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Genetic diversity and population structure of progenies half-sibling and full-siblings of sour passion fruit
No full textNas últimas décadas, houve uma expressiva expansão dos cultivos de maracujazeiro azedo nas diversas regiões brasileiras. Entretanto, a produtividade média dos cultivos é considerada baixa, frente ao potencial de produção da cultura. Fatores, como falta de cultivares adaptados a diversas regiões de produção, e alta incidência de pragas e doenças, são os limitantes para aumento da produtividade da cultura. Pesquisas visando superar estes entraves, principalmente de melhoramento genético, que visam o lançamento de cultivares superiores estão sendo desenvolvidas. O sucesso desses programas está intrinsicamente ligado ao conhecimento da estrutura e diversidade genética das populações trabalhadas e, dessa forma, permitem ao melhorista traçar eficientes estratégias de seleção para obtenção de maiores ganhos. Objetivou- se com este trabalho estudar e comparar a estrutura e a diversidade genética de progênies de meios irmãos e irmãos completos de Passiflora edulis Sims, comumente utilizadas no melhoramento da cultura. Duas progênies híbridas de irmãos completos (PHA e PHB) foram obtidas por cruzamento controlado de genitores contrastantes e uma progênie de meios irmãos foi obtida a partir de polinização aberta (PPA). Um total de 36 genótipos de cada progênie de irmãos completos e 45 genótipos da progênie de meios irmãos, juntamente com seus genitores foram analisados com marcadores SSR. A estrutura genética das populações foi verificada por meio de meio de uma abordagem bayesiana no Software Structure, e da AMOVA de Excoffier. A diversidade genética das progênies foi estudada por meio de agrupamentos hierárquicos gerados a partir da matriz de distância do índice de diversidade de Nei. Ao comparar as três progênies, maior proporção da diversidade genética é encontrada dentro das progênies. Comparando as progênies aos pares, maior diversidade é também encontrada dentro das progênies, inclusive ao comparar a progênie de meios irmãos com as progênies de irmãos completos. A estruturação das progênies pela abordagem bayesiana, estruturou as três progênies em duas progênies hipotéticas geneticamente, em que PHA e PPA apresentaram estrutura genética distinta entre si. A progênie PHB apresentou uma estrutura genética intermediária entre PHA e PPA, possivelmente pela relação de parentesco com essas duas progênies. Ao estudar a diversidade genética, observou-se que as progênies de irmãos completos apresentaram maior grau de diversidade genética, do que a progênie de meios irmãos. Quando comparadas as progênies híbridas entre si, não se observou um padrão de distribuição dos indivíduos relacionados as suas progênies, onde praticamente todos os grupos formados era constituído de indivíduos de ambas as progênies, possivelmente pela relação de parentesco. Entretanto, a progênie de meios irmãos tende a se caracterizar em relação às progênies híbridas no agrupamento, possivelmente pela menor proporção de alelos comuns com estas progênies, visto que é formada pela contribuição genética de mais de um genitor masculino. Por outro lado, esta progênie apresenta menor índice de diversidade genética entre seus indivíduos, possivelmente pela ocorrência de cruzamentos correlacionados na formação da progênie, o que pode causar implicações em estratégias de melhoramento de maracujazeiro azedo.In the last decades, there was a significant expansion of the sour passion fruit crops in several Brazilian regions. However, the average yield of crops is considered low, given the potential production of the crop. Factors, such as lack of cultivars adapted to different production regions, and high incidence of pests and diseases, are the limiting factors for increased crop productivity. Researches aiming overcome these barriers, mainly genetic improvement, aimed at the release of superior cultivars are being developed. The success of these programs is intrinsically linked to the knowledge of the structure and genetic diversity of the populations used in the presente study and, thus, allows the breeder to design efficient selection strategies to obtain greater gains. The objective of this research was to study and compare the structure and genetic diversity of Passiflora edulis Sims half-sibling and full-sibling progenies, commonly used in crop improvement. Two full-sibling progenies (PHA and PHB) were obtained by controlled crossing of contrasting parents and one half-sibling progeny was obtained from open pollination (PPA). Thirty-six genotypes of each full-sibling progeny and 45 genotypes of the half sibling progeny along with their parents were analyzed with SSR markers. The genetic structure of the populations was verified by bayesian approach in Software Structure and Excoffier AMOVA. The genetic diversity of progenies was studied through hierarchical groupings generated from the distance matrix of the Nei diversity index. When comparing the three progenies, a greater proportion of genetic diversity is found within the progenies. When the progenies are compared in pairs, greater diversity is also found within the progenies, even when comparing the half- sibling progeny with the full-sibling progeny. The bayesian approach structured the three progenies into two genetically hypothetical progenies, in which PHA and PPA presented distinct genetic structure from each other. The PHB progeny presented an intermediate genetic structure between PHA and PPA, possibly due to the relationship between these two progenies. When studying genetic diversity, it was observed that the progenies of full-siblings presented a higher degree of genetic diversity than the progeny of half-siblings. When comparing the hybrid progenies with each other, there was no pattern of distribution of individuals related to their progenies, where practically all groups formed were individuals of both progenies, possibly by their kinship. However, the half-sibling progeny tends to be characterized in relation to the hybrid progenies in the cluster, possibly due to the smaller proportion of common alleles with these progenies, since it is formed by the genetic contribution of more than one male parent. On the other hand, this progeny presents lower index of genetic diversity among its individuals, possibly due to the occurrence of correlated crosses in the progeny formation, which may have implications on strategies for the improvement of sour passion fruit.Conselho Nacional de Desenvolvimento Científico e Tecnológic
Estimativas de parâmetros genéticos em mapeamento de QTL em Sesamum indicum L.
Get PDFBrazil has experienced an exponential increase in sesame production in recent years. Still, farmers face many challenges in cropping sesame, such as the low number of available cultivars adapted to mechanized harvesting. In Brazil, few advances have been made in crop breeding. There is still a lack of germplasm characterization, and genetic breeding work is being developed to increase productivity and adapt to mechanized harvesting. The first chapter of this work presents a study of estimates of sesame genetic parameters in different environments and the characterization of the diversity available. A total of 28 sesame genotypes were phenotypically evaluated in three environments and genotyped with microsatellite and SNP markers. After statistical analysis, significant genetic variability was observed in the genotypes evaluated, which can be explored in crossings in the breeding program. Most of the phenotypic traits evaluated were highly influenced by the environment, presenting genotype x environment interaction and highlighting the complexity of improvement for this crop. In the second chapter, a QTL mapping study was carried out using SNP markers to identify genomic regions associated with traits of interest in sesame breeding. Two F2 populations (SD and SJ) were developed by hybridization, consisting of 98 and 160 genotypes, respectively. Both populations were genotyped by SNP markers and phenotyped in a greenhouse. After statistical analyses, QTL markers were found for 15 of the 17 phenotypic traits evaluated. QTL markers associated with important agronomic traits in sesame were found, such as productivity-related traits, placental adherence, and growth habit. Keywords: Sesame breeding; Selection index; Associative mapping; GxE interaction.O Brasil tem registrado nos últimos anos aumento exponencial na produção de gergelim, mas muitos desafios são enfrentados pelos produtores, como o baixo número de cultivares disponíveis e adaptados a colheita mecanizada. No Brasil poucos avanços foram conseguidos no melhoramento da cultura. Ainda faltam trabalhos de caracterização de germoplasma, e o desenvolvimento de trabalhos de melhoramento genético voltados para o aumento de produtividade e adaptação a colheita mecanizada. No primeiro capítulo deste trabalho, foi realizado um estudo de estimativas de parâmetros genéticos de gergelim em diferentes ambientes, bem como a caracterização da diversidade presente. Um total de 28 genótipos de gergelim foram avaliados fenotipicamente em três ambientes, e genotipados com marcadores microssatélites e SNPs. Considerável variabilidade genética foi observada entre os genótipos avaliados, que pode ser explorada por cruzamentos no programa de melhoramento. Significativa influência do ambiente foi observado sobre a maioria dos caracteres fenotípicos avaliados, evidenciando a complexidade do melhoramento para esta cultura. No segundo capítulo, foi realizado um estudo de mapeamento de QTLs usando marcadores SNPs para identificação de regiões genômicas associadas a características de interesse no melhoramento do gergelim. Duas populações F2 (SD e SJ) foram desenvolvidas por hibridação, compostas por 98 e 160 genótipos, respectivamente. As duas populações foram genotipadas por marcadores SNPs e fenotipadas em casa de vegetação. Após as análises estatísticas, foram encontrados marcadores QTLs para 15 das 17 características fenotípicas avaliadas. Marcadores QTLs associados a importantes características agronômicas no gergelim foram encontrados, como número de cápsulas por planta, aderência placentária e hábito de crescimento. Palavras-chave: Melhoramento de gergelim; Indice de seleção; Mapeamento associativo; Interação GxE.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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