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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352

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Resultados da Pesquisa

Agora exibindo 1 - 10 de 14
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    In vitro pollination and fluorescence microscopy for characterization of gametophytic selfincompatibility of Coffea canephora Pierre ex A. Froehner
    (Crop Breeding and Applied Biotechnology, 2021-11-20) Souza, Carolina Augusto de; Rocha, Rodrigo Barros; Santos, Maurício Reginaldo Alves dos; Lopes, Tatiane Almeida; Teixeira, Alexsandro Lara; Espindula, Marcelo Curitiba
    The objectives of this study were to optimize in vitro pollination and fluorescence microscopy procedures to characterize the gametophytic selfincompatibility of Coffea canephora genotypes. For that purpose, 115 in vitro pollinations were carried out among 30 parent plants of the Conilon (17) and Robusta (13) botanical varieties. Tester plants of compatibility groups I, II, and III were used as pollen grain donors. On the day of anthesis, pollen grains of the donor genotypes were transferred in vitro to one of the sides of the bifid stigma of each receptor flower. After 30 hours, the development of the pollen tubes was evaluated in fluorescence microscopy. Eleven genotypes (37%) were classified in compatibility Group I, thirteen (43%) in Group II, and six (20%) in Group III. In vitro pollination allowed reduction in the time necessary to diagnose compatibility, without exhibiting contamination caused by the presence of pollen grains of non-donor plants.
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    Factor analysis for plant and production variables in Coffea canephorain the Western Amazon
    (Universidade Federal de Lavras, 2022-06-09) Silva, Gabi Nunes; Barroso, Laís Mayara Azevedo; Cruz, Cosme Damião; Rocha, Rodrigo Barros; Ferreira, Fábio Medeiros
    The evaluation of morphological characters related to the hulled coffee yield subsidizes the selection of Coffea canephora plants that combine a set of favorable traits. However, the greater the number of traits considered, the more difficult the selection process becomes. In this context, multivariate analyzes can be useful to overcome this problem. The aim of this study was to identify, in a set of agronomic traits of Coffea canephora, the determining factors of biological phenomena and use these factors to recognize patterns of diversity and similarity from biological complexes of interest to the breeder. To this, eleven morphological descriptors were evaluated of 130 clones of the botanical varieties Conilon and Robusta and intervarietal hybrids over two crop years in the experimental field of Embrapa, in the municipality of Ouro Preto do Oeste, state of Rondônia (RO). To group the traits, the multivariate technique of Factor Analysis was used. The effect of genotype x year interaction was significant for the eleven traits analyzed. Based on the scree plot, three factors were established. Factors were interpreted as architecture, vigor and grains with a satisfactory percentage of explained variability. The inter-pretation of the factors highlighted the importance of the Conilon variety to improve the architecture of the Robusta botanical variety. These results show that it is possible to use factor scores to identify varieties and traits that favor higher production of hulled coffee.
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    Classification of Coffea canephora clones in botanical varieties by discriminant analysis of the k-nearest neighbors
    (Universidade Federal de Viçosa, 2021-11-08) Souza, Marciléia Santos; Ferreira, Fábio Medeiros; Rocha, Rodrigo Barros; Lopes, Maria Teresa Gomes; Oliveira, Leilane Nicolino Lamarão
    A strategy for genetic improvement of coffee Coffea canephora plants is to aggregate through artificial crossings the characteristics of the Conilon botanical variety, such as shorter height and drought resistance, with the higher average grain size and resistance to pests and diseases of the Robusta variety. Efficiently separating the clones into these two groups with the aid of appropriate analytical procedures makes field tasks easier for professionals and, thus, allows the systematic production of intervarietal hybrids. This study verifies if the non-parametric discriminant analyzes of the k-nearest neighbors (k-NN) and k-average neighbors (k-AN) would be able to correctly classify 130 coffee clones in their botanical varieties previously designated as Conilon, Robusta and Intervarietal Hybrids populations from ten quantitative agronomic characteristics, including the processed coffee beans yield, considering the existing population genetic divergence. These characteristics were found to be good discriminatory variables and the discriminant analyzes k-NN and k-AN, based on the principle of similarity by neighborhood, classified the clones with high hit rates. The k-AN discriminant analysis was able to better discriminate intervarietal hybrids from the group clones Conilon. The results correctly reflected the genetic diversity between the botanical varieties and intervarietal hybrids of Coffea canephora, allowing us to conclude that these classification methods can assist breeders in the main task of discriminating Conilon from Robusta clones.
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    Early induction of orthotropic shoots in Coffea canephora
    (Universidade Federal de Viçosa, 2020) Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento de; Schmidt, Raquel; Dias, Jairo Rafael Machado; Rocha, Rodrigo Barros
    In Coffea canephora, the number of orthotropic shoots is directly related to plant yield. The objective of this study was to evaluate the vegetative and yield performance of Coffea canephora, from the botanical variety Conilon, under different management systems for early emission of orthotropic shoots. The experiment was carried out in Ouro Preto do Oeste, Rondônia, between November 2011 and May 2014. Three types of management techniques were tested for early induction of orthotropic shoots in coffee trees (T1 = bending of the orthotropic shoot; T2 = apical pruning of the orthotropic shoot, T3 = free growing). The experiment was conducted in a randomized block design with 20 replicates. Each block consisted of a clonal genotype (clone) from the Embrapa Coffee Breeding Program. The techniques pruning and apical pruning were efficient to induce early growth of orthotropic shoots in Coffea canephora, resulting in higher yield in the first commercial bean production.
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    Tributun: a coffee cultivar developed in partnership with farmers
    (Crop Breeding and Applied Biotechnology, 2020) Partelli, Fábio Luiz; Giles, João Antonio Dutra; Oliosi, Gleison; Covre, André Monzoli; Ferreira, Adésio; Rodrigues, Valcir Meneguelli
    Tributun is a cultivar of Coffea canephora derived from breeding clones discovered by farmers. It was evaluated at 150 m asl in northern Espírito Santo for yield, plant vigor and pest and disease resistance. The cultivar with six genotypes produces a mean yield of 90.87 bags ha-1 year-1.
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    Coffea canephora breeding: estimated and achieved gains from selection in the Western Amazon, Brazil
    (Universidade Federal de Santa Maria, 2021) Rocha, Rodrigo Barros; Teixeira, Alexsandro Lara; Ramalho, Andre Rostand; Espindula, Marcelo Curitiba; Lunz, Aureny Maria Pereira; Souza, Flavio de França
    Gain from selection is an important criterion in quantifying the efficiency of breeding programs. This study quantified the selection gain estimated under experimental conditions and realized gain achieved in the field, seeking to interpret the efficiency of the Coffea canephora selection. For that purpose, we considered experiments that began in 2004 with directed hybridizations to obtain new hybrid progenies. From a breeding population composed of 288 hybrid individuals, 12 genotypes were selected in experimental conditions from 2005 to 2012, with amplitude in the estimated gains from 127.70 to−19.19%. Those genotypes were evaluated from 2012 to 2018 in clonal tests in four environments of the Western Amazon. The environment that exhibited the greatest correlation between the predicted genetic values and the realized genetic gain observed in the field was the environment of Ouro Preto do Oeste, RO (0.67), the location in which the plants were selected, followed by the environments of Alta FlorestaD´Oeste, RO (0.44), Rio Branco, AC (0.43), and Porto Velho, RO (0.37). Experimental conditions showed that the effect due to dominance deviations was approximately three times greater than the additive effect. Nine clones exhibited higher genetic gains in the experimental conditions and at field, and two clones exhibited lower estimated gains and lower field performance.The clone G17-P7 exhibited high genetic gain under experimental conditions and low field performance. The selection in experimental conditions was positively correlated with plant performance in the field (r=0.55), which allows reduction of the original breeding population to a set of more promising clones to be grown in multiple environments, optimizing time and resources.
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    Beverage quality of Coffea canephora genotypes in the western Amazon, Brazil
    (Editora da Universidade Estadual de Maringá - EDUEM, 2021) Morais, Johnnescley Anes de; Rocha, Rodrigo Barros; Alves, Enrique Anastácio; Espindula, Marcelo Curitiba; Teixeira, Alexsandro Lara; Souza, Carolina Augusto de
    This study aimed to evaluate the beverage quality of Coffea canephora genotypes in different environments of the western Amazon to assist plant selection and new cultivar development. To analyze beverage quality, samples of cherry coffee beans were collected separately for each genotype from clonal competition trials installed in the municipalities of Ouro Preto do Oeste, Alta Floresta do Oeste, Porto Velho, and Ariquemes in Rondônia State and Rio Branco in Acre State (Brazil). The beverage quality was assessed using the Robusta Cupping Protocol, which attribute to each genotype a score in a range from 0 to 100, highlighting nuances. Analysis of variance and principal components using reference points were used to quantify genotype x environment interaction (G x E). The analysis of variance indicated that genotypic and G x E interaction effects were significant (p < 0.01). By using a centroid dispersion method, we could identify four clones of low, eight of specific (to favorable or unfavorable environments), and seven of broad adaptability to the environments. The clones BRS 2314, 11, and 17 had average quality scores above 80 in all environments, with potential for specialty coffee production. The clones BRS 1216, BRS 3220, and BRS 3193 presented unstable behavior, with beans of higher quality in some of the evaluated environments. Such inconsistency in clone behavior is caused by unpredictable changes in plant performance in different environments. Our results indicate that both genotypic (clones) and G x E interaction effects are important for the expression of coffee beverage quality. However, the clones BRS 3213, BRS 3210, and BRS 2299 had less prominent nuances, with lower potential for specialty coffee production.
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    Adição de Zn e absorção, translocação e utilização de Zn e P por cultivares de cafeeiro
    (Escola Superior de Agricultura "Luiz de Queiroz", 2002-07) Reis Jr, Roberto dos Anjos; Martinez, Hermínia E. P.
    A crescente exigência de nutrientes, especialmente micronutrientes, pelos cultivares de café vem exigindo uma melhor compreensão da dinâmica desses nutrientes no sistema solo-planta. Com o objetivo de avaliar o efeito de concentrações de Zn (0,4 ; 1,3 e 2,3 μmol Zn L -1 ) na solução nutritiva sobre o crescimento, produção de matéria seca, eficiência de absorção, translocação e utilização de Zn e P em dois cultivares de café (Coffea arabica cv. Catuaí e Coffea canephora cv. Conilon), foi realizado um experimento sob delineamento inteiramente casualizado com esquema fatorial 3 × 2 (três doses de Zn e dois cultivares) com três repetições. Plantas de café dos dois cultivares estudados foram cultivadas em casa de vegetação, com solução nutritiva completa por 50 dias, após os quais receberam solução nutritiva modificada com três doses de Zn. Aos 114 dias após a transferência para a solução nutritiva modificada, as plantas foram coletadas e separadas em folhas superiores, inferiores, caule e raízes. Foram avaliadas altura do caule, número de ramificações laterais, área foliar, produção de matéria seca e conteúdos de P e Zn nas diversas partes da planta, além das eficiências de absorção, translocação e utilização de P e Zn. A dose 2,3 μmol Zn L -1 proporcionou os maiores valores para as características de crescimento avaliadas, tanto para o cultivar Catuaí, quanto para Conilon. Os maiores conteúdos de Zn observados no Catuaí indicam que este é mais exigente em Zn que o Conilon na fase de mudas. O Conilon apresentou menores eficiências de absorção e translocação e maior eficiência de utilização de Zn, refletindo sua menor demanda por este nutriente. As concentrações de Zn empregadas neste experimento não promoveram interação Zn-P.
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    Characterization of beverage quality in Coffea canephora Pierre ex A. Froehner
    (Editora UFLA, 2018-04) Souza, Carolina Augusto de; Rocha, Rodrigo Barros; Alves, Enrique Anastácio; Teixeira, Alexsandro Lara; Dalazen, Janderson Rodrigues; Fonseca, Aymbiré Francisco Almeida da
    Differentiation of coffee according to its quality can result in added value. Both the coffee genotype and the environment influence beverage quality. The main species grown in the Amazon region is C. canephora, which includes two distinct botanical varieties: Conilon and Robusta. The aim of this study was to characterize beverage quality in C. canephora and distinguish the Conilon and Robusta botanical varieties and intervarietal hybrids. We evaluated the beverage quality of 130 superior clones from samples of hulled coffee collected in the experimental field of Embrapa Rondônia in the municipality of Ouro Preto do Oeste, RO, Brazil. The beverage was classified according to the Robusta Cupping Protocols, which also considers the nuances of the beverage, described as neutral, fruit-like, exotic, refined, and mild. The final mean values classified the Robusta botanical variety and the intervarietal hybrids as coffees with a premium beverage, and the Conilon botanical variety as usual good quality. The nuances of the Conilon botanical variety were found to be predominantly neutral (78%), as compared to the Robusta botanical variety and the intervarietal hybrids, which exhibited 50% and 44% of their beverages, respectively, with fruit-like, exotic, or mild nuances. The genetic parameters indicate that the genetic component was more important than the environmental in expression of coffee quality attributes. Genetic variability was observed in the population evaluated, except for the Uniform Cup and Clean Cup beverage attributes.
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    Different volumes of tubes for clonal propagation of Coffea canephora from seedlings
    (Editora UFLA, 2018-01) Espindula, Marcelo Curitiba; Balbino, Tony José; Jaraceski, Rutinéia; Teixeira, Alexsandro Lara; Dias, Jairo Rafael Machado; Teixeira, Richelly Gisela Pasqualotto
    The aim in the present study was to evaluate the growth of Coffea canephora cv. ‘Conilon BRS Ouro Preto’ seedlings in different tube volumes. The experiment was performed at Embrapa Rondônia plant nursery in Ouro Preto do Oeste, Rondônia, Brazil, from July to November 2013. The treatments consisted of five tube volumes (50, 100, 170, 280 and 400 cm 3) plus one control composed by polyethylene bags (11 cm width x 20 cm height) with capacity of 770 cm 3 . The experimental design was a randomized complete block design with 15 replicates, formed by 15 clones that compose the Conilon ‘BRS Ouro Preto’ cultivar. The tube volume of 280 cm 3 provide the best vegetative performance of seedlings, similarly to volume of 400 cm 3 , thus, the use of larger tubes would not justify. Tubes of 50, 100 and 170 cm 3 produce seedlings with physiological quality similar to the control until 130 days after staking, but may limit the development of seedlings in a longer period.