Periódicos

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

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Resultados da Pesquisa

Agora exibindo 1 - 4 de 4
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    Amazonian Robustas - new Coffea canephora coffee cultivars for the Western Brazilian Amazon
    (Crop Breeding and Applied Biotechnology, 2020) Teixeira, Alexsandro Lara; Rocha, Rodrigo Barros; Espindula, Marcelo Curitiba; Ramalho, André Rostand; Vieira Júnior, José Roberto; Alves, Enrique Anastácio; Lunz, Aureny Maria Pereira; Souza, Flávio de França; Costa, José Nilton Medeiros; Fernandes, Cleberson de Freitas
    Amazonian Robustas are ten new clones of high yield potential with characteristics typical of the botanical varieties conilon and robusta. With individual registration, the new cultivars were developed to be grown together with other clones, with flexibility of composition of the crops according to the preference of the producer.
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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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    Adaptability and stability of Coffea canephora Pierre ex Froehner genotypes in the Western Amazon
    (Universidade Federal de Santa Maria, 2020) Moraes, Marcos Santana; Rocha, Rodrigo Barros; Teixeira, Alexsandro Lara; Espindula, Marcelo Curitiba; Silva, Camila Andrade; Lunz, Aureny Maria Pereira
    The development of Coffea canephora cultivars is based on the characterization of genotype × environment interaction, which is interpreted to quantify the differential behavior of clones at different cultivation sites. The objective of this research was to study the genotype x environment interaction aiming to select clones of broad and specific adaptation to different environments of the Western Amazon. Twelve clones with hybrid characteristics of the botanical varieties Conilon and Robusta and four open pollinated clones, had their performance evaluated in comparison with four controls. The genotype × environment interaction was interpreted based on the environmental quality index, the nonparametric estimator of Lin and Binns, 1988 and on the dispersion of the centroid method. Effects of the genotypes, environment, and genotype × environment interaction were all significant (p<0.01). The environmental quality index (Ij) classified three environments as favorable for coffee production. In terms of the Lin and Binn’s estimator (Pi), hybrid genotypes 16, 10, 13, 09 and 14 presented lower Pi indices than others, and were classified as being more stable. Five clones of low adaptability, seven clones of specific adaptability to favorable or unfavorable environments and two clones of broad adaptability to all environments were identified interpreting the dispersion of the centroid method.
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    Estimation of genetic parameters and selection of Coffea canephora progenies evaluated in Brazilian Western Amazon
    (Editora UFLA, 2020) Bergo, Celso Luis; Miqueloni, Daniela Popim; Lunz, Aureny Maria Pereira; Assis, Giselle Mariano Lessa de
    Coffee has emerged as an economic alternative culture in the State of Acre, Brazil, but without a clonal variety recommended for the state to overcome the unevenness presented by seed crops. Thus, in order to estimate genetic parameters and indicate progenies of Coffea canephora to compose a clonal variety for the State of Acre, yield, vegetative vigor and plant height were evaluated in five harvests of a randomized complete block experiment with 46 progenies, 4 repetitions and 10 plants per plot by mixed model methodology (REML/BLUP). The harvests were evaluated individually, by the model that considers one harvest, one location and the mean of progenies, and joint analysis (all harvests), by repeatability model with stability and temporal adaptability by the harmonic mean of relative performance of genotypic values method (MHPRVG), with genotypic values of progenies grouped by the Tocher method. There was variability, with possibility of selection, only for grain yield. The yield was strongly affected by production bienniality, with high environmental influence and harvests mean ranging from 14.13±4.60 to 46.20±14.94 bags ha-1 and individual heritabilities from 0.10 to 0.44. Sixteen‘Conilon’ coffee progenies with selection gains above 23% were selected. The MHPRVG method allows the refinement of progeny selection throughout the harvests, identifying the most adapted and stable.