Biblioteca do Café
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1
Navegar
3 resultados
Resultados da Pesquisa
Item Multiple-trait model by Bayesian inference applied to environment efficient Coffea arabica with low-nitrogen nutrient(Instituto Agronômico (IAC), 2023-04-14) Silva Júnior, Antônio Carlos da; Moura, Waldênia de Melo; Torres, Lívia Gomes; Santos, Iara Gonçalves dos; Silva, Michele Jorge da; Azevedo, Camila Ferreira; Cruz, Cosme DamiãoIdentifying Coffea arabica cultivars that are more efficient in the use of nitrogen is an important strategy and a necessity in the context of environmental and economic impacts attributed to excessive nitrogen fertilization. Although Coffea arabica breeding data have a multi-trait structure, they are often analyzed under a single trait structure. Thus, the objectives of this study were to use a Bayesian multitrait model, to estimate heritability in the broad sense, and to select arabica coffee cultivars with better genetic potential (desirable agronomic traits) in nitrogen-restricted cultivation. The experiment was carried out in a greenhouse with 20 arabica coffee cultivars grown in a nutrient solution with low-nitrogen content (1.5 mM). The experimental design used was in randomized blocks with three replications. Six agromorphological traits of the arabica coffee breeding program and five nutritional efficiency indices were used. The Markov Chain Monte Carlo algorithm was used to estimate genetic parameters and genetic values. The agromorphological traits were considered highly heritable, with a credibility interval (95% probability): H2 = 0.9538 – 5.89E-01. The Bayesian multitrait model presents an adequate strategy for the genetic improvement of arabica coffee grown in low-nitrogen concentrations. Coffee arabica cultivars Icatu Precoce 3282, Icatu Vermelho IAC 4045, Acaiá Cerrado MG 1474, Tupi IAC 1669-33, Catucaí 785/15, Caturra Vermelho and Obatã IAC 1669/20 demonstrated greater potential for cultivation in low-nitrogen concentration.Item Tamanho amostral e detecção de genes via GWAS em características quantitativas do cafeeiro(Embrapa Café, 2022-04) Resende, Marcos Deon Vilela de; Oliveira, Antonio Carlos Baião de; Caixeta, Eveline Teixeira; Alkimim, Emilly Ruas; Sousa, Tiago Vieira; Pereira, Antonio Alves; Alves, Rodrigo Silva; Azevedo, Camila FerreiraO presente documento refere-se à avaliação prática do potencial da GWAS no melhoramento dos cafeeiros das espécies Coffea arabica e Coffea canephora. O objetivo geral é orientar a aplicação eficiente da GWAS em características produtivas, agronômicas e de resistência a doenças e pragas do cafeeiro. Para isso, um novo método para o estudo de associações genômicas foi desenvolvido e avaliado via simulação, em termos de poder de detecção de genes. O objetivo específico é possibilitar a identificação de marcadores genéticos úteis ao melhoramento do cafeeiro.Item Genomic prediction of leaf rust resistance to Arabica coffee using machine learning algorithms(Escola Superior de Agricultura "Luiz de Queiroz", 2021) Sousa, Ithalo Coelho de; Nascimento, Moysés; Silva, Gabi Nunes; Nascimento, Ana Carolina Campana; Cruz, Cosme Damião; Silva, Fabyano Fonseca e; Almeida, Dênia Pires de; Pestana, Kátia Nogueira; Azevedo, Camila Ferreira; Zambolim, Laércio; Caixeta, Eveline TeixeiraGenomic selection (GS) emphasizes the simultaneous prediction of the genetic effects of thousands of scattered markers over the genome. Several statistical methodologies have been used in GS for the prediction of genetic merit. In general, such methodologies require certain assumptions about the data, such as the normality of the distribution of phenotypic values. To circumvent the non-normality of phenotypic values, the literature suggests the use of Bayesian Generalized Linear Regression (GBLASSO). Another alternative is the models based on machine learning, represented by methodologies such as Artificial Neural Networks (ANN), Decision Trees (DT) and related possible refinements such as Bagging, Random Forest and Boosting. This study aimed to use DT and its refinements for predicting resistance to orange rust in Arabica coffee. Additionally, DT and its refinements were used to identify the importance of markers related to the characteristic of interest. The results were compared with those from GBLASSO and ANN. Data on coffee rust resistance of 245 Arabica coffee plants genotyped for 137 markers were used. The DT refinements presented equal or inferior values of Apparent Error Rate compared to those obtained by DT, GBLASSO, and ANN. Moreover, DT refinements were able to identify important markers for the characteristic of interest. Out of 14 of the most important markers analyzed in each methodology, 9.3 markers on average were in regions of quantitative trait loci (QTLs) related to resistance to disease listed in the literature.