WorldWideScience
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Mycobacterium tuberculosis complex genetic diversity: mining the fourth international spoligotyping database (SpolDB4 for classification, population genetics and epidemiology  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1 Unique Events Polymorphism (UEP (2 Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database. Results The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network. Conclusion Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress.

Sajduda Anna

2006-03-01

2

Genetic diversity and disease susceptibility.  

OpenAIRE

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...

Bodmer, W. F.

1997-01-01

3

XML Mining Using Genetic Algorithm  

OpenAIRE

In recent years XML documents have became very popular for representing semi-structured data and a standard for data exchange over the web. Mining XML data from the web is becoming increasingly important as well. In general frequent item sets are generated from large data sets by applying association rule mining algorithms like Apriori, Partition, Pincer-Search, Incremental, Border algorithm etc., which take too much computer time to compute all the frequent item sets. By using Genetic Algori...

Amitava Nag

2011-01-01

4

XML Mining Using Genetic Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available In recent years XML documents have became very popular for representing semi-structured data and a standard for data exchange over the web. Mining XML data from the web is becoming increasingly important as well. In general frequent item sets are generated from large data sets by applying association rule mining algorithms like Apriori, Partition, Pincer-Search, Incremental, Border algorithm etc., which take too much computer time to compute all the frequent item sets. By using Genetic Algorithm (GA we can improve the scenario. The major advantage of using GA in the discovery of frequent item sets is that they perform global search and its time complexity is less compared to other algorithms as the genetic algorithm is based on the greedy approach. The main aim of this paper is to find all the frequent item sets from XML database using genetic algorithm.

Amitava Nag

2011-06-01

5

The genetic diversity of Plasmodium vivax populations.  

OpenAIRE

Little is known of the genetic diversity and population structure of Plasmodium vivax, a debilitating and highly prevalent malaria parasite of humans. This article reviews the known polymorphic genetic markers, summarizes current data on the population structure of this parasite and discusses future prospects for using knowledge of the genetic diversity to improve control measures.

Cui, L.; Escalante, Aa; Imwong, M; Snounou, G.

2003-01-01

6

Assessing Plant Genetic Diversity by Molecular Tools  

OpenAIRE

This paper is an overview of the diverse, predominantly molecular techniques, used in assessing plant genetic diversity. In recent years, there has been a significant increase in the application of molecular genetic methods for assessing the conservation and use of plant genetic resources. Molecular techniques have been applied in the analysis of specific genes, as well as to increase understanding of gene action, generate genetic maps and assist in the development of gene transfer technologi...

Linda Mondini; Arshiya Noorani; Pagnotta, Mario A.

2009-01-01

7

Data Quality Mining using Genetic Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Data quality mining (DQM as a new and promising data mining approach from the academic and the business point of view. Data quality is important to organizations. People use information attributes as a tool for assessing data quality. The goal of DQM is to employ data mining methods in order to detect, quantify, explain and correct data quality deficiencies in very large databases. Data quality is crucial for many applications of knowledge discovery in databases (KDD. In this work, we have considered four data qualities like accuracy, comprehensibility, interestingness and completeness. We have tried to develop Multi-objective Genetic Algorithm (GA based approach utilizing linkage between feature selection and association rule. The main motivation for using GA in the discovery of high-level prediction rules is that they perform a global search and cope better with attribute interaction that the greedy rule induction algorithms often used in data mining.

Sufal Das

2009-05-01

8

Mining Frequent Itemsets Using Genetic Algorithm  

CERN Document Server

In general frequent itemsets are generated from large data sets by applying association rule mining algorithms like Apriori, Partition, Pincer-Search, Incremental, Border algorithm etc., which take too much computer time to compute all the frequent itemsets. By using Genetic Algorithm (GA) we can improve the scenario. The major advantage of using GA in the discovery of frequent itemsets is that they perform global search and its time complexity is less compared to other algorithms as the genetic algorithm is based on the greedy approach. The main aim of this paper is to find all the frequent itemsets from given data sets using genetic algorithm.

Ghosh, Soumadip; Sarkar, Debasree; Sarkar, Partha Pratim; 10.5121/ijaia.2010.1411

2010-01-01

9

Mining Frequent Itemsets Using Genetic Algorithm  

OpenAIRE

In general frequent itemsets are generated from large data sets by applying association rule mining algorithms like Apriori, Partition, Pincer-Search, Incremental, Border algorithm etc., which take too much computer time to compute all the frequent itemsets. By using Genetic Algorithm (GA) we can improve the scenario. The major advantage of using GA in the discovery of frequent itemsets is that they perform global search and its time complexity is less compared to other algo...

Soumadip Ghosh; Sushanta Biswas; Debasree Sarkar; Partha Pratim Sarkar

2010-01-01

10

Mining Frequent Itemsets Using Genetic Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available In general frequent itemsets are generated from large data sets by applyingassociation rule mining algorithms like Apriori, Partition, Pincer-Search, Incremental, Borderalgorithm etc., which take too much computer time to compute all the frequent itemsets. By usingGenetic Algorithm (GA we can improve the scenario. The major advantage of using GA in thediscovery of frequent itemsets is that they perform global search and its time complexity is lesscompared to other algorithms as the genetic algorithm is based on the greedy approach. Themain aim of this paper is to find all the frequent itemsets from given data sets using geneticalgorithm.

Soumadip Ghosh

2010-10-01

11

The Genetic Algorithm for Truck Dispatching Problems in Surface Mine  

Directory of Open Access Journals (Sweden)

Full Text Available At first, this study described the characteristics of truck transport in surface mine, then construct the model of truck dispatching and expound working principle and application of genetic algorithm. Finally, the typical experiment, by using the MATLAB genetic algorithm toolbox for calculation, showed that using genetic algorithm to optimize mine vehicle dispatching is feasible and effective.

Xin- Ming Lu

2010-01-01

12

Opencast mine equipment selection using genetic algorithms  

Energy Technology Data Exchange (ETDEWEB)

The excavating and haulage equipment selection to remove the overburden in an opencast mine is an essential and complex decision that requires substantial use of practical judgement and expertise as well as vast numerical calculations and extensive data collection about the equipment, their specifications and costs. Capturing and maintaining the knowledge of experts in the field is accomplished by the use of knowledge base systems. Such a knowledge relates mainly to the selection of the equipment in broad categories based on the ecological, technical and environmental characteristics of the mine. To further identify the make, size and number of each piece of equipment that minimises the total cost of the operation, the problem needs to be presented as an optimisation model. This paper describes the development of an artificial intelligence technique, genetic algorithms, in order to find the input variables that can achieve the optimal cost. Genetic algorithms is a recent artificial technique inspired by the theory of evolution and biogenetic. Genetic algorithms has proven as a superior optimisation and search technique by emulating the process of natural evolution. Finally, the system is tested on a case to validate its performance. A sensitivity analysis is performed on the case study in order to provide potential suggestions in areas where improvements could be made. 9 refs., 5 figs.

Haider, A.D.; Naoum, S.G. [South Bank University, London (United Kingdom). School of Construction

1996-11-01

13

Effect of diversity and missing data on genetic assignment with RAD-Seq markers  

OpenAIRE

Reduced representation libraries are being used as a preferred source of markers to address population genetic questions. However, libraries of RAD-Seq variants often suffer from significant percentage of missing data. In addition, algorithms used to mine SNPs from the raw data may also underscore biological variation. We investigate the effect of biological diversity in mining SNPs from the program STACKS and the effect of missing data on individual assignment implemented in STRUCTURE. We ob...

Chattopadhyay, Balaji; Garg, Kritika M.; Ramakrishnan, Uma

2014-01-01

14

Genetic diversity of Ascaris in southwestern Uganda.  

Science.gov (United States)

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 Musezero, was carried out. Adult Ascaris worms were collected from infected individuals by chemo-expulsion using pyrantel pamoate treatment. Genetic diversity within these worms was assessed by inspection of DNA sequence variation in a mitochondrial marker and length polymorphism at microsatellite loci. Overall prevalence of ascariasis was 42.5% in mothers and 30.4% in their children and a total of 98 worms was examined from 18 hosts. Sequence analysis of a portion of the mitochondrial cytochrome c oxidase subunit 1 gene revealed 19 different haplotypes, 13 of which had not been previously encountered. Microsatellite analysis using eight loci provided evidence for high gene flow between worm populations from the two villages but comparing these worms with others obtained in a prior study on Unguja, Zanzibar, confirmed little genetic exchange and mixing of worm populations between the two areas. By adding to our understanding of the genetic diversity of Ascaris in Africa, this study provides useful information for monitoring changes in parasite population structure in the face of ongoing and future control. PMID:22192492

Betson, Martha; Nejsum, Peter; Llewellyn-Hughes, Julia; Griffin, Claire; Atuhaire, Aaron; Arinaitwe, Moses; Adriko, Moses; Ruggiana, Andrew; Turyakira, Grace; Kabatereine, Narcis B; Stothard, J Russell

2012-02-01

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Assessing Plant Genetic Diversity by Molecular Tools  

Directory of Open Access Journals (Sweden)

Full Text Available This paper is an overview of the diverse, predominantly molecular techniques, used in assessing plant genetic diversity. In recent years, there has been a significant increase in the application of molecular genetic methods for assessing the conservation and use of plant genetic resources. Molecular techniques have been applied in the analysis of specific genes, as well as to increase understanding of gene action, generate genetic maps and assist in the development of gene transfer technologies. Molecular techniques have also had critical roles in studies of phylogeny and species evolution, and have been applied to increase our understanding of the distribution and extent of genetic variation within and between species. These techniques are well established and their advantages as well as limitations have been realized and described in this work. Recently, a new class of advanced techniques has emerged, primarily derived from a combination of earlier, more basic techniques. Advanced marker techniques tend to amalgamate advantageous features of several basic techniques, in order to increase the sensitivity and resolution to detect genetic discontinuity and distinctiveness. Some of the advanced marker techniques utilize newer classes of DNA elements, such as retrotransposons, mitochondrial and chloroplast based microsatellites, thereby revealing genetic variation through increased genome coverage. Techniques such as RAPD and AFLP are also being applied to cDNA-based templates to study patterns of gene expression and uncover the genetic basis of biological responses. The most important and recent advances made in molecular marker techniques are discussed in this review, along with their applications, advantages and limitations applied to plant sciences.

Linda Mondini

2009-08-01

16

Genetic diversity in two Italian almond collections  

Scientific Electronic Library Online (English)

Full Text Available Background Sweet-seeded domesticated almonds were brought to the Mediterranean Basin from central Asia about 4000 years ago. In Italy, most of the almonds produced are cultivated in the southern part of the country. Local populations of the tree in Sardinia are largely seed-derived and mostly self-i [...] ncompatible, so have developed extensive genetic diversity. The need to protect biodiversity has prompted a revived interest in local genetic materials in almond. Two Italian collections have been established, one in Sardinia and the other in Apulia. These collections were the focus of the present evaluation of genetic diversity. Results Eleven SSRs (microsatellites) were used for fingerprinting. The Sardinian germplasm was highly polymorphic, revealing a mean of 14.5 alleles per locus and a mean heterozygosity of 0.71. Using a model-based clustering approach, two genetic clusters were distinguished: one included all the commercial varieties and most of the Sardinian accessions, and the other most of the Apulian accessions. A similar structure was produced using a distance-based cluster analysis. The Sardinian accessions could still be distinguished from the commercial germplasm with few exceptions. Conclusion The extensive genetic variability present in the Sardinian and Apulian almond germplasm indicates that these materials represent an important source of genes for the improvement of the crop.

Maria Pia, Rigoldi; Emma, Rapposelli; Donato, De Giorgio; Paolo, Resta; Andrea, Porceddu.

2015-01-01

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Fitness Uniform Selection to Preserve Genetic Diversity  

OpenAIRE

In evolutionary algorithms, the fitness of a population increases with time by mutating and recombining individuals and by a biased selection of more fit individuals. The right selection pressure is critical in ensuring sufficient optimization progress on the one hand and in preserving genetic diversity to be able to escape from local optima on the other. We propose a new selection scheme, which is uniform in the fitness values. It generates selection pressure towards sparse...

Hutter, Marcus

2001-01-01

18

Managing genetic diversity and society needs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 r [...] ange 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.

Arthur da Silva, Mariante; Andréa Alves, Egito; Maria do Socorro Maués, Albuquerque; Samuel Rezende, Paiva; Alexandre Floriani, Ramos.

2008-07-01

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Managing genetic diversity and society needs  

Directory of Open Access Journals (Sweden)

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.

Arthur da Silva Mariante

2008-07-01

20

Genetic diversity in aspen and its relation to arthropod abundance  

Science.gov (United States)

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. PMID:25674097

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

2015-01-01

21

Limited Genetic Diversity in the Endophytic Sugarcane Bacterium Acetobacter diazotrophicus  

OpenAIRE

Acetobacter diazotrophicus isolates that originated from different sugarcane cultivars growing in diverse geographic regions of Mexico and Brazil were shown to have limited genetic diversity. Measurements of polymorphism in the electrophoretic mobilities of metabolic enzymes revealed that the mean genetic diversity per enzyme locus (among the four electrophoretic types distinguished) was 0.064. The results of the genetic analysis indicate that the genetic structure of A. diazotrophicus is clo...

Caballero-mellado, Jesus; Martinez-romero, Esperanza

1994-01-01

22

Great ape genetic diversity and population history  

DEFF Research Database (Denmark)

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 all species. We discover and assign 1,982 loss-of-function variants throughout the human and great ape lineages, determining that the rate of gene loss has not been different in the human branch compared to other internal branches in the great ape phylogeny. This comprehensive catalogue of great ape genome diversity provides a framework for understanding evolution and a resource for more effective management of wild and captive great ape populations.

Prado-Martinez, Javier; Sudmant, Peter H.

2013-01-01

23

A Survey of Association Rule Mining Using Genetic Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Data mining is the analysis step of the "Knowledge Discovery in Databases" process, or KDD. It is the process that results in the discovery of new patterns in large data sets. It utilizes methods at the intersection of artificial intelligence, machine learning, statistics, and database systems. The overall goal of the data mining process is to extract knowledge from an existing data set and transform it into a human-understandable structure. In data mining, association rule learning is a popular and well researched method for discovering interesting relations between variables in large databases. Association rules are usually required to satisfy a user-specified minimum support and a user-specified minimum confidence at the same time. Genetic algorithm (GA is a search heuristic that mimics the process of natural evolution. This heuristic is routinely used to generate useful solutions to optimization and search problems. Genetic algorithms belong to the larger class of evolutionary algorithms, which generate solutions to optimization problems using techniques inspired by natural evolution, such as inheritance, mutation, selection, and crossover. In previous, many researchers have proposed Genetic Algorithms for mining interesting association rules from quantitative data. In this paper we represent a survey of Association Rule Mining Using Genetic Algorithm. The techniques are categorized based upon different approaches. This paper provides the major advancement in the approaches for association rule mining using genetic algorithms.

Anubha Sharma

2012-08-01

24

Fitness Uniform Selection to Preserve Genetic Diversity  

CERN Document Server

In evolutionary algorithms, the fitness of a population increases with time by mutating and recombining individuals and by a biased selection of more fit individuals. The right selection pressure is critical in ensuring sufficient optimization progress on the one hand and in preserving genetic diversity to be able to escape from local optima on the other. We propose a new selection scheme, which is uniform in the fitness values. It generates selection pressure towards sparsely populated fitness regions, not necessarily towards higher fitness, as is the case for all other selection schemes. We show that the new selection scheme can be much more effective than standard selection schemes.

Hutter, M

2001-01-01

25

Genetic diversity between human metapneumovirus subgroups  

International Nuclear Information System (INIS)

Complete consensus nucleotide sequences were determined for human metapneumovirus (HMPV) isolates CAN97-83 and CAN98-75, representing the two proposed genotypes or genetic subgroups of HMPV. The overall level of genome nucleotide sequence identity and aggregate proteome amino acid sequence identity between the two HMPV subgroups were 80 and 90%, respectively, similar to the respective values of 81 and 88% between the two antigenic subgroups of human respiratory syncytial virus (HRSV). The diversity between HMPV subgroups was greatest for the SH and G proteins (59 and 37% identity, respectively), which were even more divergent than their HRSV counterparts (72 and 55% cross-subgroup identity, respectively). It is reasonable to anticipate that the two genetic subgroups of HMPV represent antigenic subgroups approximately comparable to those of HRSV

26

Data Quality Mining using Genetic Algorithm  

OpenAIRE

Data quality mining (DQM) as a new and promising data mining approach from the academic and the business point of view. Data quality is important to organizations. People use information attributes as a tool for assessing data quality. The goal of DQM is to employ data mining methods in order to detect, quantify, explain and correct data quality deficiencies in very large databases. Data quality is crucial for many applications of knowledge discovery in databases (KDD). In this work, we have ...

Sufal Das

2009-01-01

27

A Survey: Web Log Mining using Genetic Algorithm .  

Directory of Open Access Journals (Sweden)

Full Text Available Web mining has become a vast area of Research in last few years. Web Mining Which deals with the extraction of interesting knowledge from logging information produced by web server. In this paper we present a survey generate clusters using a multi objective genetic algorithm. Genetic algorithm is also a very hot area of research. In this paper we will compare the error value between FCM(Fuzzy c-means and FCM-MOGA(Fuzzy CMeans multi objective Genetic algorithm. Genetic algorithm follows some steps and produce optimize solution. In using GA standard deviation and iteration value also affected. In this paper we have survey various paper based on Web log mining and FCM and GA.

Ranu Singhal

2013-05-01

28

Restoration of coral populations in light of genetic diversity estimates  

Science.gov (United States)

Due to the importance of preserving the genetic integrity of populations, strategies to restore damaged coral reefs should attempt to retain the allelic diversity of the disturbed population; however, genetic diversity estimates are not available for most coral populations. To provide a generalized estimate of genetic diversity (in terms of allelic richness) of scleractinian coral populations, the literature was surveyed for studies describing the genetic structure of coral populations using microsatellites. The mean number of alleles per locus across 72 surveyed scleractinian coral populations was 8.27 (±0.75 SE). In addition, population genetic datasets from four species ( Acropora palmata, Montastraea cavernosa, Montastraea faveolata and Pocillopora damicornis) were analyzed to assess the minimum number of donor colonies required to retain specific proportions of the genetic diversity of the population. Rarefaction analysis of the population genetic datasets indicated that using 10 donor colonies randomly sampled from the original population would retain >50% of the allelic diversity, while 35 colonies would retain >90% of the original diversity. In general, scleractinian coral populations are genetically diverse and restoration methods utilizing few clonal genotypes to re-populate a reef will diminish the genetic integrity of the population. Coral restoration strategies using 10-35 randomly selected local donor colonies will retain at least 50-90% of the genetic diversity of the original population.

Shearer, T. L.; Porto, I.; Zubillaga, A. L.

2009-09-01

29

A genetic programming based business process mining approach  

OpenAIRE

As business processes become ever more complex there is a need for companies to understand the processes they already have in place. To undertake this manually would be time consuming. The practice of process mining attempts to automatically construct the correct representation of a process based on a set of process execution logs. The aim of this research is to develop a genetic programming based approach for business process mining. The focus of this research is on automated/semi automat...

Turner, Christopher James

2009-01-01

30

Threat or opportunity? Landscape genetics in a coal mining area  

OpenAIRE

Aknowledgment The area of Sveagruva have experienced several periods of coal mining. This study aim to evaluating changes in vegetation composition, species distributions and genetic structure using a combination of field and molecular analyses, to identify whether or not coal mining have effected plant life in Svea. Investigations on species and gene level were done on two Luzula species, L. confusa Lindeb. and L. nivalis (Laest.) Spreng. No direct correlation was found, and the soil...

Skottvoll, Bente Sved

2013-01-01

31

Does genetic diversity limit disease spread in natural host populations?  

Science.gov (United States)

It is a commonly held view that genetically homogenous host populations are more vulnerable to infection than genetically diverse populations. The underlying idea, known as the ‘monoculture effect,' is well documented in agricultural studies. Low genetic diversity in the wild can result from bottlenecks (that is, founder effects), biparental inbreeding or self-fertilization, any of which might increase the risk of epidemics. Host genetic diversity could buffer populations against epidemics in nature, but it is not clear how much diversity is required to prevent disease spread. Recent theoretical and empirical studies, particularly in Daphnia populations, have helped to establish that genetic diversity can reduce parasite transmission. Here, we review the present theoretical work and empirical evidence, and we suggest a new focus on finding ‘diversity thresholds.' PMID:22713998

King, K C; Lively, C M

2012-01-01

32

Conservation of genetic diversity Assessing genetic variation using marker estimated Kinships  

OpenAIRE

This dissertation focuses on assessing genetic diversity in a quantitative way through the use of Malecots coefficients of kinship. Kinships between and within populations and individuals can be estimated using microsatellite marker genes that are assumed to be selectively neutral.Genetic diversity is estimated from such Marker Estimated Kinships (MEK) by (1 - average (MEK)), where genetic diversity of a set of breeds is defined as the maximum genetic variation in a population that can be bre...

Eding, H.

2002-01-01

33

Genetic diversity and disease control in rice.  

Science.gov (United States)

Crop heterogeneity is a possible solution to the vulnerability of monocultured crops to disease. Both theory and observation indicate that genetic heterogeneity provides greater disease suppression when used over large areas, though experimental data are lacking. Here we report a unique cooperation among farmers, researchers and extension personnel in Yunnan Province, China--genetically diversified rice crops were planted in all the rice fields in five townships in 1998 and ten townships in 1999. Control plots of monocultured crops allowed us to calculate the effect of diversity on the severity of rice blast, the major disease of rice. Disease-susceptible rice varieties planted in mixtures with resistant varieties had 89% greater yield and blast was 94% less severe than when they were grown in monoculture. The experiment was so successful that fungicidal sprays were no longer applied by the end of the two-year programme. Our results support the view that intraspecific crop diversification provides an ecological approach to disease control that can be highly effective over a large area and contribute to the sustainability of crop production. PMID:10963595

Zhu, Y; Chen, H; Fan, J; Wang, Y; Li, Y; Chen, J; Fan, J; Yang, S; Hu, L; Leung, H; Mew, T W; Teng, P S; Wang, Z; Mundt, C C

2000-08-17

34

The characterization of goat genetic diversity: Towards a genomic approach  

OpenAIRE

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 for each of the main livestock species, FAO has promoted the meta-analysis of local datasets, to achieve a global view of molecular genetic diversity. Analysis within the EU Globaldiv project of two ...

Ajmone Marsan, Paolo; Colli, Licia; Han, Jian Lin; Achilli, A.; Lancioni, H.; Joost, Ste?phane; Crepaldi, Paola; Pilla, Fabio; Stella, Alessandra; Taberlet, Pierre; Boettcher, Paul; Negrini, Riccardo; Lenstra, J. A.

2014-01-01

35

Genetic Diversity of Tunisian Date Palm Germplasm Using ISSR Markers  

OpenAIRE

Aim of the study is the analysis of the genetic diversity among a set of Tunisian date palm varieties. We used different genetic markers generated from selected ISSR primers. Inter Simple Sequence Repeat (ISSR) markers involve Polymerase Chain Reaction (PCR) amplification of DNA using a single primer composed of a microsatellite sequence. ISSR technology rapidly reveals high polymorphic fingerprints and determines genetic diversity. Seven primers were used to cluster 10 date palm varieties an...

Nouredine, D.; Richid, H.; Wafa, H.; Amel, S.; Chokri, B.; Karim, K.

2010-01-01

36

Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes.  

Science.gov (United States)

We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic-spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most tributary basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and in response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. PMID:25327780

Osborne, Megan J; Perkin, Joshuah S; Gido, Keith B; Turner, Thomas F

2014-12-01

37

Genetic Diversity and Genetic Structure in Natural Populations of Prunus davidiana Germplasm by SSR Markers  

Directory of Open Access Journals (Sweden)

Full Text Available Prunus davidiana, which is a wild species, can be used as rootstocks for cultivation of fruit trees, breeding germplasm for improving resistance to diseases and insects, pioneer trees for recovering vegetation in arid areas, decoration trees for parks and gardens, and a potential medicinal plant for human health. Despite the valuable characteristics of P. davidiana, the genetic variations of resources of P. davidiana remain unclear. In this study, we used seven natural populations (GE; GH; ST; SF; SJ; SY; NX short for Heshui, Gansu; Huating Gansu; Taibai, Shaanxi; Fuxian, Shaanxi; Jiaocheng, Shanxi; Yangquan, Shanxi; Xiji, Ningxia, respectively of P. davidiana collected at distribution center in China to generate a fingerprint using 15 SSR markers by multifluorophore fragment analysis to assess transportability of the markers, genetic diversity and genetic structure within and among populations. Our data show that a 92% transportability rate was found from closely related species of P. davidiana based on SSR markers developed, and DNA polymorphisms were also detected among accessions by the selected SSR markers. The SSR markers amplified 137 alleles in total for all accessions with an average value of 9.13 alleles, ranging from the highest value of 15 alleles for UDP96-013 to the lowest value of 3 alleles for CPPCT017. Rare alleles, present at less than or equal to 5% of all accessions by marker, showed the highest value in BPPCT 020. By analyzing all accessions, the majority of the 192 accessions from seven populations were found to cluster together according to the given populations, while the minority from the given populations was distributed within clusters. The SY population appeared to have the most diversity among populations, followed by the NX population according to comprehensive analysis of all indices. The seven populations analyzed by unweighted parsimony and principal coordinate analysis were divided into two groups: ST, SY and SF; NX, GE, SJ and GH. A stark difference was found in the genetic variation—with 16% among populations and 84% within populations. Our results from this study imply that most SSR markers developed from related species can be used for genetic analyses of P. davidiana; some markers have more relevant applications for genetic analyses such as UDP96-013 for diversity evaluation and BPPCT 020 for mining rare alleles in P. davidiana; SY and NX are preferred when considering conservation and agronomic utilization.

Zhongping Cheng

2011-11-01

38

Genetic diversity of Broussonetia papyrifera populations in southwest China.  

Science.gov (United States)

Broussonetia papyrifera is an important native tree species with high economic value in southwest China. Its resources are drastically reduced because of over-harvesting and habitat fragmentation. In this study, 17 natural populations of B. papyrifera were analyzed using inter-simple sequence repeat (ISSR) markers to assess the genetic diversity and population structure. In total, 100 bands were obtained from 16 ISSR primers. The B. papyrifera populations showed relatively high genetic diversity at the species level [percentage of polymorphic bands (PPB): 96%; Nei's genetic diversity (HE): 0.3074; Shannon's information index (I): 0.4617], while the genetic diversity at the population level was relatively low (PPB: 53.2%; HE: 0.1826; I: 0.2735). Relatively high level of genetic differentiation among populations (41%) was disclosed by analysis of molecular variance, which agrees with the Nei's genetic diversity statistics (40.59%) and Shannon's information measure (40.76%). Gene flow among populations (NM) was only 0.7318. A significant correlation was observed between genetic and geographic distance among the studied populations (r=0.2948). We conjectured that the genetic diversity of B. papyrifera resulted from human disturbance, habitat fragmentation, small effective population size, and geographic barrier. Given the high genetic differentiation among populations, some utilization and conservation strategies were proposed. This study provides a reference for the sustainable use of the species in southwest China. PMID:25222255

Liao, S X; Deng, Z H; Cui, K; Cui, Y Z; Zhang, C H

2014-01-01

39

Estimation of genetic diversity using SSR markers in sunflower.  

Science.gov (United States)

Microsatellites or simple sequence repeats (SSRs) were used for the estimation of genetic diversity among a group of 40 sunflower lines developed at the research area of Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad. Total numbers of alleles amplified by 22 polymorphic primers were 135 with an average of 6.13 alleles per locus, suggesting that SSR is a powerful technique for assessment of genetic diversity at molecular level. The expected heterozygosity (PIC) ranged from 0.17 to 0.89. The highest PIC value was observed at the locus C1779. The genetic distances ranged from 9 to 37%. The highest genetic distance was observed between the lines L50 and V3. Genetic distances were low showing lesser amount of genetic diversity among the sunflower lines. PMID:25715473

Zia, Z U; Sadaqat, H A; Tahir, M H N; Sadia, B; Bushman, B S; Hole, D; Michaels, L; Malik, W

2014-05-01

40

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...

41

Genetic diversity of human RNase 8  

Directory of Open Access Journals (Sweden)

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 (? = 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.

Chan Calvin C

2012-01-01

42

Genetic Research: Mining for Medical Treasures  

Science.gov (United States)

FASEB Breakthroughs in Bioscience article. "Knock-out" mice, in which specific genes have been inactivated, have been tremendously useful in helping researchers understand the genetic basis of disease. Moreover, "knock out" mice also serve as animal models for human diseases, allowing researchers to develop treatments and diagnostic tests for genetic diseases.

Cathryn M. Delude (The Writing Group)

2010-07-12

43

Beauveria bassiana: quercetinase production and genetic diversity  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Eula Maria de M. B, Costa; Fabiana Cristina, Pimenta; Christian, Luz; Valéria de, Oliveira; Marília, Oliveira; Elda, Bueno; Silvana, Petrofeza.

2011-03-01

44

Beauveria bassiana: quercetinase production and genetic diversity  

Directory of Open Access Journals (Sweden)

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.

Eula Maria de M. B Costa

2011-03-01

45

Genetic diversity studies of Papaya meleira virus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Papaya (Carica papaya) is a fruit crop of great economic and social importance for Brazil and other papaya-producing countries. Brazil is the second largest producer in the world. The papaya sticky disease, caused by Papaya meleira virus (PMeV), has caused great losses in the major Brazilian papaya- [...] producing states. In order to estimate the genetic diversity of PMeV, latex samples were collected from papaya plants in the states of Bahia, Espírito Santo, Pernambuco, Ceará and Rio Grande do Norte, and total RNA was extracted. Specific primer for the replicase region allowed the amplification, by RT-PCR, of a fragment of approximately 560 bp from 31 isolates. The sequence analysis indicated a level of conservation greater than 88% among isolates. Furthermore, comparative analyzes indicated that PMeV has similarity with mycoviruses of the family Totiviridae. This phylogenetic relationship was reinforced by the presence of conserved motifs within in the RdRp regions from mycoviruses.

Cleidiane B., Daltro; Emanuel Felipe Medeiros, Abreu; Francisco Jose Lima, Aragão; Eduardo C., Andrade.

2014-02-01

46

Flooding stress: acclimations and genetic diversity.  

Science.gov (United States)

Flooding is an environmental stress for many natural and man-made ecosystems worldwide. Genetic diversity in the plant response to flooding includes alterations in architecture, metabolism, and elongation growth associated with a low O(2) escape strategy and an antithetical quiescence scheme that allows endurance of prolonged submergence. Flooding is frequently accompanied with a reduction of cellular O(2) content that is particularly severe when photosynthesis is limited or absent. This necessitates the production of ATP and regeneration of NAD(+) through anaerobic respiration. The examination of gene regulation and function in model systems provides insight into low-O(2)-sensing mechanisms and metabolic adjustments associated with controlled use of carbohydrate and ATP. At the developmental level, plants can escape the low-O(2) stress caused by flooding through multifaceted alterations in cellular and organ structure that promote access to and diffusion of O(2). These processes are driven by phytohormones, including ethylene, gibberellin, and abscisic acid. This exploration of natural variation in strategies that improve O(2) and carbohydrate status during flooding provides valuable resources for the improvement of crop endurance of an environmental adversity that is enhanced by global warming. PMID:18444902

Bailey-Serres, J; Voesenek, L A C J

2008-01-01

47

Genetic diversity of Echinococcus spp. in Russia.  

Science.gov (United States)

In Russia, both alveolar and cystic echinococcoses are endemic. This study aimed to identify the aetiological agents of the diseases and to investigate the distribution of each Echinococcus species in Russia. A total of 75 Echinococcus specimens were collected from 14 host species from 2010 to 2012. Based on the mitochondrial DNA sequences, they were identified as Echinococcus granulosus sensu stricto (s.s.), E. canadensis and E. multilocularis. E. granulosus s.s. was confirmed in the European Russia and the Altai region. Three genotypes, G6, G8 and G10 of E. canadensis were detected in Yakutia. G6 was also found in the Altai region. Four genotypes of E. multilocularis were confirmed; the Asian genotype in the western Siberia and the European Russia, the Mongolian genotype in an island of Baikal Lake and the Altai Republic, the European genotype from a captive monkey in Moscow Zoo and the North American genotype in Yakutia. The present distributional record will become a basis of public health to control echinococcoses in Russia. The rich genetic diversity demonstrates the importance of Russia in investigating the evolutionary history of the genus Echinococcus. PMID:23985385

Konyaev, Sergey V; Yanagida, Tetsuya; Nakao, Minoru; Ingovatova, Galina M; Shoykhet, Yakov N; Bondarev, Alexandr Y; Odnokurtsev, Valeriy A; Loskutova, Kyunnyay S; Lukmanova, Gulnur I; Dokuchaev, Nikolai E; Spiridonov, Sergey; Alshinecky, Mikhail V; Sivkova, Tatyana N; Andreyanov, Oleg N; Abramov, Sergey A; Krivopalov, Anton V; Karpenko, Sergey V; Lopatina, Natalia V; Dupal, Tamara A; Sako, Yasuhito; Ito, Akira

2013-11-01

48

GENETIC RESOURCES AND DIVERSITY IN PAKISTANI CATTLE  

Directory of Open Access Journals (Sweden)

Full Text Available Cattle in Pakistan have traditionally been raised for producing bullocks except breeds such as Sahiwal and Red Sindhi which are established milch breeds. General production system is low-input extensive system with crossbreds mainly raised under intensive high input system in the cattle/buffalo colonies to sustain the demand of milk especially during summer, the slump period in buffalo milk. Although, draft breeds are losing utility yet, it will take many generations before they are replaced due to mechanization. Efforts, however, are needed for their in situ conservation and directional selection towards beef. Institutional records indicate weak genetic control for most of the economic traits but accurate recording of performance and pedigrees can improve these estimates. Breeding policy guidelines need adoption in letter and sprit to conserve various breeds. Institutions established for breed improvement need to be restructured for achieving the goals. Adequate diversity in performance and adaptability can be exploited for actual improvement accruing to conservation and development of indigenous cattle resources.

M. SAJJAD KHAN, ZIA-UR REHMAN1 , MUQARRAB A. KHAN2 AND SOHAIL AHMAD3

49

Nested core collections maximizing genetic diversity in Arabidopsis thaliana  

DEFF Research Database (Denmark)

The successful exploitation of natural genetic diversity requires a basic knowledge of the extent of the variation present in a species. To study natural variation in Arabidopsis thaliana, we defined nested core collections maximizing the diversity present among a worldwide set of 265 accessions. The core collections were generated based on DNA sequence data from a limited number of fragments evenly distributed in the genome and were shown to successfully capture the molecular diversity in other loci as well as the morphological diversity. The core collections are available to the scientific community and thus provide an important resource for the study of genetic variation and its functional consequences in Arabidopsis. Moreover, this strategy can be used in other species to provide a rational framework for undertaking diversity surveys, including single nucleotide polymorphism (SNP) discovery and phenotyping, allowing the utilization of genetic variation for the study of complex traits.

McKhann, Heather I; Camilleri, Christine

2004-01-01

50

Genetic Resources and the Convention on Biological Diversity  

Science.gov (United States)

This peer-reviewed article from BioScience is about effect the convention on biological diversity had on US genetic resources. At a meeting in Brazil in March, the Convention on Biological Diversity moved a step closer to finalizing an international regulatory regime for access to and benefit sharing of genetic resources. Discussions now under way will be influential in determining policies governing biodiversity research and bioprospecting.

RICHARD BLAUSTEIN (; )

2006-07-01

51

Genetic diversity in Populus nigra plantations from west of Iran  

OpenAIRE

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 conditio...

Afrooz Alimohamadi; Farhad Asadi; Reza Tabaie Aghdaei

2012-01-01

52

Genetic diversity and genetic exchange in Trypanosoma cruzi: dual drug-resistant "progeny" from episomal transformants  

Scientific Electronic Library Online (English)

Full Text Available Extensive characterisation of Trypanosoma cruzi by isoenzyme phenotypes has separated the species into three principal zymodeme groups, Z1, Z2 and Z3, and into many individual zymodemes. There is marked diversity within Z2. A strong correlation has been demonstrated between the strain clusters deter [...] mined by isoenzymes and those obtained using random amplified polymorphic DNA (RAPD) profiles. Polymorphisms in ribosomal RNA genes, in mini-exon genes, and microsatellite fingerprinting indicate the presence of at least two principal T. cruzi genetic lineages. Lineage 1 appears to correspond with Z2 and lineage 2 with Z1. Z1 (lineage 2) is associated with Didelphis. Z2 (lineage 1) may be associated with a primate host. Departures from Hardy-Weinberg equilibrium and linkage disequilibrium indicate that propagation of T. cruzi is predominantly clonal. Nevertheless, two studies show putative homozygotes and heterozygotes circulating sympatrically: the allozyme frequencies for phosphoglucomutase, and hybrid RAPD profiles suggest that genetic exchange may be a current phenomenon in some T. cruzi transmission cycles. We were able to isolate dual drug-resistant T. cruzi biological clones following copassage of putative parents carrying single episomal drug-resistant markers. A multiplex PCR confirmed that dual drug-resistant clones carried both episomal plasmids. Preliminary karyotype analysis suggests that recombination may not be confined to the extranuclear genome.

JR, Stothard; IA, Frame; MA, Miles.

1999-09-01

53

Predicting mining activity with parallel genetic algorithms  

Science.gov (United States)

We explore several different techniques in our quest to improve the overall model performance of a genetic algorithm calibrated probabilistic cellular automata. We use the Kappa statistic to measure correlation between ground truth data and data predicted by the model. Within the genetic algorithm, we introduce a new evaluation function sensitive to spatial correctness and we explore the idea of evolving different rule parameters for different subregions of the land. We reduce the time required to run a simulation from 6 hours to 10 minutes by parallelizing the code and employing a 10-node cluster. Our empirical results suggest that using the spatially sensitive evaluation function does indeed improve the performance of the model and our preliminary results also show that evolving different rule parameters for different regions tends to improve overall model performance. Copyright 2005 ACM.

Talaie, S.; Leigh, R.; Louis, S.J.; Raines, G.L.

2005-01-01

54

Keel A Data Mining Tool: Analysis With Genetic  

OpenAIRE

This work is related to the KEEL (Knowledge Extraction basedon Evolutionary Learning) tool, an open source software thatsupports data management and provides a platform for theanalysis of evolutionary learning for Data Mining problems ofdifferent kinds including as regression, classification,unsupervised learning. It includes a big collection of evolutionarylearning algorithms based on different approaches: Pittsburgh,Michigan. It empowers the user to perform complete analysis ofany genetic f...

Ms. Pooja Mittal; Manju Narwal

2012-01-01

55

TEMPORAL CHANGES OF GENETIC DIVERSITY IN SUGARCANE BREEDING POPULATIONS  

Science.gov (United States)

Concerns about decline of genetic diversity in sugarcane (Saccharum spp.) breeding programs need be addressed to define better breeding strategies aimed at achieving greater genetic gains. The objectives of this study were to reconstruct the divergence in the Canal Point breeding populations as temp...

56

Limited Genetic Diversity in the Endophytic Sugarcane Bacterium Acetobacter diazotrophicus.  

Science.gov (United States)

Acetobacter diazotrophicus isolates that originated from different sugarcane cultivars growing in diverse geographic regions of Mexico and Brazil were shown to have limited genetic diversity. Measurements of polymorphism in the electrophoretic mobilities of metabolic enzymes revealed that the mean genetic diversity per enzyme locus (among the four electrophoretic types distinguished) was 0.064. The results of the genetic analysis indicate that the genetic structure of A. diazotrophicus is clonal, with one largely predominant clone. Plasmids were present in 20 of 24 isolates, and the molecular sizes of the plasmids ranged from 2.0 to 170 kb. Two plasmids (a 20- to 24-kb plasmid detected in all 20 plasmid-containing isolates and a 170-kb plasmid observed in 14 isolates) were highly conserved among the isolates examined. Regardless of the presence of plasmids, all of the isolates shared a common pattern of nif structural gene organization on the chromosome. PMID:16349254

Caballero-Mellado, J; Martinez-Romero, E

1994-05-01

57

Genetic diversity in Populus nigra plantations from west of Iran  

Directory of Open Access Journals (Sweden)

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 term of 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.  

Afrooz Alimohamadi

2012-12-01

58

Genetic diversity in Populus nigra plantations from west of Iran  

Directory of Open Access Journals (Sweden)

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.

Afrooz Alimohamadi

2012-11-01

59

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 for food and the need for conservation of agricultural and genetic resources. In Puerto Rico (PR), the genetic diversity of sweet potato has been poorly understood, although it has been part of the diet since Pre-Columbus time. Thus, 137 landraces from different localities around PR were collected and subjected to a genetic diversity analysis using 23 SSR-markers. In addition, 8 accessions from a collection grown in Gurabo, PR at the Agricultural Experimental Station (GAES), 10 US commercial cultivars and 12 Puerto Rican accessions from the USDA repository collection were included in this assessment. The results of the analysis of the 23 loci showed 255 alleles in the 167 samples. Observed heterozygosity was high across populations (0.71) while measurements of total heterozygosity revealed a large genetic diversity throughout the population and within populations. UPGMA clustering method revealed two main clusters. Cluster 1 contained 12 PR accessions from the USDA repository collection, while cluster 2 consisted of PR landraces, US commercial cultivars and the PR accessions from GAES. Population structure analysis grouped PR landraces in five groups including four US commercial cultivars. Our study shows the presence of a high level of genetic diversity of sweet potato across PR which can be related to the genetic makeup of sweet potato, human intervention and out-crossing nature of the plant. The history of domestication and dispersal of sweet potato in the Caribbean and the high levels of genetic diversity found through this study makes sweet potato an invaluable resource that needs to be protected and further studied. PMID:25551388

Rodriguez-Bonilla, Lorraine; Cuevas, Hugo E; Montero-Rojas, Milly; Bird-Pico, Fernando; Luciano-Rosario, Dianiris; Siritunga, Dimuth

2014-01-01

60

Radiation induced mutants in elite genetic background for the augmentation of genetic diversity  

International Nuclear Information System (INIS)

Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

61

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

OpenAIRE

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.

Kesinee Gatphayak

2013-01-01

62

Genetic Diversity of Turf-Type Tall Fescue Using Diversity Arrays Technology.  

Czech Academy of Sciences Publication Activity Database

Ro?. 52, ?. 1 (2012), s. 408-412. ISSN 0011-183X Institutional research plan: CEZ:AV0Z50380511 Keywords : Festuca arundinacea * Diversity Arrays Technology (DArT) * Low genetic polymorphism Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.513, year: 2012

Baird, J. H.; Kopecký, David; Lukaszewski, A.J.; Green, R. J.; Bartoš, Jan; Doležel, Jaroslav

2012-01-01

63

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

Science.gov (United States)

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. PMID:23732666

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

2013-05-01

64

Genetic diversity in Hemileia vastatrix based on RAPD markers.  

Science.gov (United States)

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. PMID:16396347

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

2005-01-01

65

Analysis of Genetic Diversity of Yangzhou Chicken by Microsatellite Markers  

OpenAIRE

Genetic variation at 20 microsatellite loci and genetic diversity were examined for Yangzhou Chicken. Observed and effective number of alleles across the microsatellite loci varied from 2-6 with an overall mean of 3.778 and 2.404, respectively. Observed and effective heterozygosity varied from 0.129-0.755 with an average of 0.422 and 0.517, respectively. Average polymorphism information content was 0.464. The genetic structure indicated that Yangzhou Chickens have substantial genetic variatio...

Liu, G. Q.; Jiang, X. P.; Wang, J. Y.; Wang, Z. Y.; Liu, G. Y.; Mao, Y. J.

2008-01-01

66

Genetic diversity analysis of common beans based on molecular markers  

Directory of Open Access Journals (Sweden)

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.

Homar R. Gill-Langarica

2011-01-01

67

Vietnamese chickens: a gate towards Asian genetic diversity  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Chickens represent an important animal genetic resource and the conservation of local breeds is an issue for the preservation of this resource. The genetic diversity of a breed is mainly evaluated through its nuclear diversity. However, nuclear genetic diversity does not provide the same information as mitochondrial genetic diversity. For the species Gallus gallus, at least 8 maternal lineages have been identified. While breeds distributed westward from the Indian subcontinent usually share haplotypes from 1 to 2 haplogroups, Southeast Asian breeds exhibit all the haplogroups. The Vietnamese Ha Giang (HG chicken has been shown to exhibit a very high nuclear diversity but also important rates of admixture with wild relatives. Its geographical position, within one of the chicken domestication centres ranging from Thailand to the Chinese Yunnan province, increases the probability of observing a very high genetic diversity for maternal lineages, and in a way, improving our understanding of the chicken domestication process. Results A total of 106 sequences from Vietnamese HG chickens were first compared to the sequences of published Chinese breeds. The 25 haplotypes observed in the Vietnamese HG population belonged to six previously published haplogroups which are: A, B, C, D, F and G. On average, breeds from the Chinese Yunnan province carried haplotypes from 4.3 haplogroups. For the HG population, haplogroup diversity is found at both the province and the village level (0.69. The AMOVA results show that genetic diversity occurred within the breeds rather than between breeds or provinces. Regarding the global structure of the mtDNA diversity per population, a characteristic of the HG population was the occurrence of similar pattern distribution as compared to G. gallus spadiceus. However, there was no geographical evidence of gene flow between wild and domestic populations as observed when microsatellites were used. Conclusions In contrast to other chicken populations, the HG chicken population showed very high genetic diversity at both the nuclear and mitochondrial levels. Due to its past and recent history, this population accumulates a specific and rich gene pool highlighting its interest and the need for conservation.

Bed'Hom B

2010-06-01

68

Regional specificity of genetically diverse garlic varieties  

Science.gov (United States)

Garlic is a profitable crop for small to medium-sized vegetable farmers. Despite the increasing market for specialty garlic, it is remarkable how little is known about the diverse types of garlic available. Farmers need to know which garlic types perform well under their growing conditions, and th...

69

Genetic diversity and relationships of Vietnamese and European pig breeds  

International Nuclear Information System (INIS)

Indigenous resources of the Asian pig population are less defined and only rarely compared with European breeds. In this study, five indigenous pig breeds from Viet Nam (Mong Cai, Muong Khuong, Co, Meo, Tap Na), two exotic breeds kept in Viet Nam (Large White, Landrace), three European commercial breeds (Pietrain, Landrace, Large White), and European Wild Boar were chosen for evaluation and comparison of genetic diversity. Samples and data from 317 animals were collected and ten polymorphic microsatellite loci were selected according to the recommendations of the FAO Domestic Animal Diversity Information System (DAD-IS; http://www.fao.org/dad-is/). Effective number of alleles, Polymorphism Information Content (PIC), within-breed diversity, estimated heterozygosities and tests for Hardy-Weinberg equilibrium were determined. Breed differentiation was evaluated using the fixation indices of Wright (1951). Genetic distances between breeds were estimated according to Nei (1972) and used for the construction of UPGMA dendrograms which were evaluated by bootstrapping. Heterozygosity was higher in indigenous Vietnamese breeds than in the other breeds. The Vietnamese indigenous breeds also showed higher genetic diversity than the European breeds and all genetic distances had a strong bootstrap support. The European commercial breeds, in contrast, were closely related and bootstrapping values for genetic distances among them were below 60%. European Wild Boar displayed closer r60%. European Wild Boar displayed closer relation with commercial breeds of European origin than with the native breeds from Viet Nam. This study is one of the first to contribute to a genetic characterization of autochthonous Vietnamese pig breeds and it clearly demonstrates that these breeds harbour a rich reservoir of genetic diversity. (author)

70

Genetic diversity and the origins of cultural fragmentation  

OpenAIRE

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 variou...

Ashraf, Quamrul; Galor, Oded

2013-01-01

71

The genetic diversity of Plasmodium vivax: a review  

Directory of Open Access Journals (Sweden)

Full Text Available The genetic diversity of Plasmodium vivax has been investigated in several malaria-endemic areas, including the Brazilian Amazon region, where this is currently the most prevalent species causing malaria in humans. This review summarizes current views on the use of molecular markers to examine P. vivax populations, with a focus on studies performed in Brazilian research laboratories. We emphasize the importance of phylogenetic studies on this parasite and discuss the perspectives created by our increasing understanding of genetic diversity and population structure of this parasite for the development of new control strategies, including vaccines, and more effective drugs for the treatment of P. vivax malaria.

Wanessa Christina de Souza-Neiras

2007-06-01

72

Genetic diversity of Actinobacillus lignieresii isolates from different hosts  

DEFF Research Database (Denmark)

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 comprising strains isolated from horses and infected wounds of humans bitten by horses and another consisting of strains isolated from bovine and ovine hosts. The present data indicate a comparatively higher degree of genetic diversity among strains isolated from equine hosts and confirm the existence of a separate genomospecies for A. lignieresi-like isolates from horses. Among the isolates from bovine and ovine hosts some clonal lines appear to be genetically stable over time and could be detected at very distant geographic localities. Although all ovine strains investigated grouped in a single cluster, the existence of distinct genetic lineages that have evolved specificity for ovine hosts is not obvious and needs to be confirmed in other studies.

Kokotovic, Branko; Angen, Øystein

2011-01-01

73

Genetic diversity measures of the Croatian Spotted goat  

Directory of Open Access Journals (Sweden)

Full Text Available In the present study, microsatellite data of 20 loci were generated and utilized to evaluate genetic variability of the Croatian Spotted goat. Genetic variability was high, with means for expected gene diversity of 0.771, observed heterozygosity of 0.759, and 8.1 for the total number of alleles per locus. There are no indications for deviations from random breeding within the population. Level of inbreeding was only 2% and non-significant. The population was found to deviate significantly under infinitive allele model (IAM and two phase model (TPM, while stepwise mutation model (SMM and qualitative mode-shift test of allele frequencies indicate the absence of genetic bottleneck in the recent past in the population of the Croatian Spotted goat. High level of genetic diversity, as it is presented in this study, may be seen as an initial guide for conservation decisions in the future.

Pavi? Vesna

2011-01-01

74

Monitoring genetic diversity in tropical trees with multilocus dominant markers.  

Science.gov (United States)

Since no universal codominant markers are currently available, dominant genetic markers, such as amplified fragment length polymorphism (AFLP), are valuable tools for assessing genetic diversity in tropical trees. However, the measurement of genetic diversity (H) with dominant markers depends on the frequency of null homozygotes (Q) and the fixation index (F) of populations. While Q can be estimated for AFLP loci, F is less accessible. Through a modelling approach, we show that the monolocus estimation of genetic diversity is strongly dependent on the value of F, but that the multilocus diversity estimate is surprisingly robust to variations in F. The robustness of the estimate is due to a mechanistic effect of compensation between negative and positive biases of H by different AFLP loci exhibiting contrasting frequency profiles of Q. The robustness was tested across contrasting theoretical frequency profiles of Q and verified for 10 neotropical species. Practical recommendations for the implementation of this analytical method are given for genetic surveys in tropical trees, where such markers are widely applied. PMID:16106259

Kremer, A; Caron, H; Cavers, S; Colpaert, N; Gheysen, G; Gribel, R; Lemes, M; Lowe, A J; Margis, R; Navarro, C; Salgueiro, F

2005-10-01

75

Genetic diversity analysis in Cymbopogon species using DNA markers  

Directory of Open Access Journals (Sweden)

Full Text Available Genetic diversity of 25 accessions of Cymbopogon aromatic grasses including eight species, two hybrids and one mutant strain were analyzed using DNA markers generated by employing 20 primer pairs derived from cDNAs containing simple sequence repeat (SSR of rice genome. A total of 151 bands were produced ranging from 3 to 12 per primer pair. The polymorphic information content values varied from 0.143 to 0.916 with an average 0.715. Jaccard’s similarity coefficient ranged from 64 to 87% among the paired accessions. The level of diversity among different taxa/accessions observed during the present study was, however, low relative to the diversity level obtained due to RAPD markers in earlier studies. The pattern of genetic diversity neither matched with the known taxonomic classification, nor did it always match with the distribution of chemical constituents of the essential oils available in these accessions. Thus, present investigation though revealed poor correlation between the molecular and chemical diversity, indicating that chemical diversity in medicinal and aromatic species is not only result of genetic variability, but it also depends on a number of other factors. Thus this study may prove useful in several ways in Cymbopogon conservation and breeding programs and in the development of perfect markers though association mapping for genes involved in controlling agronomically important traits.

J. Kumar

2009-01-01

76

Assessment of genetic diversity in cowpea (Vigna unguiculata)  

OpenAIRE

Sixty six genotypes of cowpea (Vigna unguiculata (L.) Walp) were investigated to understand the extent of genetic diversitythrough twelve quantitative traits. Mahalanobis’s D2 analysis established the presence of wide genetic diversity among thesegenotypes by the formation of 23 clusters. Cluster I had the maximum number of genotypes i.e 22 and cluster 23 had onlyone genotype. Intra cluster distance analysis revealed that the minimum intra cluster distance was observed in the cluster II.The...

R M Nagalakshmi, R. Usha Kumari And M. B. Boranayaka

2010-01-01

77

Genetic diversity in wild populations of Paulownia fortune.  

Science.gov (United States)

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. PMID:25739286

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

2014-11-01

78

Archaeal Diversity in Waters from Deep South African Gold Mines  

OpenAIRE

A culture-independent molecular analysis of archaeal communities in waters collected from deep South African gold mines was performed by performing a PCR-mediated terminal restriction fragment length polymorphism (T-RFLP) analysis of rRNA genes (rDNA) in conjunction with a sequencing analysis of archaeal rDNA clone libraries. The water samples used represented various environments, including deep fissure water, mine service water, and water from an overlying dolomite aquifer. T-RFLP analysis ...

Takai, Ken; Moser, Duane P.; Deflaun, Mary; Onstott, Tullis C.; Fredrickson, James K.

2001-01-01

79

Eestimation of genetic diversity in walnut  

International Nuclear Information System (INIS)

Juglans regia L. belonging to the family Juglandaceae inhabits the northern parts of Pakistan. Biochemical analysis of the plant is not well documented in the country. Present research was the first documented attempt to study total seed storage proteins in 20 genotypes of Juglans regia collected from Swat, Dir and Chitral areas. A protocol was optimized for extraction and separation of seed storage protein from unprocessed seeds. Comparatively simple banding pattern (as compared to legumes and cereals) was observed in Juglans regia L. A total of 114 protein loci were detected in 20 genotypes giving an average of approximately 7 alleles per genotype. Genetic distances estimated during present study range from 0 to 60. Medium values of Genetic Distances (GDmax= 60%) was estimated among three comparisons. Twenty genotypes were grouped in three clusters based on dendrogram analysis. Genotypes collected from Chitral valley were predominantly grouped in one cluster. (author)

80

Genetic diversity and breed management in dogs  

OpenAIRE

Genetic structure and breeding practices in dog species were investigated in order to develop some management tools for dog breeds in France. Three approaches were therefore used: surveys, genealogical analysis, and polymorphism of microsatellite markers. Nine-hundred eighty-five breeders, either hobby or professional, answered a questionnaire about their breeding practices. It showed some differences according to the breed raised or the status of the breeder. Pedigree analysis results realis...

Leroy, Gre?goire

2008-01-01

81

Genetic Diversity of Escherichia Coli from Sanandaj  

OpenAIRE

Background and Objectives: The Escherichia coli strains are greatly important in nosocomial and community acquired infections. The aim of this study was to determine the transmission of bacterial infections using genetic analysis. Materials and Methods: Two hundred and thirty Escherichia coli strains, isolated from different clinical samples, were characterized by enterobacterial repetitive intergenic consensus (ERIC)–PCR technique. The results and the similarity between the strains were de...

Serveh Zamani; Rashid Ramazanzadeh; Saman Zamani

2013-01-01

82

Pheochromocytomas: from genetic diversity to new paradigms.  

Science.gov (United States)

Pheochromocytomas and paragangliomas are catecholamine-secreting tumors of neural crest origin caused by germline mutations in at least six distinct genes. This genetic heterogeneity has provided a rich source for both the discovery and functional characterization of new tumor-related genes. However, the genetic repertoire of these tumors is still not fully known, and current evidence points to the existence of additional pheochromocytoma susceptibility genes. Here, the unique contributions of three hereditary models of pheochromocytoma that can advance our knowledge of the disease pathogenesis are presented. The first model, loss of succinate dehydrogenase (SDH) function, illustrates how SDHB, C, or D mutations, components of the energy metabolism pathway, serve as a unique system to explore the pervasive metabolic shift of cancer cells towards glycolysis as a source of energy (also known as the Warburg effect) in contrast to the characteristic oxidative phosphorylation of normal cells. In the second model, mechanisms of tumorigenesis distinct from classical pheochromocytoma susceptibility genes are discussed in the context of a novel putative suppressor of neural crest-derived tumors, the KIF1B beta gene. Finally, NF1 loss is highlighted as a valuable study model to investigate the cell lineage selectivity of the Egln3-mediated developmental apoptotic defect of chromaffin precursor cells. Results from these studies may offer clues to understand the tissue specificity of hereditary pheochromocytoma syndromes. These distinct hereditary disease models illustrate how genetic-driven progress has the potential to narrow current gaps in our knowledge of pheochromocytoma and paraganglioma pathogenesis. PMID:19391076

Qin, Y; Buddavarapu, K; Dahia, P L M

2009-09-01

83

metabolicMine: an integrated genomics, genetics and proteomics data warehouse for common metabolic disease research.  

Science.gov (United States)

Common metabolic and endocrine diseases such as diabetes affect millions of people worldwide and have a major health impact, frequently leading to complications and mortality. In a search for better prevention and treatment, there is ongoing research into the underlying molecular and genetic bases of these complex human diseases, as well as into the links with risk factors such as obesity. Although an increasing number of relevant genomic and proteomic data sets have become available, the quantity and diversity of the data make their efficient exploitation challenging. Here, we present metabolicMine, a data warehouse with a specific focus on the genomics, genetics and proteomics of common metabolic diseases. Developed in collaboration with leading UK metabolic disease groups, metabolicMine integrates data sets from a range of experiments and model organisms alongside tools for exploring them. The current version brings together information covering genes, proteins, orthologues, interactions, gene expression, pathways, ontologies, diseases, genome-wide association studies and single nucleotide polymorphisms. Although the emphasis is on human data, key data sets from mouse and rat are included. These are complemented by interoperation with the RatMine rat genomics database, with a corresponding mouse version under development by the Mouse Genome Informatics (MGI) group. The web interface contains a number of features including keyword search, a library of Search Forms, the QueryBuilder and list analysis tools. This provides researchers with many different ways to analyse, view and flexibly export data. Programming interfaces and automatic code generation in several languages are supported, and many of the features of the web interface are available through web services. The combination of diverse data sets integrated with analysis tools and a powerful query system makes metabolicMine a valuable research resource. The web interface makes it accessible to first-time users, whereas the Application Programming Interface (API) and web services provide convenient data access and tools for bioinformaticians. metabolicMine is freely available online at http://www.metabolicmine.org Database URL: http://www.metabolicmine.org. PMID:23935057

Lyne, Mike; Smith, Richard N; Lyne, Rachel; Aleksic, Jelena; Hu, Fengyuan; Kalderimis, Alex; Stepan, Radek; Micklem, Gos

2013-01-01

84

Genetic diversity of Kenyan native oyster mushroom (Pleurotus).  

Science.gov (United States)

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. PMID:25344263

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

2015-01-01

85

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 ...

86

Genetic diversity of Cryptosporidium spp. in captive reptiles.  

Czech Academy of Sciences Publication Activity Database

Ro?. 70, ?. 2 (2004), s. 891-899. ISSN 0099-2240 R&D Projects: GA ?R GA524/00/P015 Institutional research plan: CEZ:AV0Z6022909 Keywords : Cryptosporidium * reptiles * genetic diversity Subject RIV: EG - Zoology Impact factor: 3.810, year: 2004

Xiao, L.; Ryan, U. M.; Graczyk, T. K.; Limor, J.; Li, L.; Kombert, M.; Junge, R.; Sulaiman, I. M.; Zhou, L.; Arrowood, M. J.; Koudela, B?etislav; Modrý, David; Lal, A. A.

2004-01-01

87

Simplified Process Model Discovery Based on Role-Oriented Genetic Mining  

OpenAIRE

Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified proc...

Weidong Zhao; Xi Liu; Weihui Dai

2014-01-01

88

Synthetic biology: advancing the design of diverse genetic systems.  

Science.gov (United States)

A major objective of synthetic biology is to make the process of designing genetically encoded biological systems more systematic, predictable, robust, scalable, and efficient. Examples of genetic systems in the field vary widely in terms of operating hosts, compositional approaches, and network complexity, ranging from simple genetic switches to search-and-destroy systems. While significant advances in DNA synthesis capabilities support the construction of pathway- and genome-scale programs, several design challenges currently restrict the scale of systems that can be reasonably designed and implemented. Thus, while synthetic biology offers much promise in developing systems to address challenges faced in the fields of manufacturing, environment and sustainability, and health and medicine, the realization of this potential is currently limited by the diversity of available parts and effective design frameworks. As researchers make progress in bridging this design gap, advances in the field hint at ever more diverse applications for biological systems. PMID:23413816

Wang, Yen-Hsiang; Wei, Kathy Y; Smolke, Christina D

2013-01-01

89

Assessment of Genetic Diversity in Iranian Fennels Using ISSR Markers  

Directory of Open Access Journals (Sweden)

Full Text Available Fennel (Foeniculum vulgare Mill. is an important medicinal plant with used for various purposes in different industries. In this study 25 different ecotypes of fennel from all over Iran were collected and their genetic diversity studied by seven ISSR primers. Seven ISSR primers generated 52 amplified fragments, of which 49 were polymorphic. The highest similarity coefficient among the ecotypes was between Chahestan and Haji abad whereas the minimum similarity coefficient observed between Fozveh and Moqan. In most cases, classifications were consistent with their geographical distribution for some ecotypes (like Givi and Khalkhal in close distance and although with similarity in climate (like Damavand and Alamot with same climate. This study revealed that ISSR marker could properly separate these ecotypes based on geographical distribution and similarity in climates and showed the wide genetic diversity among Iranian fennels. In term of conservation program, it is highly recommended at least one conservation program for several accessions with near genetical distance should be conducted.

Kaivan Bahmani

2012-07-01

90

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

Science.gov (United States)

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. PMID:20383613

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

2010-09-01

91

Genetic diversity of noroviruses in Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Norovirus (NoV) infections are a major cause of acute gastroenteritis outbreaks around the world. In Brazil, the surveillance system for acute diarrhoea does not include the diagnosis of NoV, precluding the ability to assess its impact on public health. The present study assessed the circulation of [...] NoV genotypes in different Brazilian states by partial nucleotide sequencing analysis of the genomic region coding for the major capsid viral protein. NoV genogroup II genotype 4 (GII.4) was the prevalent (78%) followed by GII.6, GII.7, GII.12, GII.16 and GII.17, demonstrating the great diversity of NoV genotypes circulating in Brazil. Thus, this paper highlights the importance of a virological surveillance system to detect and characterize emerging strains of NoV and their spreading potential.

Julia Monassa, Fioretti; Mônica Simões Rocha, Ferreira; Matias, Victoria; Carmen Baur, Vieira; Maria da Penha Trindade Pinheiro, Xavier; José Paulo Gagliardi, Leite; Marize Pereira, Miagostovich.

2011-12-01

92

Genetic diversity of noroviruses in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Norovirus (NoV infections are a major cause of acute gastroenteritis outbreaks around the world. In Brazil, the surveillance system for acute diarrhoea does not include the diagnosis of NoV, precluding the ability to assess its impact on public health. The present study assessed the circulation of NoV genotypes in different Brazilian states by partial nucleotide sequencing analysis of the genomic region coding for the major capsid viral protein. NoV genogroup II genotype 4 (GII.4 was the prevalent (78% followed by GII.6, GII.7, GII.12, GII.16 and GII.17, demonstrating the great diversity of NoV genotypes circulating in Brazil. Thus, this paper highlights the importance of a virological surveillance system to detect and characterize emerging strains of NoV and their spreading potential.

Julia Monassa Fioretti

2011-12-01

93

Genetic diversity and molecular genealogy of local silkworm varieties  

Directory of Open Access Journals (Sweden)

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.

Zhouhe Du

2013-03-01

94

Environmental pollution affects genetic diversity in wild bird populations.  

Science.gov (United States)

Many common environmental pollutants, together with nuclear radiation, are recognized as genotoxic. There is, however, very little information on pollution-related genetic effects on free-living animal populations, especially in terrestrial ecosystems. We investigated whether genetic diversity in two small insectivorous passerines, the great tit (Parus major) and the pied flycatcher (Ficedula hypoleuca), was changed near point sources of heavy metals (two copper smelters) or radioactive isotopes (nuclear material reprocessing plant). We measured concentration of heavy metals and nucleotide diversity in mitochondrial DNA in feather samples taken from nestlings in multiple polluted areas and at control sites. In both species, heavy metal concentrations - especially of arsenic - were increased in feathers collected at smelter sites. The P. major population living near a smelter showed significantly higher nucleotide diversity than a control population in an unpolluted site, suggesting increased mutation rates in a polluted environment. On the contrary, F. hypoleuca showed reduced nucleotide diversity at both smelter sites but increased nucleotide diversity near the source of radioactivity. Our results show that heavy metal pollution and low level nuclear radiation affect the nucleotide diversity in two free-living insectivorous passerines. We suggest that the different response in these two species may be due to their different ability to handle toxic compounds in the body. PMID:16807076

Eeva, Tapio; Belskii, Eugen; Kuranov, Boris

2006-09-19

95

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

Directory of Open Access Journals (Sweden)

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.

Kesinee Gatphayak

2013-03-01

96

Mitochondrial DNA perspective of Serbian genetic diversity.  

Science.gov (United States)

Although south-Slavic populations have been studied to date from various aspects, the population of Serbia, occupying the central part of the Balkan Peninsula, is still genetically understudied at least at the level of mitochondrial DNA (mtDNA) variation. We analyzed polymorphisms of the first and the second mtDNA hypervariable segments (HVS-I and HVS-II) and informative coding-region markers in 139 Serbians to shed more light on their mtDNA variability, and used available data on other Slavic and neighboring non-Slavic populations to assess their interrelations in a broader European context. The contemporary Serbian mtDNA profile is consistent with the general European maternal landscape having a substantial proportion of shared haplotypes with eastern, central, and southern European populations. Serbian population was characterized as an important link between easternmost and westernmost south-Slavic populations due to the observed lack of genetic differentiation with all other south-Slavic populations and its geographical positioning within the Balkan Peninsula. An increased heterogeneity of south Slavs, most likely mirroring turbulent demographic events within the Balkan Peninsula over time (i.e., frequent admixture and differential introgression of various gene pools), and a marked geographical stratification of Slavs to south-, east-, and west-Slavic groups, were also found. A phylogeographic analyses of 20 completely sequenced Serbian mitochondrial genomes revealed not only the presence of mtDNA lineages predominantly found within the Slavic gene pool (U4a2a*, U4a2a1, U4a2c, U4a2g, HV10), supporting a common Slavic origin, but also lineages that may have originated within the southern Europe (H5*, H5e1, H5a1v) and the Balkan Peninsula in particular (H6a2b and L2a1k). Am J Phys Anthropol 156:449-465, 2015. © 2014 Wiley Periodicals, Inc. PMID:25418795

Davidovic, Slobodan; Malyarchuk, Boris; Aleksic, Jelena M; Derenko, Miroslava; Topalovic, Vladanka; Litvinov, Andrey; Stevanovic, Milena; Kovacevic-Grujicic, Natasa

2015-03-01

97

Genetic diversity among sugarcane (Saccharum spp. varieties using molecular markers  

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Full Text Available The genetic base of today's sugarcane cultivars appears to be narrow and could be the reason for current slow progress in improving sugarcane crops. Sixty-three primer pairs (producing 263 polymorphic fragments flanking simple sequence repeats or micro-satellites were used for assessing the genetic variability of five S. officinarum clones and 33 sugarcane cultivars used in CENICAÑA breeding projects, selected for their economic and agronomic im-portance in several Central and South-American countries. NTSYS (Numerical Taxonomy and Multivariate Analy-sis System and SAS (Statistical Analysis System statistical software was used to analyse data. The number of alleles recorded per marker ranged from 1 to 16 (mean = 5. Cluster analysis showed a clear separation of cultivars from S. officinarum clones. The average of genetic similarity between sugarcane genotypes studied was 0.664, while genetic diversity analysis revealed a very different group (H: 0.973. An interesting results concerned CC 91-1880 distribu-tion very close to that of Q genotypes from Australia and also S. officinarum clones, suggesting that this cultivar would be a good candidate for further studies by breeders. The results obtained are useful for CENICAÑA's breed­ing program because, in spite of the genetic homogeneity present in today's sugarcane cultivars, it is clear that allelic variants are present in some of these cultivars and could be used in the new breeding projects. Key words: Sugarcane, genetic diversity, microsatellites, molecular markers, Saccharum officinarum.

John J. Riascos

2007-05-01

98

The diversity of culturable airborne fungi in an active South African gold mine  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Several studies have been conducted on the presence and diversity of airborne fungal spores in residential and occupational areas. This is the first investigation on this topic in the mining environment. The impact of fungi-especially as opportunistic pathogens-on their health and productivity needs [...] to be assessed, considering the compromised health of a large number of HIV-infected miners in South Africa. Accordingly, the aim of this study was to determine the abundance of fungal spores as well as the diversity of culturable airborne fungi in an active gold mine. The results indicate that three of the sampled sites in the mine contain abundant numbers of culturable airborne fungi. The first site was next to an auxiliary extraction fan, which could act as an accumulator for airborne fungal spores from the rest of the mine. The two other sites had high human activity, disturbances from which may contribute to an elevated fungal load in the air. The presence of timber supports at one site may serve as a growth substrate for several fungal genera. The diversity of filamentous fungal genera increased from outside the mine to deeper into the mine, whereas the diversity of yeast genera followed an opposite trend, with no yeasts detected deep in the mine. Although most of the isolates identified are not pathogens, they could still have a negative impact (either as opportunistic pathogens or allergens) on workers, especially immunocompromised persons if exposed to them for prolonged periods.

C.H., Pohl; W., Kriel; P., Venter; E., Van Heerden; J., Albertyn.

2007-08-01

99

Genetic diversity of Ascaris in southwestern Uganda  

DEFF Research Database (Denmark)

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 Musezero, was carried out. Adult Ascaris worms were collected from infected individuals by chemo-expulsion using pyrantel pamoate treatment. Genetic diversity within these worms was assessed by inspection of DNA sequence variation in a mitochondrial marker and length polymorphism at microsatellite loci. Overall prevalence of ascariasis was 42.5% in mothers and 30.4% in their children and a total of 98 worms was examined from 18 hosts. Sequence analysis of a portion of the mitochondrial cytochrome c oxidase subunit 1 gene revealed 19 different haplotypes, 13 of which had not been previously encountered. Microsatellite analysis using eight loci provided evidence for high gene flow between worm populations from the two villages but comparing these worms with others obtained in a prior study on Unguja, Zanzibar, confirmed little genetic exchange and mixing of worm populations between the two areas. By adding to our understanding of the genetic diversity of Ascaris in Africa, this study provides useful information for monitoring changes in parasite population structure in the face of ongoing and future control.

Betson, Martha; Nejsum, Peter

2012-01-01

100

Genetic Diversity in Brassica Species Using SDS-PAGE Analysis  

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Full Text Available Eighty five different cultivars of Brassica rapa, B.juncea, B.napus, B. carinata, B. oleracea and hexaploid Brassica, collected from Bangladesh, Japan, China and Denmark, were analyzed for seed and leaf protein variations by SDS-PAGE to identify the polymorphic genetic markers for evaluation of genetic resources. Ten polymorphic markers were identified from seed protein and no identifiable polymorphic band was found from leaf protein. However, polymorphic markers clearly distinguished these Brassica species. Brassica rapa var. `yellow sarson` of Bangladesh origin showed uniquely identifiable four polymorphic bands for seed protein in contrast to the other B.rapa of brown-seeded type. The Bangladeshi and Japanese cultivars of B. rapa differed among protein quantity. Analytical results of SDS-PAGE for seed protein showed that hexaploid Brassica has the highest indices, such as % of polymorphic band, the degree of phenotypic diversity (Ho, diversity value for genetic marker (HEP and the sum of the effective number of alleles (SENA. The genetic diversity values of hexaploid Brassica were followed by amphidiploid (B. napus, B. juncea, B. carinata and diploid (B. oleracea, B. rapa species, respectively.

Rahman Md. Mukhlesur

2004-01-01

101

Genetic diversity affects colony survivorship in commercial honey bee colonies  

Science.gov (United States)

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.

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

2013-08-01

102

On the use of genetic programming for mining comprehensible rules in subgroup discovery.  

Science.gov (United States)

This paper proposes a novel grammar-guided genetic programming algorithm for subgroup discovery. This algorithm, called comprehensible grammar-based algorithm for subgroup discovery (CGBA-SD), combines the requirements of discovering comprehensible rules with the ability to mine expressive and flexible solutions owing to the use of a context-free grammar. Each rule is represented as a derivation tree that shows a solution described using the language denoted by the grammar. The algorithm includes mechanisms to adapt the diversity of the population by self-adapting the probabilities of recombination and mutation. We compare the approach with existing evolutionary and classic subgroup discovery algorithms. CGBA-SD appears to be a very promising algorithm that discovers comprehensible subgroups and behaves better than other algorithms as measures by complexity, interest, and precision indicate. The results obtained were validated by means of a series of nonparametric tests. PMID:25415941

Luna, José María; Romero, José Raúl; Romero, Cristóbal; Ventura, Sebastián

2014-12-01

103

Genetic diversity among Zygophyllum (Zygophyllaceae) populations based on RAPD analysis.  

Science.gov (United States)

Zygophyllum species are succulent plants that are drought resistant and/or salt tolerant, growing under severe, dry climatic conditions. Despite their importance and abundance in the Mediterranean and Middle East regions, there is little information concerning molecular variations among species of this genus. Genetic diversity was assessed, using RAPD primers, of 12 populations of Z. coccineum, Z. album and Z. aegyptium collected from various locations in Egypt and Saudi Arabia. Yong leaves were used for DNA extraction. Genetic distances were calculated using Nei's method. A dendrogram was constructed based on the similarity data matrix by unweighted pair group method using arithmetic averages cluster analysis. Analysis with RAPD markers revealed genetic variation between and within populations of Zygophyllum. Zygophyllum coccineum showed higher levels of genetic variation and more unique alleles than the other species. PMID:21161890

Hammad, I; Qari, S H

2010-01-01

104

Genetic diversity of Mycosphaerella graminicola isolates from a single field.  

Science.gov (United States)

Septoria tritici blotch caused by Mycosphaerella graminicola is currently one of the most economically damaging diseases on wheat crops worldwide. Two hundred and sixty single-conidial isolates of this fungus were sampled in April 2012 in the Nord-Pas de Calais region (France). They have all been collected from 13 distinct plots in a single field. The corresponding isolates were then fingerprinted using 8 microsatellite markers in order to assess the genetic diversity and population structure of M. graminicola at the single field scale. The results revealed a high genotypic diversity within the collected population, with the detection of 83% of unique haplotypes among the isolates tested (clonal fraction = 17%). A high genic diversity was also found as indicated by the Nei's index value (0.50) and strong allele diversity obtained (number of alleles per locus ranged from 7 to 17, with an average of 10 alleles per locus). Further analyses showed a low population differentiation (G(ST) = 0.08) and a high gene flow (Nm = 5.64) between the 13 sampled plots. Our study suggests that sexual reproduction, by its frequency, plays a major role in the genetic diversification of M. graminicola at the field level and in the distribution and homogenization of this diversity in the field via wind-born ascospores. PMID:25151819

Siah, A; Reignault, Ph; Halama, P

2013-01-01

105

Evaluation of genetic diversity in different Pakistani wheat land races  

International Nuclear Information System (INIS)

Wheat is one of the main sources of nutrition worldwide. Genetic improvement of the seed makes wheat a source of high quality flour for human consumption and for other industrial uses. With the help of molecular markers, the available germplasm of wheat can be assessed for future breeding programs. Therefore, the aim of the present work was to analyze the genetic diversity among 15 Pakistani wheat land races based on Random Amplified Polymorphism DNA (RAPD) markers. A total of 284 DNA fragments were amplified, ranging in size from 200bp to 1100bp by using six primers. The number of DNA fragments for each primer varied from 2 (OPC-6) to 9 (OPC-8) with an average of 6 fragments per primer. Out of 284 amplified products, 120 were monomorphic and 137 were polymorphic showing an average of 7.8% polymorphism per primer. One specific marker was detected both for OPC-1 and OPC-8, two for OPC-5, while no RAPD specific marker was detected for the remaining primers. The genetic similarity index values ranged from 0.36 to 0.93, with an average of 0.64. Maximum genetic similarity (91%) was observed between Sur bej and Khushkawa. On the contrary, minimum genetic similarity (32%) was observed in Khushkaba-1 and Khushkawa. The dendrogram resulting from the NTSYS cluster analysis showed that the studied genotypes are divided into two main clusters from the same node. The first cluster contained 13 land races, while the second cluster contained only 2 land races. The dendrogram cluster only 2 land races. The dendrogram clustered the genotypes into 5 groups and showed efficiency in identifying genetic variability. These results indicated the usefulness of RAPD technique in estimating the genetic diversity among wheat genetic resources. (author)

106

Genetic Diversity and Population Structure of Siberian apricot (Prunus sibirica L.) in China  

OpenAIRE

The genetic diversity and population genetic structure of 252 accessions from 21 Prunus sibirica L. populations were investigated using 10 ISSR, SSR, and SRAP markers. The results suggest that the entire population has a relatively high level of genetic diversity, with populations HR and MY showing very high diversity. A low level of inter-population genetic differentiation and a high level of intra-population genetic differentiation was found, which is supported by a moderate level of gene f...

Ming Li; Zhong Zhao; Xingjun Miao; Jingjing Zhou

2013-01-01

107

The genetic diversity of Sardinian myrtle (Myrtus communis L.) populations  

Scientific Electronic Library Online (English)

Full Text Available Background: The myrtle (Myrtus communis) is a common shrub widespread in the Mediterranean Basin. Its fruit and leaves exhibit antioxidant, antibacterial and antifungal properties, and are used for their content of essential oils and for their medicinal properties, but most commonly as an ingredient [...] in locally made liquor. The uncontrolled exploitation of natural stands has reduced both the species' geographical coverage and the size of individual populations. The selection of genotypes for controlled cultivation requires a characterization of the genetic diversity present both within and between populations. Results: Genotypic variation was evaluated using ISSR profiling and genetic diversity characterized using standard population genetics approaches. Two major clusters were identified: one capturing all the candidate cultivars selected from various Sardinian localities, and the other wild individuals collected from Asinara, Corsica and Surigheddu. A moderate level of gene flow between the Sardinian and Corsican populations was identified. Discriminant analysis of principal components revealed a level of separation among the wild populations, confirming the population structure identified by the clustering methods. Conclusions: The wild accessions were well differentiated from the candidate cultivars. The level of genetic variability was high. The genetic data were compatible with the notion that myrtle has a mixed pollination system, including both out-pollination by insects and self-pollination. The candidate cultivars are suggested to represent an appropriate basis for directed breeding.

Sara, Melito; Innocenza, Chessa; Patrizia, Erre; János, Podani; Maurizio, Mulas.

2013-11-15

108

Genetic diversity revealed by AFLP markers in Albanian goat breeds  

OpenAIRE

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 cal...

Hoda Anila; Sena Lumturi; Hykaj Gentian

2012-01-01

109

Glacial refugia: hotspots but not melting pots of genetic diversity.  

Science.gov (United States)

Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse populations were not located in the south but at intermediate latitudes, a likely consequence of the admixture of divergent lineages colonizing the continent from separate refugia. PMID:12791991

Petit, Rémy J; Aguinagalde, Itziar; de Beaulieu, Jacques-Louis; Bittkau, Christiane; Brewer, Simon; Cheddadi, Rachid; Ennos, Richard; Fineschi, Silvia; Grivet, Delphine; Lascoux, Martin; Mohanty, Aparajita; Müller-Starck, Gerhard; Demesure-Musch, Brigitte; Palmé, Anna; Martín, Juan Pedro; Rendell, Sarah; Vendramin, Giovanni G

2003-06-01

110

Genetic diversity and genetic structure of the rare and endangered species, Primula ranunculoides  

Directory of Open Access Journals (Sweden)

Full Text Available The rare and endangered species Primula ranunculoides is endemic to China and is of reasonably high potential horticultural value. The genetic diversity and structure of the species was examined by surveying variation at nine microsatellite loci across 222 individuals sampled from seven natural populations. The results indicated that there was relatively low genetic diversity present within populations (He = 0.330, Ho = 0.286 and high genetic differentiation among populations. Levels of population genetic diversity and effective population size were both correlated with plant density, rather than population census size or population area. Gene flow between populations was low (Nm = 0.730 and an AMOVA analysis showed that 48.08% of the total genetic diversity was attributable to among populations and the rest (51.92% to variation within populations. Bayesian assignment and principal coordinate analyses supported clustering of the seven populations into four groups, which were correlated with topographical features. This suggested that Lianghu Plain (Dongtinghu Plain and Jianghan Plain and the farming area of Xiushui and Wuning counties were major barriers to gene flow, causing high divergence between different mountain populations. Based on the genetic structure of P. ranunculoides, four management units for conservation purposes are proposed, i.e. the Jiulingshan, Mufushan, Qizimeishan and Yinlu units.

Deyun Wang

2013-09-01

111

Mini core germplasm collections for infusing genetic diversity in plant breeding programs  

Directory of Open Access Journals (Sweden)

Full Text Available Plant genetic resources are essential components to meet future food security needs of world. Crop germplasm diversitycontributes to developing improved crop cultivars aimed at increasing crop productivity. The large size of germplasmcollections, coupled with unavailability of detailed data and information, has resulted in low use (<1% of germplasmleading to a narrow genetic base in many crops. The miniaturization of crop collections with almost full representation ofgenetic diversity in the form of mini core (~1% of the entire collection approach is an effective methodology to enrichand enhance crop improvement programs. The concept and process of developing mini core at The International CropsResearch Institute for the Semi-Arid Tropics (ICRISAT has been recognized worldwide as an “International PublicGood” (IPG. The mini core provides a means for accessing the larger collections for further exploration and also helps inproper assessment of genetic diversity and population structure and for association mapping and targeted gene mining.Use of mini core approach will lead to greater utilization of diverse germplasm for developing broad-based cultivars,especially in the context of climate change. Many national programs have shown immense interest in evaluating minicore as reflected by the supply of 114 sets of mini core of chickpea, groundnut, pigeonpea, sorghum, pearl millet, foxtailmillet and finger millet to researchers in 14 countries. Scientists have been able to identify new and diverse sources ofvariation for morpho-agronomic, quality, biotic, and abiotic stress resistance traits in various crops. The molecularcharacterization of the mini core will further enhance its use in plant breeding programs.

Hari D Upadhyaya*, Devvart Yadav, Naresh Dronavalli, CLL Gowda, and Sube Singh

2010-07-01

112

The genetic diversity of Plasmodium vivax: a review  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The genetic diversity of Plasmodium vivax has been investigated in several malaria-endemic areas, including the Brazilian Amazon region, where this is currently the most prevalent species causing malaria in humans. This review summarizes current views on the use of molecular markers to examine P. vi [...] vax populations, with a focus on studies performed in Brazilian research laboratories. We emphasize the importance of phylogenetic studies on this parasite and discuss the perspectives created by our increasing understanding of genetic diversity and population structure of this parasite for the development of new control strategies, including vaccines, and more effective drugs for the treatment of P. vivax malaria.

Wanessa Christina de, Souza-Neiras; Luciane Moreno Storti de, Melo; Ricardo Luiz Dantas, Machado.

2007-06-01

113

Low worldwide genetic diversity in the basking shark (Cetorhinus maximus).  

Science.gov (United States)

The basking shark (Cetorhinus maximus) is found in temperate waters throughout the world's oceans, and has been subjected to extensive exploitation in some regions. However, little is known about its current abundance and genetic status. Here, we investigate the diversity of the mitochondrial DNA control region among samples from the western North Atlantic, eastern North Atlantic, Mediterranean Sea, Indian Ocean and western Pacific. We find just six haplotypes defined by five variable sites, a comparatively low genetic diversity of pi=0.0013 and no significant differentiation between ocean basins. We provide evidence for a bottleneck event within the Holocene, estimate an effective population size (Ne) that is low for a globally distributed species, and discuss the implications. PMID:17148309

Hoelzel, A Rus; Shivji, Mahmood S; Magnussen, Jennifer; Francis, Malcolm P

2006-12-22

114

Comparison of genetic diversity in two alien plant species  

Directory of Open Access Journals (Sweden)

Full Text Available Bunias orientalis and Erigeron annuus are two alien herbal plant species invading native ecosystems in Lithuania. Both species have similar introduction and invasion history but differ in their life history traits and strategies of reproduction. We used random amplified polymorphic DNA (RAPD data to compare the genetic diversity in invasive populations of these species. 42 RAPD bands were identified in B. orientalis and 70 RAPD bands in E. annuus. All six populations of B. orientalis were polymorphic, while only four of eight study populations of E. annuus were polymorphic. The highest differences between species were established at the level of RAPD phenotypes. 67 RAPD phenotypes were found among 90 plants of B. orientalis but only 10 RAPD phenotypes were identified among 89 plants of E. annuus. This study shows that the level of genetic diversity in populations of different invasive species at the same geographic area may vary considerably.

Tunaitien?, Virginija

2012-03-01

115

Genetic diversity in Brazilian tall coconut populations by microsatellite markers  

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Full Text Available The tall coconut palm was introduced in Brazil in 1553, originating from the island of Cape Verde. The aim of the presentstudy was to evaluate the genetic diversity of ten populations of Brazilian tall coconut by 13 microsatellite markers. Samples werecollected from 195 individuals of 10 different populations. A total of 68 alleles were detected, with an average of 5.23 alleles perlocus. The mean expected and observed heterozygosity value was 0.459 and 0.443, respectively. The number of alleles per populationranged from 36 to 48, with a mean of 40.9 alleles. We observed the formation of two groups, the first formed by the populationsof Baía Formosa, Georgino Avelino and São José do Mipibu, and the second by the populations of Japoatã, Pacatuba and Praia doForte. These results reveal a high level of genetic diversity in the Brazilian populations.

Francisco Elias Ribeiro

2013-12-01

116

A genomic scale map of genetic diversity in Trypanosoma cruzi  

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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 population, providing an essential resource for future studies on the development of new drugs and diagnostics, for Chagas Disease. These data is available through the TcSNP database (http://snps.tcruzi.org.

Ackermann Alejandro A

2012-12-01

117

Genetic diversity for wheat improvement as a conduit to food security  

Science.gov (United States)

Genetic diversity is paramount for any crops genetic improvement and this resides in three gene pools of the Triticeae for wheat. Access to the diversity and its exploitation is based upon genetic distance of the species relatives from the wheat genomes. Apart from the conventional genetic base fo...

118

Genetic diversity of Actinobacillus lignieresii isolates from different hosts  

OpenAIRE

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 comprising strains isolated from horses and infected wounds of humans bitten by horses and another consisting of strains isolated from bovine and ovine hosts. The present data indicate a comparatively higher d...

Kokotovic, Branko; Angen, Øystein; Bisgaard, Magne

2011-01-01

119

Genetic Diversity of Echinococcus granulosus in Center of Iran  

OpenAIRE

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 stu...

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

2014-01-01

120

Genetic diversity of Prunus rootstocks analyzed by RAPD markers  

OpenAIRE

We have used RAPD markers to characterize Prunus rootstocks from different species, both commercial, and selected clones from the breeding program at Aula Dei Experimental Station (Zaragoza, Spain). Molecular markers were used to study the genetic variation among different species, and within species. Forty one genotypes were used in this study. They included P. amygdalo-persica, and P. persica × P. davidiana hybrids; P. cerasifera, P. domestica, and P. insititia clones, and other diverse in...

Casas Cendoya, Ana Mari?a; Igartua Arregui, Ernesto; Moreno Sa?nchez, Mari?a A?ngeles

1999-01-01

121

Genetic diversity in a world germplasm collection of tall fescue  

OpenAIRE

Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous). In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 cou...

Romina Cuyeu; Beatriz Rosso; Elba Pagano; Gabriela Soto; Romina Fox; Nicolás Daniel Ayub

2013-01-01

122

Low worldwide genetic diversity in the basking shark (Cetorhinus maximus)  

OpenAIRE

The basking shark (Cetorhinus maximus) is found in temperate waters throughout the world's oceans, and has been subjected to extensive exploitation in some regions. However, little is known about its current abundance and genetic status. Here, we investigate the diversity of the mitochondrial DNA control region among samples from the western North Atlantic, eastern North Atlantic, Mediterranean Sea, Indian Ocean and western Pacific. We find just six haplotypes defined by five variable sites, ...

Rus Hoelzel, A.; Shivji, Mahmood S.; Magnussen, Jennifer; Francis, Malcolm P.

2006-01-01

123

Hierarchical cluster analysis of genetic diversity in Maize germplasm  

OpenAIRE

An experiment was conducted to analyze the genetic diversity among 38 maize germplasm accessions of the maizegermplasm bank of Department of Millets, TNAU, Coimbatore. Observations regarding 25 morphological traits wererecorded and the data matrix was used for estimation of Euclidian distance by Un-weighted Paired Group ArithmeticAverage (UPGMA) method. Clustering was done by Sequential Agglomerative Hierarchical Non-overlapping (SAHN)clustering. The genotypes were grouped in to four clusters...

Subbaraman, A. Subramanian And N.

2010-01-01

124

Genetic Diversity Analysis among Greengram genotypes using RAPD Markers  

OpenAIRE

Green gram is also one of the important pulse crops. Conventional breeding methods are very much difficult to utilize in thedevelopment of new genotypes. Hence incorporation of the molecular approaches along with the conventional techniques ismost powerful method. Evaluation of the available wild accessions are more useful for selecting desirable gene sources.Genetic diversity analysis place an important role in this purpose. For this molecular analysis of selected 18 accessions ingreengram (...

M Pandiyan, N. Senthil

2010-01-01

125

Assessment of Genetic Diversity in Iranian Fennels Using ISSR Markers  

OpenAIRE

Fennel (Foeniculum vulgare Mill.) is an important medicinal plant with used for various purposes in different industries. In this study 25 different ecotypes of fennel from all over Iran were collected and their genetic diversity studied by seven ISSR primers. Seven ISSR primers generated 52 amplified fragments, of which 49 were polymorphic. The highest similarity coefficient among the ecotypes was between Chahestan and Haji abad whereas the minimum similarity coefficient observed between Foz...

Kaivan Bahmani; Ali Izadi-Darbandi; Ali Ashraf Jafari; Seyed Ahmad Sadat Noori; Mostafa Farajpour

2012-01-01

126

GeoChip-Based Analysis of the Functional Gene Diversity and Metabolic Potential of Microbial Communities in Acid Mine Drainage? †  

OpenAIRE

Acid mine drainage (AMD) is an extreme environment, usually with low pH and high concentrations of metals. Although the phylogenetic diversity of AMD microbial communities has been examined extensively, little is known about their functional gene diversity and metabolic potential. In this study, a comprehensive functional gene array (GeoChip 2.0) was used to analyze the functional diversity, composition, structure, and metabolic potential of AMD microbial communities from three copper mines i...

Xie, Jianping; He, Zhili; Liu, Xinxing; Liu, Xueduan; Nostrand, Joy D.; Deng, Ye; Wu, Liyou; Zhou, Jizhong; Qiu, Guanzhou

2010-01-01

127

Microbial diversity at the moderate acidic stage in three different sulfidic mine tailings dumps generating acid mine drainage.  

Science.gov (United States)

In freshly deposited sulfidic mine tailings the pH is alkaline or circumneutral. Due to pyrite or pyrrhotite oxidation the pH is dropping over time to pH values <3 at which acidophilic iron- and sulfur-oxidizing prokaryotes prevail and accelerate the oxidation processes, well described for several mine waste sites. The microbial communities at the moderate acidic stage in mine tailings are only scarcely studied. Here we investigated the microbial diversity via 16S rRNA gene sequence analysis in eight samples (pH range 3.2-6.5) from three different sulfidic mine tailings dumps in Botswana, Germany and Sweden. In total 701 partial 16S rRNA gene sequences revealed a divergent microbial community between the three sites and at different tailings depths. Proteobacteria and Firmicutes were overall the most abundant phyla in the clone libraries. Acidobacteria, Actinobacteria, Bacteroidetes, and Nitrospira occurred less frequently. The found microbial communities were completely different to microbial communities in tailings at

Korehi, Hananeh; Blöthe, Marco; Schippers, Axel

2014-11-01

128

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

Science.gov (United States)

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. PMID:22193366

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

129

Genetic diversity and recombination analysis of sweepoviruses from Brazil  

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Full Text Available Abstract Background Monopartite begomoviruses (genus Begomovirus, family Geminiviridae that infect sweet potato (Ipomoea batatas around the world are known as sweepoviruses. Because sweet potato plants are vegetatively propagated, the accumulation of viruses can become a major constraint for root production. Mixed infections of sweepovirus species and strains can lead to recombination, which may contribute to the generation of new recombinant sweepoviruses. Results This study reports the full genome sequence of 34 sweepoviruses sampled from a sweet potato germplasm bank and commercial fields in Brazil. These sequences were compared with others from public nucleotide sequence databases to provide a comprehensive overview of the genetic diversity and patterns of genetic exchange in sweepoviruses isolated from Brazil, as well as to review the classification and nomenclature of sweepoviruses in accordance with the current guidelines proposed by the Geminiviridae Study Group of the International Committee on Taxonomy of Viruses (ICTV. Co-infections and extensive recombination events were identified in Brazilian sweepoviruses. Analysis of the recombination breakpoints detected within the sweepovirus dataset revealed that most recombination events occurred in the intergenic region (IR and in the middle of the C1 open reading frame (ORF. Conclusions The genetic diversity of sweepoviruses was considerably greater than previously described in Brazil. Moreover, recombination analysis revealed that a genomic exchange is responsible for the emergence of sweepovirus species and strains and provided valuable new information for understanding the diversity and evolution of sweepoviruses.

Albuquerque Leonardo C

2012-10-01

130

DETECTION OF GENETIC DIVERSITY OF TRITICALE BY MICROSATELLITE MARKERS  

Directory of Open Access Journals (Sweden)

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 5 wheat SSR markers. Totally, 35 alleles with an average number of 7 alleles per locus were detected. The highest number of alleles showed out Xbarc 004 (9. Based on the number and frequencies of alleles, the diversity index (DI, the probability of identity (PI and the polymorphic information content (PIC of SSR markers were calculated. The polymorphic information content (PIC ranged from 0.264 to 0.920 with an average of 0.654, which is generally considered sufficient for this purpose. 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 three major clusters. The cultivar Terelland 22 (USA separated as unique one, second subcluster contained 3 cultivars and third one 55 cultivars. It was not possible to differentiate 15 genotypes between each other. For better differentiation it is necessary to use more polymorphic microsatellite markers. Results showed the utility of microsatellite markers for estimation of genetic diversity of triticale genotypes leading to genotype identification.

Andrej Trebichalský

2013-02-01

131

Genetic diversity of Plasmodium vivax in Kolkata, India  

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Full Text Available Abstract Background Plasmodium vivax malaria accounts for approximately 60% of malaria cases in Kolkata, India. There has been limited information on the genotypic polymorphism of P. vivax in this malaria endemic area. Three highly polymorphic and single copy genes were selected for a study of genetic diversity in Kolkata strains. Methods Blood from 151 patients with P. vivax infection diagnosed in Kolkata between April 2003 and September 2004 was genotyped at three polymorphic loci: the P. vivax circumsporozoite protein (pvcs, the merozoite surface protein 1 (pvmsp1 and the merozoite surface protein 3-alpha (pvmsp3-alpha. Results Analysis of these three genetic markers revealed that P. vivax populations in Kolkata are highly diverse. A large number of distinguishable alleles were found from three genetic markers: 11 for pvcs, 35 for pvmsp1 and 37 for pvmsp3-alpha. These were, in general, randomly distributed amongst the isolates. Among the 151 isolates, 142 unique genotypes were detected the commonest genotype at a frequency of less than 2% (3/151. The overall rate of mixed genotype infections was 10.6%. Conclusion These results indicate that the P. vivax parasite population is highly diverse in Kolkata, despite the low level of transmission. The genotyping protocols used in this study may be useful for differentiating re-infection from relapse and recrudescence in studies assessing of malarial drug efficacy in vivax malaria.

Day Nick PJ

2006-08-01

132

Indigenous cattle in Sri Lanka: production systems and genetic diversity  

International Nuclear Information System (INIS)

Production status, farming systems and genetic diversity of indigenous cattle in Sri Lanka were evaluated using six geographically distinct populations. The indigenous cattle population of the country is considered as a nondescript mixture of genotypes, and represents more than half of the total cattle population of 1.2 million heads. Five distinct indigenous populations were investigated for morphological analysis, and four were included in evaluating genetic differences. Farming systems were analysed using a pre-tested structured questionnaire. The genetic variation was assessed within and between populations using 15 autosomal and two Y-specific microsatellite markers, and compared with two indigenous populations from the African region. Farming system analysis revealed that indigenous cattle rearing was based on traditional mixed-crop integration practices and operates under limited or no input basis. The contribution of indigenous cattle to total tangible income ranged from zero to 90% reflecting the high variation in the purpose of keeping. Morphometric measurements explained specific phenotypic characteristics arising from geographical isolation and selective breeding. Though varying according to the region, the compact body, narrow face, small horns and humps with shades of brown and black coat colour described the indigenous cattle phenotype in general. Genetic analysis indicated that indigenous cattle in Sri Lanka have high diversity with average number of ave high diversity with average number of alleles per locus ranging from 7.9 to 8.5. Average heterozygosity of different regions varied within a narrow range (0.72 ± 0.04 to 0.76 ± 0.03). Genetic distances between regions were low (0.085 and 0.066) suggesting a similar mixture of genotypes across regions. Y-specific analysis indicated a possible introgression of Taurine cattle in one of the cattle populations. (author)

133

Microsatellite genetic diversity of Apis mellifera meda skorikov.  

Science.gov (United States)

The genetic diversity of three Iranian honey bee populations (Apis mellifera meda) was studied using morphological and microsatellite loci in south Iran. For this purpose ten morphological characters and five microsatellite loci were studied. Morphometric analysis resulted in a distinct classification of three investigated populations but showed low diversity among them. The grouping results of the diversity study by microsatellite markers were in agreement with the results of morphometry. The cluster analysis showed that the honey bees have clustered together in one group. These populations displayed low variability estimated from both the number of alleles and heterozygosity values. Genetic differentiation within the populations is low and low heterozygosity was also presented between diverse populations. These results indicate the existence of a single population structure. The results of current research confirmed us the previous findings concerning morphological and biochemical indications of uniformity in the honey bee population of the south Iran in spite of the fact that the cities which was studied by us separated from each other by a distance of 500 km. PMID:25103023

Rahimi, Ataollah; Mirmoayedi, Alinaghi; Kahrizi, Danial; Abdolshahi, Rohollah; Kazemi, Elham; Yari, Kheirollah

2014-12-01

134

Could contaminant induced mutations lead to a genetic diversity overestimation?  

Science.gov (United States)

Contaminant driven genetic erosion reported through the inspection of selectable traits can be underestimated using neutral markers. This divergence was previously reported in the aquatic system of an abandoned pyrite mine. The most sensitive genotypes of the microcrustacean cladoceran Daphnia longispina were found to be lacking in the impacted reservoir near the entrance of the metal rich acid mine drainage (AMD). Since that divergence could be, at least partially, accounted for by mutagenicity and genotoxicity of the AMD, the present study aimed at providing such a characterization. The Allium cepa chromosomal aberration assay, using root meristematic cells, was carried out, by exposing seeds to 100, 10, 1, and 0.1 % of the local AMD. Chromosomal aberrations, cell division phases and cell death were quantified after the AMD exposure and after 24 and 48 h recovery periods. The AMD revealed to be mutagenic and genotoxic, even after diluting it to 1 and 0.1 %. Dilutions within this range were previously found to be below the lethality threshold and to elicit sublethal effects on reproduction of locally collected D. longispina clonal lineages Significant mutagenic effects (micronuclei and chromosomal breaks) were also found at 0.1 % AMD, supporting that exposure may induce permanent genetic alterations. Recovery tests showed that AMD genotoxic effects persisted after the exposure. PMID:23686739

Sobral, Olímpia; Marin-Morales, Maria Aparecida; Ribeiro, Rui

2013-07-01

135

Genetic diversity for fermentable carbohydrates production in alfalfa  

Energy Technology Data Exchange (ETDEWEB)

Alfalfa has many attributes that renders it suitable for bioethanol production, including its adaptability to diverse environmental conditions without any need for nitrogen fertilizer. However research is needed to develop biofuel-type alfalfa with improved biomass production and standability, increased persistence, and better cell wall degradability. The ethanol conversion rates from alfalfa biomass could be increased by genetically improving the accumulation of readily fermentable non-structural carbohydrates (NSC). This presentation reported on a screening project where genotypes with superior cell wall degradability were identified. NSC accumulation within 300 genotypes was randomly selected within six genetic backgrounds from Europe and North America. Biochemical analyses of dried stems revealed a large genetic variability for NSC content, with concentrations ranging from 20 to 100 mg per g DW. NSC variability was considerably higher in a genetic background of European origin compared to the other populations, therefore emphasizing the potential for genetic improvement for that trait. A modified commercial enzymatic cocktail known as AcceleraseTM 1000 Genencor is being developed to optimize the degradation of alfalfa biomass. DNA extracted from genotypes with the highest and lowest cell wall degradability or NSC accumulation will be pooled and used for bulk segregant analysis of DNA polymorphisms using the PCR-based sequence-related amplified polymorphism technique. It was concluded that the commercial release of biofuel-type alfalfa can be accelerated if the genetic markers associated with these traits can be identified.

Castonguay, Y.; Bertrand, A.; Duceppe, M.O.; Dube, M.P.; Michaud, R. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

2009-07-01

136

Genetic and functional diversity of propagating cells in glioblastoma.  

Science.gov (United States)

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. PMID:25533637

Piccirillo, Sara G M; Colman, Sue; Potter, Nicola E; van Delft, Frederik W; Lillis, Suzanne; Carnicer, Maria-Jose; Kearney, Lyndal; Watts, Colin; Greaves, Mel

2015-01-13

137

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

Science.gov (United States)

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. PMID:25333358

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

138

Diversity Array Technology Markers: Genetic Diversity Analyses and Linkage Map Construction in Rapeseed (Brassica napus L.)  

OpenAIRE

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 a...

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

2011-01-01

139

Evaluation of genetic diversity and linkage disequilibrium in Korean-bred rice varieties using SSR markers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Background: In order to evaluate the variation among different rice types, the genetic diversity in a rice collection composed by 59 breeding lines, 23 landraces, 18 weedy rice lines, and 35 introduced lines that collected from countries worldwide was analyzed using 134 simple sequence repeat marker [...] s. Results: In total, 1264 alleles were identified (average, 9.43 per locus). Rare alleles made up a large portion (58.4%) of the detected alleles, and 29 unique alleles associated with rice accessions were also discovered. A model-based structural analysis revealed the presence of three subpopulations. The genetic relationships revealed by the neighbour-joining tree method were fairly consistent with the structure-based membership assignments for most of the accessions. A total of 105 accessions (79.5%) showed a clear relationship to each cluster, while the remaining 27 accessions (20.5%) were categorized as admixtures. Linkage disequilibrium (LD) patterns and distributions are of fundamental importance for genome-wide association mapping. The mean r² value for all intrachromosomal loci pairs was 0.1286. The LD between linked markers decreased with the genetic distance between pairs of linked loci. Conclusions: These results will provide an effective aid for future allele mining, association genetics, mapping and cloning gene(s), germplasm conservation, and improvement programs.

Xiao-Qiang, Wang; Soon-Wook, Kwon; Yong-Jin, Park.

2013-09-15

140

Genetic diversity of Qatari date palm using SSR markers.  

Science.gov (United States)

The genetic diversity in the date palm germplasm of 59 female accessions representing 12 cultivars from different locations in Qatar was investigated using 14 loci of simple-sequence repeat (SSR) primers. A total of 94 alleles, with a mean of 6.7 alleles per locus, were scored. The number of alleles per locus varied from 3 (primer mPdCIR090) to 11 (primers mPdCIR010 and mPdCIR015). The amplified SSR band sizes ranged from 104 to 330 bp. The mean gene diversity was 0.66 and ranged from 0.39 (locus mPdCIRO93) to 0.86 (locus mPdCIR015), indicating that the Qatari date palm collection has a high degree of genetic diversity. The heterozygosity ranged from 0 (marker mPdCIR090) to 98% (marker mPdCIR010). Forty-four percent of the variability is explained at the inter-population level, while 56% of the variability is maintained within individuals. However, the loci mPdCIR044, mPdCIR057, mPdCIR090, and mPdCIR093 revealed that the total gene diversity is explained at the inter-population level. The Qatari populations Khalas, Shishi, Barhi, Hillali, Khnaizi, Gar, and Jabri showed significant differentiation compared to all other populations. The average fixation index was 0.24814, showing that about 24.81% of the genetic variation was present among populations, which correlated with analysis of molecular variance. PMID:25867305

Elmeer, K; Mattat, I

2015-01-01

141

Genetic Diversity Among Irrigated Traditional and Modern Rice Germplasm  

Directory of Open Access Journals (Sweden)

Full Text Available Forty five rice genotypes originating from Bangladesh, IRRI (Philippines, Japan and China were evaluated under irrigated ecosystem with a view to finding out genetic divergence for 10 characters including yield. The genotypes were constellated into five distinct groups with the range of three genotypes in cluster V and 16 genotypes in cluster III. The inter-cluster distances were larger than the intra-cluster distances in all cases except in cluster III, suggesting wider genetic diversity among the genotypes of different groups. The intra- cluster distance was highest in cluster III and least in cluster V. Maximum inter- cluster distance was observed between genotypes of cluster I and II followed by cluster I and III; II and IV; III and IV and the minimum was found between genotypes of cluster II and III. Plant height, grains/panicle and yield/hill were mainly responsible for genetic divergence while considering mean values. Though grains/panicle, days to flowering and grain length were positive contributors to genetic diversity based on the latent vectors. Clusters with small intra-cluster distances were considered less diverse than those with large distances. The mean yield, grains/panicle, plant height and days to flowering was lowest in cluster I and therefore, crosses involving the genotypes from this cluster with those from cluster II and III may exhibit high heterosis for earliness and grains/panicle. Crosses could also be made between clusters IV with that of II and III for evolving high yielding and early maturing varieties. Closer affinity of Bangladeshi traditional varieties was observed though some of them were in different clusters. Most of the breeding lines were included in cluster III indicating homogeneity in their pedigree.

Khaleda Akter

2002-01-01

142

Low Genetic Diversity in Melanaphis sacchari Aphid Populations at the Worldwide Scale  

OpenAIRE

Numerous studies have examined the genetic diversity and genetic structure of invading species, with contrasting results concerning the relative roles of genetic diversity and phenotypic plasticity in the success of introduced populations. Increasing evidence shows that asexual lineages of aphids are able to occupy a wide geographical and ecological range of habitats despite low genetic diversity. The anholocyclic aphid Melanaphis sacchari is a pest of sugarcane and sorghum which originated i...

Nibouche, Samuel; Fartek, Benjamin; Mississipi, Stelly; Delatte, He?le?ne; Reynaud, Bernard; Costet, Laurent

2014-01-01

143

Genetic diversity in populations of Erica andevalensis, a vulnerable metallophyte species from the Iberian Peninsula  

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Full Text Available Erica andevalensis is an endemic vulnerable species that grows in metal-polluted soils from the Iberian Pyrite Belt. The genetic diversity of six E. andevalensis populations from Portugal and Spain was studied using PCR Inter-simple sequence repeat (ISSR. The obtained data showed that a there is a very low genetic diversity within the populations from Portugal, and b the populations sampled in Portugal are genetically different from the Spanish populations. The lack of genetic diversity in the Portuguese populations suggests the existence of founder effects and subsequent genetic isolation. Plant genetic diversity was also low in the Spanish populations, although the analysis showed that the studied populations were different among them. A Mantel test of the correlation between genetic and geographic distances was significant evidencing the genetic isolation by distance of the studied populations. The distinctiveness and low genetic diversity of the Portuguse populations emphasizes the importance of taking measures for their conservation.

H. Freitas

2008-11-01

144

Genetic diversity of breeding popcorn lines determined by SSR markers  

Scientific Electronic Library Online (English)

Full Text Available Information about genetic dissimilarity is very important to corroborate genealogical relationships and to predict the most heterozygotic hybrid combinations. Eight popcorn S6 lines of diverse germplasm types were evaluated using simple sequence repeats (SSR) markers. Of a total of 51 evaluated poly [...] morphic primers, 15 were used for polymerase chain reaction (PCR) amplification. The genetic distance was estimated by Rogers’ modified distance. The different popcorn breeding programs in Brazil are possibly using highly similar base-populations. The genetic similarity of lines P1-3 and P8-1 was lowest, while P3-3 and P8-2 were genetically more similar. The cophenetic correlation showed that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was reliable to discriminate the genotypes in five groups. The clusters were consistent with the estimates of genetic identity. There was a moderate coincidence degree between the groups and genealogy of lines. Higher levels of heterozygosity are expected from crosses between the group containing lines P3-3 and P7-3 with that of P1-3 and P7-4. Crosses between lines P1-3 and P8-1 are also promising.

Ana Paula, Ribeiro Trindade; Ronald José, Barth Pinto; Antonio Teixeira do, Amaral Júnior; Claudete Aparecida, Mangolin; Maria de Fátima Pires da, Silva Machado; Carlos Alberto, Scapim.

2010-01-15

145

A GENERAL SURVEY ON FREQUENT PATTERN MINING USING GENETIC ALGORITHM  

OpenAIRE

In recent years, data mining is an important aspect for generating association rules among the large number of itemsets. Association rule mining is one of the techniques in data mining that that has two sub processes. First, the process called as finding frequent itemsets and second process is association rules mining. In this sub process, the rules with the use of frequent itemsets have been extracted. Researchers developed a lot of algorithms for finding frequent itemsets and association ru...

Poornamala, K.; Lawrance, R.

2012-01-01

146

Exploiting a wheat EST database to assess genetic diversity  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Expressed sequence tag (EST) markers have been used to assess variety and genetic diversity in wheat (Triticum aestivum). In this study, 1549 ESTs from wheat infested with yellow rust were used to examine the genetic diversity of six susceptible and resistant wheat cultivars. The aim of using these [...] cultivars was to improve the competitiveness of public wheat breeding programs through the intensive use of modern, particularly marker-assisted, selection technologies. The F2 individuals derived from cultivar crosses were screened for resistance to yellow rust at the seedling stage in greenhouses and adult stage in the field to identify DNA markers genetically linked to resistance. Five hundred and sixty ESTs were assembled into 136 contigs and 989 singletons. BlastX search results showed that 39 (29%) contigs and 96 (10%) singletons were homologous to wheat genes. The database-matched contigs and singletons were assigned to eight functional groups related to protein synthesis, photosynthesis, metabolism and energy, stress proteins, transporter proteins, protein breakdown and recycling, cell growth and division and reactive oxygen scavengers. PCR analyses with primers based on the contigs and singletons showed that the most polymorphic functional categories were photosynthesis (contigs) and metabolism and energy (singletons). EST analysis revealed considerable genetic variability among the Turkish wheat cultivars resistant and susceptible to yellow rust disease and allowed calculation of the mean genetic distance between cultivars, with the greatest similarity (0.725) being between Harmankaya99 and Sönmez2001, and the lowest (0.622) between Aytin98 and Izgi01.

Ozge, Karakas; Filiz, Gurel; Ahu Altinkut, Uncuoglu.

147

Genetic diversity of Chrysoporthe cubensis in eastern and southern Africa  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Chrysoporthe cubensis is an important fungal pathogen of Eucalyptus species worldwide. The fungus is also known on many other hosts, all residing in the order Myrtales. Previous studies have suggested that Chr. cubensis might be native to South America and southeast Asia and that it has been introdu [...] ced into Africa. Recently, surveys have been conducted in eastern and southern Africa to assess the distribution of Chrysoporthe spp. in this region. Chr. cubensis was found on Eucalyptus spp. in Kenya, Malawi and Mozambique. The aim of the study reported here was to determine the genetic diversity of Chr. cubensis populations from these countries. Population diversity studies were conducted using five pairs of microsatellite markers previously developed for Chr. cubensis. Results show that there is a very low genetic diversity within the populations of Chr. cubensis from Kenya, Malawi and Mozambique, implying that the fungus was probably recently introduced in these countries. Based on phylogenetic analyses, the origin of East African Chr. cubensis is most likely Asia.

Grace, Nakabonge; Marieka, Gryzenhout; Brenda D., Wingfield; Michael J., Wingfield; Jolanda, Roux.

2007-06-01

148

Genetic diversity of polysporic isolates of Moniliophthora perniciosa (Tricholomataceae).  

Science.gov (United States)

The causal agent of witches' broom disease, Moniliophthora perniciosa is a hemibiotrophic and endemic fungus of the Amazon basin and the most important cocoa disease in Brazil. The purpose of this study was to analyze the genetic diversity of polysporic isolates of M. perniciosa to evaluate the adaptation of the pathogen from different Brazilian regions and its association with different hosts. Polysporic isolates obtained previously in potato dextrose agar cultures of M. perniciosa from different Brazilian states and different hosts (Theobroma cacao, Solanum cernuum, S. paniculatum, S. lycocarpum, Solanum sp, and others) were analyzed by somatic compatibility grouping where the mycelium interactions were distinguished after 4-8 weeks of confrontation between the different isolates of M. perniciosa based on the precipitation line in the transition zone and by protein electrophoresis through SDS-PAGE. The diversity of polysporic isolates of M. perniciosa was grouped according to geographic proximity and respective hosts. The great genetic diversity of M. perniciosa strains from different Brazilian states and hosts favored adaptation in unusual environments and dissemination at long distances generating new biotypes. PMID:22869076

Ferreira, L F R; Duarte, K M R; Gomes, L H; Carvalho, R S; Leal Junior, G A; Aguiar, M M; Armas, R D; Tavares, F C A

2012-01-01

149

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

Science.gov (United States)

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. PMID:25288994

Lee, Dong Hwan; Kim, Jin-Beom; Lim, Jeong-A; Han, Sang-Wook; Heu, Sunggi

2014-06-01

150

LYGUS GENETICS: INTER- AND INTRASPECIFIC MITOCHONDRIAL GENETIC DIVERSITY IN NORTH AMERICA  

Science.gov (United States)

Mitochondrial DNA (mtDNA) was employed to investigate inter- and intraspecific genetic diversity within the Lygus genus. The main emphasis was on L. lineolaris because it is a widely dispersed species occurring in many regions of North America. Part of the mtDNA cox1 and cox2 gene regions were used ...

151

Estimation of Genetic Diversity in Genetic Stocks of Hexaploid Wheat Using Seed Storage Proteins  

Directory of Open Access Journals (Sweden)

Full Text Available Bread wheat (Triticum aestivum L. is an allohexaploid specie, consist of three genomes AABBDD having 2n = 6x = 42 chromosomes. The wheat is a staple food of human beings due to its bread making quality which is composed of seed storage proteins of wheat especially High Molecular Weight Glutenins (HMW-GS. During present research, HMW-GS were analyzed in genetic stocks of common wheat consist of Nullisomic- tetrasomic, ditelosomic and deletion lines of group 3 homoeologous chromosomes by Sodium Dodecyle Sulpahate Polyacrylamide Gel Electrophoresis (SDS-PAGE. Protocol for protein extraction and separation was optimized. The protein profiles were used to estimate genetic distances and Phylogenetic relationships among the genetic stocks were evaluated. Genetic stocks showed different banding patterns and each protein band was considered as a locus/allele. Alleles were scored as present (1 and absent (0 to generate bivariate 1-0 data matrix. A total of 45 alleles were amplified. Genetic distance among the genetic stocks ranged from 0-72%. A dendrogram was constructed using computer program Pop Gene version 3.2. Genetic stocks of wheat were clustered in 3group A, B and C comprising 4, 4 and 1 genotypes, respectively. Maximum differences were observed among Dit-3BS and NT-3B3D and hence it is recommended that these 2 genetic stocks should be crossed to obtain maximum genetic diversity in the segregating population of wheat.

Tanweer Kumar

2014-07-01

152

Web Log Mining Based-on Improved Double-Points Crossover Genetic Algorithm  

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Full Text Available Web log files have become important data source for discoveries of user behaviors. Analyzing web log files is one of the significant research fields of web mining. This paper proposes an improved double-points crossover genetic algorithm for mining user access patterns from web log files. Our work contains three different components. First, we design a coding rule according to pre-processed web log data. Second, a fitness function is presented by analyzing user sessions. Finally, a new genetic algorithm based on double-points crossover genetic algorithm is designed. In comparison with simple genetic algorithm, double-points crossover genetic algorithm demonstrates better convergence than the other, and it is more suitable for web log mining. We conducted an experiment to verify the effectiveness of the proposed algorithm. The results show that the proposed algorithm helps the website to easily gain access patterns.

Jin Xie

2014-06-01

153

Genetic diversity and relationships of Vietnamese and European pig breeds  

International Nuclear Information System (INIS)

Full text: East Asia contains more than 50% of the world's pig population and Europe about 30% (according to FAO inventory. Both indigenous resources were domesticated from different sub-species and are assumed to be the basis of the world-wide genetic diversity in pig. Indigenous resources of Asia, however, are less defined and only rarely compared with European breeds. Taking advantage of DNA diagnostics, animals within as well as between breeds from Vietnam and Europe were analysed for numerous well defined markers in order to gain more knowledge about pig genetic biodiversity. The main objective was to investigate indigenous Vietnamese pig breeds from different local geographic regions. A set of pig breeds was chosen for this study of genetic diversity: five indigenous breeds from Vietnam (Mong Cai, Muong Khuong, Co, Meo, Tap Na), two exotic breeds kept in Vietnam (Large White, Landrace), three European commercial breeds (Pietrain, Landrace, Large White), and European Wild Boar. Samples and data from 317 animals (17 to 32 unrelated animals per breed) were collected. A panel of 27 polymorphic microsatellite loci was chosen according to FAO recommendations for diversity analyses and genetic distance studies. The loci were distributed evenly over the porcine genome with additional loci linked to immunological relevant genes (MHC, IFNG). Moreover, a few Type I loci (RYR1, FSH) were genotyped. DNA was isolated and PCR fragment lengths analysis were carried out on an ALlengths analysis were carried out on an ALF DNA sequencer (Pharmacia, Freiburg, Germany). Some of the RFLPs were analysed by agarose gel electrophoresis. Selected microsatellite alleles of equal lengths were sequenced for animals of different breeds. Within-breed diversity estimated heterozygosities and tests for Hardy-Weinberg equilibrium by taking into account sample sizes, tests per locus and breed as well as breed-locus combinations. Calculations were performed using the BIOSYS-1 software package. Breed differentiation was evaluated by the fixation indices of Wright. Genetic distances between breeds were estimated on the basis of allelic frequencies of the loci in each breed using different measures, e.g the standard Nei's distances. Distances between breeds were further analysed according to the neighbour-joining algorithm of Nei and the bootstrapping procedure of Felsenstein. In average of the marker loci, heterozygous genotypes occurred more frequently than expected, but this was, not statistically significant. Heterozygosity was higher in indigenous Vietnamese breeds than in the other breeds. Breed differentiation was shown which allowed grouping of all individuals in clusters corresponding to the breeds. Herein the Vietnamese indigenous breeds form a distinct cluster with considerable genetic distance to the European breeds. Vietnamese exotic breeds were similar to the breeds in Europe. European Wild Boar displayed closer relation with commercial breeds of European origin than with the indigenous Vietnamese breeds. The microsatellite loci which are closely linked to functional genes of immune response showed differences between breeds. This finding may indicate adaptation to local geographic conditions. Type I loci revealed considerable differences between Vietnamese and European breeds which are partly due to breeding influences. The comparative DNA sequencing showed differences between microsatellite alleles of equal lengths. About 30% of these alleles displayed length independent variants in at least one nucleotide position. Between the genetic diverse breeds, like those from Vietnam and Europe, DNA sequences between alleles differed more often. Their relevance is discussed in view of the use of microsatellite polymorphisms. (author)

154

Genetics, Genomics and Evolution of Ergot Alkaloid Diversity  

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Full Text Available The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization. The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine.

Carolyn A. Young

2015-04-01

155

Genome instability: does genetic diversity amplification drive tumorigenesis?  

Science.gov (United States)

Recent data show that catastrophic events during one cell cycle can cause massive genome damage producing viable clones with unstable genomes. This is in contrast with the traditional view that tumorigenesis requires a long-term process in which mutations gradually accumulate over decades. These sudden events are likely to result in a large increase in genomic diversity within a relatively short time, providing the opportunity for selective advantages to be gained by a subset of cells within a population. This genetic diversity amplification, arising from a single aberrant cell cycle, may drive a population conversion from benign to malignant. However, there is likely a period of relative genome stability during the clonal expansion of tumors - this may provide an opportunity for therapeutic intervention, especially if mechanisms that limit tolerance of aneuploidy are exploited. PMID:22948965

Lane, Andrew B; Clarke, Duncan J

2012-11-01

156

Genetic diversity of water use efficiency in Jerusalem artichoke (Helianthus tuberosus L.) germplasm  

Science.gov (United States)

Genetic diversity in crop germplasm is an important resource for crop improvement, but information on genetic diversity is rare for Jerusalem artichoke, especially for traits related to water use efficiency. The objectives of this study were to investigate genetic variations for water use and water...

157

Genetic diversity in Brazilian tall coconut populations by microsatellite markers  

OpenAIRE

The tall coconut palm was introduced in Brazil in 1553, originating from the island of Cape Verde. The aim of the presentstudy was to evaluate the genetic diversity of ten populations of Brazilian tall coconut by 13 microsatellite markers. Samples werecollected from 195 individuals of 10 different populations. A total of 68 alleles were detected, with an average of 5.23 alleles perlocus. The mean expected and observed heterozygosity value was 0.459 and 0.443, respectively. The number of allel...

Francisco Elias Ribeiro; Luc Baudouin; Patricia Lebrun; Lázaro José Chaves; Claudio Brondani; Emiliano Fernandes Nassau Costa; Roland Vencovsky

2013-01-01

158

Studies on genetic diversity in redgram genotypes using rapd markers  

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Full Text Available Genetic diversity was estimated among fifteen genotypes of redgram using 30 RAPD primers. A total of 172 RAPD amplicons were obtained; of which 114(66% were polymorphic. The present polymorphism ranged from 25 to 100 per cent. A wide range (18.0 to 95.2% of Jaccard's similarity coefficient was observed between the pairs of genotypes. A dendrogram constructed based on the UPGMA clustering method revealed two major clusters. Among the 15 genotypes LRG-30 was found in separate cluster (cluster I, while all other genotypes grouped into other major cluster (cluster II indicating a distinct background of this genotype

K. C. Chandana, L. Prasanthi, M. Reddi Sekhar and B. V. Bhaskara Reddy

2013-09-01

159

Genetic diversity Genetic diversity pattern in finger millet [Eleusine coracana (L. Gaertn  

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Full Text Available The genetic distance for 41 genotypes of finger millet collected from different geographical areas was estimated using D2 statistics. These genotypes were grouped into seven clusters. Cluster II, I, V, VI, and III comprised 17, 10, 7, 3 and 2 genotypes, respectively. The clusters IV and VII were mono-genotypic indicating wide divergence from other clusters. Most of the strains were from same origin and found to be one or more components of seven clusters indicating the presence of wide genetic variability among the material belonging to same geographical origin. The highest inter-cluster distance was observed between clusters II and VII followed by IV and VII suggesting the use of genotypes from these clusters to serve as potential parents for hybridization. The characters iron content (70.12% contributed maximum towards divergence followed by plant height (11.72% , days to physiological maturity (7.07% and days to 50% flowering (5.49%.

S. R. Shinde, S. V. Desai, and R. M. Pawar

2013-09-01

160

Genetic diversity Genetic diversity pattern in finger millet [Eleusine coracana (L.) Gaertn  

OpenAIRE

The genetic distance for 41 genotypes of finger millet collected from different geographical areas was estimated using D2 statistics. These genotypes were grouped into seven clusters. Cluster II, I, V, VI, and III comprised 17, 10, 7, 3 and 2 genotypes, respectively. The clusters IV and VII were mono-genotypic indicating wide divergence from other clusters. Most of the strains were from same origin and found to be one or more components of seven clusters indicating the presence of wide geneti...

S R Shinde, S. V. Desai

2013-01-01

161

Genetic diversity among and within cultured cyanobionts of diverse species of Azolla.  

Science.gov (United States)

The cyanobionts isolated from 10 Azolla accessions belonging to 6 species (Azolla mexicana, A. microphylla, A. rubra, A. caroliniana, A. filiculoides, A. pinnata) were cultured under laboratory conditions and analyzed on the basis of whole cell protein profiles and molecular marker dataset generated using repeat sequence primers (STRR(mod) and HipTG). The biochemical and molecular marker profiles of the cyanobionts were compared with those of the free-living cyanobacteria and symbiotic Nostoc strains from Anthoceros sp., Cycas sp. and Gunnera monoika. Cluster analysis revealed the genetic diversity among the selected strains, and identified 3 distinct clusters. Group 1 included cyanobionts from all the 10 accessions of Azolla, group 2 comprised all the symbiotic Nostoc strains, while group 3 included the free-living cyanobacteria belonging to the genera Nostoc and Anabaena. The interrelationships among the Azolla cyanobionts were further revealed by principal component analysis. Cyanobionts from A. caroliniana-A. microphylla grouped together while cyanobionts associated with A. mexicana-A. filiculoides along with A. pinnata formed another group. A. rubra cyanobionts had intermediate relationship with both the subgroups. This is the first study analyzing the diversity existing among the cultured cyanobionts of diverse Azolla species through the use of biochemical and molecular profiles and also the genetic distinctness of these free-living cyanobionts as compared to cyanobacterial strains of the genera Anabaena and Nostoc. PMID:18481216

Sood, A; Prasanna, R; Prasanna, B M; Singh, P K

2008-01-01

162

Molecular genetic diversity in populations of the stingless bee Plebeia remota: A case study  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Genetic diversity is a major component of the biological diversity of an ecosystem. The survival of a population may be seriously threatened if its genetic diversity values are low. In this work, we measured the genetic diversity of the stingless bee Plebeia remota based on molecular data obtained b [...] y analyzing 15 microsatellite loci and sequencing two mitochondrial genes. Population structure and genetic diversity differed depending on the molecular marker analyzed: microsatellites showed low population structure and moderate to high genetic diversity, while mitochondrial DNA (mtDNA) showed high population structure and low diversity in three populations. Queen philopatry and male dispersal behavior are discussed as the main reasons for these findings.

Flávio de Oliveira, Francisco; Leandro Rodrigues, Santiago; Maria Cristina, Arias.

163

Bioprospecting at former mining sites across Europe: microbial and functional diversity in soils.  

Science.gov (United States)

The planetary importance of microbial function requires urgently that our knowledge and our exploitation ability is extended, therefore every occasion of bioprospecting is welcome. In this work, bioprospecting is presented from the perspective of the UMBRELLA project, whose main goal was to develop an integral approach for remediation of soil influenced by mining activity, by using microorganisms in association with plants. Accordingly, this work relies on the cultivable fraction of microbial biodiversity, native to six mining sites across Europe, different for geographical, climatic and geochemical characteristics but similar for suffering from chronic stress. The comparative analysis of the soil functional diversity, resulting from the metabolic profiling at community level (BIOLOG ECOPlates) and confirmed by the multivariate analysis, separates the six soils in two clusters, identifying soils characterised by low functional diversity and low metabolic activity. The microbial biodiversity falls into four major bacterial phyla: Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes, including a total of 47 genera and 99 species. In each soil, despite harsh conditions, metabolic capacity of nitrogen fixation and plant growth promotion were quite widespread, and most of the strains showed multiple resistances to heavy metals. At species-level, Shannon's index (alpha diversity) and Sørensen's Similarity (beta diversity) indicates the sites are indeed diverse. Multivariate analysis of soil chemical factors and biodiversity identifies for each soil well-discriminating chemical factors and species, supporting the assumption that cultured biodiversity from the six mining sites presents, at phylum level, a convergence correlated to soil factors rather than to geographical factors while, at species level, reflects a remarkable local characterisation. PMID:23775004

Sprocati, Anna Rosa; Alisi, Chiara; Tasso, Flavia; Fiore, Alessia; Marconi, Paola; Langella, Francesca; Haferburg, Götz; Nicoara, Andrei; Neagoe, Aurora; Kothe, Erika

2014-06-01

164

Genetic diversity in a world germplasm collection of tall fescue  

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Full Text Available Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous. In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 countries, including 28 accessions of INTA (Argentina, by analyzing 15 polymorphic SSR markers by capillary electrophoresis. These molecular markers allowed us to detect a total of 214 alleles. The number of alleles per locus varied between 5 and 24, and the values of polymorphic information content ranged from 0.627 to 0.840. In addition, the accessions analyzed by flow cytometry showed different ploidy levels (diploid, tetraploid, hexaploid and octaploid, placing in evidence that the world germplasm collection consisted of multiple species, as previously suggested. Interestingly, almost all accessions of INTA germplasm collection were true hexaploid tall fescue, belonging to two eco-geographic races (Continental and Mediterranean. Finally, the data presented revealed an ample genetic diversity of tall fescue showing the importance of preserving the INTA collection for future breeding programs.

Romina Cuyeu

2013-01-01

165

Genetic diversity in a world germplasm collection of tall fescue  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their [...] rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous). In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 countries, including 28 accessions of INTA (Argentina), by analyzing 15 polymorphic SSR markers by capillary electrophoresis. These molecular markers allowed us to detect a total of 214 alleles. The number of alleles per locus varied between 5 and 24, and the values of polymorphic information content ranged from 0.627 to 0.840. In addition, the accessions analyzed by flow cytometry showed different ploidy levels (diploid, tetraploid, hexaploid and octaploid), placing in evidence that the world germplasm collection consisted of multiple species, as previously suggested. Interestingly, almost all accessions of INTA germplasm collection were true hexaploid tall fescue, belonging to two eco-geographic races (Continental and Mediterranean). Finally, the data presented revealed an ample genetic diversity of tall fescue showing the importance of preserving the INTA collection for future breeding programs.

Romina, Cuyeu; Beatriz, Rosso; Elba, Pagano; Gabriela, Soto; Romina, Fox; Nicolás Daniel, Ayub.

166

Genetic diversity in a world germplasm collection of tall fescue.  

Science.gov (United States)

Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous). In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 countries, including 28 accessions of INTA (Argentina), by analyzing 15 polymorphic SSR markers by capillary electrophoresis. These molecular markers allowed us to detect a total of 214 alleles. The number of alleles per locus varied between 5 and 24, and the values of polymorphic information content ranged from 0.627 to 0.840. In addition, the accessions analyzed by flow cytometry showed different ploidy levels (diploid, tetraploid, hexaploid and octaploid), placing in evidence that the world germplasm collection consisted of multiple species, as previously suggested. Interestingly, almost all accessions of INTA germplasm collection were true hexaploid tall fescue, belonging to two eco-geographic races (Continental and Mediterranean). Finally, the data presented revealed an ample genetic diversity of tall fescue showing the importance of preserving the INTA collection for future breeding programs. PMID:23885206

Cuyeu, Romina; Rosso, Beatriz; Pagano, Elba; Soto, Gabriela; Fox, Romina; Ayub, Nicolás Daniel

2013-07-01

167

On the Biological and Genetic Diversity in Neospora caninum  

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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.

John T. Ellis

2010-03-01

168

Genetic Diversity in Bread Wheat (Triticum aestivum L. Genotypes  

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Full Text Available Wheat is one most important cereal crops grown in Ethiopia. Yet, keeping in view insufficient information on exotic bread wheat genotypes is limiting the access to useful traits present among the genotypes in the Somali region of Ethiopia. The aim of the study was to assess the extent of genetic diversity among bread wheat genotypes. Twenty six bread wheat (Triticum aestivum L. genotypes obtained from ICARDA-CIMMYT were tested at Gode and Kelafo research sites at three cropping seasons (2009/10, 2010/11 and 2011/12 under irrigation. The experiment was conducted in randomized complete block design with three replications. Ten agronomic traits were included in the study. The mean values, ranges and the coefficient of variation of the 10 characters indicated the existence of sufficient variability among genotypes. Multivariate techniques were used to classify 26 bread wheat genotypes. Principal component analysis showed that the first six principal components explained about 91.87% of the total variation. D2 analysis showed the 26 bread wheat genotypes grouped into six clusters. This made to become moderate diversity among the genotypes. The crosses between genotypes selected from cluster-III with cluster-VI and cluster V with cluster VI are expected to produce better genetic recombination and segregation in their progenies. Therefore, these bread wheat genotypes need to be crossed and selected to develop high yielding pure line variety.

S. Alamerew

2013-01-01

169

A Survey of Association Rule Mining Using Genetic Algorithm  

OpenAIRE

Data mining is the analysis step of the "Knowledge Discovery in Databases" process, or KDD. It is the process that results in the discovery of new patterns in large data sets. It utilizes methods at the intersection of artificial intelligence, machine learning, statistics, and database systems. The overall goal of the data mining process is to extract knowledge from an existing data set and transform it into a human-understandable structure. In data mining, association rule learning is a popu...

Anubha Sharma

2012-01-01

170

Relationship of genetic diversity and niche centrality: a survey and analysis.  

Science.gov (United States)

The distribution of genetic diversity within and among populations in relation to species' geographic ranges is important to understanding processes of evolution, speciation, and biogeography. One hypothesis predicts that natural populations at geographic range margins will have lower genetic diversity relative to those located centrally in species' distributions owing to a link between geographic and environmental marginality; alternatively, genetic variation may be unrelated with geographic marginality via decoupling of geographic and environmental marginality. We investigate the predictivity of geographic patterns of genetic variation based on geographic and environmental marginality using published genetic diversity data for 40 species (insects, plants, birds, mammals, worms). Only about half of species showed positive relationships between geographic and environmental marginality. Three analyses (sign test, multiple linear regression, and meta-analysis of correlation effect sizes) showed a negative relationship between genetic diversity and distance to environmental niche centroid, but no consistent relationship of genetic diversity with distance to geographic range center. PMID:24372193

Lira-Noriega, Andrés; Manthey, Joseph D

2014-04-01

171

USE OF SEQUENCE-BASED POLYMORPHISMS FOR STUDING GENETIC DIVERSITY OF WINTER SQUASH  

Science.gov (United States)

Germplasm conservation of facilities require an accurate understanding of the patterns of genetic diversity within and among accessions (unique populations) that comprise germplasm collections and the ecogeographical patterns of this diversity. This information facilitates the efficient management o...

172

Genetic diversity among five T4-like bacteriophages  

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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-like phages harbour a wealth of genetic material that has not been identified previously. The mechanisms by which these genes may have arisen may differ from those previously proposed for the evolution of other bacteriophage genomes.

Bertrand Claire

2006-05-01

173

[Temporal evolution of the genetic diversity of Chaerophyllum bulbosum: consequences on the genetic resources management].  

Science.gov (United States)

To increase the germplasm necessary for varietal improvement of tuberous-rooted chervil, a food apiaceae of increasing importance, two successive surveys of wild populations were carried out in Germany, in the Rhine and the Weser River basins. These mainly riparian populations are likely to be shaped by changes in hydrographic networks that characterize their habitat. Molecular studies have shown a strong structuration between wild populations (GST?32%), but did not reveal any structuring effect of the hydrographic network on diversity or any global phenomenon of genetic erosion. A discussion about the strategy for maintaining the diversity of this species on a long-term period is proposed. PMID:24841963

Le Clerc, Valérie; Suel, Anita; Geoffriau, Emmanuel; Huet, Sébastien; Briard, Mathilde

2014-05-01

174

Genetic Diversity Analysis of Lates calcarifer (Bloch 1790) in Captive and Wild Populations Using RAPD Markers  

OpenAIRE

Lates calcarifer (Bloch 1790) is one of the major economically important cultivable fish species in India. In this study, three populations of L. calcarifer was selected to assess the genetic diversity. Of which, two wild (Mudaslodai, Muthupettai) and one captive (Mutukadu) population. The genetic diversity of three populations of this species was studied using Random Amplified Polymorphic DNA (RAPD) markers. Ten random primers were used for the assessment of their genetic diversity and const...

Subburaj, Jayachandran; Muthazhagan, Kaliyan; Thangaraj, Muthusamy; Barathkumar, Thathiredypalli R.; Rajasekar, Muthusamy

2012-01-01

175

Genetic diversity and relationships among indigenous Mozambican cattle breeds  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english Three indigenous Mozambican cattle breeds, namely the Angone, Landim and Bovino de Tete were characterized using six proteins, 13 autosomal microsatellite loci and one Y-specific microsatellite locus (INRA124). The Mashona breed from Zimbabwe was also studied to elucidate the origin of the Bovino de [...] Tete cattle. Expected mean heterozygosity ranged from 0.46 - 0.50 in the proteins and from 0.66 - 0.69 in the microsatellites. Population genetic variability was relatively high when compared to other African breeds. Only 4.5% of the total genetic variation could be attributed to the differences among the breeds. D A genetic distances and principal component analysis suggest that Mozambican breeds occupy an intermediate position between Indian Zebu and African taurine cattle. The genetic contribution from Indian Zebu, estimated by mR and average percentage of Zebu diagnostic alleles, was highest in the Angone breed and lowest in the Landim breed. The indicine Y-specific allele was fixed in the Angone breed (classified as Zebu), was found in 62% of the Bovino de Tete breed and was absent in the Landim breed (classified as Sanga). The hybrid nature of these breeds was also revealed by using an admixture model to infer population structure. Cluster analysis correctly assigned individuals to their rightful populations with probabilities ranging from 0.96 to 0.98, using prior population information. The results support the hypothesis of the Bovino de Tete cattle being a result of crossbreeding between Sanga and Zebu breeds. This study presents the first extensive information on the genetic diversity and relationships among Mozambican cattle breeds and with other breeds from different continents.

I., Bessa; I., Pinheiro; M., Matola; K., Dzama; A., Rocha; P., Alexandrino.

2009-01-01

176

Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population  

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Full Text Available 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 FIS-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 Tangjiahe 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].

Jiandong YANG, Zhihe ZHANG, Fujun SHEN, Xuyu YANG, Liang ZHANG, Limin CHEN, Wenping ZHANG, Qing ZHU, Rong HOU

2011-12-01

177

Genetic diversity and population structure of American Red Angus cattle.  

Science.gov (United States)

The objective of this study was to characterize the population structure and genetic diversity of registered American Red Angus cattle. Inbreeding and average relationship coefficients, effective population size, effective number of founders, and effective number of herds supplying grandparents to the population were calculated from the recorded pedigree. Inbreeding in 1960 was 10.7% and decreased until 1974 at a rate of 0.2% per year, whereas in 1975 inbreeding was 3.2% and increased until 2005 at a rate of 0.02% per year. The numerator relationship coefficients of the 10 individual paternal grandsires (PGS; sires of sires), paternal granddams (PGD; dams of sires), maternal grandsires (MGS; sires of dams), and maternal granddams (MGD; dams of dams) that had the greatest number of registered grandprogeny, with all other registered animals, increased with their birth year from 1960 on. Average numerator relationships of these with all other PGS, PGD, MGS, MGD, bulls, and sires were greater for paternal (PGS, PGD) than maternal (MGS, MGD) pathways. The effective population size was 445, with 649 effective founders. The effective numbers of herds supplying PGS, PGD, MGS, and MGD were 435, 369, 453, and 459, respectively. Inbreeding is at a low level and the effective population size is large. The effective number of founders and effective number of herds supplying grandparents is small in relation to the total number of animals and herds, indicating the disproportionate influence of a few founders and herds on the genetics of the breed. The calculated parameters indicate satisfactory genetic diversity in American Red Angus cattle. PMID:19783699

Márquez, G C; Speidel, S E; Enns, R M; Garrick, D J

2010-01-01

178

Late Quaternary loss of genetic diversity in muskox (Ovibos  

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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.

Mol Dick

2005-10-01

179

EFFECTS OF CHEMICAL CONTAMINANTS ON GENETIC DIVERSITY IN NATURAL POPULATIONS: IMPLICATIONS FOR BIOMONITORING AND ECOTOXICOLOGY  

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The conservation of genetic diversity has emerged as one of the central issues in conservation biology. Although researchers in the areas of evolutionary biology, population management, and conservation biology routinely investigate genetic variability in natural populations, onl...

180

Indigenous cattle in Sri Lanka: Production systems and genetic diversity  

International Nuclear Information System (INIS)

Full text: The production status, farming systems and genetic diversity of indigenous cattle in Sri Lanka were evaluated using six geographically distinct populations in Sri Lanka, which is a small island located below the southern tip of Indian subcontinent. The indigenous cattle population of the country is considered as a non-descript type mixture of genotypes, and represent more than the half of total cattle population of 1.2 million heads. Six distinct indigenous populations (NE, NC, So, No, TK and Th) were investigated for morphological and genetic differences. The respective farming systems were also evaluated to complete the requirement in developing conservation and utilization strategies. The sampling was carried out based on the non-existence of artificial insemination facilities to assure the target populations are indigenous. The six populations were assumed genetically isolated from each other in the absence of nomadic pattern of rearing and regular cattle migration. The farming systems were analyzed using a pre-tested structured questionnaire by single visits to each location. Single visits were practiced, as there is no variation in farming system according to the period of the year. Morphometric measurements were taken during the visit and the genetic variation was assessed within and between five populations using 15 autosomal and two Y-specific microsatellite markers. The farming system analysis revealed that indigenous cattle are reared as a traditt indigenous cattle are reared as a traditional practice in all the regions of the country under limited or no input situations. Since the low productivity masks its real contribution to the rural livelihood, the level of utilization was confounded within the attributes of respective farming systems. The contribution of indigenous cattle to total tangible income ranged from 0% to 90% in different regions reflecting the high variation in the purpose of keeping indigenous cattle. Integration with crop, especially with paddy was the common feature in systems across the regions. Morphometric measurements identified the specific phenotypic characteristics resulted by geographical isolation and selective breeding. Though vary according to the regional preferences, the compact body, narrow face, small horns and humps with shades of brown and black coat colour described the indigenous cattle phenotype in general. The diversity analysis based on microsatellite genotyping indicated that indigenous cattle in Sri Lanka has a high genetic diversity with average number of alleles per locus ranging from 7.9 to 8.5. Average heterozygosity of different regions varied within a narrow range (0.72 ± 0.04 to 0.76 ± 0.03). The genetic distances (DA) between regions were low (ranged between 0.085 and 0.066) suggesting a similar mixture of genotypes across regions despite the geographical isolation. However, two genetic clusters were visible though no relationship of those clusters with the geographical distribution of different regions could be observed. Introgression of taurine cattle was evidenced in one of the cattle populations (NC) as suggested by the Y-specific microsatellite analysis (author)

181

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

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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 quantitative trait loci (QTL) with small effects, which will aid in dissecting complex traits and in exploiting the rich diversity present in rice germplasm. PMID:20364375

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

2010-08-01

182

Genetic diversity revealed by AFLP markers in Albanian goat breeds  

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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.

Hoda Anila

2012-01-01

183

[Genetic diversity of microsatellite loci in captive Amur tigers].  

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The tiger is one of the most threatened wildlife species since the abundance and distribution of tiger have decreased dramatically in the last century. The wild Amur tiger (Panthera tigris altaica) only distributed in northeast China, the far east area of Russia and the north Korea and its size of wild population is about 450 in the world and 20 in China. Several hundred captive populations of Amur tigers are the main source to protect gene library of tiger and the source of recovering the wild populations. The Breeding Center for Felidae at Hengdaohezi and Haoerbin Tiger Park in Heilongjiang Province is the biggest captive breeding base in China. How to make clear the genetic pedigree and establish reasonable breeding system is the urgent issues. So we use the microsatellite DNA markers and non-invasive technology to research on the genetic diversity of captive Amur tiger in this study. Ten microsatellite loci (Fca005, Fca075, Fca094, Fca152, Fca161, Fca294, Pti002, Pti003, Pti007 and Pti010), highly variable nuclear markers, were studied their genetic diversity in 113 captive Amur tigers. The PCR amplified products of microsatellite loci were detected by non-denatured polyacrylamide gel electrophoresis. Allele numbers, allelic frequency, gene heterozygosity(H(e)), polymorphism information content(PIC) and effective number of allele(N(e)) were calculated. 41 alleles were found and their size were ranged from 110bp to 250bp in ten microsatellite loci, Fca152 had 6 alleles, Fca075, Fca094 and Fca294 had 5 alleles, Fca005 and Pti002 had 4 alleles and the others had 3 alleles in all tiger samples, respectively. The allelic frequencies were from 0.009 to 0.767; The He ranged from 0.385 to 0.707, and Fca294 and Pti010 locus had the highest and lowest value; the PIC were from 0.353 to 0.658, Fca294 and Pti010 locus had the highest and lowest value; and N(e) were from 1.626 to 3.409, Fca294 and Pti010 locus had the highest and lowest value, which showed the ten microsatellie loci had high or medium polymorphism in these Amur tigers and had high genetic diversity. At the same time, we only found even bases variability which showed the even bases repeat sequence (CA/GT) maybe the basic unit for length variability of microsatellite in all loci. In this study, the samples were made up of 75 hair specimens, 23 blood specimens and 15 tissue specimens, we obtained the genome DNA from hairs using the non-invasive DNA technology and demonstrated that DNA derived from hair samples is as good as that obtained from blood samples for the analysis of microsatellite polymorphism. These results imply that microsatellite DNA markers and non-invasive DNA technology can help study the genetic diversity of Amur tiger. This method could be used in the captive management of other endangered species. PMID:15640074

Zhang, Yu-Gaung; Li, Di-Qiang; Xiao, Qi-Ming; Rao, Li-Qun; Zhang, Xue-Wen

2004-09-01

184

A nonlinear relationship between genetic diversity and productivity in a polyphagous seed beetle.  

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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. PMID:24535057

Burls, K J; Shapiro, J; Forister, M L; Hoelzer, G A

2014-05-01

185

Concordance between genetic and species diversity in coral reef fishes across the Pacific Ocean biodiversity gradient.  

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The relationship between genetic diversity and species diversity provides insights into biogeography and historic patterns of evolution and is critical for developing contemporary strategies for biodiversity conservation. Although concordant large-scale clines in genetic and species diversity have been described for terrestrial organisms, whether these parameters co-vary in marine species remains largely unknown. We examined patterns of genetic diversity for 11 coral reef fish species sampled at three locations across the Pacific Ocean species diversity gradient (Australia: ?1600 species; New Caledonia: ?1400 species; French Polynesia: ?800 species). Combined genetic diversity for all 11 species paralleled the decline in species diversity from West to East, with French Polynesia exhibiting lowest total haplotype and nucleotide diversities. Haplotype diversity consistently declined toward French Polynesia in all and nucleotide diversity in the majority of species. The French Polynesian population of most species also exhibited significant genetic differentiation from populations in the West Pacific. A number of factors may have contributed to the general positive correlation between genetic and species diversity, including location and time of species origin, vicariance events, reduced gene flow with increasing isolation, and decreasing habitat area from West to East. However, isolation and habitat area, resulting in reduced population size, are likely to be the most influential. PMID:23206145

Messmer, Vanessa; Jones, Geoffrey P; Munday, Philip L; Planes, Serge

2012-12-01

186

Genetic diversity of six populations of red hybrid tilapia, using microsatellites genetic markers  

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Full Text Available Objective. To determine and evaluate the genetic diversity of six populations of red hybrid tilapia, with the purpose to assess the potential benefit of a future breeding program conducted at the Research Center for Aquaculture (Ceniacua, Colombia. Material and methods. A total of 300 individuals, representing a wide genetic variability, were genotyped using a fluorescent microsatellite marker set of 5 gene-based SSRs in 6 different farms belonging to 4 States of Colombia. Results. The result showed that the mean number of alleles per locus per population was 8.367. The population 5 had the highest mean number of alleles with 9.6 alleles, followed by population 4 with 9.4 alleles, population 2 with 9.2, population 3 with 8.0, population 1 with 7.2 and population 6 with 6.8 alleles. The analysis of the distribution of genetic variation was (17.32% among population, while among individuals within populations was (28.55% and within individuals was high (54.12%. The standard diversity indices showed that population 4 was the more variable (mean He=0.837 followed by population 1 (mean He=0.728, population 3 (mean He=0.721, population 5 (mean He=0.705, population 2 (mean He=0.690, population 6 (mean He=0.586. Highly significant deviations from Hardy–Weinberg, exhibited all of the populations, mostly due to deficits of heterozygotes. Genotype frequencies at loci UNH 106 of population 5 and loci UNH 172 of population 6 were Hardy-Weinberg equilibrium (HWE. Conclusions. The results of this study, contribute to the genetic breeding program of Tilapia, conduced by the Research Center for Aquaculture. The Fst distance showed that the samples are differentiated genetically and it is possible to use at the beginning of the genetic program. However, it is recommended to introduce others individuals to the crossbreeding program.

Boris Briñez R.

2011-05-01

187

Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality  

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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.

Angela R. Piergiovanni

2010-05-01

188

Genetic diversity of flavonoid content in leaf of hawthorn resources  

International Nuclear Information System (INIS)

Hawthorn (Cratageus spp.) are important medicinal plants. Flavonoids are the main active ingredient in hawthorn. With the help of hawthorn leaf flavonoids efficient detection system, vitexin, rhamnosylvitexin, hyperin, rutin and quercetin of 122 hawthorn resources was precisely measured.The flavonoid contents of 10 hawthorn species were explicited. The comparation of flavonoids revealed the abundant genetic diversity of hawthorn flavones. Large variable coefficient has been observed among 5 flavonoid monomer traits. The coefficients of variation were 44.17%, 132.2%, 157.08%, 113.91% and 31.05 for Vitexin, Rhamnosylvitexin, Hyperoside, Rutin and Quercetin respectively. The sum of these 5 flavonoid monomer contents represented the total flavonoids in hawthorn. The total coefficients of variation was 44.01%. Some high-content-flavone and valuable leaf resources were found. This research could provide accurate date for further production, breeding and the effective use of medicinal resources. (author)

189

Genetic diversity among isolates of Paenibacillus larvae from Austria.  

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Genetic diversity of 214 Paenibacillus larvae strains from Austria was studied. Genotyping of isolates was performed by polymerase chain reaction (PCR) with primers corresponding to enterobacterial repetitive intergenic consensus (ERIC), BOX repetitive and extragenic palindromic (REP) elements (collectively known as rep-PCR) using ERIC primers, BOX A1R and MBO REP1 primers. Using ERIC-PCR technique two genotypes could be differentiated (ERIC I and II), whereas using combined typing by BOX- and REP-PCR, five different genotypes were detected (ab, aB, Ab, AB and alphab). Genotypes aB and alphab are new and have not been reported in other studies using the same techniques. PMID:18831978

Loncaric, Igor; Derakhshifar, Irmgard; Oberlerchner, Josua T; Köglberger, Hemma; Moosbeckhofer, Rudolf

2009-01-01

190

Hierarchical cluster analysis of genetic diversity in Maize germplasm  

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Full Text Available An experiment was conducted to analyze the genetic diversity among 38 maize germplasm accessions of the maizegermplasm bank of Department of Millets, TNAU, Coimbatore. Observations regarding 25 morphological traits wererecorded and the data matrix was used for estimation of Euclidian distance by Un-weighted Paired Group ArithmeticAverage (UPGMA method. Clustering was done by Sequential Agglomerative Hierarchical Non-overlapping (SAHNclustering. The genotypes were grouped in to four clusters. The grouping of the genotypes was not influenced by theirgeographical origin. Maximum dissimilarity was observed between the genotypes UMI 551 and UMI 696. Widely divergentclusters and genotypes were identified which could be further evaluated for their breeding value as parents and could beexploited in maize crop improvement.

A. Subramanian and N. Subbaraman

2010-07-01

191

A decade of norovirus genetic diversity in Belgium.  

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Outbreaks of norovirus-associated gastroenteritis occur during all seasons and in various locations, and are recognized as one of the most common causes of nonbacterial food-borne infections. The molecular epidemiology of norovirus infections has not been well characterized in Belgium. To study the incidence of norovirus infections and the nature of the circulating genotypes, 3080 specimens were collected from patients with acute gastroenteritis between 2004 and 2014. Norovirus was detected with RT-PCR in 554 samples (18%). The circulating strains were genotyped based on the variability in the 5' end of the capsid gene (region C). The GII.4 genotype, which is detected predominantly worldwide, was also the most prevalent genotype in our study (87%). This study shows a high frequency and genetic diversity of norovirus in patients with acute gastroenteritis in health care facilities in Flanders, Belgium. PMID:25497349

Wollants, Elke; De Coster, Sarah; Van Ranst, Marc; Maes, Piet

2015-03-01

192

Genetic relationships and diversity of commercially relevant Echinacea species.  

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The genus Echinacea is comprised of nine species, which are perennial herbs indigenous to North America and which have been traditionally used as medicinal plants for centuries. Three Echinacea species, E. angustifolia, E. purpurea, and E. pallida, are currently being traded internationally in the natural products market. Echinacea products constitute a significant portion of this growing, multi-billion dollar industry. The increasing popularity of Echinacea products has led to the expansion of wildcrafting and commercial cultivation to meet the growing demand for plant material. Echinacea is considered of value as a nonspecific immune stimulant, and claims of its efficacy have been tentatively supported by both laboratory and clinical studies. This study used random amplified polymorphic DNA (RAPD) markers to determine the genetic relationships of the three Echinacea species of commercial interest, to evaluate the level of diversity present within germplasm of each of the three species, and to compare accessions of each species available from different sources. A total of 101 RAPD markers were generated for the 76 individuals of four species included in the analysis. NTSYS-pc was used to evaluate the genetic relationships of the three species and to determine the general level of overall diversity. Analysis of molecular variance (AMOVA) was performed using pruned marker sets corrected for the dominant nature of RAPD markers. AMOVA revealed that most of the variation occurred within accessions of the same species, though some accessions of both E. pallida and E. angustifolia were found to be significantly different from other accessions of the same species. PMID:12582540

Kapteyn, J.; Goldsbrough, B.; Simon, E.

2002-08-01

193

Genetic diversity of ITS sequences of Bursaphelenchus xylophilus.  

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The sequence variation of internal transcribed spacer (ITS) regions of ribosomal DNA has been routinely used for species identification and species-level phylogeny of the pinewood nematode, Bursaphelenchus xylophilus. In this study, the intraspecies ITS genetic diversity of B. xylophilus was evaluated. Three pinewood nematode isolates from the United States, Japan, and Portugal were used for polymerase chain reaction (PCR) ITS region amplification and sequencing. Multiple peaks were observed in sequencing chromatograms from ITS regions of American and Japanese isolates, suggesting the presence of more than one ribosomal sequence for each isolate. PCR products were further cloned and 10 clones of each isolate were subsequently sequenced. Additionally, the ITS regions of individual nematodes from each isolate were amplified, cloned and sequenced. Among the 3 B. xylophilus isolates analyzed, an intraspecific and intra-isolate molecular variability was found. The intra-isolate ITS molecular diversity in the American isolate was higher than that in the Japanese and Portuguese isolates. However, the level of sequence variation observed within isolates was about the same as that described among ITS repeats within individuals. PMID:23096915

Cardoso, J M S; Fonseca, L; Abrantes, I

2012-01-01

194

Genetic diversity of symbiotic cyanobacteria in Cycas revoluta (Cycadaceae).  

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The diversity of cyanobacterial species within the coralloid roots of an individual and populations of Cycas revoluta was investigated based on 16S rRNA gene sequences. Sixty-six coralloid roots were collected from nine natural populations of cycads on Kyushu and the Ryukyu Islands, covering the entire distribution range of the species. Approximately 400 bp of the 5'-end of 16S rRNA genes was amplified, and each was identified by denaturing gradient gel electrophoresis. Most coralloid roots harbored only one cyanobiont, Nostoc, whereas some contained two or three, representing cyanobiont diversity within a single coralloid root isolated from a natural habitat. Genotypes of Nostoc within a natural population were occasionally highly diverged and lacked DNA sequence similarity, implying genetic divergence of Nostoc. On the other hand, Nostoc genotypes showed no phylogeographic structure across the distribution range, while host cycads exhibited distinct north-south differentiation. Cycads may exist in symbiosis with either single or multiple Nostoc strains in natural soil habitats. PMID:22537413

Yamada, Shuntaro; Ohkubo, Satoshi; Miyashita, Hideaki; Setoguchi, Hiroaki

2012-09-01

195

Low genetic diversity and strong but shallow population differentiation suggests genetic homogenization by metapopulation dynamics in a social spider.  

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Mating systems and population dynamics influence genetic diversity and structure. Species that experience inbreeding and limited gene flow are expected to evolve isolated, divergent genetic lineages. Metapopulation dynamics with frequent extinctions and colonizations may, on the other hand, deplete and homogenize genetic variation, if extinction rate is sufficiently high compared to the effect of drift in local demes. We investigated these theoretical predictions empirically in social spiders that are highly inbred. Social spiders show intranest mating, female-biased sex ratio, and frequent extinction and colonization events, factors that deplete genetic diversity within nests and populations and limit gene flow. We characterized population genetic structure in Stegodyphus sarasinorum, a social spider distributed across the Indian subcontinent. Species-wide genetic diversity was estimated over approximately 2800 km from Sri Lanka to Himalayas, by sequencing 16 protein-coding nuclear loci. We found 13 SNPs in 6592 bp (? = 0.00045) indicating low species-wide nucleotide diversity. Three genetic lineages were strongly differentiated; however, only one fixed difference among them suggests recent divergence. This is consistent with a scenario of metapopulation dynamics that homogenizes genetic diversity across the species' range. Ultimately, low standing genetic variation may hamper a species' ability to track environmental change and render social inbreeding spiders 'evolutionary dead-ends'. PMID:25348843

Settepani, V; Bechsgaard, J; Bilde, T

2014-12-01

196

Assessment of genetic diversity within sour cherry clones  

DEFF Research Database (Denmark)

Harvested yields of sour cherry (Prunus cerasus) cultivar ‘Stevnsbaer’ clones grown in Denmark have been highly variable over the years, yet some propagated derived trees selected from within the two widely grown clones of ‘Stevnsbaer’ clone ‘Birgitte’ and clone ‘Viki’ have consistently produced higher yields. A number of these selections were evaluated for yield and genomic differences to investigate variation between and within the ‘Birgitte’ and ‘Viki’ clones. Variation in yield was mainly found at the clonal level. The clone ‘Viki’ was found to be the highest yielding with an average of 20 kg/tree compared to only 7.0 kg/tree from clone ‘Birgitte’. The selected trees derived from within clone ‘Birgitte’ had a significantly higher, average yield over 7 years compared to the original ‘Birgitte’, indicating that such within-clone selection may be a possible approach for selection 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 change.

Clausen, Sabine Karin; Andersen, Sven Bode

2013-01-01

197

Genetic diversity of pestivirus isolates in cattle from Western Austria.  

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The genetic diversity of bovine viral diarrhoea virus (BVDV) isolates in infected cattle from Tyrol and Vorarlberg (Austria) was investigated. Blood samples were collected within the compulsory Austrian BVDV control programme during 2005 and 2006. The 5'-untranslated region (5'-UTR) and partially the N-terminal autoprotease (N(pro)) were amplified by one-step reverse transcriptase-polymerase chain reaction (RT-PCR) and the PCR products were subsequently sequenced. Phylogenetic analysis based on 5'-UTR and N(pro) sequences demonstrated that almost all isolates (307/310) were of the BVDV-1 genotype. They were clustered into eight different subtypes, here listed by their frequency of occurrence: BVDV-1h (143), BVDV-1f (79), BVDV-1b (41), BVDV-1d (28), BVDV-1e (6), BVDV-1a (4), BVDV-1g (3) and BVDV1-k (3). Two pestivirus isolates were typed as BVDV-2 and one isolate as BDV closely related to Gifhorn strain (BDV-3). Correlation among isolates could only be observed at the farm level, i.e., within a herd. However, no correlation between the genetic and geographical distances could be observed above the farm level. Because of the wide distribution of certain BVDV-1 subtypes and the low prevalence of herd-specific strains, a determination of tracing routes of infection was not possible. Furthermore, recombination events were not detected. PMID:19019571

Hornberg, Andrea; Fernández, Sandra Revilla; Vogl, Claus; Vilcek, Stefan; Matt, Monika; Fink, Maria; Köfer, Josef; Schöpf, Karl

2009-03-30

198

Genetic diversity among sea otter isolates of Toxoplasma gondii  

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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.

Sundar, N.; Cole, R.A.; Thomas, N.J.; Majumdar, D.; Dubey, J.P.; Su, C.

2008-01-01

199

Genetic diversity analysis of groundnut genotypes using SSR markers  

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Full Text Available Groundnut (Arachis hypogaea L., an important oilseed crop is a rich source of oil and protein. Molecular marker technologies are the effectivetools and they are used for the assessment of genetic variability because they are not influenced by the environment. Among the molecularmarkers, Simple Sequence Repeat (SSR has proved to be the most powerful tool for variety identification in groundnut and has much potential ingenetic and breeding studies. Among the 17 SSR primer pairs used for assessing the genetic diversity, 6 primer pairs (24.0 per cent werepolymorphic. The genotype TMV 2 was susceptible to rust and late leaf spot diseases and it was separately clustered in the dendrogram andamong the eleven foliar disease resistant genotypes, the genotypes viz., COG 0423, COG 0436 and COG 0432 were distantly clustered fromTMV 2. Hence, by using the genotypes viz., TMV 2, COG 0423, COG 0436 and COG 0432, three combinations viz., TMV 2 x COG 0423, TMV2 x COG 0436 and TMV 2 x C0G 0432 could be made for further studies.

D. Shoba, N. Manivannan and P.Vindhiyavarman

2010-12-01

200

The effect of inoculum dose on the genetic diversity detected within Helicoverpa armigera nucleopolyhedrovirus populations.  

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Environmental and infection variables may affect the genetic diversity of baculovirus populations. In this study, Helicoverpa armigera nucleopolyhedrovirus (HearNPV) was used as a model system for studying the effects of a key infection variable, inoculum dose, on the genetic diversity within nucleopolyhedrovirus populations. Diversity and equitability indices were calculated from DNA polymerase-specific denaturing gradient gel electrophoresis profiles obtained from individual H. armigera neonate larvae inoculated with either an LD5 or LD95 of HearNPV. Although the genetic diversity detected in larvae treated with an LD95 was not statistically different from the diversity detected in the HearNPV inoculum samples, there was a statistically significant difference in the genetic diversity detected in the LD5-inoculated larvae compared with the genetic diversity detected in the HearNPV samples used for the inoculations. The study suggests that inoculum dose needs to be considered carefully in experiments that evaluate HearNPV genetic diversity or in studies where differences in genetic diversity may have phenotypic consequences. PMID:23929831

Baillie, Vicky Lynne; Bouwer, Gustav

2013-11-01

201

Assessment of Genetic Diversity across differentially adopted rice ecotypes  

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Full Text Available Rice is an important staple food and a rich source of carbohydrates for 90% of South and Southeast Asians. Geneticdiversity of naturally adopted upland lines along with few germplasm collections in Karnataka were studied basedon 13 SSR loci on chromosome 1. A total of 24 individuals belonging to 3 differentially adopted groups [Upland(8, landraces (8 and cultivated varieties (8] had a moderate to high level of genetic variability at groups level withnumber of alleles ranging from 5 to 23 (average 11.5 and PIC from 0.51 to 0.94 (average 0.79. The heterozygosityvaried from 0.39 to as high as 0.70. Over all genetic diversity of 0.81 was revealed indicating a high level of geneticvariation among these individuals. At the similarity coefficient of 7, all the lines were clearly grouped in 3 clusters.All cultivated types grouped in one cluster (cluster 1 except Rasi and CTH 1 which were included in cluster 2 andcluster 3 respectively. Cluster 1 contained 9 cultivated genotypes, where as cluster 2 contained 11 land races andcluster 3 had 4 upland lines. Out of 4 upland lines one line (AC-35341 intermixed, with C1 and three lines (PS-229,JBT-37/4 and AC-35310 with C3. The study of SSR markers on chromosome 1 facilitated the classification of theselines according to their adaptability. The information about the genetics of these populations will be for specificchromosomes and will be very useful for rice breeding programs, especially for gene mapping and ultimately formarker assisted selection programs.

Sridevi, G1., Raju, B.R2., Mohankumar, M.V2* and Sheshshayee, M, S.

2012-03-01

202

A preliminary examination of genetic diversity in the Indian false vampire bat Megaderma lyra  

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Full Text Available Habitat loss and fragmentation have serious consequences for species extinction as well as genetic diversity within a species. Random Amplified Polymorphic DNA (RAPD analysis was employed to assess the genetic diversity within and between four natural populations of M. lyra. Our results suggest that the genetic diversity varied from 0.21 to 0.26 with a mean of 0.11 to 0.13 (± SD. The mean Gst value of 0.15 was obtained from all four populations and estimated average Nm (1.41 showing gene flow between the populations. AMOVA analysis showed 88.96% within and 11.04% among the studied populations. Cluster analyses of RAPD phenotypes showed that specimens were not grouped by geographical origin. The genetic diversity found in the M. lyra population may be explained by its breeding behaviors. Though preliminary, the results indicate that all four populations should be considered to maintain the genetic diversity.

Emmanuvel Rajan, K.

2006-12-01

203

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

OpenAIRE

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 l...

Juliana Morini Küpper Cardoso Perseguini; Alisson Fernando Chioratto; Maria Imaculada Zucchi; Carlos Augusto Colombo; Sérgio Augusto Moraes Carbonell; Jorge Mauricio Costa Mondego; Rodrigo Gazaffi; Antonio Augusto Franco Garcia; Tatiana de Campos; Anete Pereira de Souza; Luciana Benchimol Rubiano

2011-01-01

204

The Role of Propagule Pressure, Genetic Diversity and Microsite Availability for Senecio vernalis Invasion  

OpenAIRE

Genetic diversity is supposed to support the colonization success of expanding species, in particular in situations where microsite availability is constrained. Addressing the role of genetic diversity in plant invasion experimentally requires its manipulation independent of propagule pressure. To assess the relative importance of these components for the invasion of Senecio vernalis, we created propagule mixtures of four levels of genotype diversity by combining seeds across remote populatio...

Erfmeier, Alexandra; Hantsch, Lydia; Bruelheide, Helge

2013-01-01

205

Diversity and Genetic structure of the Spanish collection of durum wheat (Triticum turgidum L) landraces  

OpenAIRE

The objectives of this study were to assess diversity and genetic structure of a collection of Spanish durum wheat (Triticum turgidum L) landraces, using SSRs, DArTs and gliadin-markers, and to correlate the distribution of diversity with geographic and climatic features, as well as agro-morphological traits. A high level of diversity was detected in the genotypes analyzed, which were separated into nine populations with a moderate to great genetic divergence among them. The three subspecies ...

Ruiz Valca?rcel, Magdalena; Giraldo Carbajo, Patricia; Royo, Conchita; Villegas, Dolores; Aranzana, Maria Jose?; Carrillo Becerril, Jose Maria

2012-01-01

206

Intracolonial genetic diversity in honey bee (Apis mellifera) colonies increases pollen foraging efficiency  

Science.gov (United States)

Multiple mating by honey bee queens results in colonies of genotypically diverse workers. Recent studies have demonstrated that increased genetic diversity within a honey bee colony increases the variation in the frequency of tasks performed by workers. We show that genotypically diverse colonies, ...

207

Genetic Diversity of Andean Tuber Crop Species in the in situ Microcenter of Huanuco, Peru  

OpenAIRE

Andean tuber crop species oca (Oxalis tuberosa Molina), ulluco (Ullucus tuberosus Caldas), and mashua (Tropaeolum tuberosum Ruiz & Pav.) play major roles in Andean communities. These species show high variability but are threatened with genetic erosion. To study the management of genetic resources of neglected vegetatively propagated crop species, we studied genetic diversity and structure of these species in an in situ diversity microcenter (Huanuco, Peru). A sample of 15 varieties of oca, 1...

Malice, Marie; Bizoux, Jean-philippe; Blas, Raul; Baudoin, Jean-pierre

2010-01-01

208

Genetic diversity characterization of cassava cultivars (Manihot esculenta Crantz).: I) RAPD markers  

OpenAIRE

RAPD markers were used to investigate the genetic diversity of 31 Brazilian cassava clones. The results were compared with the genetic diversity revealed by botanical descriptors. Both sets of variates revealed identical relationships among the cultivars. Multivariate analysis of genetic similarities placed genotypes destinated for consumption "in nature" in one group, and cultivars useful for flour production in another. Brazil’s abundance of landraces presents a broad dispersion and is co...

Colombo Carlos; Second Gérard; Valle Tereza Losada; Charrier André

1998-01-01

209

Genetic Structure and Diversity of the Giant Frog (Limnonectes blythii) in Northern Thailand  

OpenAIRE

The aim of this study is to analyse genetic diversity, structure and differentiation of the giant frogs (Limnonectes blythii). One hundred and sixty four individuals from 4 populations in Mae Hong Son Province, Thailand were used for the analysis of genetic polymorphism at 7 microsatellite loci. The collection showed considerable polymorphism with observed number of alleles per locus ranging for seven different loci, with an average of 3.4 alleles per locus. Mean genetic diversity of the four...

Suwannapoom, C.; Wongkham, W.; Sitasuwan, N.; Phalaraksh, C.; Kunpradid, T.; Osathanunkul, M.; Kutanan, W.; Phairuang, W.; Chomdej, S.

2012-01-01

210

Assessing the contribution of breeds to genetic diversity in conservation schemes  

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Full Text Available Abstract The quantitative assessment of genetic diversity within and between populations is important for decision making in genetic conservation plans. In this paper we define the genetic diversity of a set of populations, S, as the maximum genetic variance that can be obtained in a random mating population that is bred from the set of populations S. First we calculated the relative contribution of populations to a core set of populations in which the overlap of genetic diversity was minimised. This implies that the mean kinship in the core set should be minimal. The above definition of diversity differs from Weitzman diversity in that it attempts to conserve the founder population (and thus minimises the loss of alleles, whereas Weitzman diversity favours the conservation of many inbred lines. The former is preferred in species where inbred lines suffer from inbreeding depression. The application of the method is illustrated by an example involving 45 Dutch poultry breeds. The calculations used were easy to implement and not computer intensive. The method gave a ranking of breeds according to their contributions to genetic diversity. Losses in genetic diversity ranged from 2.1% to 4.5% for different subsets relative to the entire set of breeds, while the loss of founder genome equivalents ranged from 22.9% to 39.3%.

Groenen Martien AM

2002-09-01

211

Genetic Algorithm Calibration of Probabilistic Cellular Automata for Modeling Mining Permit Activity  

Science.gov (United States)

We use a genetic algorithm to calibrate a spatially and temporally resolved cellular automata to model mining activity on public land in Idaho and western Montana. The genetic algorithm searches through a space of transition rule parameters of a two dimensional cellular automata model to find rule parameters that fit observed mining activity data. Previous work by one of the authors in calibrating the cellular automaton took weeks - the genetic algorithm takes a day and produces rules leading to about the same (or better) fit to observed data. These preliminary results indicate that genetic algorithms are a viable tool in calibrating cellular automata for this application. Experience gained during the calibration of this cellular automata suggests that mineral resource information is a critical factor in the quality of the results. With automated calibration, further refinements of how the mineral-resource information is provided to the cellular automaton will probably improve our model.

Louis, S.J.; Raines, G.L.

2003-01-01

212

Genetic recolonization of mangrove: Genetic diversity still increasing in the Mekong delta 30 years after Agent Orange  

OpenAIRE

The widespread use of Agent Orange (a mixture of phenoxyl herbicides) over Southern Vietnam by US Forces led to the decimation of mangrove forests in the Mekong Delta. Mangrove trees Avicennia alba were sampled across the Mekong Delta; their age was assessed using models based on internode growth and samples were genotyped for 6 microsatellite loci. The evolution of genetic diversity over time elapsed since local extinction was reconstructed and compared with the genetic diversity of an unaff...

Arnaud-haond, S.; Duarte, C. M.; Teixeira, S.; Massa, S. I.; Terrados, J.; Tri, N. H.; Hong, P. N.; Serra?o, Ester

2009-01-01

213

Genetic structure, diversity, and allelic richness in composite collection and reference set in chickpea (Cicer arietinum L.  

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Full Text Available Abstract Background Plant genetic resources (PGR are the basic raw materials for future genetic progress and an insurance against unforeseen threats to agricultural production. An extensive characterization of PGR provides an opportunity to dissect structure, mine allelic variations, and identify diverse accessions for crop improvement. The Generation Challenge Program http://www.generationcp.org conceptualized the development of "composite collections" and extraction of "reference sets" from these for more efficient tapping of global crop-related genetic resources. In this study, we report the genetic structure, diversity and allelic richness in a composite collection of chickpea using SSR markers, and formation of a reference set of 300 accessions. Results The 48 SSR markers detected 1683 alleles in 2915 accessions, of which, 935 were considered rare, 720 common and 28 most frequent. The alleles per locus ranged from 14 to 67, averaged 35, and the polymorphic information content was from 0.467 to 0.974, averaged 0.854. Marker polymorphism varied between groups of accessions in the composite collection and reference set. A number of group-specific alleles were detected: 104 in Kabuli, 297 in desi, and 69 in wild Cicer; 114 each in Mediterranean and West Asia (WA, 117 in South and South East Asia (SSEA, and 10 in African region accessions. Desi and kabuli shared 436 alleles, while wild Cicer shared 17 and 16 alleles with desi and kabuli, respectively. The accessions from SSEA and WA shared 74 alleles, while those from Mediterranean 38 and 33 alleles with WA and SSEA, respectively. Desi chickpea contained a higher proportion of rare alleles (53% than kabuli (46%, while wild Cicer accessions were devoid of rare alleles. A genotype-based reference set captured 1315 (78% of the 1683 composite collection alleles of which 463 were rare, 826 common, and 26 the most frequent alleles. The neighbour-joining tree diagram of this reference set represents diversity from all directions of the tree diagram of the composite collection. Conclusion The genotype-based reference set, reported here, is an ideal set of germplasm for allele mining, association genetics, mapping and cloning gene(s, and in applied breeding for the development of broad-based elite breeding lines/cultivars with superior yield and enhanced adaptation to diverse environments.

Gowda Cholenahalli LL

2008-10-01

214

Genetic diversity of siderophore-producing bacteria of tobacco rhizosphere.  

Science.gov (United States)

The genetic diversity of siderophore-producing bacteria of tobacco rhizosphere was studied by amplified ribosomal DNA restriction analysis (ARDRA), 16S rRNA sequence homology and phylogenetics analysis methods. Studies demonstrated that 85% of the total 354 isolates produced siderophores in iron limited liquid medium. A total of 28 ARDRA patterns were identified among the 299 siderophore-producing bacterial isolates. The 28 ARDRA patterns represented bacteria of 14 different genera belonging to six bacterial divisions, namely ?-, ?-, ?-Proteobacteria, Sphingobacteria, Bacilli, and Actinobacteria. Especially, ?-Proteobacteria consisting of Pseudomonas, Enterobacter, Serratia, Pantoea, Erwinia and Stenotrophomonas genus encountered 18 different ARDRA groups. Results also showed a greater siderophore-producing bacterial diversity than previous researches. For example, Sphingobacterium (isolates G-2-21-1 and G-2-27-2), Pseudomonas poae (isolate G-2-1-1), Enterobacter endosymbiont (isolates G-2-10-2 and N-5-10), Delftia acidovorans (isolate G-1-15), and Achromobacter xylosoxidans (isolates N-46-11HH and N-5-20) were reported to be able to produce siderophores under low-iron conditions for the first time. Gram-negative isolates were more frequently encountered, with more than 95% total frequency. For Gram-positive bacteria, the Bacillus and Rhodococcus were the only two genera, with 1.7% total frequency. Furthermore, the Pseudomonas and Enterobacter were dominant in this environment, with 44.5% and 24.7% total frequency, respectively. It was also found that 75 percent of the isolates that had the high percentages of siderophore units (% between 40 and 60) belonged to Pseudomonas. Pseudomonas sp. G-229-21 screened out in this study may have potential to apply to low-iron soil to prevent plant soil-borne fungal pathogen diseases. PMID:24031358

Tian, Fang; Ding, Yanqin; Zhu, Hui; Yao, Liangtong; Du, Binghai

2009-04-01

215

Genetic Diversity Among Botulinum Neurotoxin Producing Clostridial Strains  

Energy Technology Data Exchange (ETDEWEB)

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.

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

216

Limited genetic diversity in Salmonella enterica Serovar Enteritidis PT13  

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Full Text Available Abstract Background Salmonella enterica serovar Enteritidis has emerged as a significant foodborne pathogen throughout the world and is commonly characterized by phage typing. In Canada phage types (PT 4, 8 and 13 predominate and in 2005 a large foodborne PT13 outbreak occurred in the province of Ontario. The ability to link strains during this outbreak was difficult due to the apparent clonality of PT13 isolates in Canada, as there was a single dominant pulsed-field gel electrophoresis (PFGE profile amongst epidemiologically linked human and food isolates as well as concurrent sporadic strains. The aim of this study was to perform comparative genomic hybridization (CGH, DNA sequence-based typing (SBT genomic analyses, plasmid analyses, and automated repetitive sequence-based PCR (rep-PCR to identify epidemiologically significant traits capable of subtyping S. Enteritidis PT13. Results CGH using an oligonucleotide array based upon chromosomal coding sequences of S. enterica serovar Typhimurium strain LT2 and the Salmonella genomic island 1 successfully determined major genetic differences between S. Typhimurium and S. Enteritidis PT13, but no significant strain-to-strain differences were observed between S. Enteritidis PT13 isolates. Individual loci (safA and fliC that were identified as potentially divergent in the CGH data set were sequenced in a panel of S. Enteritidis strains, and no differences were detected between the PT13 strains. Additional sequence-based typing was performed at the fimA, mdh, manB, cyaA, citT, caiC, dmsA, ratA and STM0660 loci. Similarly, no diversity was observed amongst PT13 strains. Variation in plasmid content between PT13 strains was observed, but macrorestriction with BglII did not identify further differences. Automated rep-PCR patterns were variable between serovars, but S. Enteritidis PT13 strains could not be differentiated. Conclusion None of the methods identified any significant variation between PT13 strains. Greater than 11,300 base pairs of sequence for each of seven S. Enteritidis PT13 strains were analyzed without detecting a single polymorphic site, although diversity between different phage types of S. Enteritidis was observed. These data suggest that Canadian S. Enteritidis PT13 strains are highly related genetically.

Ng Lai-King

2007-10-01

217

Genetic Diversity in A Core Subset of Wild Barley Germplasm  

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Full Text Available Wild barley [Hordeum vulgare ssp. spontaneum (C. Koch Thell.] is a part of the primary gene pool with valuable sources of beneficial genes for barley improvement. This study attempted to develop a core subset of 269 accessions representing 16 countries from the Plant Gene Resources of Canada (PGRC collection of 3,782 accessions, and to characterize them using barley simple sequence repeat (SSR markers. Twenty-five informative primer pairs were applied to screen all samples and 359 alleles were detected over seven barley chromosomes. Analyses of the SSR data showed the effectiveness of the stratified sampling applied in capturing country-wise SSR variation. The frequencies of polymorphic alleles ranged from 0.004 to 0.708 and averaged 0.072. More than 24% or 7% SSR variation resided among accessions of 16 countries or two regions, respectively. Accessions from Israel and Jordan were genetically most diverse, while accessions from Lebanon and Greece were most differentiated. Four and five optimal clusters of accessions were obtained using STRUCTURE and BAPS programs and partitioned 16.3% and 20.3% SSR variations, respectively. The five optimal clusters varied in size from 15 to 104 and two clusters had only country-specific accessions. A genetic separation was detected between the accessions east and west of the Zagros Mountains only at the country, not the individual, level. These SSR patterns enhance our understanding of the wild barley gene pool, and are significant for conserving wild barley germplasm and exploring new sources of useful genes for barley improvement.

Yong-Bi Fu

2012-06-01

218

Genetic diversity of Phytophthora infestans in the Northern Andean region  

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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, ?-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.

Grünwald Niklaus J

2011-02-01

219

A Novel Association Rules Method Based on Genetic Algorithm and Fuzzy Set Strategy for Web Mining  

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Full Text Available The use of fuzzy techniques has been considered to be one of the key components of data mining systems because of the affinity with human knowledge representation. A hybridization of fuzzy sets with genetic algorithms is described for Web mining in this paper. It is based on a hybrid technique that combines the strengths of rough set theory and genetic algorithm. The algorithm through the introduction of selection operators, crossover operators and mutation operators, improves the global convergence speed, and can effectively avoid prematurity. The role of fuzzy sets in handling the different types of uncertainties/impreciseness is highlighted. Experimental results indicate that this adaptive method significantly improves the performance in Web mining.

Chunlai Chai

2010-09-01

220

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 be [...] an, 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.

Juliana Morini Küpper Cardoso, Perseguini; Alisson Fernando, Chioratto; Maria Imaculada, Zucchi; Carlos Augusto, Colombo; Sérgio Augusto Moraes, Carbonell; Jorge Mauricio Costa, Mondego; Rodrigo, Gazaffi; Antonio Augusto Franco, Garcia; Tatiana de, Campos; Anete Pereira de, Souza; Luciana Benchimol, Rubiano.

221

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

Directory of Open Access Journals (Sweden)

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.

Juliana Morini Küpper Cardoso Perseguini

2011-01-01

222

Genetic Diversity of Some Capparis L. Species Growing in Syria  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english This work investigated the genetic diversity and relationships among Capparis species growing in Syria using IRAP and ISSR techniques. Forty-seven samples of three Capparis species genotypes were collected from 21 different locations in Syria. The genotypes were morphologically identified based on t [...] he descriptions available in the literature. When IRAP technique was used, an average of 71.5% of the amplified fragments were polymorphic compared to 82.04% in ISSR. Morphological characterization along with the cluster and PCoA analyses of the data divided the studied genotypes into three groups. The groups included genotypes identified as Capparis spinosa L, C. sicula Duh., and C. aegyptia Lam. Based on the morphological description, molecular studies and statistical analyses of this study, C. aegyptia could be suggested as a separate species and not a varietal rank of C. spinosa (C. spinosa var. aegyptia (Lam.). Two samples (Alep1 and Idl) were not placed in any of the three distinctive groups, despite their closeness morphologically to C. spinosa. In PCoA analysis, sample Alep1 came between C. sicula and C. spinosa and Idl was placed between C. sicula and C. aegyptia. Although hybridization between Capparis species could occur, it was not clear from the present study if these two genotypes were hybrids.

Bassam, Al- Safadi; Hussam, Faouri; Rana, Elias.

2014-12-01

223

Genetic diversity of Chlamydia among captive birds from central Argentina.  

Science.gov (United States)

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. PMID:25469538

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

2015-01-01

224

Genetic diversity of bluetongue viruses in south east Asia.  

Science.gov (United States)

Bluetongue viruses (BTV) were isolated from sentinel cattle in Malaysia and at two sites in Indonesia. We identified eight serotypes some of which appeared to have a wide distribution throughout this region, while others were only isolated in Malaysia or Australia. Nearly half of the 24 known BTV serotypes have now been identified in Asia. Further, we investigated the genetic diversity of their RNA segments 3 and 10. Using partial nucleotide sequences of the RNA segment 3 (540 bp) which codes for the conserved core protein (VP3), the BTV isolates were found to be unique to the previously defined Australasian topotype and could be further subdivided into four distinct clades or genotypes. Certain of these genotypes appeared to be geographically restricted while others were distributed widely throughout the region. Similarly, the complete nucleotide sequences of the RNA segment 10 (822 bp), coding for the non-structural protein (NS3/3A), were also conserved and grouped into the five genotypes; the BTV isolates could be grouped into three Asian genotypes and two Nth American/Sth African genotypes. PMID:15041187

Pritchard, L I; Sendow, I; Lunt, R; Hassan, S H; Kattenbelt, J; Gould, A R; Daniels, P W; Eaton, B T

2004-05-01

225

Assessment of Genetic Diversity, Relationships and Structure among Korean Native Cattle Breeds Using Microsatellite Markers.  

Science.gov (United States)

Four Korean native cattle (KNC) breeds-Hanwoo, Chikso, Heugu, and Jeju black-are entered in the Domestic Animal Diversity Information System of the United Nations Food and Agriculture Organization (FAO). The objective of this study was to assess the genetic diversity, phylogenetic relationships and population structure of these KNC breeds (n = 120) and exotic breeds (Holstein and Charolais, n = 56). Thirty microsatellite loci recommended by the International Society for Animal Genetics/FAO were genotyped. These genotypes were used to determine the allele frequencies, allelic richness, heterozygosity and polymorphism information content per locus and breed. Genetic diversity was lower in Heugu and Jeju black breeds. Phylogenetic analysis, Factorial Correspondence Analysis and genetic clustering grouped each breed in its own cluster, which supported the genetic uniqueness of the KNC breeds. These results will be useful for conservation and management of KNC breeds as animal genetic resources. PMID:25358313

Suh, Sangwon; Kim, Young-Sin; Cho, Chang-Yeon; Byun, Mi-Jeong; Choi, Seong-Bok; Ko, Yeoung-Gyu; Lee, Chang Woo; Jung, Kyoung-Sub; Bae, Kyoung Hun; Kim, Jae-Hwan

2014-11-01

226

Polygyny can increase rather than decrease genetic diversity contributed by males relative to females: evidence from red deer.  

Science.gov (United States)

Polygyny is expected to erode genetic variability by reducing the diversity of genetic contribution of males to the next generation, although empirical evidence shows that genetic variability in polygynous populations is not lost as rapidly as expected. We used microsatellite markers to study the genetic variability transmitted by mothers and fathers to offspring during a reproductive season in wild populations of a polygynous mammal, the red deer. Contrary to expectations, we found that males contributed more genetic diversity than females. Also, we compared study populations with different degrees of polygyny to find that polygyny was not related to a decrease in genetic diversity contributed by males. On the contrary, when population genetic diversity was relatively low, polygyny associated with higher genetic diversity of paternal lineage. Our results show that sexual selection, by favouring heterozygote individuals, may compensate the potential reduction of effective population size caused by polygyny, thus contributing to explain why genetic diversity is not depleted in polygynous systems. PMID:19302345

Pérez-González, J; Mateos, C; Carranza, J

2009-04-01

227

Astrophysical data mining with GPU. A case study: genetic classification of globular clusters  

CERN Document Server

We present a multi-purpose genetic algorithm, designed and implemented with GPGPU / CUDA parallel computing technology. The model was derived from our CPU serial implementation, named GAME (Genetic Algorithm Model Experiment). It was successfully tested and validated on the detection of candidate Globular Clusters in deep, wide-field, single band HST images. The GPU version of GAME will be made available to the community by integrating it into the web application DAMEWARE (DAta Mining Web Application REsource (http://dame.dsf.unina.it/beta_info.html), a public data mining service specialized on massive astrophysical data. Since genetic algorithms are inherently parallel, the GPGPU computing paradigm leads to a speedup of a factor of 200x in the training phase with respect to the CPU based version.

Cavuoti, Stefano; Brescia, Massimo; Paolillo, Maurizio; Pescape', Antonio; Longo, Giuseppe; Ventre, Giorgio

2013-01-01

228

Genetic diversity and differentiation of exotic and American commercial cattle breeds raised in Brazil.  

Science.gov (United States)

The Brazilian cattle population is mainly composed of breeds of zebuine origin and their American derivatives. Comprehensive knowledge about the genetic diversity of these populations is fundamental for animal breeding programs and the conservation of genetic resources. This study aimed to assess the phylogenetic relationships, levels of genetic diversity, and patterns of taurine/zebuine admixture among 9 commercial cattle breeds raised in Brazil. Analysis of DNA polymorphisms was performed on 2965 animals using the 11 microsatellite markers recommended by the International Society of Animal Genetics. High genetic diversity was detected in all breeds, even though significant inbreeding was observed within some. Differences among the breeds accounted for 14.72% of the total genetic variability, and genetic differentiation was higher among taurine than among zebuine cattle. Of note, Nelore cattle presented with high levels of admixture, which is consistent with the history of frequent gene flow during the establishment of this breed in Brazil. Furthermore, significant genetic variability was partitioned within the commercial cattle breeds formed in America, which, therefore, comprise important resources of genetic diversity in the tropics. The genetic characterization of these important Brazilian breeds may now facilitate the development of management and breeding programs for these populations. PMID:24301922

Brasil, B S A F; Coelho, E G A; Drummond, M G; Oliveira, D A A

2013-01-01

229

Genetic diversity and differentiation of Mongolian indigenous cattle populations  

International Nuclear Information System (INIS)

Livestock production plays an important role in Mongolian economy. Over the last decade it has contributed to around 80-90% of the gross domestic agricultural products and to 30% of the revenues generated from exportations. Cattle is one of the five traditional and most important livestock species of Mongolia together with horse, sheep, goat and camel. Out of a total of 1.57 millions Mongolian cattle, 1.55 millions supposedly belong to three indigenous Bos taurus cattle breeds, namely Mongol, Selenge and Khalkhun Golun, all herded under extensive pastoral systems. Indigenous Mongolian cattle are generally small but look sturdy and strong. They have a well-off coat of hair, solid forward looking shoulders and short stubby snouts, and they are used for meat, milk and transport. Beef production contributes to 30% of the total meat supply in Mongolia. The Mongol breed is by the far the commonest with 1.53 million animals and it is found almost throughout the country. The Selenge breed, found in Selenge province and numbering 9000 heads, was developed in middle of the 20th century by crossing the Kazakh Whiteheaded with the local Mongol cattle. The Khalkhun Golun breed was developed from local Mongol cattle and it is distributed in Eastern and Suhbaatar provinces with about 10,000 heads. Until now, to the best of our knowledge, only a single population of Mongolian cattle has been studied with microsatellite DNA markers and no information is available on the genetic relatirmation is available on the genetic relationship between the Mongolian indigenous cattle breeds. In this study, we collected samples from two populations of the Mongol cattle (sampled at Ikhtamir soum in North Hangay province and Tsogt soum in Govi Altay province) and one population of the Khalkhun Golun cattle (sampled at Tumentsogt soum in Suhbaatar province). Samples were characterised with nine microsatellite markers MGTG4B, ILSTS005, ILSTS006, ILSTS008, ILSTS023, ILSTS028, ILSTS036, ILSTS050 and ILSTS103. To assess the genetic diversity and relationship of Mongolian cattle populations with breeds from neighboring countries and exotic breeds, data from the ILRI cattle genotyping database were included. More particularly, we used previously obtained data from Asian taurine (Hanwoo, Yanbian and Japanese Black), two European taurine (Friesian and Charolais), two African taurine (Baoule and N'Dama) and two zebu breeds (Sahiwal and Ongole). For each breed, observed (Ho) and expected (He) heterozygosities as well as the mean number of alleles (MNA) across the nine loci were calculated between pairs of populations were also estimated and a UPGMA tree was constructed. The heterozygosities (Ho and He) in Mongolian cattle populations are similar to those obtained in Northeast Asian taurine breeds but the values are higher compared to the ones obtained for the European and African taurine breeds. The Mongol cattle in North Hangay has the highest corrected MNA value (all animals or 28 animals only). The UPGMA tree, built with the Reynolds' genetic distances, shows all six Northeast Asian cattle populations clustering into one group linked to the two European taurine breed. Interestingly, the two populations of the Mongol cattle are not closely related to each other. However, bootstrap values between the Northeast Asian taurine breeds, with the exception of the bootstrap value between Yanbian and Hanwoo, are relatively low, therefore the relationship between the Northeast Asian populations should be taken with caution. Fst values between the three Mongolian cattle populations are significant (P < 0.01), with the Govi Altay population being more differentiated from the North Hangay population than from the Khalkhun Golun breed (data not shown). Our data suggest that the traditional classification of Govi Altay and North Hangay populations as one breed, the Mongol cattle, should be revisited

230

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

Science.gov (United States)

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. PMID:22954156

Patzak, Josef; Paprštein, František; Henychová, Alena; Sedlák, Ji?í

2012-09-01

231

Effect of mining landscape history on local species diversity: a case study of the Yimin open-pit coal mine in Inner Mongolia  

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Full Text Available The exploration and utilization of mineral resources accelerates local economic and social development and simultaneously exacerbates the effects of climate and landscape changes, resulting in landscape fragmentation. Landscape change is widely considered as a major threat to species loss at a regional and global scale. However, how species diversity responds to landscape changes on a temporal scale has usually been ignored. In this study, we explored relationships between landscape and biodiversity (species level and functional group level during different years (1975, 1990, 2000 and 2010 at the Yimin open-pit coal mine, a mine that has been exploited for more than 30 years and that has produced obvious fragmentation effects on the landscape in Hulunbuir City. The ongoing patterns of transformation of the landscape were measured using the landscape dominance index, the habitat integral index of connectivity (IIC, and the habitat probability of connectivity (PC at seven different spatial scales. The main results were as follows: The present species diversity is significantly correlated with the landscape pattern indices of previous and earlier mining at a medium-sized spatial scale (4–8 km buffers. Different plant functional groups responded in various ways to changing landscape patterns. The species richness of perennial rhizome grasses was significantly correlated with the present small-scale landscape pattern (1–3 km, and the species richness of perennial forbs was significantly correlated with the previous and earlier mining large-scale landscape patterns (4–10 km. Perennial bunchgrasses were not significantly correlated with landscape patterns. We concluded that the time lag expressed by changes in plant species diversity occurred in response to changing patterns of construction and configurations of habitats in the landscape. The regional species pool determined the local species diversity. The connected habitat patches within a 4–8 km buffer region represented the principal species pool. The propagation strategies and dispersal traits of various functional groups were important mechanisms maintaining species diversity in a fragmented area.

Sarula Kang

2014-03-01

232

Assessment of genetic diversity of Typha angustifolia in the development of cattail stands  

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Full Text Available Typha angustifolia has ecological characteristics of clonal growth similar to Phragmites australis. The plant spreads byclonal growth and seed dispersal. In this study, for the three stands which have different settlement age at the Baksiljiwetland in Korea, genetic diversity was estimated by random amplification of polymorphic DNA analysis to evaluate thechange in genetic diversity of T. angustifolia during stand development in the same population. Stand (ST 1 was the oldestand ST 4 was the youngest. ST 5 was in a small ditch out of the Baksilji. Although the ST 1, ST 2, and ST 3 did not differsignificantly in vegetational or physical environment, the genetic diversity estimated according to Nei’s gene diversity(h and the Shannon index (i increased in the order of ST 1 < ST 2 < ST 3 contrary to formative age. The genetic diversityof ST 4 was much higher than that of the other three stands. ST 4 has similar abiotic environmental conditions withslight T. angustifolia dominance, and seems to be in the early establishment stage. ST 5 differed from the other stands invegetational and soil environments, which can result in stressful cattail conditions. Even though the ST 5 stand was notyounger than the ST 4 stand, ST 5 showed the highest genetic diversity. Our results indicate that after early settlement ofthe T. angustifolia population, genetic diversity within the species decreased over time and that the decreasing pattern ofgenetic diversity within T. angustifolia stands is not likely to occur under stressful conditions.

Jae Geun Kim*

2012-03-01

233

[Genetic structure and genetic diversity of Artemisia annua varieties (strains) populations based on SCoT markers].  

Science.gov (United States)

To reveal the genetic diversity and genetic structure in Artemisia annua varieties (strains) populations, we detected the genetic polymorphism within and among eight varieties (strains) populations (192 individuals) by the approach of Start Codon Targeted Polymorphism (SCoT). The associated genetic parameters were calculated by POPGENE1.31 and the relationship was constructed based on UPGMA method. The results showed that, using 20 screened primers, a total of 145 bands were produced, of which 122 were polymorphic loci. At species level, there was a high level of genetic diversity among eight varieties (strains) populations (PPB = 84.1% ,H = 0.217 3 and H(sp) = 0.341 9). However, at the variety (strains) population level, genetic diversity was lower, the average of genetic parameters was PPB = 41.9%, H = 0.121 5, H(pop) = 0.186 8. The Nei's genetic differentiation coefficient was 0.441 0, indicate that most of the genetic variation in this species existed within the variety populations. The gene flow (N(m) = 0.633 9) was less among populations, indicating that the degree of genetic differentiation was higher. Genetic similarity coefficient were changed from 0.755 1 to 0.985 7. By clustering analysis, eight varieties (strains) were clustered into two major categories and it was also showed the same or similar genetic background varieties (strains) have a tendency to gather in the same group. Results suggest that, in variety breeding, breeders should strengthen the exchange of bred germplasm and increase mutual penetration of excellent genes, which would broaden the genetic base of A. annua. PMID:25522606

Chen, Da-xia; Cui, Guang-lin; Zhang, Xue; Li, Long-yun

2014-09-01

234

Genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands  

OpenAIRE

Investigations of genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands indicated that almost all of identified genets occurring in those stands were small and occupied only a single stump. In some cases two, three or even four genets could effectively exist in an individual stump. Genetic similarity of H. annosum s.s. genets varied from 0% to 62%, H. parviporum from 0% to 38% and H. abietinum from 0% to 55%. The oldest and biggest genet was foun...

Piotr ?akomy; Zbigniew Broda; Antoni Werner

2007-01-01

235

Genetic diversity and population structure of Plasmodium vivax isolates from Sudan, Madagascar, French Guiana and Armenia.  

Science.gov (United States)

Polymorphic genetic markers and especially microsatellite analysis can be used to investigate multiple aspects of the biology of Plasmodium species. In the current study, we characterized 7 polymorphic microsatellites in a total of 281 Plasmodium vivax isolates to determine the genetic diversity and population structure of P. vivax populations from Sudan, Madagascar, French Guiana, and Armenia. All four parasite populations were highly polymorphic with 3-32 alleles per locus. Mean genetic diversity values was 0.83, 0.79, 0.78 and 0.67 for Madagascar, French Guiana, Sudan, and Armenia, respectively. Significant genetic differentiation between all four populations was observed. PMID:25102032

Menegon, Michela; Durand, Patrick; Menard, Didier; Legrand, Eric; Picot, Stéphane; Nour, Bakri; Davidyants, Vladimir; Santi, Flavia; Severini, Carlo

2014-10-01

236

Genetic diversity measures of local European beef cattle breeds for conservation purposes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract This study was undertaken to determine the genetic structure, evolutionary relationships, and the genetic diversity among 18 local cattle breeds from Spain, Portugal, and France using 16 microsatellites. Heterozygosities, estimates of Fst, genetic distances, multivariate and diversity analyses, and assignment tests were performed. Heterozygosities ranged from 0.54 in the Pirenaica breed to 0.72 in the Barrosã breed. Seven percent of the total genetic variability can be attributed to differences among breeds (mean Fst = 0.07; P

Pereira Albano

2001-05-01

237

Genetic Diversity of Some Mediterranean Populations of the Cultivated Alfalfa (Medicago sativa L. Using SSR Markers  

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Full Text Available This species study was to investigate the differentiation level among 26 populations wich 12 are locals originating from the Tunisian South and 14 introduced from Italy, Austerely, France and Morocco with two SSR markers. These highly polymorphic and co dominant markers, together with recent population genetic statistic extended to autotetraploids, offer tools to analyse genetic diversity in alfalfa. The number of alleles per locus varied between 8 and 9. The genetic similarity between these various populations is estimated by the index of Rogers and Tanimoto. Genetic diversity is analysed by two statistical procedures: Hierarchical classification and Correspondence Factorial Analysis (CFA. Four large groups were obtained.

L. Touil

2008-01-01

238

Genetic Phylogeny and Diversity of some Romanian Silkworms Based on RAPD Technique  

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Full Text Available Randomly amplified polymorphic DNA (RAPD markers were used in the present study to analyze genetic diversity and phylogenetic relationships among some race and hybrids of Romanian Bombyx mori. DNA from 8 hybrids and 1 race was amplified with 35 highly polymorphic RAPD primers, of which 21 markers generated polymorphic bands that were used to analyze genetic phylogeny and diversity. A total of 921 polymorphic bands were detected and UPGMA cluster analysis of Jaccard’s genetic distance grouped silkworm strains on the basis of their origin, obtaining a dendogram reflecting their genetic relationship.

Emilia Maria Furdui

2011-05-01

239

Investigation of Web Mining Optimization Using Microbial Genetic Algorithm  

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Full Text Available In today's modern internet era peopleneed searching on the web and finding relevant information on the web to be efficient and fast. But traditional search engines like Google suppose to be more intelligent, still use the traditional crawling algorithms to find data relevant to the search query. But most of the times it returns irrelevant data as well which becomes confusing for the user. In a normal XML data the user inputs the search query in terms of a keyword or a question and the answer to the search query should be more precise and more relevant. So, using the traditional crawling algorithms over XML data would lead to irrelevant results. Genetic algorithms are the modern algorithms which replicates the Darwinian theory of the natural evolution. The genetic algorithms are best suited for the traditional search problem as the genetic algorithms always tend to return quality as solution for any domain data. It would be a good approach to investigate how the genetic algorithms would be suitable for the search over the XML data of different domains. So, this system implements a steady state tournament selection Microbial Genetic Algorithm over the XML data of the different domains. This would be an investigation of how the genetic algorithm would return accurate results over XML data of different domains.

Dipali Tungar

2014-02-01

240

Mining Interesting Positive and Negative Association Rule Based on Improved Genetic Algorithm (MIPNAR_GA  

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Full Text Available Association Rule mining is very efficient technique for finding strong relation between correlated data. The correlation of data gives meaning full extraction process. For the mining of positive and negative rules, a variety of algorithms are used such as Apriori algorithm and tree based algorithm. A number of algorithms are wonder performance but produce large number of negative association rule and also suffered from multi-scan problem. The idea of this paper is to eliminate these problems and reduce large number of negative rules. Hence we proposed an improved approach to mine interesting positive and negative rules based on genetic and MLMS algorithm. In this method we used a multi-level multiple support of data table as 0 and 1. The divided process reduces the scanning time of database. The proposed algorithm is a combination of MLMS and genetic algorithm. This paper proposed a new algorithm (MIPNAR_GA for mining interesting positive and negative rule from frequent and infrequent pattern sets. The algorithm is accomplished in to three phases: a.Extract frequent and infrequent pattern sets by using apriori method b.Efficiently generate positive and negative rule. c.Prune redundant rule by applying interesting measures. The process of rule optimization is performed by genetic algorithm and for evaluation of algorithm conducted the real world dataset such as heart disease data and some standard data used from UCI machine learning repository.

Nikky Suryawanshi Rai

2014-01-01

241

Effects of Habitat Fragmentation on Population Genetic Diversity of Endangered Plant Euonymus chloranthoides Yang  

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Full Text Available Habitat fragmentation is the main threat to the survival of many species, species response to habitat fragmentation differently; the information of genetic diversity has great significance to protect species. Euonymus chloranthoides Yang is an endangered plant endemic to Chongqing. The population of this plant in Jinyun Mountain has been fragmented seriously because of the highway construction, tour development and so on. Some populations are small and isolated. Four populations in Jinyun maintain were selected to study the effects of habitat fragmentation on population genetic diversity of E. chloranthoides. The results of ISSR experiment show that the GST is 0.406 2 which means 59.38% of the genetic diversity exists within the population, and 40.62% of the genetic diversity exists among populations, the level of population differentiation is high due to long isolation, low dispersal distance of pollen and seed. The PPB of the population with highest genetic diversity is 64.58%, The genetic diversity of Banzigou population, the smallest one, is the lowest, and the PPB of this population is 29.17%, which means small population do harm to the maintenance of genetic diversity. The gene flow (Nm is 0.730 9, which is difficult to counteract the differentiation caused by genetic drift. Cluster analysis show he nearest populations cluster first, which mean that the genetic differentiation is affected by spatial distance. In-situ conservation should be strengthened to protect the small populations, and gene flow among populations should be improved to prevent the further genetic loss of small populations.

HU Shi-jun

2013-03-01

242

Genetic diversity and population structure of Bretschneidera sinensis, an endangered species  

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Full Text Available Amounts and distribution of intraspecific genetic variation provide benchmarks for developing conservation strategies. Bretschneidera sinensis is a monotypic relic species listed in the First Grade of the List of Wild Plants Under State Protection (First Batch in China. We examined the genetic diversity and genetic structure of 219 B. sinensis individuals sampled from 15 natural populations distributed in Hunan, Jiangxi, Guangdong, Guangxi, and Guizhou using inter-simple sequence repeat (ISSR markers generated by seven ISSR primers. The percentage of polymorphic bands (PPB at the species and population level was 74.42% and 38.06%, respectively. Shannon’s index (I of phenotypic diversity at the species and population level was 0.3630 and 0.2081, respectively, and Nei’s genetic diversity (He at the species and population level was 0.2397 and 0.1405, respectively. These results indicate that B. sinensis contains relatively high levels of genetic diversity. Analysis of molecular variance (AMOVA and estimates of the coefficient of genetic differentiation based on phenotypic diversity index also indicated high levels of population subdivision (GST = 0.2973; FST = 0.4267 in the species. Analysis of the ISSR data using UPGMA further revealed that populations were genetically clustered into two groups, while a Mantel test showed that genetic divergence was significantly correlated with geographical distance among populations (Mantel test; r = 0.3096, P = 0.008. We conclude from our results that B. sinensis is not endangered due to low evolutionary potential stemming from low genetic diversity, but by habitat destruction coupled with a low reproductive capacity, poor adaptability and weak competitiveness. The Mt. Yangming, Mt. Mangshan, Ruyang, and Mt. Bamianshan populations of the species with higher genetic diversity should be given priority for conservation, and inbreeding depression monitoring should be conducted.

Gangbiao Xu

2013-11-01

243

Genetic diversity in caribou linked to past and future climate change  

Science.gov (United States)

Climate-driven range fluctuations during the Pleistocene have continuously reshaped species distribution leading to populations of contrasting genetic diversity. Contemporary climate change is similarly influencing species distribution and population structure, with important consequences for patterns of genetic diversity and species' evolutionary potential. Yet few studies assess the impacts of global climatic changes on intraspecific genetic variation. Here, combining analyses of molecular data with time series of predicted species distributions and a model of diffusion through time over the past 21kyr, we unravel caribou response to past and future climate changes across its entire Holarctic distribution. We found that genetic diversity is geographically structured with two main caribou lineages, one originating from and confined to Northeastern America, the other originating from Euro-Beringia but also currently distributed in western North America. Regions that remained climatically stable over the past 21kyr maintained a high genetic diversity and are also predicted to experience higher climatic stability under future climate change scenarios. Our interdisciplinary approach, combining genetic data and spatial analyses of climatic stability (applicable to virtually any taxon), represents a significant advance in inferring how climate shapes genetic diversity and impacts genetic structure.

Yannic, Glenn; Pellissier, Loïc; Ortego, Joaquín; Lecomte, Nicolas; Couturier, Serge; Cuyler, Christine; Dussault, Christian; Hundertmark, Kris J.; Irvine, R. Justin; Jenkins, Deborah A.; Kolpashikov, Leonid; Mager, Karen; Musiani, Marco; Parker, Katherine L.; Røed, Knut H.; Sipko, Taras; Þórisson, Skarphéðinn G.; Weckworth, Byron V.; Guisan, Antoine; Bernatchez, Louis; Côté, Steeve D.

2014-02-01

244

Genetic diversity in Brazilian populations of Aedes albopictus  

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Full Text Available Random amplified polymorphic DNA (RAPD analysis technique was undertaken in Aedes albopictus populations from three states in Brazil, Rio de Janeiro (RJ, Minas Gerais (MG and Pernambuco (PE, to estimate the level of genetic variability and levels of genetic exchange between populations. Allele and genotype frequencies were measured on 47 RAPD loci. Average observed heterozigosity (Ho ranged from 0.282 in MG to 0.355 in Casa Forte (PE population. Genetic distances estimates indicated that RJ and MG were more genetically similar than populations from PE. Genetic variation observed in local Brazilian populations was attributed to genetic drift associated with restricted gene flow in recently established populations.

Ayres CFJ

2002-01-01

245

Genetic diversity of rhizobia nodulating lentil (Lens culinaris) in Bangladesh.  

Science.gov (United States)

In order to determine the bacterial diversity and the identity of rhizobia nodulating lentil in Bangladesh, we performed a phylogenetic analysis of housekeeping genes (16S rRNA, recA, atpD and glnII) and nodulation genes (nodC, nodD and nodA) of 36 bacterial isolates from 25 localities across the country. Maximum likelihood (ML) and Bayesian analyses based on 16S rRNA sequences showed that most of the isolates (30 out of 36) were related to Rhizobium etli and Rhizobium leguminosarum. Only these thirty isolates were able to re-nodulate lentil under laboratory conditions. The protein-coding housekeeping genes of the lentil nodulating isolates showed 89.1-94.8% genetic similarity to the corresponding genes of R. etli and R. leguminosarum. The same analyses showed that they split into three distinct phylogenetic clades. The distinctness of these clades from closely related species was also supported by high resolution ERIC-PCR fingerprinting and phenotypic characteristics such as temperature tolerance, growth on acid-alkaline media (pH 5.5-10.0) and antibiotic sensitivity. Our phylogenetic analyses based on three nodulation genes (nodA, nodC and nodD) and cross-inoculation assays confirmed that the nodulation genes are related to those of R. leguminosarum biovar viciae, but clustered in a distinct group supported by high bootstrap values. Thus, our multi-locus phylogenetic analysis, DNA fingerprinting and phenotypic characterizations suggest that at least three different clades are responsible for lentil nodulation in Bangladesh. These clades differ from the R. etli-R. leguminosarum group and may correspond to novel species in the genus Rhizobium. PMID:22280898

Rashid, Md Harun-or; Schäfer, Holger; Gonzalez, Javier; Wink, Michael

2012-03-01

246

Molecular biology and genetic diversity of Rift Valley fever virus.  

Science.gov (United States)

Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, genus Phlebovirus, is the causative agent of Rift Valley fever (RVF), a mosquito-borne disease of ruminant animals and humans. The generation of a large sequence database has facilitated studies of the evolution and spread of the virus. Bayesian analyses indicate that currently circulating strains of RVFV are descended from an ancestral species that emerged from a natural reservoir in Africa when large-scale cattle and sheep farming were introduced during the 19th century. Viruses descended from multiple lineages persist in that region, through infection of reservoir animals and vertical transmission in mosquitoes, emerging in years of heavy rainfall to cause epizootics and epidemics. On a number of occasions, viruses from these lineages have been transported outside the enzootic region through the movement of infected animals or mosquitoes, triggering outbreaks in countries such as Egypt, Saudi Arabia, Mauritania and Madagascar, where RVF had not previously been seen. Such viruses could potentially become established in their new environments through infection of wild and domestic ruminants and other animals and vertical transmission in local mosquito species. Despite their extensive geographic dispersion, all strains of RVFV remain closely related at the nucleotide and amino acid level. The high degree of conservation of genes encoding the virion surface glycoproteins suggests that a single vaccine should protect against all currently circulating RVFV strains. Similarly, preservation of the sequence of the RNA-dependent RNA polymerase across viral lineages implies that antiviral drugs targeting the enzyme should be effective against all strains. Researchers should be encouraged to collect additional RVFV isolates and perform whole-genome sequencing and phylogenetic analysis, so as to enhance our understanding of the continuing evolution of this important virus. This review forms part of a series of invited papers in Antiviral Research on the genetic diversity of emerging viruses. PMID:22710362

Ikegami, Tetsuro

2012-09-01

247

Molecular biology and genetic diversity of Rift Valley fever virus  

Science.gov (United States)

Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, genus Phlebovirus, is the causative agent of Rift Valley fever (RVF), a mosquito-borne disease of ruminant animals and humans. The generation of a large sequence database has facilitated studies of the evolution and spread of the virus. Bayesian analyses indicate that currently circulating strains of RVFV are descended from an ancestral species that emerged from a natural reservoir in Africa when large-scale cattle and sheep farming were introduced during the 19th century. Viruses descended from multiple lineages persist in that region, through infection of reservoir animals and vertical transmission in mosquitoes, emerging in years of heavy rainfall to cause epizootics and epidemics. On a number of occasions, viruses from these lineages have been transported outside the enzootic region through the movement of infected animals or mosquitoes, triggering outbreaks in countries such as Egypt, Saudi Arabia, Mauritania and Madagascar, where RVF had not previously been seen. Such viruses could potentially become established in their new environments through infection of wild and domestic ruminants and other animals and vertical transmission in local mosquito species. Despite their extensive geographic dispersion, all strains of RVFV remain closely related at the nucleotide and amino acid level. The high degree of conservation of genes encoding the virion surface glycoproteins suggests that a single vaccine should protect against all currently circulating RVFV strains. Similarly, preservation of the sequence of the RNA-dependent RNA polymerase across viral lineages implies that antiviral drugs targeting the enzyme should be effective against all strains. Researchers should be encouraged to collect additional RVFV isolates and perform whole-genome sequencing and phylogenetic analysis, so as to enhance our understanding of the continuing evolution of this important virus. This review forms part of a series of invited papers in Antiviral Research on the genetic diversity of emerging viruses. PMID:22710362

Ikegami, Tetsuro

2013-01-01

248

Genetic diversity of a large set of horse breeds raised in France assessed by microsatellite polymorphism  

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Full Text Available Abstract The genetic diversity and structure of horses raised in France were investigated using 11 microsatellite markers and 1679 animals belonging to 34 breeds. Between-breed differences explained about ten per cent of the total genetic diversity (Fst = 0.099. Values of expected heterozygosity ranged from 0.43 to 0.79 depending on the breed. According to genetic relationships, multivariate and structure analyses, breeds could be classified into four genetic differentiated groups: warm-blooded, draught, Nordic and pony breeds. Using complementary maximisation of diversity and aggregate diversity approaches, we conclude that particular efforts should be made to conserve five local breeds, namely the Boulonnais, Landais, Merens, Poitevin and Pottok breeds.

Mériaux Jean-Claude

2009-01-01

249

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

Science.gov (United States)

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. PMID:22615891

Oliveira, Hugo R; Campana, Michael G; Jones, Huw; Hunt, Harriet V; Leigh, Fiona; Redhouse, David I; Lister, Diane L; Jones, Martin K

2012-01-01

250

DEVELOPMENT OF AQUATIC MODELS FOR TESTING THE RELATIONSHIP BETWEEN GENETIC DIVERSITY AND POPULATION EXTINCTION RISK  

Science.gov (United States)

The relationship between population adaptive potential and extinction risk in a changing environment is not well understood. Although the expectation is that genetic diversity is directly related to the capacity of populations to adapt, the statistical and predictive aspects of ...

251

Global diversity and genetic contributions of chicken populations from African, Asian and European regions.  

Science.gov (United States)

Genetic diversity and population structure of 113 chicken populations from Africa, Asia and Europe were studied using 29 microsatellite markers. Among these, three populations of wild chickens and nine commercial purebreds were used as reference populations for comparison. Compared to commercial lines and chickens sampled from the European region, high mean numbers of alleles and a high degree of heterozygosity were found in Asian and African chickens as well as in Red Junglefowl. Population differentiation (FST ) was higher among European breeds and commercial lines than among African, Asian and Red Junglefowl populations. Neighbour-Net genetic clustering and structure analysis revealed two main groups of Asian and north-west European breeds, whereas African populations overlap with other breeds from Eastern Europe and the Mediterranean region. Broilers and brown egg layers were situated between the Asian and north-west European clusters. structure analysis confirmed a lower degree of population stratification in African and Asian chickens than in European breeds. High genetic differentiation and low genetic contributions to global diversity have been observed for single European breeds. Populations with low genetic variability have also shown a low genetic contribution to a core set of diversity in attaining maximum genetic variation present from the total populations. This may indicate that conservation measures in Europe should pay special attention to preserving as many single chicken breeds as possible to maintain maximum genetic diversity given that higher genetic variations come from differentiation between breeds. PMID:25315897

Lyimo, C M; Weigend, A; Msoffe, P L; Eding, H; Simianer, H; Weigend, S

2014-12-01

252

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

OpenAIRE

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 inlan...

Zlatko Liber; Vesna Židovec; Sandro Bogdanovi?; Ivan Radosavljevi?; Monika Pruša; Maja Filipovi?; Ines Han Dovedan; Marija Jug-Dujakovi?; Zlatko Šatovi?

2014-01-01

253

Genotyping-By-Sequencing for Plant Genetic Diversity Analysis: A Lab Guide for SNP Genotyping  

OpenAIRE

Genotyping-by-sequencing (GBS) has recently emerged as a promising genomic approach for exploring plant genetic diversity on a genome-wide scale. However, many uncertainties and challenges remain in the application of GBS, particularly in non-model species. Here, we present a GBS protocol we developed and use for plant genetic diversity analysis. It uses two restriction enzymes to reduce genome complexity, applies Illumina multiplexing indexes for barcoding and has a custom bioinformatics pip...

Peterson, Gregory W.; Yibo Dong; Carolee Horbach; Yong-Bi Fu

2014-01-01

254

Comparing genetic diversity and population structure of common beans grown in Kyrgyzstan using microsatellites  

OpenAIRE

Common bean (Phaseolus vulgaris L.) is an important export crop in Kyrgyzstan. The aim of this study was to assess the extent of genetic diversity, determine the population structure, and relate to the main gene pools grown in Kyrgyzstan. Twenty-eight common bean accessions (including five Kyrgyz cultivars, and main references from the Mesoamerica and South America) were evaluated with microsatellites. Nine polymorphic microsatellites were used to estimate genetic diversity and heterozygosity...

Sergey Hegay; Mulatu Geleta; Tomas Bryngelsson; Larisa Gustavsson; Helena Persson Hovmalm; Rodomiro Ortiz

2012-01-01

255

Genetic Diversity Within and Among Populations of Roseroot (Rhodiola rosea L.) Based on Molecular Markers  

OpenAIRE

Rhodiola rosea L. is a perennial adaptogenic medicinal plant found in cool climate of the northern hemisphere. The species is very diverse both in terms of morphological characteristics and in the content of the pharmacologically active substances. The genetic diversity of four geographically distant roseroot populations was studied with ISSR and SSR markers. Using 7 ISSR primers 64 DNA fragments were generated and 85,94% of those were found to be polymorphic, indicating high genetic variabil...

Pedryc, Andrzej; Bacharov, Dmitry; Szabo, Maria; Gyorgy, Zsuzsanna

2012-01-01

256

Genetic Diversity Analysis of Sugarcane Parents in Chinese Breeding Programmes Using gSSR Markers  

OpenAIRE

Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the popu...

Qian You; Liping Xu; Yifeng Zheng; Youxiong Que

2013-01-01

257

Genetic diversity and combining abilities for root traits of sugar beet pollinators  

OpenAIRE

Information about genetic diversity and combining abilities of sugar beet parental components are of a great importance for hybrid creation. The aim of this research was to evaluate genetic diversity among sugar beet pollinators from different breeding programs and their combining abilities for main root traits of sugar beet, root weight, sugar content and sugar yield. As plant material were used eight pollinators originating from three different USDA-ARS b...

?ur?i? Živko; Nagl Nevena; Taški-Ajdukovi? Ksenija; Danojevi? Dario; Stojakovi? Željka; Kova?ev Lazar

2013-01-01

258

Genetic Diversity in Jatropha curcas L. Assessed with SSR and SNP Markers  

OpenAIRE

Jatropha curcas L. (jatropha) is an undomesticated plant that has recently received great attention for its utilization in biofuel production, rehabilitation of wasteland, and rural development. Knowledge of genetic diversity and marker-trait associations is urgently needed for the design of breeding strategies. The main goal of this study was to assess the genetic structure and diversity in jatropha germplasm with co-dominant markers (Simple Sequence Repeats (SSR) and Single Nucleotide Polym...

Montes, Juan M.; Frank Technow; Matthias Martin; Klaus Becker

2014-01-01

259

Genetic diversity of Norway spruce [Picea abies (L.) Karst.] in Romanian Carpathians  

OpenAIRE

The genetic diversity of Romanian most important coniferous tree species, the Norway spruce, was estimated by means of allozyme markers. A total of 695 adult trees sampled from eleven populations grouped in six mountainous areas in the Romanian Carpathians were analyzed. In three metapopulations (Maramure?, Post?var and Parâng), to evaluate the influence of altitudinal gradient on genetic diversity, samples were collected from populations located at high and low altitude. At other location...

Raul Gheorghe Radu; Lucian Alexandru Curtu; Gheorghe Spârchez; Neculae ?ofletea

2014-01-01

260

Assessment of Genetic Diversity, Relationships and Structure among Korean Native Cattle Breeds Using Microsatellite Markers  

OpenAIRE

Four Korean native cattle (KNC) breeds—Hanwoo, Chikso, Heugu, and Jeju black—are entered in the Domestic Animal Diversity Information System of the United Nations Food and Agriculture Organization (FAO). The objective of this study was to assess the genetic diversity, phylogenetic relationships and population structure of these KNC breeds (n = 120) and exotic breeds (Holstein and Charolais, n = 56). Thirty microsatellite loci recommended by the International Society for Animal Genetics/FA...

Suh, Sangwon; Kim, Young-sin; Cho, Chang-yeon; Byun, Mi-jeong; Choi, Seong-bok; Ko, Yeoung-gyu; Lee, Chang Woo; Jung, Kyoung-sub; Bae, Kyoung Hun; Kim, Jae-hwan

2014-01-01

261

Assessment of genetic diversity of Typha angustifolia in the development of cattail stands  

OpenAIRE

Typha angustifolia has ecological characteristics of clonal growth similar to Phragmites australis. The plant spreads byclonal growth and seed dispersal. In this study, for the three stands which have different settlement age at the Baksiljiwetland in Korea, genetic diversity was estimated by random amplification of polymorphic DNA analysis to evaluate thechange in genetic diversity of T. angustifolia during stand development in the same population. Stand (ST) 1 was the oldestand ST 4 was the...

Jae Geun Kim; Heung-Tae Kim; So Jung Min

2012-01-01

262

Genetic Diversity in Fusarium graminearum from a Major Wheat-Producing Region of Argentina  

OpenAIRE

The Fusarium graminearum species complex (FGSC) is a group of mycotoxigenic fungi that are the primary cause of Fusarium head blight (FHB) of wheat worldwide. The distribution, frequency of occurrence, and genetic diversity of FGSC species in cereal crops in South America is not well understood compared to some regions of Asia, Europe and North America. Therefore, we examined the frequency and genetic diversity of a collection of 183 FGSC isolates recovered from wheat grown during multiple gr...

Giuseppina Mulè; Antonio Moretti; Virginia Fernandez Pinto; Stefania Somma; Cora Lilia Alvarez; Logrieco, Antonio F.; Gaetano Stea; Proctor, Robert H.

2011-01-01

263

Greater Genetic Diversity in Spatially Restricted Coral Reef Fishes Suggests Secondary Contact among Differentiated Lineages  

OpenAIRE

The maintenance of genetic diversity is a central goal of conservation. It is the raw material for evolutionary change and if lost, can accelerate extinction of species. According to theory, total genetic diversity should be less in species with restricted ranges and in populations on the margins of distributional ranges, making such species or populations more vulnerable to environmental perturbations. Using mtDNA and nuclear Inter Simple Sequence Repeat (ISSR) data we investigated how the g...

Julian Caley, M.; Bay, Line K.

2011-01-01

264

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

OpenAIRE

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. cam...

Fatima Sabin; Bajwa Rukhsana; Anjum Tehmina; Saleem Zafar

2012-01-01

265

'Landscape shape interpolation' for defining spatial pattern of beech genetic diversity in Serbia  

Directory of Open Access Journals (Sweden)

Full Text Available Knowledge about spatial distribution of genetic diversity is very important for foresters in order to make right decisions during establishing of management plans for conservation, afforestation or reforestation. Advanced molecular technologies provide us with efficiently measured genetic information's which can be analyzed powerful statistical tools. Landscape Shape Interpolation analysis was applied on protein based marker data sets from six natural populations of Balkan beech. Results indicate existence of three genetically distinct groups: 1 Djerdap, Kopaonik, Zubin potok and Ivanjica; 2 Bor and 3 Pirot. These results were compared with results of UPGMA clustering of sampled population based on NEI original distances, Principal Coordinate Analysis and Monmonier's Maximum Difference Algorithm Analysis. Landscape Shape Interpolation analysis represent a powerful tool in spatial genetic diversity research. Combining of Landscape Shape Interpolation analysis results with digitalized maps of investigated area in some of numerous GIS applications will for certainly improve visualization of results and provide better understanding of causal factors of genetic diversity.

Iveti? Vladan

2008-01-01

266

Estimation of Genetic Diversity in Sheep (Ovis aries using Randomly Amplified Polymorphic DNA  

Directory of Open Access Journals (Sweden)

Full Text Available Domestic sheep (Ovis aries belongs to order Artiod actyla. Despite its great economic importance, not much work has been done in Pakistan on breeding and genetics of sheep. Present research was initiated to analyze DNA based genetic diversity in Pakistani breeds of sheep. Total genomic DNA was isolated from blood of Rambouillet, Kaghani and Ramghani breeds. Polymerase Chain Reactions (PCR were carried out using six Randomly Amplified Polymorphic DNA (RAPD primers. Amplified fragments ranged in size from 500 bp to 2000 bp. On average, 3 alleles per genotype were amplified. Average genetic distance estimate ranged from 30-100%. Eleven comparisons showed maximum genetic diversity (GD = 100% while 6 comparisons sowed minimum genetic diversity (GD = 30% for the loci detected using 6 RAPD primers. Phylogenetic elaboration among the 14 sheep accessions were carried out using dendrogram analysis. The 14 accessions of sheep were grouped into 5 clusters comprising 3 , 3, 3, 3 and 2 accessions, respectively.

M. Qasim,

2011-02-01

267

Genetic diversity characterization of cassava cultivars (Manihot esculenta Crantz.: I RAPD markers  

Directory of Open Access Journals (Sweden)

Full Text Available RAPD markers were used to investigate the genetic diversity of 31 Brazilian cassava clones. The results were compared with the genetic diversity revealed by botanical descriptors. Both sets of variates revealed identical relationships among the cultivars. Multivariate analysis of genetic similarities placed genotypes destinated for consumption "in nature" in one group, and cultivars useful for flour production in another. Brazil?s abundance of landraces presents a broad dispersion and is consequently an important resource of genetic variability. The botanical descriptors were not able to differentiate thirteen pairs of cultivars compared two-by-two, while only one was not differentiated by RAPD markers. These results showed the power of RAPD markers over botanical descriptors in studying genetic diversity, identifying duplicates, as well as validating, or improving a core collection. The latter is particularly important in this vegetatively propagated crop.

Colombo Carlos

1998-01-01

268

Genetic diversity in major farm crops on the farm and in reserve  

Energy Technology Data Exchange (ETDEWEB)

Genetic vulnerability does not at this time present a major threat to production of United States field crops, according to a 1981 survey of US crop breeding directors. But plant breeders do regard genetic vulnerability as an important and potentially dangerous problem. The 1981 survey indicated that although the genetic base of US field crop production is not as narrow as in 1970, it still is concentrated on a relatively small number of favored cultivars. Genetic diversity is provided, nevertheless, in other and less obvious ways. Survey responses indicated that the genetic base of the elite germplasm pool is wider and provides more useful diversity than is usually supposed. However, breeders also value the national germplasm repositories as indispensable sources of needed diversity. 36 references, 1 figure, 25 tables.

Duvick, D.N.

269

Genetic Diversity among Clinical Isolates of Candida glabrata Analyzed by Randomly Amplified Polymorphic DNA and Multilocus Enzyme Electrophoresis Analyses  

OpenAIRE

The genetic diversity of 47 clinical and reference strains of Candida glabrata from several geographical origins and diverse clinical disorders, with different antifungal susceptibilities, as well as their genetic relationships were studied through multilocus enzyme electrophoresis (MLEE) and randomly amplified polymorphic DNA (RAPD) techniques. The genetic diversity estimated for 11 MLEE loci measured as average heterozygosity (h) was 0.055. A high level of genetic relatedness among isolates...

Boldo, Xavier M.; Villa-tanaca, Lourdes; Zu?n?iga, Gerardo; Herna?ndez-rodri?guez, Ce?sar

2003-01-01

270

Genetic diversity and population structure among six cattle breeds in South Africa using a whole genome SNP panel  

OpenAIRE

Information about genetic diversity and population structure among cattle breeds is essential for genetic improvement, understanding of environmental adaptation as well as utilization and conservation of cattle breeds. This study investigated genetic diversity and the population structure among six cattle breeds in South African (SA) including Afrikaner (n = 44), Nguni (n = 54), Drakensberger (n = 47), Bonsmara (n = 44), Angus (n = 31), and Holstein (n = 29). Genetic diversity within cattle b...

Makina, Sithembile O.; Muchadeyi, Farai C.; Marle-ko?ster, Este; Macneil, Michael D.; Maiwashe, Azwihangwisi

2014-01-01

271

Genetic diversity and structure analysis based on hordein protein polymorphism in barley landrace populations from jordan  

International Nuclear Information System (INIS)

Jordan is unanimously considered to be one of the centers of genetic diversity for barley, where wild and landraces of barley has been grown under different climatic conditions. The genetic diversity and genetic structure based on hordein polymorphism was assessed in 90 different accessions collected from four different sites of Jordan. A-PAGE was used to reveal hordein polymorphism among the genotypes. A total of 29 distinct bands were identified, out of them 9 bands were distinguished for D, 11 for C, and 9 for the B hordein regions. The observed genetic similarity was an exceptionally high between the populations than expected, which is probably due to high gene flow estimated between them. The genetic diversity parameters were not differ largely among the populations, indicating that local selection of a particular site did not play a key role in shaping genetic diversity. Analysis of molecular variance (AMOVA) revealed significant population structure when accessions were structured according to population site. There was 94% of hordein variation resided within the populations and only 8% present among the populations. Both Bayesian and Principale Coordinate Analysis (PCoA) concordantly demonstrated admixture genotypes of the landraces barley populations. Consequently, none of the population found to be clustered separately according to its population site. It is concluded that this approach can be useful to explore the germplasm for genetic diversity but perhaps is not suitable for determining phylogenic relations in barley. (author)

272

Genetic Diversity in Commercial Rapeseed (Brassica napus L. Varieties from Turkey as Revealed by RAPD  

Directory of Open Access Journals (Sweden)

Full Text Available In cultivated commercial crop species, genetic diversity tends to decrease because of the extensive breeding processes. Therefore, germplasm of commercial crop species, such as Brassica napus L. should be evaluated and the genotypes, which have higher genetic diversity index, should be addressed as potential parental cross materials in breeding programs. In this study, the genetic diversity was analysed by using randomly amplified polymorphic DNA analysis (RAPD technique in nine Turkish commercial rapeseed varieties. The RAPD primers (10-mer oligonucleotides produced 51 scorable loci, 31 loci of which were polymorphic (60.78% and 20 loci (39.22% were monomorphic The RAPD bands were scored as binary matrix data and were analysed using POPGENE version 1.32. At locus level, the values of genetic diversity within population (Hs and total (HT were 0.15 and 0.19 respectively. The genetic differentiation (GST and the gene flow (Nm values between the populations were 0.20 and 2.05 respectively. The mean number of alleles (na, the mean number of effective alleles (nae, and the mean value of genetic diversity (He were 2.00, 1.26, and 0.19 respectively. According to Pearson’s correlation, multiple regression and principal component analyses, eco-geographical conditions in combination had significant effect on genetic indices of commercial B. napus L. varieties were discussed.

Özlem ÖZBEK

2013-02-01

273

Relationship between the genetic diversity of Artemisia halodendron and climatic factors  

Science.gov (United States)

Artemisia halodendron (Asteraceae) is a dominant sand-fixing semi-shrub species native to the Horqin Sandy Land of northeastern China. In this study, we evaluated levels of genetic variation within and among sampled A. halodendron populations from two different hydrothermal regions of the Horqin Sandy Land using inter-simple sequence repeat (ISSR) markers. We also investigated possible relationships between genetic diversity of this species and climatic factors. Our analysis revealed that A. halodendron is highly genetically diverse, with populations from a low hydrothermal level region having higher genetic diversity index values than those from a high hydrothermal level region. An analysis of molecular variation (AMOVA) revealed relatively high levels (>89.83%) of within-population genetic variation. Based on cluster analysis, the 13 studied A. halodendron populations can be clustered into two clades. Genetic diversities of all populations have been influenced by many climatic factors, and Nei's genetic diversity (h) is strongly correlated with annual temperature range (ART). These results have important implications for restoration and management of degraded ecosystems in arid and semi-arid areas.

Huang, Wenda; Zhao, Xueyong; Zhao, Xin; Li, Yuqiang; Lian, Jie; Yun, Jianying

2014-02-01

274

Elevated genetic diversity of mitochondrial genes in asexual populations of Bark Lice ('Psocoptera': Echmepteryx hageni).  

Science.gov (United States)

Asexual reproduction is commonly thought to be associated with low genetic diversity in animals. Echmepteryx hageni (Insecta: 'Psocoptera') is one of several psocopteran species that are primarily parthenogenetic, but also exists in small, isolated sexual populations. We used mitochondrial DNA sequences to investigate the population history and genealogical relationships between the sexual and asexual forms of this species. The asexual population of E. hageni exhibits extremely high mitochondrial haplotype diversity (H=0.98), whereas the sexual forms had significantly lower haplotypic diversity (H=0.25, after correcting for sample size). This diversity in asexuals represents one the greatest genetic diversities reported for asexual animals in the literature. Nucleotide diversities were also higher in asexual compared to sexual populations (?=0.0071 vs. 0.00027). Compared to other reported estimates of ? in insects, asexual nucleotide diversity is high, but not remarkably elevated. Three hypotheses might explain the elevated genetic diversity of asexual populations: (i) larger effective population size, (ii) greater mutation rate or (iii) possible recent origin of sexuals. In addition, phylogeographic analysis revealed little geographic structure among asexual E. hageni, although specimens from the upper Midwest form a single clade and are genetically differentiated. The mismatch distribution and neutrality tests indicate a historical population size increase, possibly associated with expansion from glacial refugia. PMID:21981306

Shreve, Scott M; Mockford, Edward L; Johnson, Kevin P

2011-11-01

275

Assessment of genetic diversity of local and exotic Brassica napus germplasm.  

Science.gov (United States)

Estimation of genetic diversity of Brassica germplasm provides the basis for rapeseed/mustard genetic improvement. Studies were undertaken to estimate the genetic diversity of 30 lines of Brassica napus using Randomly Amplified Polymorphic DNA (RAPD) primers. A total of 30 B. napus genotypes of local and exotic origin were characterized using molecular markers. Four RAPD primers were used to estimate the genetic distances among the genotypes in all the possible combinations. The genetic diversity study revealed different levels of genetic polymorphism for RAPD primers GLA05, GLA07, GLA09 and GLA 10, resulting in amplification of 5.7, 3.5, 3.1 and 5.4 scorable bands (loci) per genotype, respectively. Individual genetic distances observed among B. napus genotypes ranged from 6.5 to 51%. Bivariate data matrix was generated and genetic distances were calculated using Unweighted Pair Group of Arithmetic Mean (UPGMA) procedure. The UPGMA cluster analyses revealed maximum genetic dissimilarity for 8966-1 and 8969-1 genotypes, closely followed by Ganyou-5, 89127-1, 89111-2 and Mlep-048. It is recommended that among the thirty B. napus genotypes, genetically distinct lines pointed out in the present study, should be used in future breeding programs for improvement of Brassica napus. PMID:19070120

Ahmad, Mian Afaq; Munir, Iqbal; Ali, Waqar; Swati, Zahoor Ahmad; Khattak, Muhammad Saeed; Sohail, Quahir; Khan, Imran

2007-08-01

276

Measurement of quantitative species diversity on reclaimed coal mine lands: A brief overview of the Wyoming regulatory proposal  

International Nuclear Information System (INIS)

The Wyoming Land Quality Division (LQD) Coal Rules and Regulations require mine operators to specify quantitative procedures for evaluating postmining species diversity and composition. Currently, permit commitments range from deferring to commit to a quantitative procedure until some future date to applying various similarity/diversity indices for comparison of reclaimed lands to native vegetation communities. Therefore, the LQD began trying to develop a standardized procedure to evaluate species diversity and composition, while providing operator flexibility. Review of several technical publications on the use of similarity and diversity indices, and other measurement techniques indicate that a consensus has not been reached on which procedure is most appropriate for use on reclaimed mine lands. In addition, implementation of many of the recommended procedures are not practical with regards to staff and data limitations. As a result, the LQD has developed an interim procedure, based on site-specific baseline data, to evaluate postmining species diversity and composition success with respect to bond release requests. This paper reviews many of the recommended procedures, outlines some of the pros and cons, and provides a specific example of how the proposed interim procedure was applied to an actual coal mine permit. Implementation of this or a similar procedure would allow for site-specific standardization of permits and regulatory requirements, thus reducing reviewulatory requirements, thus reducing review time and reducing some of the subjectivity surrounding a component of the Wyoming bond release requirements

277

Genetic diversity of Persea bombycina from goalpara district of Assam, India  

OpenAIRE

Assam of the northeastern region of India is unique in terms of its rich biodiversity and multiple ethnicity of its people. The impact of the resultant socio-religio-cultural diversity is also reflected in the diverse traditional ways of silkworm farming. We report the genetic diversity of Persea bombycinaSom” from different locations of Goalpara district of Assam, India, where random amplified polymorphic DNA (RAPD) marker was used in this study. R...

Azizur Rahman; Bhaben Tanti; Gajen Chandra Sarma; Jatin Kalita

2012-01-01

278

Evaluation of Genetic Diversity of Iranian Pomegranate Cultivars Using Fruit Morphological Characteristics and AFLP Markers  

OpenAIRE

The present research evaluated the diversity of a number of Iranian pomegranate cultivars using fruit morphological characteristics and AFLP markers. Thirty-one pomegranate cultivars were collected from Yazd Pomegranate Collection in Iran to study their diversity. Seven AFLP primer combinations were used to amplify a total of 112 polymorphic fragments (47.26%). By use of AFLPs, a low genetic diversity level was detected among cultivars. The relationship between fruit characteristics was analy...

Khayat, Mehdi; Nemati, Hossein; Farsi, Mohammad; Nemati, Zahra; Mirshamsi Kakhki, Amin; Tehranifar, Ali

2012-01-01

279

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

OpenAIRE

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’ indivi...

Geo Coppens d’Eeckenbrugge; Christian Leclerc

2011-01-01

280

[Genetic diversity of modern Russian durum wheat cultivars at the gliadin-coding loci].  

Science.gov (United States)

The allelic diversity at four gliadin-coding loci was examined in modern cultivars of the spring and winter durum wheat Triticum durum Desf. Comparative analysis of the allelic diversity showed that the gene pools of these two types of durum wheat, having different life styles, were considerably different. For the modern spring durum wheat cultivars, a certain reduction of the genetic diversity was observed compared to the cultivars bred in the 20th century. PMID:25715471

2014-05-01

281

An Analysis of Genetic Diversity Across the Maize Genome Using Microsatellites  

OpenAIRE

How domestication bottlenecks and artificial selection shaped the amount and distribution of genetic variation in the genomes of modern crops is poorly understood. We analyzed diversity at 462 simple sequence repeats (SSRs) or microsatellites spread throughout the maize genome and compared the diversity observed at these SSRs in maize to that observed in its wild progenitor, teosinte. The results reveal a modest genome-wide deficit of diversity in maize relative to teosinte. The relative defi...

Vigouroux, Yves; Mitchell, Sharon; Matsuoka, Yoshihiro; Hamblin, Martha; Kresovich, Stephen; Smith, J. Stephen C.; Jaqueth, Jennifer; Smith, Oscar S.; Doebley, John

2005-01-01

282

Genetic Diversity, Population Structure, and Resistance to Phytophthora capsici of a Worldwide Collection of Eggplant Germplasm  

OpenAIRE

Eggplant (Solanum melongena L.) is an important solanaceous crop with high phenotypic diversity and moderate genotypic diversity. Ninety-nine genotypes of eggplant germplasm (species (S. melongena, S. incanum, S. linnaeanum and S. gilo), landraces and heirloom cultivars) from 32 countries and five continents were evaluated for genetic diversity, population structure, fruit shape, and disease resistance to Phytophthora fruit rot. Fruits from each line were measured for fruit shape and evaluate...

Naegele, Rachel P.; Boyle, Samantha; Quesada-ocampo, Lina M.; Hausbeck, Mary K.

2014-01-01

283

Genetic diversity of four protected indigenous chicken breeds in China using microsatellite markers  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The genetic diversity of four protected indigenous chicken breeds was evaluated with 25 microsatellite markers. Polymorphism information content (PIC), heterozygosity with the estimator of genetic differentiation F ST and Nei's genetic distance were evaluated. The results showed that these four prot [...] ected local chicken populations showed high levels of diversity. The proportion of inter-population subdivision among the four protected local chicken populations was 16.0%. The average heterozygosity was 0.514, 0.581, 0.567 and 0.589 in Dongan, Xuefeng black-bone, Xianghuang and Taoyuan chickens, respectively, while the average PIC estimates were 0.455, 0.581, 0.557 and 0.576. A phylogenetic tree was constructed using genetic distance and the neighbour-joining method. Its topology reflects the general pattern of genetic differentiation among the four chicken breeds. The results also showed high genetic diversity and genetic variation among all the breeds. The information about the four local breeds estimated by microsatellite analysis may be useful as an initial guide for the effective conservation of chicken genetic diversity and developing conservation strategies.

Lin, Wei; Bin, Chen; Xiao-ying, Li; Sheng-gui, Liu; Jing-jing, Wang.

284

Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast  

Science.gov (United States)

Thirty nine sea beet [Beta vulgaris L. subsp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluat...

285

Temporal changes on genetic diversity in a sugarcane breeding population using TRAP markers  

Science.gov (United States)

The potential effect of a genetic bottleneck or founder event may explain the reduced level of genetic diversity observed in sugarcane (Saccharum spp.) breeding populations, which were founded on a very small group of interspecific clones. Understanding the impact of plant breeding in reducing this ...

286

Study of Genetic Diversity and Relationships of Diploid and Tetraploid Annual Medics Using Microsatellite Markers  

Directory of Open Access Journals (Sweden)

Full Text Available Annual medics are used for hey production, soil protection, biological fixation of N2 and green manure. In the present study, the inter and intra specific genetic diversity and relatedness of 4 diploid and two tetraploid (M. rugosa and M. scutellata annual medics were evaluated using microsatellite markers. PCR analysis was performed on genomic DNA from individual plant and PCR products were detected using standard polyacrylamide sequencing gel. Totally twenty five polymorphic alleles were observed in the studied species. Average intra-specific genetic diversity ranged from zero (0.0 in both M. rugosa and M. scutellata to 0.114 in M. minima species, and the level of genetic diversity was similar in both M. orbicularis and M. truncatula species. Analysis of molecular variance (AMOVA was used to partition the overall genetic diversity into within and among species, and between diploids and tetraploids. The results revealed significant (P<0.05 inter and intra-specific genetic variation. Pairwise comparisons based on Fst indicated significant differences among all of the species. Clustering analysis using UPGMA algorithm based on coancestary coefficient revealed a clear genetic relationship among species. The hypothesis on a common origin of two tetraploid species was supported by UPGMA clustering and phylogenetic analysis. The high level of Genetic diversity in spiny pod species respect to spineless pod species suggested the high importance of species with spiny pods in annual medics evolution. The findings support the usefulness of microsatellite markers for assessing inter and intra specific genetic diversity, differentiation and genetic relationships.

S. A. Mohammadi

2006-10-01

287

Mine, Yours, Ours? Sharing Data on Human Genetic Variation  

OpenAIRE

The achievement of a robust, effective and responsible form of data sharing is currently regarded as a priority for biological and bio-medical research. Empirical evaluations of data sharing may be regarded as an indispensable first step in the identification of critical aspects and the development of strategies aimed at increasing availability of research data for the scientific community as a whole. Research concerning human genetic variation represents a potential forerunner in the establi...

Milia, Nicola; Congiu, Alessandra; Anagnostou, Paolo; Montinaro, Francesco; Capocasa, Marco; Sanna, Emanuele; Bisol, Giovanni Destro

2012-01-01

288

Genetic diversity in Brazilian populations of Aedes albopictus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Random amplified polymorphic DNA (RAPD) analysis technique was undertaken in Aedes albopictus populations from three states in Brazil, Rio de Janeiro (RJ), Minas Gerais (MG) and Pernambuco (PE), to estimate the level of genetic variability and levels of genetic exchange between populations. Allele a [...] nd genotype frequencies were measured on 47 RAPD loci. Average observed heterozigosity (Ho) ranged from 0.282 in MG to 0.355 in Casa Forte (PE) population. Genetic distances estimates indicated that RJ and MG were more genetically similar than populations from PE. Genetic variation observed in local Brazilian populations was attributed to genetic drift associated with restricted gene flow in recently established populations.

CFJ, Ayres; TPA, Romão; MAV, Melo-Santos; AF, Furtado.

2002-09-01

289

Genetic structure and diversity of the endangered bath sponge Spongia lamella.  

OpenAIRE

1.Natural populations of Mediterranean commercial sponges have declined substantially over recent decades. The present study explored the distribution of genetic diversity of the endangered bath sponge Spongia lamella along the western Mediterranean and the Portuguese coast. Seven microsatellite markers were used to genotype 231 individuals scattered over nine populations. Basic genetic descriptors and population genetic analyses based on FST test, analyses of the molecular variance (AM...

Pe?rez-portela, R.; Noyer, Charlotte; Becerro, Mikel

2014-01-01

290

Comparison of three microsatellite analysis methods for detecting genetic diversity in Phytophthora sojae (Stramenopila: Oomycete)  

OpenAIRE

Analysis of an organism’s genetic diversity requires a method that gives reliable, reproducible results. Microsatellites are robust markers, however, detection of allele sizes can be difficult with some systems as well as consistency among laboratories. In this study, our two laboratories used 219 isolates of Phytophthora sojae to compare three microsatellite methods. Two capillary electrophoresis methods, the Applied Biosystems 3730 Genetic Analyzer and the CEQ 8000 Genetic Analysis system...

Stewart, Silvina; Wickramasinghe, Damitha; Dorrance, Anne E.; Robertson, Alison E.

2011-01-01

291

Prioritization based on neutral genetic diversity may fail to conserve important characteristics in cattle breeds  

OpenAIRE

Conservation of the intraspecific genetic diversity of livestock species requires protocols that assess between-breed genetic variability and also take into account differences among individuals within breeds. Here, we focus on variation between breeds. Conservation of neutral genetic variation has been seen as promoting, through linkage processes, the retention of useful and potentially useful variation. Using public information on beef cattle breeds, with a total of 165 data sets each relat...

Hall, S. J. G.; Lenstra, J. A.; Deeming, D. C.

2012-01-01

292

Genetic structure and diversity of cultivated soybean (Glycine max (L.) Merr.) landraces in China  

OpenAIRE

The Chinese genebank contains 23,587 soybean landraces collected from 29 provinces. In this study, a representative collection of 1,863 landraces were assessed for genetic diversity and genetic differentiation in order to provide useful information for effective management and utilization. A total of 1,160 SSR alleles at 59 SSR loci were detected including 97 unique and 485 low-frequency alleles, which indicated great richness and uniqueness of genetic variation in this core collection. Seven...

Li, Yinghui; Guan, Rongxia; Liu, Zhangxiong; Ma, Yansong; Wang, Lixia; Li, Linhai; Lin, Fanyun; Luan, Weijiang; Chen, Pengyin; Yan, Zhe; Guan, Yuan; Zhu, Li; Ning, Xuecheng; Smulders, M. J. M.; Li, W.

2008-01-01

293

High Genetic Diversity and Structured Populations of the Oriental Fruit Moth in Its Range of Origin  

OpenAIRE

The oriental fruit moth Grapholita (?=?Cydia) molesta is a key fruit pest globally. Despite its economic importance, little is known about its population genetics in its putative native range that includes China. We used five polymorphic microsatellite loci and two mitochondrial gene sequences to characterize the population genetic diversity and genetic structure of G. molesta from nine sublocations in three regions of a major fruit growing area of China. Larval samples were collected thr...

Zheng, Yan; Peng, Xiong; Liu, Gaoming; Pan, Hongyan; Dorn, Silvia; Chen, Maohua

2013-01-01

294

Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings?†  

OpenAIRE

The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rh...

Hur, Moonsuk; Kim, Yongho; Song, Hae-ryong; Kim, Jong Min; Choi, Young Im; Yi, Hana

2011-01-01

295

Mining for Optimised Data Using Clustering Along with Fuzzy Association Rules and Genetic Algorithms  

Directory of Open Access Journals (Sweden)

Full Text Available Data mining also known as knowledge discovery in databases has been recognized as a promising newarea for database research. The proposed work in this paper is about optimizing the data with clusteringand fuzzy association rules using multi-objective genetic algorithms. This algorithm is implemented in twophases. In the first phase it optimizes the data to reduce the number of comparisons using clustering. Inthe second phase it is implemented with multi-objective genetic algorithms to find the optimum number offuzzy association rules using threshold value and fitness function.

G.V.S.N.R.V.Prasad

2010-04-01

296

Genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands  

Directory of Open Access Journals (Sweden)

Full Text Available Investigations of genetic diversity of Heterobasidion spp. in Scots pine, Norway spruce and European silver fir stands indicated that almost all of identified genets occurring in those stands were small and occupied only a single stump. In some cases two, three or even four genets could effectively exist in an individual stump. Genetic similarity of H. annosum s.s. genets varied from 0% to 62%, H. parviporum from 0% to 38% and H. abietinum from 0% to 55%. The oldest and biggest genet was found in laying fir log and overgrew the wood for at least 14 years. This genet belonged to H. abietinum. The size of genets was related to thinning operation, spore dispersal, age of stand or competition in wood colonization.

Piotr ?akomy

2007-12-01

297

Genotyping-By-Sequencing for Plant Genetic Diversity Analysis: A Lab Guide for SNP Genotyping  

Directory of Open Access Journals (Sweden)

Full Text Available Genotyping-by-sequencing (GBS has recently emerged as a promising genomic approach for exploring plant genetic diversity on a genome-wide scale. However, many uncertainties and challenges remain in the application of GBS, particularly in non-model species. Here, we present a GBS protocol we developed and use for plant genetic diversity analysis. It uses two restriction enzymes to reduce genome complexity, applies Illumina multiplexing indexes for barcoding and has a custom bioinformatics pipeline for genotyping. This genetic diversity-focused GBS (gd-GBS protocol can serve as an easy-to-follow lab guide to assist a researcher through every step of a GBS application with five main components: sample preparation, library assembly, sequencing, SNP calling and diversity analysis. Specifically, in this presentation, we provide a brief overview of the GBS approach, describe the gd-GBS procedures, illustrate it with an application to analyze genetic diversity in 20 flax (Linum usitatissimum L. accessions and discuss related issues in GBS application. Following these lab bench procedures and using the custom bioinformatics pipeline, one could generate genome-wide SNP genotype data for a conventional genetic diversity analysis of a non-model plant species.

Gregory W. Peterson

2014-10-01

298

Genetic diversity and structure found in samples of Eritrean bread wheat  

DEFF Research Database (Denmark)

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 sequence repeat markers. A total of 539 alleles were detected. The allele number per locus ranged from 2 to 21, with a mean allele number of 9.2. The average genetic diversity index was 0.66, with values ranging from 0.01 to 0.89. Comparing the three genomes of wheat, the B genome had the highest genetic diversity (0.66) and the D genome the lowest diversity (0.61). A STRUCTURE analysis based on the Bayesian model-based cluster analysis followed by a graphical representation of the distances by non-parametric multidimensional scaling revealed a distinct partition of the Eritrean wheat accessions into two major groups. This is the first report of the genetic diversity and structure of Eritrean bread wheat. © 2013 NIAB.

Desta, Zeratsion Abera; Orabi, Jihad

2014-01-01

299

Assessment of Genetic Diversity in Seed Plants Based on a Uniform ? Criterion  

Directory of Open Access Journals (Sweden)

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 (?, and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform ? criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level ? 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 ? values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower ? 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.

Bin Ai

2014-12-01

300

Genetic Diversity in Mazandaranian Native Cattle: A Comparison with Holstein Cattle, using ISSR Marker  

Directory of Open Access Journals (Sweden)

Full Text Available This study was carried out to investigate genetic diversity in Mazandaranian native cattle population comparised to the Holstein breed, using Inter Simple Sequence Repeats (ISSR marker. A total of 175 animals, including 71 native and 104 cattle of Holstein breed were screened. The extraction of DNA samples were carried out, using modified salting out method. A 19-mer oligonucleotide, (GA9C, was used as primer in PCR reactions. The PCR products showed 15 different fragments with length ranged from 120 to1600 bp in the two breeds.. Genetic variation indexes, including effective number of alleles, Shannon index, Nei’s gene diversity and standard genetic distance were estimated, using POPGene software. Generally, the estimated genetic variation indexes showed low levels of diversity in the two breeds. However, Nei's gene diversity and Shannon index estimation was observed almost two folds in native cattle compared to Holstein breed. Less levels of diversity in Holstein cattle may be because of applying intensive selection programs. Conversely, native cattle have been less affected by selection. Therefore, it seems that Mazandaranian native cattle probably are better for breeding programs than Holstein cattle. Results showed that ISSR Markers are reliable and can be used in genetic diversity investigations.

S. Pashaei

2009-01-01

301

Assessment of genetic diversity in seed plants based on a uniform ? criterion.  

Science.gov (United States)

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 (?), and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform ? criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level ? 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 ? values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower ? 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. PMID:25470277

Ai, Bin; Kang, Ming; Huang, Hongwen

2014-01-01

302

Genetic diversity and population structure of an extremely endangered species: the world's largest Rhododendron  

Science.gov (United States)

Comprehensive studies on the genetic diversity and structure of endangered species are urgently needed to promote effective conservation and management activities. The big tree rhododendron, Rhododendron protistum var. giganteum, is a highly endangered species with only two known endemic populations in a small area in the southern part of Yunnan Province in China. Unfortunately, limited information is available regarding the population genetics of this species. Therefore, we conducted amplified fragment length polymorphism (AFLP) analysis to characterize the genetic diversity and variation of this species within and between remaining populations. Twelve primer combinations of AFLP produced 447 unambiguous and repetitious bands. Among these bands, 298 (66.67 %) were polymorphic. We found high genetic diversity at the species level (percentage of polymorphic loci = 66.67 %, h = 0.240, I = 0.358) and low genetic differentiation (Gst = 0.110) between the two populations. Gene flow between populations (Nm) was relatively high at 4.065. Analysis of molecular variance results revealed that 22 % of the genetic variation was partitioned between populations and 78 % of the genetic variation was within populations. The presence of moderate to high genetic diversity and low genetic differentiation in the two populations can be explained by life history traits, pollen dispersal and high gene flow (Nm = 4.065). Bayesian structure and principal coordinate analysis revealed that 56 sampled trees were clustered into two groups. Our results suggest that some rare and endangered species are able to maintain high levels of genetic diversity even at small population sizes. These results will assist with the design of conservation and management programmes, such as in situ and ex situ conservation, seed collection for germplasm conservation and reintroduction. PMID:25477251

Wu, Fu Qin; Shen, Shi Kang; Zhang, Xin Jun; Wang, Yue Hua; Sun, Wei Bang

2015-01-01

303

Molecular diversity of arbuscular mycorrhizal fungi at a large-scale antimony mining area in southern China.  

Science.gov (United States)

Arbuscular mycorrhizal fungi (AMF) have great potential for assisting heavy metal hyperaccumulators in the remediation of contaminated soils. However, little information is available about the community composition of AMF under natural conditions in soils contaminated by antimony (Sb). The objective of this study was to investigate the characteristics of AMF molecular diversity, and to explore the effects of Sb content and soil properties on the AMF community structure in an Sb mining area. Four Sb mine spoils and one adjacent reference area were selected from around the Xikuangshan mine in southern China. The association of AMF molecular diversity and community composition with the rhizosphere soils of the dominant plant species was studied by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE). Results from all five studied sites showed that the diversity of AMF decreased with increasing Sb concentration. Principal component analysis (PCA) indicated that the AMF community structure was markedly different among these groups. Further redundancy analysis (RDA) showed that Sb contamination was the dominating factor influencing the AMF community structure in the Sb mine area. However, the multivariate analysis showed that, apart from the soil Sb content, extractable nitrogen content and organic matter content also attributed to AMF sequence distribution type. Some AMF sequences were only found in the highly contaminated area and these might be ideal candidates for improving phytoremediation efficiency in Sb mining regions. Gene sequencing analysis revealed that most species were affiliated with Glomus, suggesting that Glomus was the dominant AMF genus in the studied Sb mining area. PMID:25766009

Wei, Yuan; Chen, Zhipeng; Wu, Fengchang; Hou, Hong; Li, Jining; Shangguan, Yuxian; Zhang, Juan; Li, Fasheng; Zeng, Qingru

2015-03-01

304

Endemic and widespread coral reef fishes have similar mitochondrial genetic diversity.  

Science.gov (United States)

Endemic species are frequently assumed to have lower genetic diversity than species with large distributions, even if closely related. This assumption is based on research from the terrestrial environment and theoretical evolutionary modelling. We test this assumption in the marine environment by analysing the mitochondrial genetic diversity of 33 coral reef fish species from five families sampled from Pacific Ocean archipelagos. Surprisingly, haplotype and nucleotide diversity did not differ significantly between endemic and widespread species. The probable explanation is that the effective population size of some widespread fishes locally is similar to that of many of the endemics. Connectivity across parts of the distribution of the widespread species is probably low, so widespread species can operate like endemics at the extreme or isolated parts of their range. Mitochondrial genetic diversity of many endemic reef fish species may not either limit range size or be a source of vulnerability. PMID:25355471

Delrieu-Trottin, Erwan; Maynard, Jeffrey; Planes, Serge

2014-12-22

305

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

DEFF Research Database (Denmark)

Cattle play a very important role in agriculture and food security in Vietnam. A high level of cattle diversity exists and serves different needs of Vietnamese cattle keepers but has not yet been molecularly characterized. This study evaluates the genetic diversity and structure of Vietnamese indigenous cattle populations, using microsatellite markers. A total of 410 individuals from six indigenous cattle populations and an exotic breed was characterized using 27 microsatellite markers A total of 362 alleles was detected and the number of alleles per locus ranged from 8 (INRA005 and ILSTS005) to 17 (ETH185). The level of gene diversity was high indicated by a mean expected heterozygosity (He) across populations and loci of 0.73. Level of inbreeding (mean FIS=0.05) and genetic differentiation (mean FST=0.04) was moderate. The phylogenetic tree based on Reynolds genetic distance reflected 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 diversity.

Pham, Lan Doan; Do, Duy Ngoc

2013-01-01

306

Genetic diversity and variation among botanical varieties of old Portuguese wheat cultivars revealed by ISSR assays.  

Science.gov (United States)

Inter-simple sequence repeats (ISSRs) were used for genetic diversity analyses of an Old Portuguese wheat collection. Eighteen primers produced 96.3 and 98.5% of ISSR polymorphism in bread and durum wheat cultivars, respectively. The unweighted pair group method with arithmetical averages (UPGMA) phenogram clearly split all cultivars based on their species/ploidy, reflecting a defined genetic structure. ISSRs revealed high genetic diversity at interspecific, intraspecific, and intercultivar levels. Thirty-three exclusive ISSR markers were found. Cultivars were clustered according to their botanical varieties and, in a few cases, with their homonym(s). No statistically significant differences were found between genetic diversity parameters of durum and bread wheat, probably due to high intraspecific diversity. Similar analyses were performed among botanical varieties, and their relationships were defined. Cladograms resembled UPGMA clustering. This highly genetically diverse Old wheat collection will be conserved and maintained, and it could be further used in breeding programs to widen the narrow genetic basis of modern wheat varieties and to avoid the loss of rare and unique alleles. PMID:19184405

Carvalho, Ana; Lima-Brito, José; Maçãs, Benvindo; Guedes-Pinto, Henrique

2009-04-01

307

Stress-related hormones and genetic diversity in sea otters (Enhydra lutris)  

Science.gov (United States)

Sea otters (Enhydra lutris) once ranged throughout the coastal regions of the north Pacific, but were extirpated throughout their range during the fur trade of the 18th and 19th centuries, leaving only small, widely scattered, remnant populations. All extant sea otter populations are believed to have experienced a population bottleneck and thus have lost genetic variation. Populations that undergo severe population reduction and associated inbreeding may suffer from a general reduction in fitness termed inbreeding depression. Inbreeding depression may result in decreased testosterone levels in males, and reduced ability to respond to stressful stimuli associated with an increase in the stress-related adrenal glucocorticoid hormones, cortisol and corticosterone. We investigated correlations of testosterone, cortisol, and corticosterone with genetic diversity in sea otters from five populations. We found a significant negative correlation between genetic diversity and both mean population-level (r2 = 0.27, P < 0.001) and individual-level (r2 = 0.54, P < 0.001) corticosterone values, as well as a negative correlation between genetic diversity and cortisol at the individual level (r2 = 0.17, P = 0.04). No relationship was found between genetic diversity and testosterone (P = 0.57). The strength of the correlations, especially with corticosterone, suggests potential negative consequences for overall population health, particularly for populations with the lowest genetic diversity. ?? 2009 by the Society for Marine Mammalogy.

Larson, S.; Monson, D.; Ballachey, B.; Jameson, R.; Wasser, S.K.

2009-01-01

308

Genetic Diversity among Clinical Isolates of Candida glabrata Analyzed by Randomly Amplified Polymorphic DNA and Multilocus Enzyme Electrophoresis Analyses  

Science.gov (United States)

The genetic diversity of 47 clinical and reference strains of Candida glabrata from several geographical origins and diverse clinical disorders, with different antifungal susceptibilities, as well as their genetic relationships were studied through multilocus enzyme electrophoresis (MLEE) and randomly amplified polymorphic DNA (RAPD) techniques. The genetic diversity estimated for 11 MLEE loci measured as average heterozygosity (h) was 0.055. A high level of genetic relatedness among isolates was established by cluster analysis. Forty-nine RAPD markers were analyzed, and the average genetic diversity among isolates, estimated by Shannon's index (Ho), was 0.372. The ?ST values estimated through an analysis of molecular variance to assess genetic differentiation among isolates revealed no genetic differentiation among them. Our results revealed very low genetic diversity among isolates, a lack of differentiation, and no association with their geographic origin and the clinical characteristics. PMID:14532225

Boldo, Xavier M.; Villa-Tanaca, Lourdes; Zúñiga, Gerardo; Hernández-Rodríguez, César

2003-01-01

309

Genetic diversity of domestic pigs as revealed by microsatellites: a mini review  

Directory of Open Access Journals (Sweden)

Full Text Available Of the several hundred breeds of pigs in the world, many are in danger of extinction and others are threatened by inefficient use or loss due to cross breeding. Special efforts are required to conserve these genetic resources for food security and rural development but it is not possible to conserve all breeds. Microsatellites, which are short tandem nucleotide repeats found scattered throughout the genome of eukaryotes, have been used to evaluate genetic diversity present within livestock populations to assist in rationalising breed conservation programmes and ensure the greatest possible conservation of diversity. This review provides insights into the use of microsatellite markers to reveal origin, genetic structure and diversity within and across various domestic pig breeds around the world. However, in future, microsatellites may be replaced by panels of single nucleotide polymorphism (SNP markers for genome-wide population genetic analysis. Meanwhile, microsatellites are still widely employed and for some species may never be replaced by SNP.

C. Moran

2011-02-01

310

Genetic diversity within and among Lepidium draba populations from Eastern Anatolia based on RAPD analysis.  

Science.gov (United States)

Genetic variation and structure of six natural populations of Lepidium draba L. from Eastern Anatolia were assessed using random amplified polymorphic DNA (RAPD) markers. For RAPD analysis, 12 primers generated 218 reproducible bands across the six populations analyzed, of which 73 bands (33.3%) were polymorphic. The mean Nei's gene diversity value for all six populations was 0.1771. Shannon's information index varied with population (0.2278-0.3082), averaging 0.2608. Analysis of molecular variance (AMOVA) showed that genetic diversity was greater within populations (58.66%) than among populations (30.68%). In addition, the variation between groups was 10.33%. The genetic differentiation among populations (G (ST)) was 0.3210, indicating that most genetic diversity occurs within populations. Gene flow (Nm) was low, at only 0.5288. PMID:20496111

Aksakal, Ozkan; Sunar, Serap; Kaya, Yusuf; Agar, Guleray

2010-08-01

311

Diversity, genetic mapping, and signatures of domestication in the carrot (Daucus carota L.) genome, as revealed by Diversity Arrays Technology (DArT) markers  

Science.gov (United States)

Carrot is one of the most economically important vegetables worldwide, however, genetic and genomic resources supporting carrot breeding remain limited. We developed a Diversity Arrays Technology (DArT) platform for wild and cultivated carrot and used it to investigate genetic diversity and to devel...

312

Low genetic diversity and minimal population substructure in the endangered Florida manatee: implications for conservation  

Science.gov (United States)

Species of management concern that have been affected by human activities typically are characterized by low genetic diversity, which can adversely affect their ability to adapt to environmental changes. We used 18 microsatellite markers to genotype 362 Florida manatees (Trichechus manatus latirostris), and investigated genetic diversity, population structure, and estimated genetically effective population size (Ne). The observed and expected heterozygosity and average number of alleles were 0.455 ± 0.04, 0.479 ± 0.04, and 4.77 ± 0.51, respectively. All measures of Florida manatee genetic diversity were less than averages reported for placental mammals, including fragmented or nonideal populations. Overall estimates of differentiation were low, though significantly greater than zero, and analysis of molecular variance revealed that over 95% of the total variance was among individuals within predefined management units or among individuals along the coastal subpopulations, with only minor portions of variance explained by between group variance. Although genetic issues, as inferred by neutral genetic markers, appear not to be critical at present, the Florida manatee continues to face demographic challenges due to anthropogenic activities and stochastic factors such as red tides, oil spills, and disease outbreaks; these can further reduce genetic diversity of the manatee population.

Tucker, Kimberly Pause; Hunter, Margaret E.; Bonde, Robert K.; Austin, James D.; Clark, Ann Marie; Beck, Cathy A.; McGuire, Peter M.; Oli, Madan K.

2012-01-01

313

Local genetic diversity of sorghum in a village in northern Cameroon: structure and dynamics of landraces.  

Science.gov (United States)

We present the first study of patterns of genetic diversity of sorghum landraces at the local scale. Understanding landrace diversity aids in deciphering evolutionary forces under domestication, and has applications in the conservation of genetic resources and their use in breeding programs. Duupa farmers in a village in Northern Cameroon distinguished 59 named sorghum taxa, representing 46 landraces. In each field, seeds are sown as a mixture of landraces (mean of 12 landraces per field), giving the potential for extensive gene flow. What level of genetic diversity underlies the great morphological diversity observed among landraces? Given the potential for gene flow, how well defined genetically is each landrace? To answer these questions, we recorded spatial patterns of planting and farmers' perceptions of landraces, and characterized 21 landraces using SSR markers. Analysis using distance and clustering methods grouped the 21 landraces studied into four clusters. These clusters correspond to functionally and ecologically distinct groups of landraces. Within-landrace genetic variation accounted for 30% of total variation. The average F(is) over landraces was 0.68, suggesting high inbreeding within landraces. Differentiation among landraces was substantial and significant (F(st) = 0.36). Historical factors, variation in breeding systems, and farmers' practices all affected patterns of genetic variation. Farmers' practices are key to the maintenance, despite gene flow, of landraces with different combinations of agronomically and ecologically pertinent traits. They must be taken into account in strategies of conservation and use of genetic resources. PMID:17089177

Barnaud, Adeline; Deu, Monique; Garine, Eric; McKey, Doyle; Joly, Hélène I

2007-01-01

314

The genetic diversity of the mangrove kandelia obovata in China revealed by ISSR analysis  

International Nuclear Information System (INIS)

The genetic diversity of 7 populations of Kandelia obovata in China was characterized using inter simple sequence repeats (ISSR) technique. A total of 50 primers were screened, of which 9 polymorphic and informative patterns were selected to determine genetic relationships. ISSR amplification was conducted on 140 individuals from 7 populations, and 88 polymorphic loci were detected from 106 total loci. The total percentage of polymorphic loci (PPL) was 83.02%. The percentage of PPL at the population level ranged from 32.08% to 47.17%, with an average of 39.89%. Nei's gene diversity (H) and Shannon's information index (I) of K. obovata at the species level were 0.3631 and 0.5203, respectively. The genetic differentiation coefficient (Gst) among populations was 0.5548. Among populations component accounted for 55.48% of the total variation, whereas the within populations component accounted for 44.52%, suggesting that genetic differentiation among K. obovata populations was relatively high. The gene flow among populations was 0.4012, indicating that gene flow was low among geographically diverse populations of K. obovata. The results of the genetic diversity and cluster analysis suggest that geographical isolation of K. obovata populations mainly results in low gene flow and random genetic drift, leading to genetic differentiation. (author)

315

Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa  

Energy Technology Data Exchange (ETDEWEB)

A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv, viciae genotypes in the absence of its host plant.

Zhang, X.X.; Kosier, B.; Priefer, U.B. [Rheinisch-Westfaelische TH Aachen, Aachen (Germany)

2001-09-01

316

Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa.  

Science.gov (United States)

A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv. viciae genotypes in the absence of its host plant. PMID:11555271

Zhang, X X; Kosier, B; Priefer, U B

2001-09-01

317

Genetic diversity of agricultural crops in Flanders over the last five decades  

OpenAIRE

In this study, we describe the evolution of crop diversity in Flanders, using three indicators to measure diversity between crops and within crops: the Shannon index (H), the evenness index (E) - both used for diversity between and within crops - and genetic relatedness between varieties (CP). Despite the significant increase in the number of crops in Flanders, from 67 in 1950 to 101 in 2002, the results show a weak decrease in crop diversity between 1950 and 2002: H decreased from 2.52 to 2....

Meul, Marijke; Nevens, Frank; Reheul, Dirk

2005-01-01

318

Analysis of genetic diversity of Guizotia abyssinica from Ethiopia using inter simple sequence repeat markers.  

Science.gov (United States)

Within and among population genetic diversity of 37 Guizotia abyssinica populations from Ethiopia were analyzed using inter simple sequence repeats (ISSRs). Five primers amplified a total of 118 genomic DNA fragments across a total of 370 individuals of which 106 were polymorphic (89.83%). The average number of polymorphic bands per primer was 21.2. More bands were generated by primer UBC 888 (BDB(CA)(7.) The total genetic diversity (Ht) and the coefficient of genetic differentiation (Gst) were 0.4115 and 0.0918 respectively, while the within population genetic diversity (Hs) and the among population genetic diversity(Dst) were 0.3738 and 0.03776 respectively suggesting more variability within the populations than among them. The standard genetic distances between the G. abyssinica populations of the eight regions ranged from 0.0281 (between Wollo and Gojam) to 0.1148 (between Jimma and Hararghe). Generally, the standard genetic distances are smaller between populations of neighboring regions and highest between those of Jimma and the other regions, ranging from 0.0696 (between Jimma and Shewa) to 0.1148 (between Jimma and Hararghe). The ISSR based UPGMA clustering using the standardized genetic distances matrix also placed populations from neighboring regions closer than those from farther apart areas, while the UPGMA clustering by regions based on the standard genetic distances produced three clusters following the proximity and the contiguity of the regions. The mean Shannon Weaver diversity indices for the populations of the eight regions ranged from 0.8197 (Jimma) to 0.9176 (Hararghe), with a mean of 0.8841 for the whole material. PMID:17567436

Petros, Yohannes; Merker, Arnulf; Zeleke, Habtamu

2007-03-01

319

Estimation of Genetic Diversity of Four Chrysanthemum Mini Cultivars Using RAPD  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of the present study was to estimate the genetic relationship among the different Chrysanthemum cultivars with relation to their morphological and biochemical characteristics and geographical distribution. DNA fingerprinting using RAPD is very easy and inexpensive way to study the genetic diversity. Genetic distance between four mini Chrysanthemum cultivars was studied through RAPD analysis. Total of 40 primers have been screened from which four have been trailed for all the four genotypes. Similarity among the cultivars was very high showing low genetic diversity, which is quite expected. One of these primers can differentiate cultivars from each other. So RAPD can be used successfully to estimate the genetic distance and also for the species identification.

J. Chatterjee

2005-01-01

320

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

Science.gov (United States)

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. PMID:24615092

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

2014-01-01

321

Analysis of the genetic diversity and differentiation of Fenneropenaeus penicillatus populations using AFLP technology  

Science.gov (United States)

Fenneropenaeus penicillatus (redtail shrimp) is an important marine commercial animal in China. Recently, its resources have been depleted rapidly as a result of, for example, over-exploitation and environmental degradation of spawning grounds. Therefore, we analyzed the genetic diversity and differentiation of nine wild populations of F. penicillatus of China (Ningde, Lianjiang, Putian, Xiamen, Quanzhou, Zhangpu, Dongshan, Nanao, and Shenzhen populations) by amplified fragment length polymorphism (AFLP) technology, to provide genetic information necessary for resource protection, rejuvenation, artificial breeding, and sustainable use of the resource. Eight AFLP primer pairs were used for amplification, and 508 bands were detected among the populations. The results show that the percentage of polymorphic loci ( P) ranged from 41.34% to 63.58%; the Nei's gene diversity ( H) of the populations was 0.119 4-0.230 5; and Shannon's Information Index ( I) was 0.184 1-0.342 5. These genetic data indicate that the genetic diversity of F. penicillatus was high. The genetic differentiation coefficient ( G ST=0.216 2) and gene flow ( N m=1.812 4) show that there was a high level of genetic differentiation and a moderate level of gene flow among populations. More studies on the genetic differentiation mechanism of F. penicillatus along the south-eastern coast of China need to be conducted to find more effective scientific protection strategies for the conservation of F. penicillatus genetic resources.

Zhang, Guiling; Cao, Yuanyu; Li, Zhongbao; Chen, Jin; Zhao, Binli; Lei, Guanggao; Wang, Zhanlin

2012-05-01

322

Description and analysis of genetic diversity among squash accessions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A abobrinha de inverno compõe um cultivo agrícola com valor econômico determinado exercendo, no entanto, um papel importante em zonas caracterizadas por um cultivo menos intensivo. Na Grécia, o cultivo da abobrinha se baseia, principalmente, em variedades locais conservadas a muitos anos por agricul [...] tores locais. Uma parte do cultivo nuclear da abobrinha, que é conservada pelo Banco Grego de Genes, foi melhorada utilizando-se dados morfológicos e moleculares, especialmente dezesseis cultivos de abobrinha classificados incompletamente, que foram diferenciados apenas com base em características morfológicas, em relação a uma avaliação à resistência contra o Fusarium Oxysporum, em dois isolamentos. Foi realizada uma análise molecular utilizando DNA Polimórficos Casual Amplificados índices (RAPDs), revelando um alto nível de polimorfismo. Para estudar a diversidade genética entre a coleção de abobrinhas, um procedimento de agrupamento foi realizado usando-se o algoritmo U.P.G.M.A. Dois dendrogramas independentes, um morfofisiológico e outro para dados moleculares, foram coletados, classificando as coleções em dois e três grupos básicos, respectivamente. Apesar do número diferente dos grupos, foram introduzidas muitas semelhanças entre os dois dendrogramas e um terceiro dendrograma foi produzido como resultado da combinação dos dois primeiros, baseado na distância de Gower e no algoritmo de agrupamento U.P.G.M.A. Para determinar o número ótimo dos grupos, a aproximação "upper tail" foi aplicada. O grupo mais aceitável das coleções foi conseguido usando-se índices RAPD, assim como a combinação dos dois grupos de dados diferentes, classificando as coleções em três grupos consideravelmente diferentes. Os grupos que correspondem às três espécies cultivadas diferentemente, que correspondem às três espécies cultivadas diferentemente por C.máxima Duch., C.moschata Duch. e C. pepo L. além disso, os mesmos resultados foram conseguidos usando-se a "Principal Component Analysis". Abstract in english In this work, the part of the squash core collection, maintained in the Greek Gene Bank, was assessed using the morphological and molecular data. Sixteen incompletely classified accessions of the squash were characterized along with an evaluation of their resistance against two isolates of Fusarium [...] oxysporum. A molecular analysis using Random Amplified Polymorphic DNA (RAPD) markers was also performed, revealing high level of polymorphism. To study the genetic diversity among the squash accessions, a clustering procedure using Unweighed Pair Group Method and Arithmetic Average (UPGMA) algorithm was also adopted. Two independent dendrograms, one for the morphophysiological and one for molecular data were obtained, classifying the accessions into two and three main clusters, respectively. Despite the different number of the clusters there were many similarities between these two dendrograms, and a third dendrogram resulting from their combination was also produced, based on Gower's distance and UPGMA clustering algorithm. In order to determine the optimal number of clusters, the upper tail approach was applied. The more reliable clustering of the accessions was accomplished using RAPD markers as well as the combination of the two different data sets, classifying the accessions into three significantly different groups. These groups corresponded to the three different cultivated species of C. maxima Duch., C. moschata Duch., and C. pepo L. The same results were also obtained using Principal Component Analysis.

Athanasios L., Tsivelikas; Olga, Koutita; Anastasia, Anastasiadou; George N., Skaracis; Ekaterini, Traka-Mavrona; Metaxia, Koutsika-Sotiriou.

2009-04-01

323

Description and analysis of genetic diversity among squash accessions  

Directory of Open Access Journals (Sweden)

Full Text Available In this work, the part of the squash core collection, maintained in the Greek Gene Bank, was assessed using the morphological and molecular data. Sixteen incompletely classified accessions of the squash were characterized along with an evaluation of their resistance against two isolates of Fusarium oxysporum. A molecular analysis using Random Amplified Polymorphic DNA (RAPD markers was also performed, revealing high level of polymorphism. To study the genetic diversity among the squash accessions, a clustering procedure using Unweighed Pair Group Method and Arithmetic Average (UPGMA algorithm was also adopted. Two independent dendrograms, one for the morphophysiological and one for molecular data were obtained, classifying the accessions into two and three main clusters, respectively. Despite the different number of the clusters there were many similarities between these two dendrograms, and a third dendrogram resulting from their combination was also produced, based on Gower's distance and UPGMA clustering algorithm. In order to determine the optimal number of clusters, the upper tail approach was applied. The more reliable clustering of the accessions was accomplished using RAPD markers as well as the combination of the two different data sets, classifying the accessions into three significantly different groups. These groups corresponded to the three different cultivated species of C. maxima Duch., C. moschata Duch., and C. pepo L. The same results were also obtained using Principal Component Analysis.A abobrinha de inverno compõe um cultivo agrícola com valor econômico determinado exercendo, no entanto, um papel importante em zonas caracterizadas por um cultivo menos intensivo. Na Grécia, o cultivo da abobrinha se baseia, principalmente, em variedades locais conservadas a muitos anos por agricultores locais. Uma parte do cultivo nuclear da abobrinha, que é conservada pelo Banco Grego de Genes, foi melhorada utilizando-se dados morfológicos e moleculares, especialmente dezesseis cultivos de abobrinha classificados incompletamente, que foram diferenciados apenas com base em características morfológicas, em relação a uma avaliação à resistência contra o Fusarium Oxysporum, em dois isolamentos. Foi realizada uma análise molecular utilizando DNA Polimórficos Casual Amplificados índices (RAPDs, revelando um alto nível de polimorfismo. Para estudar a diversidade genética entre a coleção de abobrinhas, um procedimento de agrupamento foi realizado usando-se o algoritmo U.P.G.M.A. Dois dendrogramas independentes, um morfofisiológico e outro para dados moleculares, foram coletados, classificando as coleções em dois e três grupos básicos, respectivamente. Apesar do número diferente dos grupos, foram introduzidas muitas semelhanças entre os dois dendrogramas e um terceiro dendrograma foi produzido como resultado da combinação dos dois primeiros, baseado na distância de Gower e no algoritmo de agrupamento U.P.G.M.A. Para determinar o número ótimo dos grupos, a aproximação "upper tail" foi aplicada. O grupo mais aceitável das coleções foi conseguido usando-se índices RAPD, assim como a combinação dos dois grupos de dados diferentes, classificando as coleções em três grupos consideravelmente diferentes. Os grupos que correspondem às três espécies cultivadas diferentemente, que correspondem às três espécies cultivadas diferentemente por C.máxima Duch., C.moschata Duch. e C. pepo L. além disso, os mesmos resultados foram conseguidos usando-se a "Principal Component Analysis".

Athanasios L. Tsivelikas

2009-04-01

324

Induced genetic diversity in mungbean (Vigna radiata L. Wilczek)  

International Nuclear Information System (INIS)

Variability and genetic divergence for 8 economically important metric traits were studied in 34 micromutants of mungbean and 2 base genotypes. Primary branches, pods per cluster and clusters per plant showed high heritability with high genetic advance. On the basis of D2-values, micromutants could be grouped into 9 clusters, indicating that mutation is effective in creating genetic divergence. Primary branches, pods per cluster and days to maturity contributed maximum to the divergence of the micromutants. Thus hybridization among the selected micro-mutants would have maximum chance for generation of variability with transgressive segregants of partical utility. (author). 5 tabs., 6 refs

325

Estimation of breed contributions to present and future genetic diversity of 44 North Eurasian cattle breeds using core set diversity measures  

OpenAIRE

Abstract Extinction of breeds threatens genetic diversity of livestock species. The need to conserve genetic diversity is widely accepted but involves in general two questions: (i) is the expected loss of diversity in a set of breeds within a defined future time horizon large enough to establish a conservation plan, and if so (ii) which breeds should be prioritised for such a conservation plan? The present study uses a marker assisted methodology to address these questions. The methodology co...

Popov Ruslan; Kiselyova Tatyana; Ivanova Zoya; Ammosov Innokentyi; Vilkki Johanna; Kalm Ernst; Li Meng; Tapio Ilma; Kantanen Juha; Bennewitz Jörn; He, Meuwissen Theo

2006-01-01

326

Genetically Diverse Group A Streptococci from Children in Far-Western Nepal Share High Genetic Relatedness with Isolates from Other Countries  

OpenAIRE

The genetic diversity of group A streptococci (GAS) throughout much of the world has not been adequately explored. To assess genetic variation among GAS in western Nepal, 120 noninvasive GAS, collected from eight different villages, were genetically characterized using emm typing, sof sequencing, and multilocus sequence typing (MLST). A high level of genetic diversity was observed among these isolates, with 51 genotypes based upon 51 multilocus sequence types (STs), 45 emm sequence types, and...

Sakota, Varja; Fry, Alicia M.; Lietman, Thomas M.; Facklam, Richard R.; Li, Zhongya; Beall, Bernard

2006-01-01

327

Genetic diversity and relationships among Italian Merino derived breeds assessed by microsatellites  

Directory of Open Access Journals (Sweden)

Full Text Available The conservation of genetic variability is one of the main objectives in the field of genetics applied to domestic livestock. Among molecular markers, microsatellites are particularly appreciated and widely utilized for the study of animal genome. In this study a genetic characterization of three Italian Merino derived sheep breeds was carried out by 30 microsatellites markers; the genetic relationships between these breeds and the Spanish ancestors were also investigated. All the microsatellites examined resulted polymorphic and a total of 375 alleles were detected. FIS values of the three Italian Merinos demonstrate a low level of inbreeding. The results show a good genetic variability of all the studied breeds; at the same time, the genetic identity of each breed is confirmed. These molecular data can be utilized to improve the present selection schemes and the plans to preserve genetic diversity.

Francesca Maria Sarti

2010-01-01

328

Genetic diversity of Persea bombycina from goalpara district of Assam, India  

Directory of Open Access Journals (Sweden)

Full Text Available Assam of the northeastern region of India is unique in terms of its rich biodiversity and multiple ethnicity of its people. The impact of the resultant socio-religio-cultural diversity is also reflected in the diverse traditional ways of silkworm farming. We report the genetic diversity of Persea bombycinaSom” from different locations of Goalpara district of Assam, India, where random amplified polymorphic DNA (RAPD marker was used in this study. RAPD analyses of ten genotypes of “Som” from Goalpara district of Assam, India with B19 RAPD primer generated 86 bands, showing an average of 8.6 bands per sample and 30.2% (26 bands of these were polymorphic. The number of bands per accession ranged from 5 to 10 with a mean of 8.6 and the size range of the amplified bands was 250 - 6000 bp. In a UPGMA phenetic dendrogram based on Jaccard’s coefficient, the P. bombycina accessions showed a high level of genetic variation, as indicated by genetic similarity and revealed 10 “Som” genotypes in to three major clusters. This study may be useful in identifying diverse genetic stocks of P. bombycina, which may then be conserved on a priority basis. The RAPD primer used in this study was able to distinguish all the 10 genotypes of “Som” plants, which can be used to assess genetic diversity.

Azizur Rahman

2012-02-01

329

Genetic Diversity Analysis of CIMMYT Bread Wheat (Triticum aestivum L. Lines by SRAP Markers  

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Full Text Available Genetic diversity is one of the key factors for the improvement of many crop plants including wheat. Many wheat scientistshave studied genetic diversity in wheat germplasm using different molecular markers which have provided a powerfulapproach to analyze genetic relationships among wheat germplasms. In this study, genetic diversity of CIMMYT(International maize and wheat improvement center bread wheat lines collected from Russia was evaluated using 30sequence-related amplified polymorphism (SRAP primer combinations. 686 DNA band was obtained from the 23 primercombinations and approximately 90% of them were found to be polymorphic. Ratio of polymorphic loci, Shannon'sdiversity index and gene diversity were found 82.61%, 0.39 and 0.26 respectively. The three main clusters were found byusing UPGMA (Unweighted Pair Group Method with Arithmetic Mean cluster analysis method and the average rate ofgenetic similarity with 0.462. Two main clusters were shown in principal component analysis (PCA which is consistentwith the result of UPGMA. It can be concluded that SRAP markers can be used for wheat genetic diversity studies and havepotential linkage mapping, molecular characterizations and marker assisted selection (MAS breeding.

Ertugrul FILIZ

2012-12-01

330

Genetic diversity of native potatoes (Solanumspp. conserved in landraces from Peru  

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Full Text Available This paper analyzes the genetic diversity of 79 accessions of native potato varieties (Solanum spp. using 18 microsatellite markers. A random sample from Ayacucho, Cajamarca, Cusco, Huancavelica and Puno from "chacras" of farmers who collaborated with the "In situ conservation of native crops and wild relatives" were used. 17 markers amplified one single polymorphic locus, the mean number of alleles per locus was 8.79. The mean similarity was 0.62 and clustering indexes varied between 0.41 and 0.98. 19 loci showed a total of 166 alleles. Cuzco had the highest number of alleles (130 alleles. Of the 166 characterized alleles, 72 alleles (43.37% were common or shared with 5 sampling sites. Puno had the highest number of exclusive alleles (8 alleles. The 42 varieties of S. tuberosum subsp. andigena showed a mean diversity of 0.74 and 18 varieties of S. x chauchaan average diversity of 0.70. Polymorphism (PIC = 0.55 to 0.85 and genetic diversity indices show that microsatellites evaluated can identify high levels of genetic diversity, but also are not sufficient to discriminate differentiated by origin or species groups. Our analyzes indicate a high genetic diversity and are consistent with inventories and morphological characterizations performed in situ, we can also conclude that there would be a common pool of genes would be found widely distributed among the regions studied.

Julián Soto

2014-03-01

331

Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific hydrothermal vents  

Science.gov (United States)

Background: Deep-sea hydrothermal vent animals occupy patchy and ephemeral habitats supported by chemosynthetic primary production. Volcanic and tectonic activities controlling the turnover of these habitats contribute to demographic instability that erodes genetic variation within and among colonies of these animals. We examined DNA sequences from one mitochondrial and three nuclear gene loci to assess genetic diversity in the siboglinid tubeworm, Riftia pachyptila, a widely distributed constituent of vents along the East Pacific Rise and Galpagos Rift. Results: Genetic differentiation (FST) among populations increased with geographical distances, as expected under a linear stepping-stone model of dispersal. Low levels of DNA sequence diversity occurred at all four loci, allowing us to exclude the hypothesis that an idiosyncratic selective sweep eliminated mitochondrial diversity alone. Total gene diversity declined with tectonic spreading rates. The southernmost populations, which are subjected to superfast spreading rates and high probabilities of extinction, are relatively homogenous genetically. Conclusions: Compared to other vent species, DNA sequence diversity is extremely low in R. pachyptila. Though its dispersal abilities appear to be effective, the low diversity, particularly in southern hemisphere populations, is consistent with frequent local extinction and (re)colonization events. ?? 2011 Coykendall et al; licensee BioMed Central Ltd.

Coykendall, D.K.; Johnson, S.B.; Karl, S.A.; Lutz, R.A.; Vrijenhoek, R.C.

2011-01-01

332

Diversity, genetic mapping, and signatures of domestication in the carrot (Daucus carota L.) genome, as revealed by Diversity Arrays Technology (DArT) markers  

OpenAIRE

Carrot is one of the most economically important vegetables worldwide, but genetic and genomic resources supporting carrot breeding remain limited. We developed a Diversity Arrays Technology (DArT) platform for wild and cultivated carrot and used it to investigate genetic diversity and to develop a saturated genetic linkage map of carrot. We analyzed a set of 900 DArT markers in a collection of plant materials comprising 94 cultivated and 65 wild carrot accessions. The accessions were attribu...

Grzebelus, Dariusz; Iorizzo, Massimo; Senalik, Douglas; Ellison, Shelby; Cavagnaro, Pablo; Macko-podgorni, Alicja; Heller-uszynska, Kasia; Kilian, Andrzej; Nothnagel, Thomas; Allender, Charlotte; Simon, Philipp W.; Baranski, Rafal

2013-01-01

333

Genetic diversity among sugarcane (Saccharum spp.) varieties using molecular markers  

OpenAIRE

The genetic base of today's sugarcane cultivars appears to be narrow and could be the reason for current slow progress in improving sugarcane crops. Sixty-three primer pairs (producing 263 polymorphic fragments) flanking simple sequence repeats or micro-satellites were used for assessing the genetic variability of five S. officinarum clones and 33 sugarcane cultivars used in CENICAÑA breeding projects, selected for their economic and agronomic im-portance in several Central and South-America...

Riascos, John J.; Victoria, Jorge I.; Fernando Angel

2007-01-01

334

Genetic diversity of Sardinian goat population based on microsatellites  

Directory of Open Access Journals (Sweden)

Full Text Available During the last century, the selection for production traits of the main livestock species has led to a reduction in number of local populations with consequent loss of genetic variability. In Sardinia, the genetic improvement strategy has been based on selection for the local pure breed in sheep, whereas in the other species (cattle, swine and goat, an often unplanned crossbreeding with improved breeds has been applied.

A. Carta

2010-01-01

335

Genetic diversity of Plantago ovata Forsk. through RAPD markers  

OpenAIRE

Genetic variability of 15 sets of Plantago ovata Forsk. studied using 11 arbitrary oligonucleotide primers. Among the 90 DNAfragments produced 71 fragments were found to be polymorphic. The mean number of polymorphic bands per primer among 15Plantago ovata genotypes was 6.45 . The higher polymorphism (90.00 %) was exhibited by primer OPF-17, while the lowerpolymorphism (60.00 %) was detected by OPF-2. The genetic similarity matrix from RAPD data for 15 genotypes was calculatedbased on Jaccard...

Ashish G Vala, R. S. Fougat And G. C. Jadeja

2011-01-01

336

Genetic diversity in yellow passion fruit (Passiflora edulis Sims based on RAPD  

Directory of Open Access Journals (Sweden)

Full Text Available This study aimed to evaluate the genetic diversity by RAPD markers in 20 genotypes of ‘yellow’ passion fruit (Passiflora edulis Sims. The 16 primers generated 92 markers, 57 (62% of which were polymorphic. The genetic distance (gdij estimated by the complement of the Dice index (gdij = 0.19 and genotype grouping based on UPGMA algorithm showed low variability among genotypes. These results show a narrower genetic basis than reported for other Passiflora populations and the need to increase this variability by germplasm introduction. Divergent genotypes were also identified for the choice of parents for crosses for genetic gains in traits previously selected within the population studied.

Carlos Bernard Moreno Cerqueira-Silva

2010-01-01

337

High genetic differentiation and cross-shelf patterns of genetic diversity among Great Barrier Reef populations of Symbiodinium  

Science.gov (United States)

The resilience of Symbiodinium harboured by corals is dependent on the genetic diversity and extent of connectivity among reef populations. This study presents genetic analyses of Great Barrier Reef (GBR) populations of clade C Symbiodinium hosted by the alcyonacean coral, Sinularia flexibilis. Allelic variation at four newly developed microsatellite loci demonstrated that Symbiodinium populations are genetically differentiated at all spatial scales from 16 to 1,360 km (pairwise ?ST = 0.01-0.47, mean = 0.22); the only exception being two neighbouring populations in the Cairns region separated by 17 km. This indicates that gene flow is restricted for Symbiodinium C hosted by S. flexibilis on the GBR. Patterns of population structure reflect longshore circulation patterns and limited cross-shelf mixing, suggesting that passive transport by currents is the primary mechanism of dispersal in Symbiodinium types that are acquired horizontally. There was no correlation between the genetic structure of Symbiodinium populations and their host S. flexibilis, most likely because different factors affect the dispersal and recruitment of each partner in the symbiosis. The genetic diversity of these Symbiodinium reef populations is on average 1.5 times lower on inshore reefs than on offshore reefs. Lower inshore diversity may reflect the impact of recent bleaching events on Sinularia assemblages, which have been more widespread and severe on inshore reefs, but may also have been shaped by historical sea level fluctuations or recent migration patterns.

Howells, E. J.; van Oppen, M. J. H.; Willis, B. L.

2009-03-01

338

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

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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 ?ST 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.

Zlatko Liber

2014-09-01

339

Genetic diversity and relationships of korean chicken breeds based on 30 microsatellite markers.  

Science.gov (United States)

The effective management of endangered animal genetic resources is one of the most important concerns of modern breeding. Evaluation of genetic diversity and relationship of local breeds is an important factor towards the identification of unique and valuable genetic resources. This study aimed to analyze the genetic diversity and population structure of six Korean native chicken breeds (n = 300), which were compared with three imported breeds in Korea (n = 150). For the analysis of genetic diversity, 30 microsatellite markers from FAO/ISAG recommended diversity panel or previously reported microsatellite markers were used. The number of alleles ranged from 2 to 15 per locus, with a mean of 8.13. The average observed heterozygosity within native breeds varied between 0.46 and 0.59. The overall heterozygote deficiency (F IT) in native chicken was 0.234±0.025. Over 30.7% of F IT was contributed by within-population deficiency (F IS). Bayesian clustering analysis, using the STRUCTURE software suggested 9 clusters. This study may provide the background for future studies to identify the genetic uniqueness of the Korean native chicken breeds. PMID:25178290

Suh, Sangwon; Sharma, Aditi; Lee, Seunghwan; Cho, Chang-Yeon; Kim, Jae-Hwan; Choi, Seong-Bok; Kim, Hyun; Seong, Hwan-Hoo; Yeon, Seong-Hum; Kim, Dong-Hun; Ko, Yeoung-Gyu

2014-10-01

340

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

Science.gov (United States)

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. PMID:25178197

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

2014-10-01

341

Analysis of genetic diversity in Brown Swiss, Jersey and Holstein populations using genome-wide single nucleotide polymorphism markers  

OpenAIRE

Abstract Background Studies of genetic diversity are essential in understanding the extent of differentiation between breeds, and in designing successful diversity conservation strategies. The objective of this study was to evaluate the level of genetic diversity within and between North American Brown Swiss (BS, n?=?900), Jersey (JE, n?=?2,922) and Holstein (HO, n?=?3,535) cattle, using genotyped bulls. GENEPOP and FSTAT software were used to evaluate the level of genetic diversi...

Melka Melkaye G; Schenkel Flavio S

2012-01-01

342

Genetic diversity analysis of sugarcane ( Saccharum sp.) clones using simple sequence repeat markers of sugarcane and rice  

OpenAIRE

Molecular markers are powerful tools, which help in differentiating plant varieties at the DNA level and have been widelyused for genetic diversity studies in a number of crop species'. Understanding the genetic diversity of available clones of S.officinarum and S. spontaneum will be helpful in breeding programs. In the present study, a set of 48 sugarcane clones fromNational Hybridization Garden, Sugarcane Breeding Institute, Coimbatore was subjected to genetic diversity analysisinvolving 40...

G Banumathi, V. Krishnasamy

2010-01-01

343

Low genetic diversity and significant structuring in the endangered Mentha cervina populations and its implications for conservation  

OpenAIRE

Eighteen populations of the endangered aromatic and medicinal plant Mentha cervina (Lamiaceae) were sampled across its natural range, in the western half of the Iberian Peninsula, and inter-simple sequence repeats (ISSRs) markers were used to assess genetic diversity and population structure. M. cervina populations exhibited a relatively low genetic diversity (percentage of polymorphic loci PPB ¼ 14.2–58.3%, Nei’s genetic diversity He ¼ 0.135–0.205, Shannon’s informat...

Rodrigues, Leandra; Berg, Ca?ssio Den; Po?voa, Orlanda; Monteiro, Ana

2013-01-01

344

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

Directory of Open Access Journals (Sweden)

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 ?PT 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.

Rabinowicz Pablo D

2010-01-01

345

Simplified process model discovery based on role-oriented genetic mining.  

Science.gov (United States)

Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified process model. Using a new metric of process complexity in terms of roles as the fitness function, we can find simpler process models. The new role complexity metric of process models is designed from role cohesion and coupling, and applied to discover roles in process models. Moreover, the higher fitness derived from role complexity metric also provides a guideline for redesigning process models. Finally, we conduct case study and experiments to show that the proposed method is more effective for streamlining the process by comparing with related studies. PMID:24616618

Zhao, Weidong; Liu, Xi; Dai, Weihui

2014-01-01

346

Suitability of blood protein polymorphisms in assessing genetic diversity in indigenous sheep in Kenya  

International Nuclear Information System (INIS)

Knowledge of genetic diversity is important as it forms the basis for designing breeding programmes and making rational decisions on sustainable utilization of animal genetic resources. This study was designed to assess the efficiency of blood protein polymorphism as a rapid tool for assessing genetic diversity, using seven blood proteins (transferrin, albumin, haemoglobin, esterase A, esterase C, carbonic anhydrase and X-protein) and 457 indigenous fat-tailed (351) and fat-rumped (106) hair sheep in Kenya from 7 populations, with 40 Merino as controls. Transferrin was analysed using polyacrylamide gel electrophoresis and starch gel electrophoresis was used to analyse the other six loci. Of the seven loci analysed, two - carbonic anhydrase and X-protein - could not be interpreted. The five interpretable markers, however, showed low levels of polymorphism in allele numbers and heterozygosity. Multilocus mean FST values of 0.083 indicated a moderate genetic differentiation between the populations analysed. The Dm and Da genetic distance estimates showed the indigenous sheep populations in Kenya to be closely related genetically, with the dendrogram failing to resolve indigenous sheep into fat-tailed sheep and fat-rumped hair sheep. Due to its costs and modest equipment demands, blood protein polymorphism can be used as a rapid tool to assess genetic diversity and prioritize breeds to be analysed by microsatellite DNA markers. (author)markers. (author)

347

Genetic Diversity and Population Structure of Siberian apricot (Prunus sibirica L. in China  

Directory of Open Access Journals (Sweden)

Full Text Available The genetic diversity and population genetic structure of 252 accessions from 21 Prunus sibirica L. populations were investigated using 10 ISSR, SSR, and SRAP markers. The results suggest that the entire population has a relatively high level of genetic diversity, with populations HR and MY showing very high diversity. A low level of inter-population genetic differentiation and a high level of intra-population genetic differentiation was found, which is supported by a moderate level of gene flow, and largely attributable to the cross-pollination and self-incompatibility reproductive system. A STRUCTURE (model-based program analysis revealed that the 21 populations can be divided into two main groups, mainly based on geographic differences and genetic exchanges. The entire wild Siberia apricot population in China could be divided into two subgroups, including 107 accessions in subgroup (SG 1 and 147 accessions in SG 2. A Mantel test revealed a significant positive correlation between genetic and geographic distance matrices, and there was a very significant positive correlation among three marker datasets. Overall, we recommend a combination of conservation measures, with ex situ and in situ conservation that includes the construction of a core germplasm repository and the implement of in situ conservation for populations HR, MY, and ZY.

Ming Li

2013-12-01

348

Genetic diversity and population structure of Siberian apricot (Prunus sibirica L.) in China.  

Science.gov (United States)

The genetic diversity and population genetic structure of 252 accessions from 21 Prunus sibirica L. populations were investigated using 10 ISSR, SSR, and SRAP markers. The results suggest that the entire population has a relatively high level of genetic diversity, with populations HR and MY showing very high diversity. A low level of inter-population genetic differentiation and a high level of intra-population genetic differentiation was found, which is supported by a moderate level of gene flow, and largely attributable to the cross-pollination and self-incompatibility reproductive system. A STRUCTURE (model-based program) analysis revealed that the 21 populations can be divided into two main groups, mainly based on geographic differences and genetic exchanges. The entire wild Siberia apricot population in China could be divided into two subgroups, including 107 accessions in subgroup (SG) 1 and 147 accessions in SG 2. A Mantel test revealed a significant positive correlation between genetic and geographic distance matrices, and there was a very significant positive correlation among three marker datasets. Overall, we recommend a combination of conservation measures, with ex situ and in situ conservation that includes the construction of a core germplasm repository and the implement of in situ conservation for populations HR, MY, and ZY. PMID:24384840

Li, Ming; Zhao, Zhong; Miao, Xingjun; Zhou, Jingjing

2014-01-01

349

Assessment of Genetic Diversity among Sugarcane Cultivars (Saccharum officinarum L. using Simple Sequence Repeats Markers  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Increasing sugar productivity is the main concern of sugarcane (Saccharum officinarum L. breeding programs. The complexity and size of the sugarcane genome is a major limitation in its genetic improvement. Characterization of sugarcane provides essential information of genetic diversity for breeders utilize for crop improvement. Approach and Results: The objective of this study was to evaluate the microsatellite markers (SSR with 17 sugarcane accessions to access the genetic diversity and inter relationships in sugarcane. Genetic distances for SSR data (polymorphic fragments were determined and relationships between samples were portrayed graphically in the form of a dendrogram and similarities are ranging from 36% to 100% were observed. The lowest genetic similarity of 36% was seen between sample 9 and 11 with other samples. These two genotypes differed from each other with only 68% similarity. Conclusion: Results illustrate that SSR markers could be useful for structuring the genetic diversity of collections according to geographical origin and ploidy level, assessment or formation of a core collection and especially construction of a genetic map.

Ashutosh Pandey

2011-01-01

350

Genetic Structure and Diversity of the Giant Frog (Limnonectes blythii in Northern Thailand  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study is to analyse genetic diversity, structure and differentiation of the giant frogs (Limnonectes blythii. One hundred and sixty four individuals from 4 populations in Mae Hong Son Province, Thailand were used for the analysis of genetic polymorphism at 7 microsatellite loci. The collection showed considerable polymorphism with observed number of alleles per locus ranging for seven different loci, with an average of 3.4 alleles per locus. Mean genetic diversity of the four populations with moderate level, but in populations with lower genetic diversity. Furthermore, the NJ tree approach clustering conWrmed the results of PAM is more differentiated than the others. The signiWcant levels of genetic structure among the sites were found in which could be resulting from isolation by distance rather than a position relative to habitat. The results of this study indicate that genetic structure could be useful for evaluation of neutral genetic variation particularly as the basis for inferring population and species capacity for species conservation and management decisions.

C. Suwannapoom

2012-08-01

351

Genetic Diversity Between Two Populations of Heteropneustes fossilis (Bloch Using RAPD Profile  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was aimed to elucidate its genetic diversity based on RAPD markers from 6 individuals belonging to two ecological habitats i.e., upper lake and lower lake of Bhopal. Ten random 10-mer primers were scored in each of the individuals from two locations out of which three primers, which gave polymorphism, were selected for Polymerase Chain Reaction (PCR and used in the final RAPD analysis. The complementary approach of RAPD was used to evaluate the genetic diversity among all the accessions using 3 highly polymorphic primers. Using these primers, 128 scorable DNA fragments were found, of which 24 (18.75% were polymorphic. By comparing RAPD banding patterns, small variations were found between and within the populations. The present study yielded data elucidating the usefulness of complementary approaches to make diversity analysis more explanatory and purposeful for optimum genetic amelioration and effective conservation of its genotypic variability.

N.N. Mehrotra

2009-01-01

352

Mine simulation  

Energy Technology Data Exchange (ETDEWEB)

The technical sessions covered: simulation - open pit mining operations; simulation - underground mining operations; general topics; expert systems - genetic algorithms; neural networks; mine safety - training; modelling, planning and production scheduling; rock mechanics; and mine equipment. The book contains abstracts of the papers. The full papers are included on the enclosed CD-ROM.

Panagiotou, G.N.; Sturgul, J.R. [eds.] [National Technical University of Athens, Athens (Greece)

1997-12-31

353

Genetic Diversity of Bt Resistance: Implications for Resistance Management  

Directory of Open Access Journals (Sweden)

Full Text Available The bacterium Bacillus thuringiensis is the main source of insecticidal proteins in insect resistant plants. However, biochemical and genetic studies have shown that insect resistance to B. thuringiensis (Bt toxins can occur and with the advent of Bt transgenic crops this is a major concern. Several insect species have shown resistance to these toxins in the laboratory but the diamondback moth, Plutella xylostella is the only species which has evolved resistance under field conditions to date. Many studies have been done to elucidate the mode of action of the toxins and the mechanisms and genetics of resistance. In this article Bt toxins, their mode of action, mechanisms and genetics of resistance and management strategies for delaying resistance are reviewed. The emphasis is placed on examining the presently recommended high dose/refuge strategy.

Ali H. Sayyed

2002-01-01

354

Genetic diversity of geographically distinct Streptococcus dysgalactiae isolates from fish  

Directory of Open Access Journals (Sweden)

Full Text Available Streptococcus dysgalactiae is an emerging pathogen of fish. Clinically, infection is characterized by the development of necrotic lesions at the caudal peduncle of infected fishes. The pathogen has been recently isolated from different fish species in many countries. Twenty S. dysgalactiae isolates collected from Japan, Taiwan, Malaysia and Indonesia were molecularly characterized by biased sinusoidal field gel electrophoresis (BSFGE using SmaI enzyme, and tuf gene sequencing analysis. DNA sequencing of ten S. dysgalactiae revealed no genetic variation in the tuf amplicons, except for three strains. The restriction patterns of chromosomal DNA measured by BSFGE were differentiated into six distinct types and one subtype among collected strains. To our knowledge, this report gives the first snapshot of S. dysgalactiae isolates collected from different countries that are localized geographically and differed on a multinational level. This genetic unrelatedness among different isolates might suggest a high recombination rate and low genetic stability.

M. Abdelsalam

2015-03-01

355

Phosphorylation networks regulating JNK activity in diverse genetic backgrounds  

DEFF Research Database (Denmark)

Cellular signaling networks have evolved to enable swift and accurate responses, even in the face of genetic or environmental perturbation. Thus, genetic screens may not identify all the genes that regulate different biological processes. Moreover, although classical screening approaches have succeeded in providing parts lists of the essential components of signaling networks, they typically do not provide much insight into the hierarchical and functional relations that exist among these components. We describe a high-throughput screen in which we used RNA interference to systematically inhibit two genes simultaneously in 17,724 combinations to identify regulators of Drosophila JUN NH(2)-terminal kinase (JNK). Using both genetic and phosphoproteomics data, we then implemented an integrative network algorithm to construct a JNK phosphorylation network, which provides structural and mechanistic insights into the systems architecture of JNK signaling.

Bakal, Chris; Linding, Rune

2008-01-01

356

Genetic diversity of Plantago ovata Forsk. through RAPD markers  

Directory of Open Access Journals (Sweden)

Full Text Available Genetic variability of 15 sets of Plantago ovata Forsk. studied using 11 arbitrary oligonucleotide primers. Among the 90 DNAfragments produced 71 fragments were found to be polymorphic. The mean number of polymorphic bands per primer among 15Plantago ovata genotypes was 6.45 . The higher polymorphism (90.00 % was exhibited by primer OPF-17, while the lowerpolymorphism (60.00 % was detected by OPF-2. The genetic similarity matrix from RAPD data for 15 genotypes was calculatedbased on Jaccard’s coefficients of similarity ranged from 0.45 to 0.80. UPGMA cluster analysis reveals that the 15 genotypeswere clustered in to three clusters. Genetically distinct genotypes identified using RAPD markers could be potential sources ofgermplasm for Isabgol improvement.

Ashish G Vala1*, R.S.Fougat1 and G.C.Jadeja

2011-12-01

357

Self-Adaptation Mechanism to Control the Diversity of the Population in Genetic Algorithm  

CERN Document Server

One of the problems in applying Genetic Algorithm is that there is some situation where the evolutionary process converges too fast to a solution which causes it to be trapped in local optima. To overcome this problem, a proper diversity in the candidate solutions must be determined. Most existing diversity-maintenance mechanisms require a problem specific knowledge to setup parameters properly. This work proposes a method to control diversity of the population without explicit parameter setting. A self-adaptation mechanism is proposed based on the competition of preference characteristic in mating. It can adapt the population toward proper diversity for the problems. The experiments are carried out to measure the effectiveness of the proposed method based on nine well-known test problems. The performance of the adaptive method is comparable to traditional Genetic Algorithm with the best parameter setting.

Jassadapakorn, Chaiwat; 10.5121/ijcsit.2011.3409

2011-01-01

358

Genetic diversity in Algerian sheep breeds, using microsatellite markers  

International Nuclear Information System (INIS)

Two breeds - Ouled-Djellal and Hamra (85 animals) - were genotyped for 12 microsatellites using PCR and sequencing. Allele number and frequency were calculated, and 141 different alleles were found for these microsatellites, reflecting high genetic variability within these breeds. This study is being extended to other Algerian breeds to estimate variability and genetic distances between them. In parallel, blood samples from the various breeds are being collected to build up a DNA bank. The results should support establishment of a strategy to promote the use and development of locally adapted sheep resources. (author)

359

Molecular diversity of the ammonia-oxidizing bacteria community in disused tin-mining ponds located within Kampar, Perak, Malaysia.  

Science.gov (United States)

Disused tin-mining ponds make up a significant amount of water bodies in Malaysia particularly at the Kinta Valley in the state of Perak where tin-mining activities were the most extensive, and these abundantly available water sources are widely used in the field of aquaculture and agriculture. However, the natural ecology and physicochemical conditions of these ponds, many of which have been altered due to secondary post-mining activities, remains to be explored. As ammonia-oxidizing bacteria (AOB) are directly related to the nutrient cycles of aquatic environments and are useful bioindicators of environmental variations, the focus of this study was to identify AOBs associated with disused tin-mining ponds that have a history of different secondary activities in comparison to ponds which were left untouched and remained as part of the landscape. The 16S rDNA gene was used to detect AOBs in the sediment and water sampled from the three types of disused mining ponds, namely ponds without secondary activity, ponds that were used for lotus cultivation and post-aquaculture ponds. When the varying pond types were compared with the sequence and phylogenetic analysis of the AOB clone libraries, both Nitrosomonas and Nitrosospira-like AOB were detected though Nitrosospira spp. was seen to be the most ubiquitous AOB as it was present in all ponds types. However, AOBs were not detected in the sediments of idle ponds. Based on rarefaction analysis and diversity indices, the disused mining pond with lotus culture indicated the highest richness of AOBs. Canonical correspondence analysis indicated that among the physicochemical properties of the pond sites, TAN and nitrite were shown to be the main factors that influenced the community structure of AOBs in these disused tin-mining ponds. PMID:24078113

Sow, S L S; Khoo, G; Chong, L K; Smith, T J; Harrison, P L; Ong, H K A

2014-02-01

360

A simple method for estimating genetic diversity in large populations from finite sample sizes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Sample size is one of the critical factors affecting the accuracy of the estimation of population genetic diversity parameters. Small sample sizes often lead to significant errors in determining the allelic richness, which is one of the most important and commonly used estimators of genetic diversity in populations. Correct estimation of allelic richness in natural populations is challenging since they often do not conform to model assumptions. Here, we introduce a simple and robust approach to estimate the genetic diversity in large natural populations based on the empirical data for finite sample sizes. Results We developed a non-linear regression model to infer genetic diversity estimates in large natural populations from finite sample sizes. The allelic richness values predicted by our model were in good agreement with those observed in the simulated data sets and the true allelic richness observed in the source populations. The model has been validated using simulated population genetic data sets with different evolutionary scenarios implied in the simulated populations, as well as large microsatellite and allozyme experimental data sets for four conifer species with contrasting patterns of inherent genetic diversity and mating systems. Our model was a better predictor for allelic richness in natural populations than the widely-used Ewens sampling formula, coalescent approach, and rarefaction algorithm. Conclusions Our regression model was capable of accurately estimating allelic richness in natural populations regardless of the species and marker system. This regression modeling approach is free from assumptions and can be widely used for population genetic and conservation applications.

Rajora Om P

2009-12-01

361

Genetic diversity of superior Salix clones selected for intensive forestry plantations  

Energy Technology Data Exchange (ETDEWEB)

A number of willow clones are today in use in short rotation intensive culture plantations. The clonal nature of this crop makes it an easy target for pests and pathogens when grown in monocultures. This is a major concern as plantations of coppice must remain viable for up to 20 years to be profitable. In this paper the genetic diversity of 114 selected willow clones was examined and the possible solution of growing willows in multiclonal plantations is discussed. Forty five Salix eriocephala clones, 53 S. exigua clones and 16 clones of their inter-specific hybrid (12 S. eriocephala x exigua clones and 4 S. exigua x eriocephala clones), were evaluated. Starch gel electrophoresis was employed and 12 enzyme systems were used for the assessment of the genetic variation in the clonal material. A total of 29 loci and 57 alleles were revealed. Three measures of genetic diversity were used in order to evaluate the genetic base of the clonal set: average number of alleles per locus, percentage of polymorphic loci and mean heterozygosity. Results indicated that the genetic diversity within a species, is generally lower than the genetic diversity observed in natural populations or full-sib families of the same species. These results, however, are within the limits obtained from natural populations of the Salicaceae family. Heterozygosity values were found to be greater than similar values from poplar clonal material. In contrast to the results within species, inter-specific hybrid clones presented relatively high amounts of genetic diversity. The significance of these results in the management of clonal plantations is discussed from both the operational and conservation points of view.

Aravanopoulos, F.A. [Aristotle University of Thessaloniki (Greece). Dept. of Forestry and Natural Environment; Kim, K.H.; Zsuffa, L. [University of Toronto (Canada). Faculty of Forestry

1999-04-01

362

Within-Host Genetic Diversity of Endemic and Emerging Parvoviruses of Dogs and Cats ?  

OpenAIRE

Viral emergence can result from the adaptation of endemic pathogens to new or altered host environments, a process that is strongly influenced by the underlying sequence diversity. To determine the extent and structure of intrahost genetic diversity in a recently emerged single-stranded DNA virus, we analyzed viral population structures during natural infections of animals with canine parvovirus (CPV) or its ancestor, feline panleukopenia virus (FPV). We compared infections that occurred shor...

Hoelzer, Karin; Shackelton, Laura A.; Holmes, Edward C.; Parrish, Colin R.

2008-01-01

363

SPAR profiles and genetic diversity amongst pomegranate (Punica granatum L.) genotypes  

OpenAIRE

We are interested in studying the distribution and range of diversity amongst the pomegranates in India. Single Primer Amplification Reaction (SPAR) profiling using Random Amplified Polymorphic DNA (RAPD) and Directed Amplification of Minisatellite DNA (DAMD) methods enabled the determination of the genetic diversity amongst a total of 64 Indian pomegranate genotypes including 15 wild, 34 semi-wild and 14 cultivated types. SPAR profile data were scored for the computation of pairwise distance...

Ranade, S. A.; Rana, T. S.; Narzary, D.

2009-01-01

364

A neutral theory for interpreting correlations between species and genetic diversity in communities.  

Science.gov (United States)

Spatial patterns of biological diversity have been extensively studied in ecology and population genetics, because they reflect the forces acting on biodiversity. A growing number of studies have found that genetic (within-species) and species diversity can be correlated in space (the so-called species-gene diversity correlation [SGDC]), which suggests that they are controlled by nonindependent processes. Positive SGDCs are generally assumed to arise from parallel responses of genetic and species diversity to variation in site size and connectivity. However, this argument implicitly assumes a neutral model that has yet to be developed. Here, we build such a model to predict SGDC in a metacommunity. We describe how SGDC emerges from competition within sites and variation in connectivity and carrying capacity among sites. We then introduce the formerly ignored mutation process, which affects genetic but not species diversity. When mutation rate is low, our model confirms that variation in the number of migrants among sites creates positive SGDCs. However, when considering high mutation rates, interactions between mutation, migration, and competition can produce negative SGDCs. Neutral processes thus do not always contribute positively to SGDCs. Our approach provides empirical guidelines for interpreting these novel patterns in natura with respect to evolutionary and ecological forces shaping metacommunities. PMID:25560553

Laroche, Fabien; Jarne, Philippe; Lamy, Thomas; David, Patrice; Massol, Francois

2015-01-01

365

Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy.  

Science.gov (United States)

Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed. PMID:25588302

Maggioni, Lorenzo; von Bothmer, Roland; Poulsen, Gert; Branca, Ferdinando; Bagger Jørgensen, Rikke

2014-12-01

366

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

Directory of Open Access Journals (Sweden)

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.

Almeida Sabrina E. Matos

2000-01-01

367

Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy  

DEFF Research Database (Denmark)

Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed.

Maggioni, Lorenzo; von Bothmer, Roland

2014-01-01

368

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

Directory of Open Access Journals (Sweden)

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.

Fatima Sabin

2012-01-01

369

Genetic Diversity in a Bacillus anthracis Historical Collection (1954 to 1988)?  

OpenAIRE

Bacillus anthracis, the etiologic agent of anthrax, has been widely described as a genetically monomorphic species. We used both multiple-locus variable-number tandem-repeat analysis (MLVA) and pagA gene sequencing to determine the genetic diversity of a historical collection of B. anthracis isolates collected from the 1950s to the 1980s from various geographic locations and sources. We sequenced the pagA gene of 124 diverse B. anthracis isolates and found all previously identified B. anthrac...

Sue, David; Marston, Chung K.; Hoffmaster, Alex R.; Wilkins, Patricia P.

2007-01-01

370

Genetic Diversity and Population Structure of North China Mountain Walnut Revealed by ISSR  

OpenAIRE

North China Mountain Walnut (NCMW) is one of the ancestors of extant cultivated species, and a valuable gene resource for resistance breeding of walnut in China. Inter-Simple Sequence Repeat (ISSR) primers were designed to evaluate the level and pattern of genetic diversity in eight populations of NCMW. Nine ISSR primers yielded 91 amplification products with different sizes, of which 84 (92.31%) were polymorphic. A high species-level genetic diversity was detected with Nei’s (H = 0.2592) a...

Aiqing Ji; Yina Wang; Guoliang Wu; Wenjiang Wu; Hongyan Yang; Qihai Wang

2014-01-01

371

Bringing genetic diversity to the forefront of conservation policy and management  

DEFF Research Database (Denmark)

In this essay we explore questions on how to increase the visibility and utility of genetic information for biodiversity managers and policy makers. This is discussed in the light of Aichi CBD Target 13, which for the first time impels signatories to minimise genetic erosion and safeguard genetic diversity. Drawing on qualitative results from a questionnaire sent to European conservation professionals by the ConGRESS Framework 7 Support Action (http://www.congressgenetics.eu), we summarise our preliminary findings on the attitudes and experiences of European conservation professionals in using genetics. We then discuss the implications of these findings for academics involved in conservation genetics and suggest that a much closer partnership between academic conservation geneticists and conservation practitioners is necessary if the full potential of genetic tools in conservation is to be realised. © 2013 Springer Science+Business Media Dordrecht.

Hoban, S.M.; Hauffe, H.C.

2013-01-01

372

Genetic diversity assessment in sorghum accessions using qualitative morphological and amplified fragment length polymorphism markers  

Scientific Electronic Library Online (English)

Full Text Available Qualitative morphological and amplified fragment length polymorphism (AFLP) markers were compared for assessment of genetic diversity. Nine qualitative morphological traits were recorded to compare genetic relationships among 17 sorghum accessions with information derived from six AFLP primer combin [...] ations analysis. The mean morphological genetic similarity was lower in comparison to similarity computed using AFLP markers. Genetic similarity measured by AFLP markers was similar within the Ethiopian and South African material, as well as between South African and Ethiopian material. Morphological similarity was much higher in the Ethiopian material than in the South African material, indicating that the genotypes were related. The two techniques described genetic variability in different ways. Dendrogram generated from the morphological data matrix separated accession 216737 as being genetically distinct from the rest of the accessions. Accessions M101 and 97MW6127 were the most dissimilar accessions based on AFLP data.

Abe Shegro, Gerrano; Maryke Tine, Labuschagne; Angeline, van Biljon; Nemera Geleta, Shargie.

2014-10-01

373

Population demographics and genetic diversity in remnant and translocated populations of sea otters  

Science.gov (United States)

The effects of small population size on genetic diversity and subsequent population recovery are theoretically predicted, but few empirical data are available to describe those relations. We use data from four remnant and three translocated sea otter (Enhydra lutris) populations to examine relations among magnitude and duration of minimum population size, population growth rates, and genetic variation. Metochondrial (mt)DNA haplotype diversity was correlated with the number of years at minimum population size (r = -0.741, p = 0.038) and minimum population size (r = 0.709, p = 0.054). We found no relation between population growth and haplotype diversity, altough growth was significantly greater in translocated than in remnant populations. Haplotype diversity in populations established from two sources was higher than in a population established from a single source and was higher than in the respective source populations. Haplotype frequencies in translocated populations of founding sizes of 4 and 28 differed from expected, indicating genetic drift and differential reproduction between source populations, whereas haplotype frequencies in a translocated population with a founding size of 150 did not. Relations between population demographics and genetic characteristics suggest that genetic sampling of source and translocated populations can provide valuable inferences about translocations.

Bodkin, J.L.; Ballachey, B.E.; Cronin, M.A.; Scribner, K.T.

1999-01-01

374

Bovine coronaviruses from the respiratory tract: Antigenic and genetic diversity  

Science.gov (United States)

Bovine corona viruses (BoCV) isolated from respiratory tract, nasal swab and broncho alveolar washing fluid samples were evaluated for genetic and antigenic differences. These BoCV from the respiratory tract of healthy and clinically ill cattle with BRD signs were compared to reference and vaccine ...

375

GENETIC DIVERSITY OF CARICA PAPAYA AS REVEALED BY AFLP MARKERS  

Science.gov (United States)

Genetic relationships among Carica papaya cultivars, breeding lines, unimproved germplasm, and related species were established using amplified fragment length polymorphism (AFLP) markers. Seventy-one papaya accessions and related species were analyzed with nine EcoRI-MseI primer combinations. A t...

376

Assessment of genetic diversity among selected raspberry cultivars  

Science.gov (United States)

Genetic markers, Random Amplification of Polymorphic DNA (RAPD), were developed for screening raspberry for cold/heat tolerance. Growing raspberries in southern United States is a challenging task as they are high chill-loving plants. Cultivation of raspberry in Florida is significantly hampered du...

377

Genetic diversity assessment of wild Malus sieversii populations in Kazakhstan  

Science.gov (United States)

Malus sieversii is one of the major progenitor species of the dessert apple, Malus x domestica. Wild M. sieversii trees are found in the mountainous regions of Kazakhstan and other central Asian countries. The Plant Genetic Resources Unit (PGRU) in Geneva, NY maintains large field and seed collectio...

378

Cryptic genetic and wing pattern diversity in a mimetic Heliconius butterfly  

OpenAIRE

Despite rampant color pattern diversity in South America, Heliconius erato exhibits a “postman” wing pattern throughout most of Central America. We examined genetic variation across the range of H. erato, including dense sampling in Central America, and discovered a deep genetic break, centered on the mountain range that runs through Costa Rica. This break is characterized by a novel mitochondrial lineage, which is nearly fixed in northern Central America, that branches basal to all previ...

Hill, R. I.; Gilbert, L. E.; Kronforst, M. R.

2013-01-01

379

Measurement of genetic diversity of virulence in populations of Xanthomonas oryzae pv. oryzae in India  

OpenAIRE

This work was designed to ascertain the extent of genetic diversity in the pathogen population of Xanthomonas oryzae pv. oryzae (Xoo), the causal organism of bacterial blight of rice. The virulence of 52 strains of Xoo, collected from 12 rice growing states of India, were clip-inoculated on 16 rice genotypes possessing known genes for resistance. Based on the genetic distance, estimated by multivariate analysis isolates of Xoo could be classified into 13 clusters and five broad groups. The ge...

Debabrata Nayak; Bose, Lotan K.; Singh, Udaya D.; Sanjay Singh; Parsuram Nayak

2008-01-01

380

Genetic diversity of Gobio gobio populations in the Czech Republic and Slovakia, based on RAPD markers.  

Czech Academy of Sciences Publication Activity Database

Ro?. 54, Suppl. 1 (2005), s. 13-24. ISSN 0139-7893. [Distribution, taxonomy and genetic status of the European species of the genus Gobio. Brno, 09.09.2003-11.09.2003] R&D Projects: GA AV ?R(CZ) IAA6045005; GA AV ?R IBS5045111 Institutional research plan: CEZ:AV0Z60930519 Keywords : Gobio * diagnostic markers * intraspecific diversity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.585, year: 2005

Mendel, Jan; Lusková, V?ra; Hala?ka, Karel; Lusk, Stanislav; Vetešník, Lukáš

2005-01-01

381

Study on Seed Morphology and Genetic Diversity of Jatropha curcas L. from Different Provenances  

Directory of Open Access Journals (Sweden)

Full Text Available Jatropha curcas L., a multipurpose shrub has acquired signi?cant economic importance for its seed oil which can be converted to biodiesel, is emerging as an alternative to petro-diesel. The present study aims at characterization of the seed morphology and genetic diversity of Jatropha curcas L. from eight different provenances for providing support for the breeding and allocation of seed. Five traits were investigated, including hundred seed weight, seed length, width, lateral diameter, seed length and width ratio. The genetic diversity of eight populations from different provenances was estimated using DALP method (5 primers. The results showed that seed morphology had significant variation among locations. Five DALP primers generated highly reproducible and stable DNA fragments. 219 of 244 loci were polymorphic, i.e., PPB was 89.75%. And POPGENE analysis indicated the total Nei’s gene diversity (H was 0.2878, the total Shannon's Information index (I was 0.4331, and the coefficient of Gene differentiation (Gst was 0.8200 among populations, namely 82.00% genetic variation occurring among populations and 20.00% remaining within population. It was suggested that a high level of genetic variation should be occur among the different populations of J. curcas. The high genetic differentiation among the populations could be caused by not only the limited gene flow (Nm = 0.1097 but also the genetic drift. The result indicates that the seed morphology among populations showed some certain differentiation. The eight populations had high level of genetic diversity and show apparent genetic differentiation. So that provenance selection has great potentiality.

Junjiao Guan

2013-02-01

382

Estimation of Genetic Diversity in Sheep (Ovis aries) using Randomly Amplified Polymorphic DNA  

OpenAIRE

Domestic sheep (Ovis aries) belongs to order Artiod actyla. Despite its great economic importance, not much work has been done in Pakistan on breeding and genetics of sheep. Present research was initiated to analyze DNA based genetic diversity in Pakistani breeds of sheep. Total genomic DNA was isolated from blood of Rambouillet, Kaghani and Ramghani breeds. Polymerase Chain Reactions (PCR) were carried out using six Randomly Amplified Polymorphic DNA (RAPD) primers. Amplified fragments range...

M. Qasim,

2011-01-01

383

Genetic Diversity and Population Structure of Miscanthus sinensis Germplasm in China  

Science.gov (United States)

Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n?=?2x?=?38), as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei’s genetic diversity index (He) of 0.32 and polymorphism information content (PIC) of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83%) was substantially greater than the between-subpopulation variation (17%). Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits. PMID:24116066

He, Junrong; Yang, Junpin; Pan, Lei; Sun, Dongfa; Peng, Junhua

2013-01-01

384

Fluorescent amplified fragment length polymorphism (fAFLP) analyses and genetic diversity in Litopenaeus vannamei (Penaeidae)  

OpenAIRE

The Pacific white shrimp, Litopenaeus vannamei (Penaeidae), represents about 95% of all Brazilian shrimp production. The Brazilian L. vannamei foundation broodstock was made up of specimens collected from different American Pacific sites, but little information was collected on the genetic structure of the broodstock. We used the fluorescence amplified fragment length polymorphism (fAFLP) method to study the genetic diversity of L. vannamei broodstock lines 03CMF1 and 03CBF1 originally produc...

Michelle Mantovani Gonçalves; Manoel Victor Franco Lemos; Pedro Manoel Galetti Junior; Patrícia Domingues de Freitas; Manuel Antonio Andrade Furtado Neto

2005-01-01

385

Molecular strategies for genetic diversity analysis and development of markers linked to resistance traits in apple  

OpenAIRE

The goal of many plant scientists’ research is to explain natural phenotypic variation in term of simple changes in DNA sequence. DNA-based molecular markers are extensively used for the construction of genome-wide molecular maps and to perform genetic analysis for simple and complex traits. The PhD thesis was divided into two main research lines according to the different approaches adopted. The first research line is to analyze the genetic diversity in an Italian apple germplasm collectio...

Liang, Wei

2013-01-01

386

[Genetic diversity of different populations of lilyturf revealed by RSAP analysis].  

Science.gov (United States)

Restriction site amplification polymorphism (RSAP) markers were employed to access the genetic diversity and relationship of 120 lilyturf germplasms from different geographical origins. Sixteen RSAP primer pairs generated 326 polymorphic bands, of which 318 (97.55%) were polymorphic. The value of polymorphism information content (PIC) ranged from 0.87 to 0.95 with an average of 0.92. These results indicated there was abundant genetic diversity among samples. The results of data analysis on 20 population showed that the value of percentage of polymorphic locus (PPL), Nei's gene diversity (H) and Shannon's information index (I) were 19.94%-85.58%, 0.082 6-0.210 7, 0.120 6-0.328 1 respectively. The most abundant genetic diversity was found in the O. japonicus population from Zhejiang and the least in the Liriope minor population. The genetic distance among 20 population was 0.024 6-0.286 8, of which the minimum genetic distance was 0.024 6 between population I and population 13 while the maximum 0.286 8 between population 5 and population 15. Coefficient of genetic differentiation among natural populations was 0.115 3 (Gst). And the gene differentiation contributed to 43.07% of the total genetic variation among populations and to 56.93% within populations. The total gene flow (Nm) was 0.660 9. UPMGA clustering analysis was basically similar to of the principle coordinate analysis (PCA). The 120 samples were classified into four major groups, which were basically corresponded with the genetic relationships based on morphological traits. The results of UPMGA and PCA were also consistent with geographical origins. PMID:25751940

Xu, Hu-Chao; Zhang, Jun-Yi; Si, Can

2014-10-01

387

Whole genome SNP discovery and analysis of genetic diversity in Turkey (Meleagris gallopavo)  

OpenAIRE

Background The turkey (Meleagris gallopavo) is an important agricultural species and the second largest contributor to the world’s poultry meat production. Genetic improvement is attributed largely to selective breeding programs that rely on highly heritable phenotypic traits, such as body size and breast muscle development. Commercial breeding with small effective population sizes and epistasis can result in loss of genetic diversity, which in turn can lead to reduced individual fitness an...

Aslam, M. L.; Bastiaansen, J. W. M.; Elferink, M. G.; Megens, H. J. W. C.; Crooijmans, R. P. M. A.; Blomberg, L.; Fleischer, G.; Groenen, M.

2012-01-01

388

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

OpenAIRE

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 we...

Matos Almeida, Sabrina E.; Machado, Ma?rcia S. N.; Clara Sabina Steigleder; Gama, Cleonice L.; Mara Helena Hutz; Luiz Ernani Henkes; Moraes, Jose? Carlos F.; Tania Azevedo Weimer

2000-01-01

389

Demographic characterization, inbreeding and maintenance of genetic diversity in the endangered Catalonian donkey breed  

OpenAIRE

This study characterizes the demographic and genealogical structure of a limited-size population in danger of extinction: the Catalonian donkey breed. The purpose of this paper is to establish the most suitable breeding criteria and guidelines to achieve the ’Programme of Conservation and Maintenance of Animal Genetic Resources’ in this population. The two main objectives proposed are: 1) to maintain the maximum genetic diversity, with 2) the minimum possible consanguinity increase per ge...

Jordana Jordi; Folch Pilar

1998-01-01

390

Genome-wide genetic diversity, population structure and admixture analysis in African and Asian cattle breeds.  

Science.gov (United States)

Knowledge about genetic diversity and population structure is useful for designing effective strategies to improve the production, management and conservation of farm animal genetic resources. Here, we present a comprehensive genome-wide analysis of genetic diversity, population structure and admixture based on 244 animals sampled from 10 cattle populations in Asia and Africa and genotyped for 69,903 autosomal single-nucleotide polymorphisms (SNPs) mainly derived from the indicine breed. Principal component analysis, STRUCTURE and distance analysis from high-density SNP data clearly revealed that the largest genetic difference occurred between the two domestic lineages (taurine and indicine), whereas Ethiopian cattle populations represent a mosaic of the humped zebu and taurine. Estimation of the genetic influence of zebu and taurine revealed that Ethiopian cattle were characterized by considerable levels of introgression from South Asian zebu, whereas Bangladeshi populations shared very low taurine ancestry. The relationships among Ethiopian cattle populations reflect their history of origin and admixture rather than phenotype-based distinctions. The high within-individual genetic variability observed in Ethiopian cattle represents an untapped opportunity for adaptation to changing environments and for implementation of within-breed genetic improvement schemes. Our results provide a basis for future applications of genome-wide SNP data to exploit the unique genetic makeup of indigenous cattle breeds and to facilitate their improvement and conservation. PMID:25359181

Edea, Z; Bhuiyan, M S A; Dessie, T; Rothschild, M F; Dadi, H; Kim, K S

2015-02-01

391

Simian Genogroup I Picobirnaviruses: Prevalence, Genetic Diversity, and Zoonotic Potential  

OpenAIRE

We previously reported the first detection of simian picobirnaviruses (PBVs) by polyacrylamide gel electrophoresis in fecal specimens of two monkeys with diarrhea in China. We now report the detection of genogroup I PBVs in 48% (44/92) of the fecal specimens by reverse transcriptase PCR (RT-PCR) and amplicon sequencing using primers specific for the RNA-dependent RNA polymerase (RDRP) gene. Molecular characterization of these 44 strains demonstrated both sequence conservation and diversity am...

Wang, Yuhuan; Ba?nyai, Krisztia?n; Tu, Xinming; Jiang, Baoming

2012-01-01

392

AFLP assessment of genetic diversity among Indian Mucuna accessions  

OpenAIRE

Amplified fragment length polymorphism (AFLP) marker was used to assess diversity in germplasm collection of Mucuna species which has gained tremendous attention in the recent past due to its promising nutritional, agronomic and medicinal attributes. Twenty five accessions comprising five species, collected from seven states of India were evaluated with twelve AFLP primer combinations that generated a total of 1,612 fragments with an average of 134 fragments per primer combination. The values...

Sathyanarayana, N.; Leelambika, M.; Mahesh, S.; Jaheer, Mahammad

2011-01-01

393

Genetic diversity and microevolution of Burkholderia pseudomallei in the environment.  

OpenAIRE

BACKGROUND: The soil dwelling Gram-negative pathogen Burkholderia pseudomallei is the cause of melioidosis. The diversity and population structure of this organism in the environment is poorly defined. METHODS AND FINDINGS: We undertook a study of B. pseudomallei in soil sampled from 100 equally spaced points within 237.5 m(2) of disused land in northeast Thailand. B. pseudomallei was present on direct culture of 77/100 sampling points. Genotyping of 200 primary plate colonies from three inde...

Chantratita, N.; Wuthiekanun, V.; Limmathurotsakul, D.; Vesaratchavest, M.; Thanwisai, A.; Amornchai, P.; Tumapa, S.; Feil, Ej; Day, Np; Peacock, Sj

2008-01-01

394

Raps markers for genetic diversity analysis in rice (Oryza sativa L)  

International Nuclear Information System (INIS)

The establishment of relationships between genotypes existing in gene banks that may be used in new crosses, and about genetic diversity in available germplasm, is very useful for plant breeders. In this work, a genetic diversity analysis among 20 varieties of the Cuban rice germplasm bank was performed by using RAPD markers. Twenty four decamer primers were screened which produced 61 polymorphic bands out of 105 consistent and reproducible amplified fragments (58.1 %). The proportion of polymorphic bands varied for each primer, with an average of 3 polymorphic bands per primer, these results agreed with previous reports on RAPD polymorphism in rice germplasm. Depending on the primer, 1 to 7 distinct patterns were obtained among the screened genotypes. Pair-wise genetic distances between genotypes were computed based on Dice's coefficient. Three major, statistically robust groups were obtained in the UPGMA dendrogram (A, B and C) which clearly corresponded to different genetic pools. Additionally, more insight could be gained according to the sub-grouping pattern within group A, which included the principal semi-dwarf commercial varieties. The present study allowed to prove the efficiency of RAPD markers for genetic diversity analysis in closely related germplasm, particularly for the semi-dwarf Cuban commercial rice cultivars. Also, the existence of a narrow genetic base among these varieties has been confirmed, pointing at the urgent necessity of widen ithe urgent necessity of widen it

395

Genetic diversity of Paris polyphylla var. yunnanensis, a traditional Chinese medicinal herb, detected by ISSR markers.  

Science.gov (United States)

Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. is an important Chinese medicinal herb. Because of overharvesting, the wild populations of this herb have greatly declined and become fragmentized. In this paper, ISSR markers were used to determine the genetic diversity and genetic structure of this variety represented by a total of 153 individuals from three natural populations and three cultivated populations. Fourteen primers produced a total of 251 bands, of which 227 were polymorphic (PPB=90.44%). For the natural populations, the results showed that genetic differentiation was mainly within populations (GST=0.1952), with low genetic diversity at the population level. At the population level, genetic diversity of the cultivated populations was relatively higher than that of the natural populations (PPB=57.24% vs. 53.38%, HE=0.153 vs. 0.151, HO=0.241 vs. 0.235). This pattern can be explained by the recent introduction and artificial selection of cultivars from comparatively wide areas of origin, and subsequent gene flow among populations in cultivation. Although the neighbour-joining cluster analysis seemed to suggest that there was conspicuous genetic differentiation between the natural and cultivated populations, the AMOVA showed that only 4.84% of the total variance existed between groups of natural and cultivated populations, while 67.51% of the variance occurred within populations. In the end, some suggestions for conservation of this important herb are proposed. PMID:17973204

He, Jun; Wang, Hong; Li, De-Zhu; Chen, Shao-Feng

2007-10-01

396

Evaluation of genetic diversity and population structure of West-Central Indian cattle breeds.  

Science.gov (United States)

Evaluations of genetic diversity in domestic livestock populations are necessary to implement region-specific conservation measures. We determined the genetic diversity and evolutionary relationships among eight geographically and phenotypically diverse cattle breeds indigenous to west-central India by genotyping these animals for 22 microsatellite loci. A total of 326 alleles were detected, and the expected heterozygosity ranged from 0.614 (Kenkatha) to 0.701 (Dangi). The mean number of alleles among the cattle breeds ranged from 7.182 (Khillar) to 9.409 (Gaolao). There were abundant genetic variations displayed within breeds, and the genetic differentiation was also high between the Indian cattle breeds, which displayed 15.9% of the total genetic differentiation among the different breeds. The genetic differentiation (pairwise FST ) among the eight Indian breeds varied from 0.0126 for the Kankrej-Malvi pair to 0.2667 for Khillar-Kenkatha pair. The phylogeny, principal components analysis, and structure analysis further supported close grouping of Kankrej, Malvi, Nimari and Gir; Gaolao and Kenkatha, whereas Dangi and Khillar remained at distance from other breeds. PMID:23216283

Shah, Tejas M; Patel, Jaina S; Bhong, Chandrakant D; Doiphode, Aakash; Umrikar, Uday D; Parmar, Shivnandan S; Rank, Dharamshibhai N; Solanki, Jitendra V; Joshi, Chaitanya G

2013-08-01

397

Genetic Diversity of Tick-Borne Rickettsial Pathogens; Insights Gained from Distant Strains.  

Science.gov (United States)

The ability to capture genetic variation with unprecedented resolution improves our understanding of bacterial populations and their ability to cause disease. The goal of the pathogenomics era is to define genetic diversity that results in disease. Despite the economic losses caused by vector-borne bacteria in the Order Rickettsiales, little is known about the genetic variants responsible for observed phenotypes. The tick-transmitted rickettsial pathogen Anaplasma marginale infects cattle in tropical and subtropical regions worldwide, including Australia. Genomic analysis of North American A. marginale strains reveals a closed core genome defined by high levels of Single Nucleotide Polymorphisms (SNPs). Here we report the first genome sequences and comparative analysis for Australian strains that differ in virulence and transmissibility. A list of genetic differences that segregate with phenotype was evaluated for the ability to distinguish the attenuated strain from virulent field strains. Phylogenetic analyses of the Australian strains revealed a marked evolutionary distance from all previously sequenced strains. SNP analysis showed a strikingly reduced genetic diversity between these strains, with the smallest number of SNPs detected between any two A. marginale strains. The low diversity between these phenotypically distinct bacteria presents a unique opportunity to identify the genetic determinants of virulence and transmission. PMID:25364572

Pierlé, Sebastián Aguilar; Rosshandler, Ivan Imaz; Kerudin, Ammielle Akim; Sambono, Jacqueline; Lew-Tabor, Ala; Rolls, Peter; Rangel-Escareño, Claudia; Brayton, Kelly A

2014-01-14

398

GENETIC DIVERSITY WITHIN THE SOUTHERN PLAINS WOODRAT (NEOTOMA MICROPUS) IN SOUTHERN TEXAS  

OpenAIRE

Genetic diversity within a population of the southern plains woodrat was examined using DNA sequences (967 base pairs [bp]) obtained from the control or d-loop region of the mitochondrial genome. One hundred fourteen individuals from 10 collection sites were assigned to 42 haplotypes. Haplotype diversity values were moderate to high (0.974 overall and ranged from 0.524 to 0.964 across collecting sites), whereas nucleotide diversity values were low (0.008 overall and ranged from 0.001 to 0.010...

Me?ndez-harclerode, Francisca M.; Hanson, J. Delton; Fulhorst, Charles F.; Milazzo, Mary L.; Ruthven, Donald C.; Bradley, Robert D.

2005-01-01

399

Mitochondrial control region genetic diversity and maternal ancestry of a Brangus-Ibage cattle populations  

OpenAIRE

The genetic diversity of 277 nucleotides in the mitochondrial DNA control region (nt 15,964 to 16,240 in reference sequence) was analyzed in crossbreed beef cattle (Brangus-Ibage, 5/8 Bos primigenius taurus x 3/8 Bos primigenius indicus) as well as in some Nellore samples (B. p. indicus). Fifty-seven mutations were found in Brangus-Ibage comprising 18 haplotypes (haplotype diversity, h = 0.851 ± 0.041 and nucleotide diversity, ntd = 0.009 ± 0.006) and 66 in Nellore (h = 1.00 ± 0.27, ntd = ...

Luiz Ernani Henkes; Wilson Araújo Silva Jr; José Carlos Ferrugem Moraes; Tania Azevedo Weimer

2005-01-01

400

Minor improvement for intertidal seaweeds and invertebrates after acid mine drainage diversion at Britannia Beach, Pacific Canada.  

Science.gov (United States)

In December 2001, acid mine drainage (AMD) from an abandoned copper mine at Britannia Beach (British Columbia, Canada) was diverted to flow from Britannia Creek into an outfall at 30 m depth in Howe Sound. Britannia Beach was studied in early 2003 to determine whether AMD diversion resulted in improved conditions for intertidal organisms. Species number and abundance have increased at the intertidal zone since AMD diversion, although they were still lower than at an unpolluted control site nearby (Furry Creek). Survivorship and growth rates of transplanted Mytilus trossulus (mussel) have increased since AMD diversion, although they were still significantly lower than at the control site. Transplanted Fucus gardneri (seaweed) performed better than before the AMD diversion; at Britannia Beach the chlorophyll a concentration in tissues was not significantly different from that at the control site, although the concentration of chlorophyll c in tissues and the chlorophyll c to a ratio was lower than at the control site six weeks after transplantation. Britannia Beach is still subject to leaching of metals from surrounding soils, low levels of AMD coming down the creek, and AMD discharge from the deep outfall. Although there has been an improvement, the intertidal environment at Britannia Beach still seems unable to support normal growth and survival of organisms. PMID:15172809

Zis, Thalia; Ronningen, Vera; Scrosati, Ricardo

2004-06-01

401

Influence of plant genetic diversity on interactions between higher trophic levels  

Science.gov (United States)

While the ecological consequences of plant diversity have received much attention, the mechanisms by which intraspecific diversity affects associated communities remains understudied. We report on a field experiment documenting the effects of patch diversity in the plant Baccharis salicifolia (genotypic monocultures versus polycultures of four genotypes), ants (presence versus absence) and their interaction on ant-tended aphids, ants and parasitic wasps, and the mechanistic pathways by which diversity influences their multi-trophic interactions. Five months after planting, polycultures (versus monocultures) had increased abundances of aphids (threefold), ants (3.2-fold) and parasitoids (1.7-fold) owing to non-additive effects of genetic diversity. The effect on aphids was direct, as plant genetic diversity did not mediate ant–aphid, parasitoid–aphid or ant–parasitoid interactions. This increase in aphid abundance occurred even though plant growth (and thus aphid resources) was not higher in polycultures. The increase in ants and parasitoids was an indirect effect, due entirely to higher aphid abundance. Ants reduced parasitoid abundance by 60 per cent, but did not affect aphid abundance or plant growth, and these top-down effects were equivalent between monocultures and polycultures. In summary, intraspecific plant diversity did not increase primary productivity, but nevertheless had strong effects across multiple trophic levels, and effects on both herbivore mutualists and enemies could be predicted entirely as an extension of plant–herbivore interactions. PMID:23485879

Moreira, Xoaquín; Mooney, Kailen A.

2013-01-01

402

The Effect of Chromosome Geometry on Genetic Diversity  

OpenAIRE

Although organisms with linear chromosomes must solve the problem of fully replicating their chromosome ends, this chromosome configuration has emerged repeatedly during bacterial evolution and is evident in three divergent bacterial phyla. The benefit usually ascribed to this topology is the ability to boost genetic variation through increased recombination. But because numerous processes can impact linkage disequilibrium, such an effect is difficult to assess by comparing across bacterial t...

Marri, Pradeep Reddy; Harris, Leigh K.; Houmiel, Kathryn; Slater, Steven C.; Ochman, Howard

2008-01-01

403

GENETIC DIVERSITY OF FLEXIVIRUSES INFECTING POME FRUIT TREES  

OpenAIRE

Three amplicons corresponding to the variable genome regions of Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) and Apple stem pitting virus (ASPV) were sequenced from different apple cultivars and geographic areas in Europe and Asia. Multiple alignments of nucleotide sequence of these isolates with those from databases showed a very high divergence. Genetic variability at the nucleotide level among ACSLV and ASPV isolates was very high, ranging from 83.5 to 85.0% an...

Gadiou, S.; Kundu, Jk; Paunovic, S.; Garcia-diez, P.; Komorowska, B.; Gospodaryk, A.; Handa, A.; Massart, S.; Birisik, N.; Takur, Pd; Polischuk, V.

2010-01-01

404

Inhibition of BET Bromodomain Targets Genetically Diverse Glioblastoma  

OpenAIRE

PURPOSE: Glioblastoma is refractory to conventional therapies. The bromodomain and extraterminal domain (BET) proteins are epigenetic readers that selectively bind to acetylated lysine residues on histone tails. These proteins recently emerged as important therapeutic targets in NUT midline carcinoma and several types of hematopoietic cancers. In this study, the therapeutic potential of a novel BET bromodomain inhibitor, JQ1, was assessed in a panel of genetically heterogeneous glioblastoma s...

Cheng, Z.; Gong, Y.; Ma, Y.; Lu, K.; Lu, X.; Pierce, La; Thompson, Rc; Muller, S.; Knapp, S.; Wang, J.

2013-01-01