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| Registros recuperados: 41 | |
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| COSTA, J. A. da; AZEVEDO, C. F.; NASCIMENTO, M.; SILVA, F. F. e; RESENDE, M. D. V. de; NASCIMENTO, A. C. C.. |
| multicollinearity and high dimensionality problems, making it impossible to obtain stable estimates through the traditional method of estimation based on ordinary least squares. To overcome such challenges, dimensionality reduction methods have been proposed, because of their simple theory and easy application. We compared three dimensionality reduction methods: Principal Components Regression (PCR), Partial Least Squares (PLS), and Independent Components Regression (ICR). An important step for dimensionality reduction and prediction is selecting the number of components, as it affects the linear combinations of the explanatory variables. The linear combinations are inserted into the model to predict the response based on a reduced number of parameters. We... |
| Tipo: Artigo de periódico |
Palavras-chave: Regression analysis; Genomics. |
| Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139234 |
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| TEODORO, P. E.; FARIAS, F. J. C.; CARVALHO, L. P. de; RIBEIRO, L. P.; NASCIMENTO, M.; AZEVEDO, C. F.; CRUZ, C. D.; BHERING, L. L.. |
| The performance of textile processes and the quality of the products depends on the several cotton (Gossypium hirsutum L.) fiber quality traits, such as micronaire index, fiber length, and fiber strength. This research aims to recommend cotton genotypes for the Brazilian Cerrado based on fiber yield and fiber quality traits. Nineteen cotton cultivar variety trials were performed in the 2013?2014 and 2014?2015 crop seasons. Each trial was conducted as a randomized complete block design with 12 treatments and four replications. The evaluated traits were fiber yield, fiber length, fiber strength, and micronaire. For each trait, a modified Lin and Binns method was used to recommend the best genotypes for all environments (favorable and unfavorable). This... |
| Tipo: Artigo de periódico |
Palavras-chave: Gossypium Hirsutum; Algodão; Fibra; Fiber quality; Micronaire; Cotton. |
| Ano: 2019 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1118672 |
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| SILVA, F. F.; JEREZ, E. A. Z.; RESENDE, M. D. V. de; VIANA, J. M. S.; AZEVEDO, C. F.; LOPES, P. S.; NASCIMENTO, M.; LIMA, R. O. de; GUIMARÃES, S. E. F.. |
| We combined linkage (LA) and linkage disequilibrium (LDA) analyses (emerging the term ?LALDA?) for genomic selection (GS) purposes. The models were fitted to a simulated dataset and to a real data of feed conversion ratio in pigs. Firstly, the significant QTLs (quantitative trait locus) were identified through LA-based mixed models considering the QTL-genotypes as random effects by means of genotypic identity by descent matrix. This matrix was calculated at the positions of significant QTLs (based on LA) allowing to include the QTL-genotype effects additionally to SNP (single nucleotide polymorphism) markers (based on LDA) and additive polygenic effects in several GS models (Bayesian Ridge Regression ? BRR; Bayes A ? BA; Bayes B ? BB; Bayes C ? BC and... |
| Tipo: Artigo de periódico |
Palavras-chave: X. |
| Ano: 2018 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1093541 |
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| TORRES, L. G.; OLIVEIRA, E. J. de; OGBONNA, A. C.; BAUCHET, G. J.; MUELLER, L. A.; AZEVEDO, C. F.; SILVA, F. F.; SIMIQUELI, G. F.; RESENDE, M. D. V. de. |
| Genomic prediction (GP) offers great opportunities for accelerated genetic gains by optimizing the breeding pipeline. One of the key factors to be considered is how the training populations (TP) are composed in terms of genetic improvement, kinship/origin, and their impacts on GP. Hydrogen cyanide content (HCN) is a determinant trait to guide cassava?s products usage and processing. This work aimed to achieve the following objectives: (i) evaluate the feasibility of using cross-country (CC) GP between germplasm?s of Embrapa Mandioca e Fruticultura (Embrapa, Brazil) and The International Institute of Tropical Agriculture (IITA, Nigeria) for HCN; (ii) provide an assessment of population structure for the joint dataset; (iii) estimate the genetic parameters... |
| Tipo: Artigo de periódico |
Palavras-chave: Genoma; Germoplasma; Cianeto; Mandioca; Population structure; Breeding; Genomics; Hydrogen cyanide; Cassava. |
| Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1149230 |
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| TORRES, L. G.; OLIVEIRA, E. J. de; OGBONNA, A. C.; BAUCHET, G. J.; MUELLER, L. A.; AZEVEDO, C. F.; SILVA, F. F.; SIMIQUELI, G. F.; RESENDE, M. D. V. de. |
| Genomic prediction (GP) offers great opportunities for accelerated genetic gains by optimizing the breeding pipeline. One of the key factors to be considered is how the training populations (TP) are composed in terms of genetic improvement, kinship/origin, and their impacts on GP. Hydrogen cyanide content (HCN) is a determinant trait to guide cassava?s products usage and processing. This work aimed to achieve the following objectives: (i) evaluate the feasibility of using cross-country (CC) GP between germplasm?s of Embrapa Mandioca e Fruticultura (Embrapa, Brazil) and The International Institute of Tropical Agriculture (IITA, Nigeria) for HCN; (ii) provide an assessment of population structure for the joint dataset; (iii) estimate the genetic parameters... |
| Tipo: Artigo de periódico |
Palavras-chave: Genoma; Germoplasma; Cianeto; Mandioca; Population structure; Breeding; Genomics; Hydrogen cyanide; Cassava. |
| Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139241 |
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| ANDRADE, L. R. B. de; SOUSA, M. B. e; OLIVEIRA, E. J. de; RESENDE, M. D. V. de; AZEVEDO, C. F.. |
| Genomic selection (GS) has been used to optimize genetic gains when phenotypic selection is considered costly and difficult to measure. The objective of this work was to evaluate the efficiency and consistency of GS prediction for cassava yield traits (Manihot esculenta Crantz) using different methods, taking into account the effect of population structure. BLUPs and deregressed BLUPs were obtained for 888 cassava accessions and evaluated for fresh root yield, dry root yield and dry matter content in roots in 21 trials conducted from 2011 to 2016. The deregressed BLUPs obtained for the accessions from a 48K single nucleotide polymorphism dataset were used for genomic predictions based on the BayesB, BLASSO, RR-BLUP, G-BLUP and RKHS methods. The accessions?... |
| Tipo: Artigo de periódico |
Palavras-chave: Genomic predictions; Heredity; Mandioca; Melhoramento Genético Vegetal; Plant breeding; Cassava. |
| Ano: 2019 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1115740 |
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| SUELA, M. M.; LIMA, L. P.; AZEVEDO, C. F.; RESENDE, M. D. V. de; NASCIMENTO, M.; SILVA, F. F. e. |
| A cultura do arroz tem grande importância nacional e mundial por ser um dos cereais mais produzidos e consumidos no mundo, caracterizando-se como o principal alimento de mais da metade da população mundial. Em função de sua importância alimentar, desenvolver métodos eficientes que visam a predição e a seleção de indivíduos geneticamente superiores, quanto a características da planta, é de extrema importância para os programas de melhoramento. Diante disso, o objetivo deste trabalho foi avaliar e comparar a eficiência do método Delta-p, G-BLUP, BayesCpi, BLASSO e o índice Delta-p/G-BLUP, índice Delta-p/BayesCpi e índice Delta-p/BLASSO, na estimação de valores genômicos e dos efeitos de marcadores SNPs (Single Nucleotide Polymorphisms) em dados fenotípicos... |
| Tipo: Artigo de periódico |
Palavras-chave: Predição genômica; Ganho genético; Genomic prediction; Genetic gain; Bayesian alphabet; Molecular bases; Regression; Índice de Seleção; Selection index. |
| Ano: 2019 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1110881 |
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| AZEVEDO, C. F.; NASCIMENTO, M.; SILVA, F. F.; RESENDE, M. D. V. de; LOPES, P. S.; GUIMARÃES, S. E. F.; GLÓRIA, L. S.. |
| A significant contribution of molecular genetics is the direct use of DNA information to identify genetically superior individuals. With this approach, genome-wide selection (GWS) can be used for this purpose. GWS consists of analyzing a large number of single nucleotide polymorphism markers widely distributed in the genome; however, because the number of markers is much larger than the number of genotyped individuals, and such markers are highly correlated, special statistical methods are widely required. Among these methods, independent component regression, principal component regression, partial least squares, and partial principal components stand out. Thus, the aim of this study was to propose an application of the methods of dimensionality reduction... |
| Tipo: Separatas |
Palavras-chave: Quadrados mínimos parciais; Componente de regressão independente; Componente principal de regressão; Componente principal parcial; Partial least squares; Independent component regression; Principal component regression; Partial principal component. |
| Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1030362 |
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| LAGROTTA, M. R.; SILVA, F. F. e; RESENDE, M. D. V. de; NASCIMENTO, M.; DUARTE, D. A. S.; AZEVEDO, C. F.; MOTA, R. R.. |
| Em seleção genômica (SG), o grande número de marcadores moleculares utilizados, bem como a demanda computacional dos modelos bayesianos, fundamentados nos algoritmos Monte Carlo Via Cadeias de Markov, faz com que as análises exijam semanas ou até meses de processamento. A computação paralela representa uma solução natural para este problema, visto que esta subdividi um algoritmo em várias tarefas independentes, as quais podem ser processadas em paralelo, reduzindo o tempo de processamento. Objetivou-se comparar a eficiência de processamento do método BayesCπ programado em paralelo com o seu algoritmo sequencial padrão. Duas estratégias de paralelização foram estudadas. A primeira envolveu a análise de múltiplas cadeias MCMC em paralelo, e a... |
| Tipo: Artigo de periódico |
Palavras-chave: Marcadores SNP; Regressão Bayesiana; Statistics; Genetic improvement. |
| Ano: 2017 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1084055 |
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| MOURA, A. de A. A.; AZEVEDO, C. F.; LOBO, R. N. B.; MARTINS FILHO, R.. |
| Um estudo foi conduzido com a finalidade de avaliar os efeitos de fatores de meio sobre os pesos ao nascer (PN) e aos 205 (P205), 365 (P365) e 550 dias de idade (P550) em animais Nelore e Guzerá, criados no estado do Rio Grande do Norte, entre 1977 e 1997. Foram utilizadas 3.116 informações de bezerros (2.017 Guzerá e 1.099 Nelore), provenientes de 14 propriedades. Por meio de análise de variância, avaliou-se modelos com os efeitos fixos da raça, propriedade dentro da raça, ano e mês de nascimento, sexo da cria, regime alimentar (somente a partir do desmame) e idade da vaca ao parto como covariável. As médias e erros-padrão para as variáveis PN, P205, P365 e P550 foram 29,1 ± 0,3 kg; 171,8 ± 2,3 kg; 246,6 ± 4,6 kg e 335,4 ± 5,8 kg para a raça Nelore e,... |
| Tipo: Anais e Proceedings de eventos |
Palavras-chave: Desenvolvimento ponderal.; Gado Nelore; Gado Guzerá.. |
| Ano: 2002 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/903937 |
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| COSTA, J. A. da; AZEVEDO, C. F.; NASCIMENTO, M.; SILVA, F. F.; RESENDE, M. D. V. de; NASCIMENTO, A. C. C.. |
| The principal component regression (PCR) and the independent component regression (ICR) are dimensionality reduction methods and extremely important in genomic prediction. These methods require the choice of the number of components to be inserted into the model. For PCR, there are formal criteria; however, for ICR, the adopted criterion chooses the number of independent components (ICs) associated to greater accuracy and requires high computational time. In this study, seven criteria based on the number of principal components (PCs) and methods of variable selection to guide this choice in ICR are proposed and evaluated in simulated and real data. For both datasets, the most efficient criterion and that drastically reduced computational time determined... |
| Tipo: Artigo de periódico |
Palavras-chave: Melhoramento Genético Vegetal; Produtividade; Arroz; Genomics; Plant breeding; Yields; Rice. |
| Ano: 2022 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139185 |
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| RESENDE, M. A. V. de; FREITAS, J. A. de; LANZA, M. A.; RESENDE, M. D. V. de; AZEVEDO, C. F.. |
| As características tecnológicas da fibra do algodoeiro são determinantes da qualidade de seus produtos e de sua remuneração. Este trabalho objetivou estimar a divergência genética entre acessos de algodoeiro e ordenar os melhores, com base em um índice de seleção combinando todas essas características de interesse. Foram avaliados 248 acessos de algodoeiro, empregando-se análise multivariada (distância de Mahalanobis e agrupamento de Tocher) e índice de seleção baseado em rank médio via metodologia de modelos mistos (REML/BLUP). A análise de agrupamento de Tocher permitiu a estruturação populacional dos acessos, resumindo-os em 14 grupos divergentes. As acurácias seletivas foram altas para todas as características avaliadas, variando de 0,89 a 0,94,... |
| Tipo: Separatas |
Palavras-chave: Algodoeiro; Divergência genética; Melhoramento genético.; Fibra.. |
| Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1003335 |
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| COSTA, E. V.; DINIZ, D. B.; VERONEZE, R.; RESENDE, M. D. V. de; AZEVEDO, C. F.; GUIMARÃES, S. E. F.; SILVA, F. F.; LOPES, P. S.. |
| Knowledge of dominance effects should improve genetic evaluations, provide the accurate selection of purebred animals, and enable better breeding strategies, including the exploitation of heterosis in crossbreeds. In this study, we combined genomic and pedigree data to study the relative importance of additive and dominance genetic variation in growth and carcass traits in an F2 pig population. Two GBLUP models were used, a model without a polygenic effect (ADM) and a model with a polygenic effect (ADMP). Additive effects played a greater role in the control of growth and carcass traits than did dominance effects. However, dominance effects were important for all traits, particularly in backfat thickness. The narrow-sense and broad-sense heritability... |
| Tipo: Separatas |
Palavras-chave: Melhoramento genético; Seleção genômica ampla; Métodos de seleção; Herdabilidade; Dominance; Genetic parameters; Polygenic effect; Piau pigs. |
| Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1021860 |
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| MIRANDA, T. L. R.; RESENDE, M. D. V. de; AZEVEDO, C. F.; NUNES, A. C. P.; TAKAHASHI, E. K.; SIMIQUELI, G. F.; SILVA, F. F. e; ALVES, R. S.. |
| The Fisher?s infinitesimal model is traditionally used in quantitative genetics and genomic selection, and it attributes most genetic variance to additive variance. Recently, the dominance maximization model was proposed and it prioritizes the dominance variance based on alternative parameterizations. In this model, the additive effects at the locus level are introduced into the model after the dominance variance is maximized. In this study, the new parameterizations of additive and dominance effects on quantitative genetics and genomic selection were evaluated and compared with the parameterizations traditionally applied using the genomic best linear unbiased prediction method. As the parametric relative magnitude of the additive and dominance effects... |
| Tipo: Artigo de periódico |
Palavras-chave: Melhoramento Genético Vegetal; Seleção Genética; Molecular models; Plant selection guides; Plant breeding. |
| Ano: 2022 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139183 |
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| LIMA, L. P.; AZEVEDO, C. F.; RESENDE, M. D. V. de; NASCIMENTO, M.; SILVA, F. F. e. |
| The development of efficient methods for genome-wide association studies (GWAS) between quantitative trait loci (QTL) and genetic values is extremely important to animal and plant breeding programs. Bayesian approaches that aim to select regions of single nucleotide polymorphisms (SNPs) proved to be efficient, indicating genes with important effects. Among the selection criteria for SNPs or regions, selection criterion by percentage of variance can be explained by genomic regions (%var), selection of tag SNPs, and selection based on the window posterior probability of association (WPPA). To also detect potentially associated regions, we proposed measuring posterior probability of the interval PPint), which aims to select regions based on the markers of... |
| Tipo: Artigo de periódico |
Palavras-chave: Método de Melhoramento; Melhoramento Genético Vegetal; Genomics; Molecular models; Genetic variance; Plant breeding. |
| Ano: 2022 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139182 |
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| TEIXEIRA, F. R. F.; NASCIMENTO, M.; NASCIMENTO, A. C. C.; SILVA, F. F. e; CRUZ, C. D.; AZEVEDO, C. F.; PAIXÃO, D. M.; BARROSO, L. M. A.; VERARDO, L. L.; RESENDE, M. D. V. de; GUIMARÃES, S. E. F.; LOPES, P. S.. |
| The aim of the present study was to propose and evaluate the use of factor analysis (FA) in obtaining latent variables (factors) that represent a set of pig traits simultaneously, for use in genome-wide selection (GWS) studies. We used crosses between outbred F2 populations of Brazilian Piau X commercial pigs. Data were obtained on 345 F2 pigs, genotyped for 237 SNPs, with 41 traits. FA allowed us to obtain four biologically interpretable factors: ?weight?, ?fat?, ?loin?, and ?performance?. These factors were used as dependent variables in multiple regression models of genomic selection (Bayes A, Bayes B, RR-BLUP, and Bayesian LASSO). The use of FA is presented as an interesting alternative to select individuals for multiple variables simultaneously in GWS... |
| Tipo: Artigo de periódico |
Palavras-chave: Genome enabled prediction; SNP effects; Análise multivariada.; Melhoramento genético animal; Estatística; Seleção genética.; Animal breeding; Multivariate analysis. |
| Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1047516 |
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| RESENDE, R. T.; RESENDE, M. D. V. de; AZEVEDO, C. F.; SILVA, F. F. e; MELO, L. C.; PEREIRA, H. S.; SOUZA, T. L. P. O. de; VALDISSER, P. A. M. R.; BRONDANI, C.; VIANELLO, R. P.. |
| The availability of high-density molecular markers in common bean has allowed to explore the genetic basis of important complex agronomic traits with increased resolution. Genome-Wide Association Studies (GWAS) and Regional Heritability Mapping (RHM) are two analytical approaches for the detection of genetic variants. We carried out GWAS and RHM for plant architecture, lodging and productivity across two important growing environments in Brazil in a germplasm of 188 common bean varieties using DArTseq genotyping strategies. The coefficient of determination of G · E interaction (c2 int) was equal to 17, 21 and 41%, respectively for the traits architecture, lodging, and productivity. Trait heritabilities were estimated at 0.81 (architecture), 0.79 (lodging)... |
| Tipo: Artigo de periódico |
Palavras-chave: RHM QTL; GWAS QTL; DArTseq; Herdabilidade; Phaseolus Vulgaris; Feijão; Melhoramento Genético Vegetal; Heritability; Beans; Plant breeding. |
| Ano: 2018 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1095838 |
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| SUELA, M. M.; AZEVEDO, C. F.; NASCIMENTO, A. C. C.; MOMEN, M.; OLIVEIRA, A. C. B. de; CAIXETA, E. T.; MOROTA, G.; NASCIMENTO, M.. |
| Yield is one of the most important traits of arabica coffee. Plant breeders seek to maximize yield directly or indirectly, using other related traits. The standard multi-trait genome-wide association study (MTM-GWAS) does not accommodate the network structure of phenotypes, therefore, does not address how traits are interrelated. We applied structural equation modeling (SEM) to GWAS to explore interrelated dependencies between phenotypes related to morphology (fruit size and number of reproductive nodes), physiology (vegetative vigor), and productivity (yield) traits using 195 Coffea arábica individuals genotyped with 21,211 single-nucleotide polymorphism markers. We inferred the probabilistic phenotypic network by the Hill-Climbing algorithm to estimate... |
| Tipo: Artigo de periódico |
Palavras-chave: Structural equation modeling; Genome-wide association study; Single nucleotide polymorphism; Coffea arabica var. arabica. |
| Ano: 2023 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1157822 |
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| SANTOS, V. S.; MARTINS FILHO, S.; RESENDE, M. D. V. de; AZEVEDO, C. F.; LOPES, P. S.; GUIMARÃES, S. E. F.; SILVA, F. F.. |
| Age at the time of slaughter is a commonly used trait in animal breeding programs. Since studying this trait involves incomplete observations (censoring), analysis can be performed using survival models or modified linear models, for example, by sampling censored data from truncated normal distributions. For genomic selection, the greatest genetic gains can be achieved by including non-additive genetic effects like dominance. Thus, censored traits with effects on both survival models have not yet been studied under a genomic selection approach. We aimed to predict genomic values using the Cox model with dominance effects and compare these results with the linear model with and without censoring. Linear models were fitted via the maximum likelihood method.... |
| Tipo: Artigo de periódico |
Palavras-chave: GBLUP; Modelo mixto; Censored data; Mixed model; Survival models; Porco; Suíno; Swine; Animal breeding. |
| Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1072712 |
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| Registros recuperados: 41 | |
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