas. Nowadays, in response to market demands, old landraces are gradually being replaced by improved cultivars. However, landraces still survive in marginal areas of several Italian regions. Most of them appear severely endangered with risk of extinction due to the advanced age of the farmers and the socio-cultural context where they are cultivated. The present contribution is an overview of the state of the art about the knowledge of Italian common bean germplasm, describing the most important and recent progresses made in its characterization, including genetic diversity and nutritional aspects.

  17. Genetic diversity assessment of summer squash landraces using molecular markers.

    Science.gov (United States)

    Mady, Emad A; Helaly, Alaa Al-Din; Abu El-Hamd, Abdel Naem; Abdou, Arafa; Shanan, Shamel A; Craker, Lyle E

    2013-07-01

    Plant identification, classification, and genotyping within a germplasm collection are essential elements for establishing a breeding program that enhances the probability of plants with desirable characteristics in the market place. In this study, random amplified polymorphic DNA (RAPD) was used as a molecular tool to assess the diversity and relationship among 20 summer squash (Curcubita pepo L.) landraces traditionally used to treat hypertension and prostate hyperplasia. A total of 10 RAPD primers produced 65 reproducible bands of which 46 (70.77 %) were polymorphic, indicating a large number of genotypes within the summer squash lines. Cluster analysis divided the summer squash germplasm into two groups, one including one landrace and a second containing 19 landraces that could be divided into five sub-groups. Results of this study indicate the potential of RAPD markers for the identification and assessment of genetic variations among squash landraces and provide a number of choices for developing a successful breeding program to improve summer squash.

  18. Genetic diversity of Quercus glandulifera var. brevipetiolata populations in three forest communities with different succession stages

    Institute of Scientific and Technical Information of China (English)

    Junmin LI; Zexin JIN; Qiping GU; Wenyan LOU

    2009-01-01

    In order to understand the relationship between population succession and its genetic behavior, random amplified polymorphic DNA (RAPD) technique was used to analyze the genetic diversity of Quercu glandulifera var.brevipetiolata populations in three forest communities with different succession stages (coniferous forest, coniferous and broad-leaved mixed forest, evergreen broad-leaved forest). The results showed that 145 repetitive loci were produced in 60 individuals of Q. glandulifera using 11 primers, among which 120 loci were polymorphic, and the total percentage of polymorphic loci was 82.76% with an average of 64.14%. Estimated by the Shannon information index, the total genetic diversity of the three populations was 0.4747, with an average of 0.3642, while it was 0.3234, with an average of 0.2484, judged from the Nei index. Judged from percentage of polymorphic loci,Shannon inform at ion index and Nei index, the genetic diversity followed a decreasing order: coniferous forest >broad-leaved mixed forest > evergreen broad-leaved for-est. Analysis of molecular variance (AMOVA) showed that 69.73% of the genetic variance existed within populations and 30.27% of the genetic variance existed among popu-lations. The coefficient of gene differentiation (Gst) was 0.2319 and the gene flow (Nm) was 1.6539. The mean of genetic identity among populations of Q. glandulifera was 0.8501 and the mean of genetic distance was 0.1626. The genetic identity between the Q. glandulifera population in the coniferous forest and that in the coniferous and broad-leaved mixed forest was the highest. UPGMA cluster analysis based on Nei's genetic distance showed that the population in the coniferous forest gathered with that in the coniferous and broad-leaved mixed forest firstly, then with that in the evergreen broad-leaved forest. The genetic structure of Q. glandulifera was not only characteristic of the biological characteristics of this species, but was also influenced by the

  19. High local genetic diversity of canine parvovirus from Ecuador.

    Science.gov (United States)

    Aldaz, Jaime; García-Díaz, Juan; Calleros, Lucía; Sosa, Katia; Iraola, Gregorio; Marandino, Ana; Hernández, Martín; Panzera, Yanina; Pérez, Ruben

    2013-09-27

    Canine parvovirus (CPV) comprises three antigenic variants (2a, 2b, and 2c) that are distributed globally with different frequencies and levels of genetic variability. CPVs from central Ecuador were herein analyzed to characterize the strains and to provide new insights into local viral diversity, evolution, and pathogenicity. Variant prevalence was analyzed by PCR and partial sequencing for 53 CPV-positive samples collected during 2011 and 2012. The full-length VP2 gene was sequenced in 24 selected strains and a maximum-likelihood phylogenetic tree was constructed using both Ecuadorian and worldwide strains. Ecuadorian CPVs have a remarkable genetic diversity that includes the circulation of all three variants and the existence of different evolutionary groups or lineages. CPV-2c was the most prevalent variant (54.7%), confirming the spread of this variant in America. Ecuadorian CPV-2c strains clustered in two lineages, which represent the first evidence of polyphyletic CPV-2c circulating in South America. CPV-2a strains constituted 41.5% of the samples and clustered in a single lineage. The two detected CPV-2b strains (3.8%) were clearly polyphyletic and appeared related to Ecuadorian CPV-2a or foreign CPV-2b strains. Besides the substitution at residue 426 that is used to identify the variants, two amino acid changes occurred in Ecuadorian strains: Val139Iso and Thr440Ser. Ser(440) occurred in a biologically relevant domain of VP2 and is here described for the first time in CPV. The associations of Ecuadorian CPV-2c and CPV-2a with clinical symptoms indicate that dull mentation, hemorrhagic gastroenteritis and hypothermia occurred more frequently in infection with CPV-2c than with CPV-2a.

  20. Epidemiology and genetic diversity of Taenia asiatica: a systematic review.

    Science.gov (United States)

    Ale, Anita; Victor, Bjorn; Praet, Nicolas; Gabriël, Sarah; Speybroeck, Niko; Dorny, Pierre; Devleesschauwer, Brecht

    2014-01-22

    Taenia asiatica has made a remarkable journey through the scientific literature of the past 50 years, starting with the paradoxical observation of high prevalences of T. saginata-like tapeworms in non-beef consuming populations, to the full description of its mitochondrial genome. Experimental studies conducted in the 1980s and 1990s have made it clear that the life cycle of T. asiatica is comparable to that of T. saginata, except for pigs being the preferential intermediate host and liver the preferential location of the cysts. Whether or not T. asiatica can cause human cysticercosis, as is the case for Taenia solium, remains unclear. Given the specific conditions needed to complete its life cycle, in particular the consumption of raw or poorly cooked pig liver, the transmission of T. asiatica shows an important ethno-geographical association. So far, T. asiatica has been identified in Taiwan, South Korea, Indonesia, the Philippines, Thailand, south-central China, Vietnam, Japan and Nepal. Especially this last observation indicates that its distribution is not restricted to South-East-Asia, as was thought so far. Indeed, the molecular tools developed over the last 20 years have made it increasingly possible to differentiate T. asiatica from other taeniids. Such tools also indicated that T. asiatica is related more closely to T. saginata than to T. solium, feeding the debate on its taxonomic status as a separate species versus a subspecies of T. saginata. Furthermore, the genetic diversity within T. asiatica appears to be very minimal, indicating that this parasite may be on the verge of extinction. However, recent studies have identified potential hybrids between T. asiatica and T. saginata, reopening the debate on the genetic diversity of T. asiatica and its status as a separate species.

  1. Genetic Diversity in ex-situ Conserved Lens culinaris for Botanical Descriptors, Biochemical and Molecular Markers and Identification of Landraces from Indigenous Genetic Resources of Pakistan

    Institute of Scientific and Technical Information of China (English)

    Tayyaba Sultana; Abdul Ghafoor

    2008-01-01

    Lentil, one of the oldest legumes was Investigated for diversity based on botanical descriptors, total seed proteins,isozymes and random amplified polymorphic DNA (RAPD) markers. About one fourth of accessions were heterogeneous for botanical descriptors and a seed protein profile. The germplaem collected from the province of Baluchistan revealed the prevalence of indigenous landraces as high diversity was observed for all of the techniques. Diversity explored through various techniques revealed validity Irrespective of the sample size or geographic pattern, RAPD being the best choice for Investigating both inter- and intra-accession variation In lentil. Although all of the techniques were able to resolve genetic diversity In lentil, isozymes and seed proteins gave low levels of genetic diversity, suggesting that more investigation into isozymes of specific proteins is required. RAPD is the best option for determining inter- and Intra-accession variation, and will be required to extend germplasme and primers to continue the study of botanical descriptors.

  2. Genetic diversity of microsatellite loci in hierarchically structured populations.

    Science.gov (United States)

    Song, Seongho; Dey, Dipak K; Holsinger, Kent E

    2011-08-01

    Microsatellite loci are widely used for investigating patterns of genetic variation within and among populations. Those patterns are in turn determined by population sizes, migration rates, and mutation rates. We provide exact expressions for the first two moments of the allele frequency distribution in a stochastic model appropriate for studying microsatellite evolution with migration, mutation, and drift under the assumption that the range of allele sizes is bounded. Using these results, we study the behavior of several measures related to Wright's F(ST), including Slatkin's R(ST). Our analytical approximations for F(ST) and R(ST) show that familiar relationships between N(e)m and F(ST) or R(ST) hold when the migration and mutation rates are small. Using the exact expressions for F(ST) and R(ST), our numerical results show that, when the migration and mutation rates are large, these relationships no longer hold. Our numerical results also show that the diversity measures most closely related to F(ST) depend on mutation rates, mutational models (stepwise versus two-phase), migration rates, and population sizes. Surprisingly, R(ST) is relatively insensitive to the mutation rates and mutational models. The differing behaviors of R(ST) and F(ST) suggest that properties of the among-population distribution of allele frequencies may allow the roles of mutation and migration in producing patterns of diversity to be distinguished, a topic of continuing investigation.

  3. Genetic signatures of ecological diversity along an urbanization gradient

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    Ryan P. Kelly

    2016-09-01

    Full Text Available Despite decades of work in environmental science and ecology, estimating human influences on ecosystems remains challenging. This is partly due to complex chains of causation among ecosystem elements, exacerbated by the difficulty of collecting biological data at sufficient spatial, temporal, and taxonomic scales. Here, we demonstrate the utility of environmental DNA (eDNA for quantifying associations between human land use and changes in an adjacent ecosystem. We analyze metazoan eDNA sequences from water sampled in nearshore marine eelgrass communities and assess the relationship between these ecological communities and the degree of urbanization in the surrounding watershed. Counter to conventional wisdom, we find strongly increasing richness and decreasing beta diversity with greater urbanization, and similar trends in the diversity of life histories with urbanization. We also find evidence that urbanization influences nearshore communities at local (hundreds of meters rather than regional (tens of km scales. Given that different survey methods sample different components of an ecosystem, we then discuss the advantages of eDNA—which we use here to detect hundreds of taxa simultaneously—as a complement to traditional ecological sampling, particularly in the context of broad ecological assessments where exhaustive manual sampling is impractical. Genetic data are a powerful means of uncovering human-ecosystem interactions that might otherwise remain hidden; nevertheless, no sampling method reveals the whole of a biological community.

  4. Genetic and functional diversity of Pseudomonas aeruginosa lipopolysaccharide

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    Joseph S. Lam

    2011-06-01

    Full Text Available Lipopolysccharide (LPS is an integral component of the Pseudomonas aeruginosa cell envelope, occupying the outer leaflet of the outer membrane in this Gram-negative opportunistic pathogen. It is important for bacteria-host interactions and has been shown to be a major virulence factor for this organism. Structurally, P. aeruginosa LPS is composed of three domains, namely, lipid A, core oligosaccharide, and the distal O antigen (O-Ag. Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band, and the other a heteropolymer of three to five distinct (and often unique dideoxy sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band. Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa. The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa. The underlying factors contributing to this diversity will be thoroughly discussed and presented in the context of its contributions to host-pathogen interactions and the control/prevention of infection.

  5. Internal lattice reconfiguration for diversity tuning in Cellular Genetic Algorithms.

    Science.gov (United States)

    Morales-Reyes, Alicia; Erdogan, Ahmet T

    2012-01-01

    Cellular Genetic Algorithms (cGAs) have attracted the attention of researchers due to their high performance, ease of implementation and massive parallelism. Maintaining an adequate balance between exploitative and explorative search is essential when studying evolutionary optimization techniques. In this respect, cGAs inherently possess a number of structural configuration parameters that are able to sustain diversity during evolution. In this study, the internal reconfiguration of the lattice is proposed to constantly or adaptively control the exploration-exploitation trade-off. Genetic operators are characterized in their simplest form since algorithmic performance is assessed on implemented reconfiguration mechanisms. Moreover, internal reconfiguration allows the adjacency of individuals to be maintained. Hence, any improvement in performance is only a consequence of topological changes. Two local selection methods presenting opposite selection pressures are used in order to evaluate the influence of the proposed techniques. Problems ranging from continuous to real world and combinatorial are tackled. Empirical results are supported statistically in terms of efficiency and efficacy.

  6. Molecular identification and genetic diversity among Photorhabdus and Xenorhabdus isolates.

    Science.gov (United States)

    Moghaieb, Reda E A; Abdelhadi, Abdelhadi A; El-Sadawy, Hanan A; Allam, Nesreen A T; Baiome, Baiome Abdelmaguid; Soliman, Mohamed H

    2017-05-01

    Five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (Galleria mellonella) infected with the entomopathogenic nematodes: Heterorhabditis bacteriophora HP88, Heterorhabditis indicus RM1 and Heterorhabditis sp (S1), Steinernema abbasi and Steinernema sp. (S II). Strains were identified as Photorhabdus luminescens HRM1, P. luminescens HS1, P. luminescens HP88, Xenorhabdus indica and X. nematophila ATTC19061 using 16S rDNA sequence analysis. To reveal the genetic diversity among these strains, three molecular markers (RAPD, ISSR and SRAP) were employed. RAPD analysis showed 73.8 and 54.5 polymorphism percentages for the Photorhabdus and Xenorhabdus strains, respectively. ISSR analysis resulted in 70.1 and 75.2 polymorphism percentages among the Photorhabdus and Xenorhabdus strains, respectively. The SRAP analysis indicated that 75.6 and 61.2% genetic polymorphism was detected among Photorhabdus and Xenorhabdus strains, respectively. The cluster analysis grouped the three Photorhabdus strains together in one cluster and the two Xenorhabdus strains together in another cluster indicating the phylogenetic relationships among them. The genotype-specific markers detected from the three molecular markers (RAPD, ISSR and SRAP) were sufficient to distinguish between the different bacterial strains tested and can be used in the future IBM program that could be built on the use of these strains.

  7. Genetic diversity of human blastocystis isolates in khorramabad, central iran.

    Directory of Open Access Journals (Sweden)

    Ebrahim Badparva

    2014-03-01

    Full Text Available There are some genetic differences in Blastocystis that show the existence of species or genotypes. One of these genes that help in identifying Blastocystis is SSUrRNA. The aim of this study was assessment of genetic diversity of Blastocystis by PCR with seven pairs of STS primers.This study was done on 511 stool samples collected from patients referred to the health care centers of Khorramabad, Central Iran, in 2012. Genomic DNA was extracted and in order to determine the Blastocystis subtype in contaminated samples, seven pairs of primers STS (subtype specific sequence-tagged site were used.Out of 511 samples, 33 (6.5% samples were infected with Blastocystis. Subtype (ST of 30 samples was identified and three subtypes 2, 3 and 4 were determined. Mix infection was reported 10% which 3.33% of the infection was for the mixture of ST 3 and ST5 and 6.67% was for the mixture of ST 2 and ST 3.The predominant subtype was ST3 that is the main human subtype. The dominance of ST2 and 5 are important in this study. This superiority has been reported in some of the studies in ST 2 which is different from the studies in other countries, because they have announced priorities of the ST1 and ST6 after ST3.

  8. Genetic diversity among sea otter isolates of Toxoplasma gondii

    Science.gov (United States)

    Sundar, N.; Cole, R.A.; Thomas, N.J.; Majumdar, D.; Dubey, J.P.; Su, C.

    2008-01-01

    Sea otters (Enhydra lutris) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. Here, we determined genotypes of 39 T. gondii isolates from 37 sea otters in two geographically distant locations (25 from California and 12 from Washington). Six genotypes were identified using 10 PCR-RFLP genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and by DNA sequencing of loci SAG1 and GRA6 in 13 isolates. Of these 39 isolates, 13 (33%) were clonal Type II which can be further divided into two groups at the locus Apico. Two of the 39 isolates had Type II alleles at all loci except a Type I allele at locus L358. One isolate had Type II alleles at all loci except the Type I alleles at loci L358 and Apico. One isolate had Type III alleles at all loci except Type II alleles at SAG2 and Apico. Two sea otter isolates had a mixed infection. Twenty-one (54%) isolates had an unique allele at SAG1 locus. Further genotyping or DNA sequence analysis for 18 of these 21 isolates at loci SAG1 and GRA6 revealed that there were two different genotypes, including the previously identified Type X (four isolates) and a new genotype named Type A (14 isolates). The results from this study suggest that the sea otter isolates are genetically diverse.

  9. Population structure and genetic diversity of moose in Alaska.

    Science.gov (United States)

    Schmidt, Jennifer I; Hundertmark, Kris J; Bowyer, R Terry; McCracken, Kevin G

    2009-01-01

    Moose (Alces alces) are highly mobile mammals that occur across arboreal regions of North America, Europe, and Asia. Alaskan moose (Alces alces gigas) range across much of Alaska and are primary herbivore consumers, exerting a prominent influence on ecosystem structure and functioning. Increased knowledge gained from population genetics provides insights into their population dynamics, history, and dispersal of these unique large herbivores and can aid in conservation efforts. We examined the genetic diversity and population structure of moose (n = 141) with 8 polymorphic microsatellites from 6 regions spanning much of Alaska. Expected heterozygosity was moderate (H(E) = 0.483-0.612), and private alleles ranged from 0 to 6. Both F(ST) and R(ST) indicated significant population structure (P moose from the Yakutat and Tetlin regions versus all other moose, with slight substructure observed among the second population. Estimates of dispersal differed between analytical approaches, indicating a high level of historical or current gene flow. Mantel tests indicated that isolation-by-distance partially explained observed structure among moose populations (R(2) = 0.45, P moose in Alaska with population expansion from interior Alaska westward toward the coast.

  10. Genome-wide distribution of genetic diversity and linkage disequilibrium in elite sugar beet germplasm

    Directory of Open Access Journals (Sweden)

    Weißleder Knuth

    2011-10-01

    Full Text Available Abstract Background Characterization of population structure and genetic diversity of germplasm is essential for the efficient organization and utilization of breeding material. The objectives of this study were to (i explore the patterns of population structure in the pollen parent heterotic pool using different methods, (ii investigate the genome-wide distribution of genetic diversity, and (iii assess the extent and genome-wide distribution of linkage disequilibrium (LD in elite sugar beet germplasm. Results A total of 264 and 238 inbred lines from the yield type and sugar type inbreds of the pollen parent heterotic gene pools, respectively, which had been genotyped with 328 SNP markers, were used in this study. Two distinct subgroups were detected based on different statistical methods within the elite sugar beet germplasm set, which was in accordance with its breeding history. MCLUST based on principal components, principal coordinates, or lapvectors had high correspondence with the germplasm type information as well as the assignment by STRUCTURE, which indicated that these methods might be alternatives to STRUCTURE for population structure analysis. Gene diversity and modified Roger's distance between the examined germplasm types varied considerably across the genome, which might be due to artificial selection. This observation indicates that population genetic approaches could be used to identify candidate genes for the traits under selection. Due to the fact that r2 >0.8 is required to detect marker-phenotype association explaining less than 1% of the phenotypic variance, our observation of a low proportion of SNP loci pairs showing such levels of LD suggests that the number of markers has to be dramatically increased for powerful genome-wide association mapping. Conclusions We provided a genome-wide distribution map of genetic diversity and linkage disequilibrium for the elite sugar beet germplasm, which is useful for the application of

  11. Genetic diversity of Leishmania tropica strains isolated from clinical forms of cutaneous leishmaniasis in rural districts of Herat province, Western Afghanistan, based on ITS1-rDNA.

    Science.gov (United States)

    Fakhar, Mahdi; Pazoki Ghohe, Hossein; Rasooli, Sayed Abobakar; Karamian, Mehdi; Mohib, Abdul Satar; Ziaei Hezarjaribi, Hajar; Pagheh, Abdol Sattar; Ghatee, Mohammad Amin

    2016-07-01

    Despite the high incidence of cutaneous leishmaniasis (CL) in Afghanistan, there is a little information concerning epidemiological status of the disease and phylogenetic relationship and population structure of causative agents. This study was conducted to determine the prevalence and distribution of CL cases and investigate the Leishmania tropica population structure in rural districts of Heart province in the West of Afghanistan in comparison to neighboring foci. Overall, 4189 clinically suspected CL cases from 177 villages (including 12 districts) in Herat province were enrolled in the referral laboratory of WHO sub-office in Herat city from January 2012 to December 2013. 3861 cases were confirmed as CL by microscopic examination of Giemsa-stained slides. ITS1 PCR-RFLP analysis showed dominance of L. tropica (more than 98%) among 127 randomly chosen samples. Analysis of the ITS1 sequences revealed 4 sequence types among the 21 L. tropica isolates. Comparison of sequence types from Herat rural districts with the representatives of L. tropica from Iran, India, and Herat city showed two main population groups (cluster A and B). All isolates from Herat province, India and Southeast, East, and Central Iran were found exclusively in cluster A. The close proximity of West Afghanistan focus and Birjand county as the capital of Southern Khorasan province in East Iran can explain relatively equal to the genetic composition of L. tropica in these two neighboring regions. In addition, two populations were found among L. tropica isolates from Herat rural districts. Main population showed more similarity to some isolates from Birjand county in East Iran while minor population probably originated from the Southeast and East Iranian L. tropica. Recent study provided valuable information concerning the population structure of L. tropica and epidemiology of ACL in the West of Afghanistan, which could be the basis for molecular epidemiology studies in other regions of Afghanistan.

  12. Genetic diversity analysis of mitochondrial DNA control region in artificially propagated Chinese sucker Myxocyprinus asiaticus.

    Science.gov (United States)

    Wan, Yuan; Zhou, Chun-Hua; Ouyang, Shan; Huang, Xiao-Chen; Zhan, Yang; Zhou, Ping; Rong, Jun; Wu, Xiao-Ping

    2015-08-01

    The genetic diversity of the three major artificially propagated populations of Chinese sucker, an endangered freshwater fish species, was investigated using the sequences of mitochondrial DNA (mtDNA) control regions. Among the 89 individuals tested, 66 variable sites (7.26%) and 10 haplotypes were detected (Haplotype diversity Hd = 0.805, Nucleotide diversity π = 0.0287). In general, genetic diversity was lower in artificially propagated populations than in wild populations. This reduction in genetic diversity may be due to population bottlenecks, genetic drift and human selection. A stepping-stone pattern of gene flow was detected in the populations studied, showing much higher gene flow between neighbouring populations. To increase the genetic diversity, wild lineages should be introduced, and more lineages should be shared among artificially propagated populations.

  13. Genetic diversity and biogeography of red turpentine beetle Dendroctonus valens in its native and invasive regions

    Institute of Scientific and Technical Information of China (English)

    Yan-Wen Cai; Xin-Yue Cheng; Ru-Mei Xu; Dong-Hong Duan; Lawrence R. Kirkendall

    2008-01-01

    Sequences of 479 bp region of the mitochondrial COI gene were applied to detect population genetic diversity and structure of Dendroctonus valens populations. By comparing the genetic diversity between native and invasive populations, it was shown that the genetic diversity of Chinese populations was obviously lower than that of native populations with both indices of haplotype diversity and Nei's genetic diversity, suggesting genetic bottleneck occurred in the invasive process of D. valens, and was then followed by a relatively quick population buildup. According to phylogenetic analyses of haplotypes, we suggested that the origin of the Chinese population was from California, USA. Phylogenetic and network analysis of native populations of D. valens revealed strong genetic structure at two distinct spatial and temporal scales in North America. The main cause resulting in current biogeographic pattern was supposedly due to recycled glacial events. Meanwhile, a cryptic species might exist in the Mexican and Guatemalan populations.

  14. A nonlinear relationship between genetic diversity and productivity in a polyphagous seed beetle.

    Science.gov (United States)

    Burls, K J; Shapiro, J; Forister, M L; Hoelzer, G A

    2014-05-01

    There has been a renewed interest in the effects of genetic diversity on population-level and community-level processes. Many of these studies have found non-additive, positive effects of diversity, but these studies have rarely examined ecological mechanisms by which diverse populations increase productivity. We used the seed beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) to study genetic diversity in insect host preference and fecundity and its effects on total productivity and resource use. We created genetically distinct lineages that varied in host preference and fecundity and then assembled groups consisting of one, three, five, or all ten lineages. We found that lineages with intermediate diversity had the highest productivity, though resource use did not change in diverse groups. In addition, lineages showed substantial plasticity in host preference when preference was assayed either individually or in groups, and productivity was much lower in groups than predicted by individual assays. These results highlight the interplay of genetic diversity, resource variation, and phenotypic plasticity in determining the ecological consequences of genetic diversity. In addition, when plasticity modifies a population's response to population density, this may create a complex interaction between genetic diversity and density, influencing selective pressures on the population and potentially maintaining genetic diversity across generations.

  15. Genetic diversity of neotropical Myotis (chiroptera: vespertilionidae with an emphasis on South American species.

    Directory of Open Access Journals (Sweden)

    Roxanne J Larsen

    Full Text Available BACKGROUND: Cryptic morphological variation in the Chiropteran genus Myotis limits the understanding of species boundaries and species richness within the genus. Several authors have suggested that it is likely there are unrecognized species-level lineages of Myotis in the Neotropics. This study provides an assessment of the diversity in New World Myotis by analyzing cytochrome-b gene variation from an expansive sample ranging throughout North, Central, and South America. We provide baseline genetic data for researchers investigating phylogeographic and phylogenetic patterns of Myotis in these regions, with an emphasis on South America. METHODOLOGY AND PRINCIPAL FINDINGS: Cytochrome-b sequences were generated and phylogenetically analyzed from 215 specimens, providing DNA sequence data for the most species of New World Myotis to date. Based on genetic data in our sample, and on comparisons with available DNA sequence data from GenBank, we estimate the number of species-level genetic lineages in South America alone to be at least 18, rather than the 15 species currently recognized. CONCLUSIONS: Our findings provide evidence that the perception of lower species richness in South American Myotis is largely due to a combination of cryptic morphological variation and insufficient sampling coverage in genetic-based systematic studies. A more accurate assessment of the level of diversity and species richness in New World Myotis is not only helpful for delimiting species boundaries, but also for understanding evolutionary processes within this globally distributed bat genus.

  16. Genetic diversity and breeding of larch (Larix decidua Mill. in Romania

    Directory of Open Access Journals (Sweden)

    Georgeta Mihai

    2009-12-01

    effective from both genetic and economic point of view. The broad-sense heritability coefficients for diameter breast height (h2 = 0.773, branch thickness (h2 = 0.759, angle of insertion (h2 = 0.775 and stem form (h2 = 0.591 indicate a strong genetic control for these characters. The expected genetic gain by means of selection of the best 10 clones ranges between 16 to 36%, depending on the character considered. The study of genetic diversity, based on the izoenzymatic markers in provenances comparative trials of larch indicates a high level of intrapopulation genetic diversity, especially for populations located in the South of Eastern Carpathians. Regarding the interpopulation genetic diversity, the provenance Ceahlău is significantly different from other surveyed populations. The obtained results provide important information in terms of long-term breeding, conservation of forest genetic resources, and also for reconsideration of this species in forestation works

  17. Loss of Genetic Diversity of Jatropha curcas L. through Domestication: Implications for Its Genetic Improvement

    DEFF Research Database (Denmark)

    Sanou, Haby; Angel Angulo-Escalante, Miguel; Martinez-Herrera, Jorge

    2015-01-01

    populations. Results confirmed very low genetic diversity in African and Asian landraces. Mexican populations from the regions of Veracruz, Puebla, and Morelos were also found to have low levels of diversity (mostly monomorphic), while populations from Chiapas were polymorphic with an expected heterozygosity....... Mating system could not be estimated in the landraces from Mali and populations from Veracruz, Puebla, and Morelos (Mexico), as these were highly monomorphic. The observed low level of genetic diversity in some of the populations and landraces suggests that breeding programs should test for genetic...

  18. Diversidade genética de pitayas nativas do cerrado com base em marcadores RAPD Genetic diversity of native pitaya native from brazilian savannas with basis on RAPD markers

    Directory of Open Access Journals (Sweden)

    Keize Pereira Junqueira

    2010-09-01

    naturally vegetate on solid rocky sandstone or quartzite, tree trunks and on rocky fields sand soils at Minas Gerais, Goiás, Distrito Federal, Tocantins, Rio de Janeiro and Bahia, with strong evidences that Brazil central region is the biggest pitayas dispersion center, because of wide phenotypic diversity observed in collected accesses. We had the objective to realize genetic diversity study of 13 pitaya accesses maintained at Embrapa Cerrados germoplasm collection through RAPD (Random Amplified Polymorphic DNA molecular markers. Each access genomic DNA were extracted and fourteen decamer initiators were used to obtain RAPD molecular markers, that were converted in a binary data matrix, from where we estimate genetic distances between accesses and realize grouping and graphic dispersion analysis. 162 RAPD markers were obtained, making 11,57 markers medium per primer. From markers total, 154 (95,06% were polymorphic. Genetic distances varied within 0,088 and 0,848, biggest values observed refer to distance between Unaí, MG access and Seleção Embrapa Cerrados access. The most different access was "Unaí, MG", that showed 0,675 of genetic distance avarege in relation to others accessions. The high genetic distance verified is due to the fact that the referred accesses do not belong to the same species. Pitaya accesses groups had little relation to their geographic origin. The genetic diversity found at brazilian savannas allow to include this biome at pitaya species diversity center, showing good perspectives to studies about this fruit potential.

  19. A Genomic Encyclopedia of the Root Nodule Bacteria: assessing genetic diversity through a systematic biogeographic survey.

    Science.gov (United States)

    Reeve, Wayne; Ardley, Julie; Tian, Rui; Eshragi, Leila; Yoon, Je Won; Ngamwisetkun, Pinyaruk; Seshadri, Rekha; Ivanova, Natalia N; Kyrpides, Nikos C

    2015-01-01

    Root nodule bacteria are free-living soil bacteria, belonging to diverse genera within the Alphaproteobacteria and Betaproteobacteria, that have the capacity to form nitrogen-fixing symbioses with legumes. The symbiosis is specific and is governed by signaling molecules produced from both host and bacteria. Sequencing of several model RNB genomes has provided valuable insights into the genetic basis of symbiosis. However, the small number of sequenced RNB genomes available does not currently reflect the phylogenetic diversity of RNB, or the variety of mechanisms that lead to symbiosis in different legume hosts. This prevents a broad understanding of symbiotic interactions and the factors that govern the biogeography of host-microbe symbioses. Here, we outline a proposal to expand the number of sequenced RNB strains, which aims to capture this phylogenetic and biogeographic diversity. Through the Vavilov centers of diversity (Proposal ID: 231) and GEBA-RNB (Proposal ID: 882) projects we will sequence 107 RNB strains, isolated from diverse legume hosts in various geographic locations around the world. The nominated strains belong to nine of the 16 currently validly described RNB genera. They include 13 type strains, as well as elite inoculant strains of high commercial importance. These projects will strongly support systematic sequence-based studies of RNB and contribute to our understanding of the effects of biogeography on the evolution of different species of RNB, as well as the mechanisms that determine the specificity and effectiveness of nodulation and symbiotic nitrogen fixation by RNB with diverse legume hosts.

  20. Modelling the loss of genetic diversity in vole populations in a spatially and temporally varying environment

    DEFF Research Database (Denmark)

    Topping, Christopher John; Østergaard, Siri; Pertoldi, Cino

    2003-01-01

    to habitat availability and their influence on vole behaviour. Interaction between spatial and temporal dynamics altered the ratio of effective population size to census size. This indicates an altered reproductive potential, crucial in conservation biology applications. However, when the loss...... a genetically explicit individual-based model (IBM) coupled to a dynamic landscape model was used to obtain measures for the genetic status of simulated vole populations. The rate of loss of expected heterozygosity (He) was calculated for simulated populations using two levels of spatial and temporal...... heterogeneity. Results showed that both spatial and temporal heterogeneity exerted an influence on the rate of loss of genetic diversity, but the precise effect was a balance between the effects of population sub-structuring, the frequency of founder effects and population size. These were in turn related...

  1. Genetic diversity of Chilean and Brazilian alstroemeria species assessed by AFLP analysis.

    Science.gov (United States)

    Han, T H; de Jeu, M; van Eck, H; Jacobsen, E

    2000-05-01

    One to three accessions of 22 Alstroemeria species, an interspecific hybrid (A. aurea x A. inodora), and single accessions of Bomarea salsilla and Leontochir ovallei were evaluated using the AFLP-marker technique to estimate the genetic diversity within the genus Alstroemeria. Three primer combinations generated 716 markers and discriminated all Alstroemeria species. The dendrogram inferred from the AFLP fingerprints supported the conjecture of the generic separation of the Chilean and Brazilian Alstroemeria species. The principal co-ordinate plot showed the separate allocation of the A. ligtu group and the allocation of A. aurea, which has a wide range of geographical distribution and genetic variation, in the middle of other Alstroemeria species. The genetic distances, based on AFLP markers, determined the genomic contribution of the parents to the interspecific hybrid.

  2. 不同种源红椿SRAP标记的遗传多样性分析%Genetic Diversity of Toona ciliata from Different Provenances Based on Sequence-Related Amplified Polymorphism ( SRAP) Markers

    Institute of Scientific and Technical Information of China (English)

    李培; 阙青敏; 欧阳昆唏; 李俊成; 湛欣; 朱芹; 张俊杰; 邓小梅; 陈晓阳

    2016-01-01

    果与地理分布格局基本吻合.在红椿保护和管理的过程中,在对原有生境进行保护的同时,要加强人工繁育技术研究,并注意最大限度地保护红椿的遗传多样性.%[Objective]Poor natural regeneration and over-exploitation have resulted in the continual decline of natural forests and trees of Toona ciliata. In depth studies of genetic diversity and structure of T. ciliata of different provenances are particularly important for conservation,utilization of genetic resources,and the development of future breeding programs for the species.[Method]Sequence-related amplified polymorphism ( SRAP) markers were used to investigate genetic diversity of 29 provenances from China and one provenance from Australia of T. ciliata to define the level of genetic diversity and the relationships among different provenances. Samples from China were collected from natural stands. Each provenance was represented by 30 sample trees with a distance of at least 50 m among the sample trees. The Australian provenance was taken from the resources collection nursery of the South China Agricultural University. The POPGENE1. 32 software was used for genetic diversity parameters calculation. The NTSYS-pc2. 1 software was used for cluster analysis based on the matrix of Nei's genetic distances and the degree of genetic relatedness among provenances was assessed by principal coordinates analysis (PCoA) and MANTEL analysis with GenAIEx 6. 5. STRUCTRUE 2. 3 was used to analysis the genetic structure. [Result]A total of 505 polymorphic bands were amplified by 24 pairs of primers. The average value of polymorphism information content (PIC) was 0. 41. The average value of Nei's gene diversity index (H) was 0. 377 0. Shannon's information index (I) within provenances ranged from 0. 157 5 to 0. 467 5,the average value was 0. 556 9 among provenances. The AMOVA indicated that 79. 24% of the total variation was among provenances and 20. 76% was within provenances,revealing that provenance

  3. APPLICATION OF RYE SSR MARKERS FOR DETECTION OF GENETIC DIVERSITY IN TRITICALE

    Directory of Open Access Journals (Sweden)

    Želmíra Balážová

    2016-06-01

    Full Text Available Present study aims to testify usefulness of particular rye SSR markers for the detection of genetic diversity degree in the set of 20 triticale cultivars coming from different European countries. For this purpose, a set of six rye SSR markers were used. The set of six polymorphic markers provided 22 alleles with an average frequency of 3.67 alleles per locus. The number of alleles ranged between 2 (SCM43 and 5 (SCM28, SCM86. Resulting from the number and frequency of alleles diversity index (DI, polymorphic information content (PIC and probability of identity (PI were calculated. An average value of PIC for 6 SSR markers was 0.505, the highest value was calculated for rye SSR marker SCM86 (0.706. Based on UPGMA algorithm, a dendrogram was constructed. In dendrogram cultivars were divided into two main clusters. The first cluster contained two cultivars, Russian cultivar Greneder and Slovak cultivar Largus, and second included 18 cultivars. Genetically the closest were two Greek cultivars (Niobi and Thisbi and were close to other Greek cultivar Vrodi. It was possible to separate triticale cultivars of spring and winter form in dendrogram. Results showed the utility of rye microsatellite markers for estimation of genetic diversity of European triticale genotypes leading to genotype identification.

  4. PRODUCTIVITY AND GENETIC DIVERSITY OF LOCAL CATTLE IN CIAMIS-WEST JAVA

    Directory of Open Access Journals (Sweden)

    N. Hilmia

    2013-03-01

    Full Text Available The objectives of this study were to identify the productivity and genetic diversity of local cattle in Ciamis West Java based on DNA microsatellite, in order to provide the basic information for its rearing, conservation and development. Eighteen of local cattle were kept for 58 days by feeding concentrates and rice straw. The measured parameters were weekly body weight as well as carcass percentage. The percentage of comparing carcass was taken from PO, Bali and crossbred cattle from local cattle with Limousin, Simmental, Brahman and Angus cattle. Data were analyzed using Excel software and SAS (2004. Blood samples were taken from two subpopulations i.e., 46 and 52 samples from Tambaksari and Cijulang areas, respectively. Other DNA samples were collected from Bali, PO, Limousin, Simental, Brahman and Angus cattle. Genetic diversity and phylogenetic analysis were analyzed using 3 microsatellite loci, that were INRA35, HEL9 and BM2113. The genotyping data were analyzed using POPGENE.32 program, while phylogenetic trees were analyzed by MEGA 4. Average daily gain (ADG of local cattle in Ciamis was 0.62±0.23 kg/head/day with a carcass percentage was 51.62±1.80%. The carcasses percentage of local cattle in Ciamis was not significantly different from those of Bali, PO, and crossbred cattle. The genetic diversity of local cattle in Ciamis was categorized in the medium level, the diversity of local cattle in Tambaksari subpopulation was higher than in Cijulang subpopulation. Local cattle in Ciamis had a closer genetic distance with the PO cattle.

  5. Characterization of casein gene complex and genetic diversity analysis in Indian goats.

    Science.gov (United States)

    Rout, P K; Kumar, A; Mandal, A; Laloe, D; Singh, S K; Roy, R

    2010-04-01

    Milk protein polymorphism plays an important role in genetic diversity analysis, phylogenetic studies, establishing geographical diversity, conservation decision, and improving breeding goals. Milk protein polymorphism in Indian goat breeds has not been well studied; therefore, an investigation was carried out to analyze the genetic structure of the casein gene and milk protein diversity at six milk protein loci in nine Indian goat breeds/genetic groups from varied agro-climatic zones. Milk protein genotyping was carried out in 1098 individual milk samples by SDS-PAGE at alphaS1-CN (CSN1S1), beta-CN (CSN2), alphaS2-CN (CSN1S2), kappa-CN (CSN3), beta-LG, and alpha-LA loci. Indian goats exhibited alphaS1-casein A allele in higher frequency in the majority of breeds except Ganjam and local goats. The alphaS1-casein A allele frequencies varied from 0.45 to 0.77. A total of 16 casein haplotypes were observed in seven breeds and breed specific haplotypes were observed with respect to geographic region. The average number of alleles was lowest in Ganjam (1.66 +/- 0.81) and highest in Sirohi goats (2.50 +/- 1.05). Expected heterozygosity at six different loci demonstrated genetic diversity and breed fragmentation. Neighbor-Joining tree was built basing on Nei's distance. There was about 16.95% variability due to differences between breeds, indicating a strong subdivision. Principal component analysis was carried out to highlight the relationship among breeds. The variability among goat breeds was contributed by alphaS2-CN, beta-LG and alphaS1-CN. The Indian goats exhibited alphaS1-CN (CSN1S1) A allele in higher frequency in all the breeds indicating the higher casein yield in their milk.

  6. Genetic diversity and antigenicity variation of Babesia bovis merozoite surface antigen-1 (MSA-1) in Thailand.

    Science.gov (United States)

    Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki

    2016-07-01

    Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our phylogenetic analysis, Thai msa-1 gene sequences occurred in 18 clades; seven among them were composed of sequences exclusively from Thailand. To investigate differential antigenicity of isolated MSA-1 proteins, we expressed and purified eight recombinant MSA-1 (rMSA-1) proteins, including an rMSA-1 from B. bovis Texas (T2Bo) strain and seven rMSA-1 proteins based on the Thai msa-1 sequences. When these antigens were analyzed in a western blot assay, anti-T2Bo cattle serum strongly reacted with the rMSA-1 from T2Bo, as well as with three other rMSA-1 proteins that shared 54.9-68.4% sequence similarity with T2Bo MSA-1. In contrast, no or weak reactivity was observed for the remaining rMSA-1 proteins, which shared low sequence similarity (35.0-39.7%) with T2Bo MSA-1. While demonstrating the high genetic diversity of the B. bovis msa-1 gene in Thailand, the present findings suggest that the genetic diversity results in antigenicity variations among the MSA-1 antigens of B. bovis in Thailand.

  7. Function Optimization Based on Quantum Genetic Algorithm

    OpenAIRE

    Ying Sun; Hegen Xiong

    2014-01-01

    Optimization method is important in engineering design and application. Quantum genetic algorithm has the characteristics of good population diversity, rapid convergence and good global search capability and so on. It combines quantum algorithm with genetic algorithm. A novel quantum genetic algorithm is proposed, which is called Variable-boundary-coded Quantum Genetic Algorithm (vbQGA) in which qubit chromosomes are collapsed into variable-boundary-coded chromosomes instead of binary-coded c...

  8. Function Optimization Based on Quantum Genetic Algorithm

    OpenAIRE

    Ying Sun; Yuesheng Gu; Hegen Xiong

    2013-01-01

    Quantum genetic algorithm has the characteristics of good population diversity, rapid convergence and good global search capability and so on.It combines quantum algorithm with genetic algorithm. A novel quantum genetic algorithm is proposed ,which is called variable-boundary-coded quantum genetic algorithm (vbQGA) in which qubit chromosomes are collapsed into variableboundary- coded chromosomes instead of binary-coded chromosomes. Therefore much shorter chromosome strings can be gained.The m...

  9. Diversity surveys of soil bacterial community by cultivation-based methods and molecular fingerprinting techniques

    Institute of Scientific and Technical Information of China (English)

    LUO Hai-feng; QI Hong-yan; ZHANG Hong-xun

    2004-01-01

    By combining the cultivation methods with molecular fingerprinting techniques, the diversity surveys of soil bacterial community in 13 areas of China were carried out. The cultivable heterotrophic diversity was investigated by colony morphology on solid LB medium. Genetic diversity was measured as bands on denaturing gradient gel electrophoresis(DGGE) by the extraction and purification of the total soil DNA, and amplification of bacterial 16S rDNA fragments by polymerase chain reaction ( PCR). The Shannon-Wiener indices of diversity (H), richness (S)and evenness( EH ) were employed to estimate the diversity of soil bacterial community. The results showed that there was an obvious diversification existed in soil from the different areas. However, the genetic diversity estimated by PCR-DGGE can provide more comprehensive information on bacterial community than the cultivation-based methods. Therefore, it is suggested to combine the traditional methods with genetic fingerprinting techniques to survey and estimate soil bacterial diversity.

  10. Noninvasive genetics provides insights into the population size and genetic diversity of an Amur tiger population in China.

    Science.gov (United States)

    Wang, Dan; Hu, Yibo; Ma, Tianxiao; Nie, Yonggang; Xie, Yan; Wei, Fuwen

    2016-01-01

    Understanding population size and genetic diversity is critical for effective conservation of endangered species. The Amur tiger (Panthera tigris altaica) is the largest felid and a flagship species for wildlife conservation. Due to habitat loss and human activities, available habitat and population size are continuously shrinking. However, little is known about the true population size and genetic diversity of wild tiger populations in China. In this study, we collected 55 fecal samples and 1 hair sample to investigate the population size and genetic diversity of wild Amur tigers in Hunchun National Nature Reserve, Jilin Province, China. From the samples, we determined that 23 fecal samples and 1 hair sample were from 7 Amur tigers: 2 males, 4 females and 1 individual of unknown sex. Interestingly, 2 fecal samples that were presumed to be from tigers were from Amur leopards, highlighting the significant advantages of noninvasive genetics over traditional methods in studying rare and elusive animals. Analyses from this sample suggested that the genetic diversity of wild Amur tigers is much lower than that of Bengal tigers, consistent with previous findings. Furthermore, the genetic diversity of this Hunchun population in China was lower than that of the adjoining subpopulation in southwest Primorye Russia, likely due to sampling bias. Considering the small population size and relatively low genetic diversity, it is urgent to protect this endangered local subpopulation in China.

  11. Environmental factors influence both abundance and genetic diversity in a widespread bird species

    NARCIS (Netherlands)

    Liu, Yang; Webber, Simone; Bowgen, Katharine; Schmaltz, Lucie; Bradley, Katharine; Halvarsson, Peter; Abdelgadir, Mohanad; Griesser, Michael

    2013-01-01

    Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors

  12. Is there a positive relationship between naturalness and genetic diversity in forest tree communities?

    Energy Technology Data Exchange (ETDEWEB)

    Wehenkel, C.; Corral-Rivas, J. J.; Castellanos-Bocaz, H. A.; Pinedo-Alvarez, A.

    2009-07-01

    Abstract The concepts of genetic diversity and naturalness are well known as measures of conservation values and as descriptors of state or condition. A lack of research evaluating the relationship between genetic diversity and naturalness in biological communities, along with the possible implications in terms of evolutionary aspects and conservation management, make this subject particularly important as regards forest tree communities.We therefore examined the following hypothesis: the genetic diversity of a central-European tree stand averaged over species increases with the naturalness of the stand, as defined by the Potential Natural Vegetation (PNV). The results obtained show that the hypothesis is unsustainable because differences between the averaged genetic diversities of the unnatural and semi-natural stand classes (69 cases) were mostly non-significant. Moreover in three cases, the average genetic diversity of unnatural stand classes was significantly higher than the average genetic diversity of the semi-natural stand classes. A significantly lower average genetic diversity of unnatural stand class was not detected in the statistical analysis. Thus, the naturalness of a tree species community, as inferred from PNV, does not serve as a straightforward indicator of ecological stability when the genetic diversity and the adaptability of tree species are unknown. (Author) 30 refs.

  13. Genetic Diversity and Relationships among Diploid and Tetraploid Cotton Using RAPD Markers

    Institute of Scientific and Technical Information of China (English)

    MOGHADDAM Mohammad Reza Ramazani; MAJIDI Eslam; MOFIDABADI Ali Jafari

    2008-01-01

    @@ Gossypium species (+49) represent a vast resource of genetic diversity for improvement of cultivated cotton.To determine intra- and inter-specific genetic diversity and relationships,we employed 30 RAPD random detainer primers on twenty eight cotton accessions from 2 diploid cultivated species (G.arboreum,G.herbaceum) and 2 tetraploid cultivated species (G.hirsuturn,G.barbadense).

  14. Do Farmers reduce genetic diversity when they domesticate tropical trees? a case study from Amazonia.

    NARCIS (Netherlands)

    Hollingsworth, P.M.; Dawson, I.K.; Goodall-Copestake, W.P.; Richardson, J.E.; Weber, J.C.; Sotelo Montes, C.; Pennington, R.T.

    2005-01-01

    Agroforestry ecosystems may be an important resource for conservation and sustainable use of tropical trees, but little is known of the genetic diversity they contain. Inga edulis, a widespread indigenous fruit tree in South America, is used as a model to assess the maintenance of genetic diversity

  15. Genetic diversity and structure found in samples of Eritrean bread wheat

    DEFF Research Database (Denmark)

    Desta, Zeratsion Abera; Orabi, Jihad; Jahoor, Ahmed;

    2014-01-01

    Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple ...

  16. Genetic Diversity of Rhizobia Isolated from White Clover (Trifolium repens)in Sichuan Based on SRAP Markers%四川白三叶根瘤菌SRAP遗传多样性分析

    Institute of Scientific and Technical Information of China (English)

    马洪平; 潘明洪; 彭丹丹; 李州; 李亚萍; 彭燕

    2016-01-01

    Genetic diversity and relationship of 71 accessions of rhizobia were analyzed based on SRAP markers.These rhizobia were isolated from wild white clovers which were collected from six different sampling sites (Ya’an,Kangding,Luding,Xichang,Chengdu and Leshan)in Sichuan province in China. The results showed that:(1)A total of 292 bands were detected by using 23 primer pairs,and 279 bands (95.55%)were polymorphic loci.(2 )The average percentage of polymorphism information content (PIC),band informativeness (BI),resolving power (RP),marker index (MI)was 0.341,0.429,6.226 and 4.507,respectively.(3)Genetic similarity (GS)among accessions ranged from 0.493 to 0.962 with an average of 0.673.(4)Based on the UPGMA cluster analysis,71 accessions were divided into three groups at GS=0.59,and the accessions collected from the same or similar geographical origin clustered to-gether to a great extent.(5 )85.05% genetic variation was observed among geographical groups,and 14.95% among geographical groups according to the molecular variance analysis (AMOVA).These re-sults suggested that SRAP maker had a good ability to identify the rhizobia of white clover and was an ef-fective way for analyzing genetic diversity of rhizobia.The tested rhizobia had rich genetic diversity and smaller phylogenetic relationship at molecular level.Moreover,the results also revealed that the genetic variation of Rhizobium strains in different geographical groups was associated with their geographical dis-tributions.%利用 SRAP 分子标记对来自四川省雅安、康定、泸定、西昌、成都和乐山6个地区的71份白三叶根瘤菌株的遗传多样性和遗传关系进行分析,结果表明:(1)23对引物组合共扩增出292条带,其中多态性条带279条,多态位点百分率95.55%;(2)单引物组合平均多态信息量(PIC)为0.341,条带信息指数(BI)为0.429,分辨力(RP)为6.226,标记指数(MI)为4.507;(3)供试菌株间遗传相似系数(GS)值介于0.493~0.962

  17. Genetic Diversity Among Botulinum Neurotoxin Producing Clostridial Strains

    Energy Technology Data Exchange (ETDEWEB)

    Hill, K K; Smith, T J; Helma, C H; Ticknor, L O; Foley, B T; Svennson, R T; Brown, J L; Johnson, E A; Smith, L A; Okinaka, R T; Jackson, P J; Marks, J D

    2006-07-06

    Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore forming rod-shaped bacteria which have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and even death in humans and various other animal species. A collection of 174 C. botulinum strains were examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine genetic diversity within this species. This collection contained representatives of each of the seven different serotypes of botulinum neurotoxins (BoNT A-G). Analysis of the16S rRNA sequences confirmed earlier reports of at least four distinct genomic backgrounds (Groups I-IV) each of which has independently acquired one or more BoNT serotypes through horizontal gene transfer. AFLP analysis provided higher resolution, and can be used to further subdivide the four groups into sub-groups. Sequencing of the BoNT genes from serotypes A, B and E in multiple strains confirmed significant sequence variation within each serotype. Four distinct lineages within each of the BoNT A and B serotypes, and five distinct lineages of serotype E strains were identified. The nucleotide sequences of the seven serotypes of BoNT were compared and show varying degrees of interrelatedness and recombination as has been previously noted for the NTNH gene which is linked to BoNT. These analyses contribute to the understanding of the evolution and phylogeny within this species and assist in the development of improved diagnostics and therapeutics for treatment of botulism.

  18. Genetic diversity of Phytophthora infestans in the Northern Andean region

    Directory of Open Access Journals (Sweden)

    Grünwald Niklaus J

    2011-02-01

    Full Text Available Abstract Background Phytophthora infestans (Mont. de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. Countries in the northern part of the Andes dedicate a large proportion of the highlands to the production of potato, and more recently, solanaceous fruits such as cape gooseberry (Physalis peruviana and tree tomato (Solanum betaceum, all of which are hosts of this oomycete. In the Andean region, P. infestans populations have been well characterized in Ecuador and Peru, but are poorly understood in Colombia and Venezuela. To understand the P. infestans population structure in the Northern part of the Andes, four nuclear regions (ITS, Ras, β-tubulin and Avr3a and one mitochondrial (Cox1 region were analyzed in isolates of P. infestans sampled from different hosts in Colombia and Venezuela. Results Low genetic diversity was found within this sample of P. infestans isolates from crops within several regions of Colombia and Venezuela, revealing the presence of clonal populations of the pathogen in this region. We detected low frequency heterozygotes, and their distribution patterns might be a consequence of a high migration rate among populations with poor effective gene flow. Consistent genetic differentiation exists among isolates from different regions. Conclusions The results here suggest that in the Northern Andean region P. infestans is a clonal population with some within-clone variation. P. infestans populations in Venezuela reflect historic isolation that is being reinforced by a recent self-sufficiency of potato seeds. In summary, the P. infestans population is mainly shaped by migration and probably by the appearance of variants of key effectors such as Avr3a.

  19. Pulsed Field Gel Electrophoresis and Genetic Diversity in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Mohammad Poyeede

    2013-07-01

    Full Text Available AbstractBackground and objective: Tuberculosis is a considerable public health problem due to its high risk of person-to-person transmission, morbidity, and mortality especially in developing countries. According to the World Health Organization there is the emergence of multi-drug resistant M. tuberculosis and the association of TB with HIV has led to TB being declared. Molecular genotyping methods are important in detecting the dominance of transmission or reinfection in a population. During one year study genotyping of 100 of M. tuberculosis (M.t. isolates from patients referred to Pasteur Institute of Iran were accomplished with PFGE method. Material and methods: After identification of M.t. isolates and performing of antibiotic susceptibility test using standard methods, Melted Incert agarose and lysozyme were mixed with bacterial suspension to prepare PFGE plaques. After lyses and washing process the plaques digested with XbaI restriction enzyme. Finally the digested DNA fragments on 1% agarose with PFGE method were stained with ethidium bromide and analyzed with GelcomparII software.Results: Dendrogram of genetic diversity among 100 M.t. isolates were obtained in comparison of molecular weight marker and revealed two common types. Pulsotype A with 71 isolates and just one MDR and pulsotype B included 29 isolates and 3 MDR cases. No correlation between antibiotypes and pulsotypes were observed.Conclusion: It is very important to know about the existence of any clonal expansion of special M.t. genotypes with resistant strains. Our research shows 3 MDR isolates into the low incidence pulsotype B which could be an alarm for more accurate MDR-TB surveillance program. Probably such observed limited polymorphism may be due to conservation of restriction sites of XbaI enzyme. In order to investigate the genetic relatedness of isolates using other restriction enzymes and different molecular typing methods simultaneously were recommended.

  20. Nested PCR for detection and genotyping of Ehrlichia ruminantium: use in genetic diversity analysis.

    Science.gov (United States)

    Martinez, Dominique; Vachiéry, Nathalie; Stachurski, Frederic; Kandassamy, Yane; Raliniaina, Modestine; Aprelon, Rosalie; Gueye, Arona

    2004-10-01

    Ehrlichia ruminantium, the agent of cowdriosis transmitted by Amblyomma ticks, presents an extensive genetic and antigenic diversity of key importance for vaccine formulation. Two means of nested polymerase chain reaction (PCR) targeting were developed to conduct molecular epidemiology studies in the Caribbean and Africa. The first used a conserved DNA fragment for detection of the pathogen in animals and vectors, and the second relied on the polymorphic map1 gene for genotyping. As compared to a PCR, the nested PCR showed a 2-Log10 improvement of sensitivity and allowed amplification from ticks, blood, brain, and lungs from infected animals, providing a more accurate picture of the tick infection rate. In Guadeloupe, this rate reached 36% (N = 212) instead of 1.7% (N = 224), as previously estimated. Genetic typing was done by restriction fragment length polymorphism or sequencing of map1 amplification products. Molecular epidemiology studies conducted in field sites selected for vaccination trials with inactivated vaccine, revealed the circulation of genetically divergent strains in limited geographical areas. It is known, then, that genetic clustering based on map1 has no predictive value regarding the protective value of a given strain against a new strain. However, tracing the strains by this technique revealed the extent of E. ruminantium diversity that one can expect in a given region, and the method allows differentiation between an inadequate immune response and the challenge by a breakthrough strain on animals dying despite vaccination. Up to now, genetic typing does not avoid cross-protection studies, which were conducted in parallel, although on a more limited scale. The importance of pathogen diversity studies for optimization of vaccine design is discussed as well as the research for new polymorphic genes. These genes may allow better predictions on cross-protection, given the recent completion of the sequence of the full genome of two E. ruminantium