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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Resultados da Pesquisa
Item Morphological, physiological, and agronomic traits of crossings of 'Icatu' x 'Catimor' coffee tree subjected to water deficit(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2022-07-27) Coelho, Larissa Sousa; Tassone, Guilherme Augusto Teixeira; Carvalho, Gladyston Rodrigues; Silva, Vânia Aparecida; Viana, Mariana Thereza Rodrigues; Pereira, Fernanda Aparecida Castro; Nadaleti, Denis Henrique Silva; Silveira, Helbert Rezende de Oliveira; Botelho, Cesar EliasThe objective of this work was to select genotypes of Coffea arabica with good yield and potential tolerance to water deficit, as well as to try to understand the physiological and anatomical mechanisms involved in the adaptability of these genotypes to water stress. The physiological, anatomical, and agronomic traits of 19 genotypes of C. arabica were evaluated under the two following water conditions: regular irrigation and no irrigation (soil water deficit). The 'IPR 100', 2, 5, and 7 genotypes showed agronomic, physiological, and anatomical traits that contributed to a better water status maintenance in the initial development of coffee plants. Based on these results, these genotypes are potentially tolerant to water deficit. The 4, 10, 11, 14, 15, and 'Bourbon Amarelo IAC J10' genotypes show a lower adaptability of the anatomical structures under soil-water deficit conditions. The coffee tree genotypes display leaf plasticity, such as the thickness of palisade and spongy parenchyma, and the number, position, dimensions, and mobility of stomata under water deficit conditions.Item Early selection of drought-tolerant Coffea arabica genotypes at the seedling stage using functional divergence(Escola de Agronomia - UFG, 2022-08-15) Reis, André Moraes; Mendes, Antônio Nazareno Guimarães; Abrahão, Juliana Costa de Rezende; Santos, Meline de Oliveira; Silva, Vânia AparecidaThe development of more drought-tolerant cultivars is essential for the maintenance of global agricultural production. This study aimed to perform an early selection of drought-tolerant Coffea arabica genotypes by evaluating their functional divergence using morphological, anatomical and physiological analyses. Seedlings of 14 genotypes were subjected to the drought stress imposed by irrigation for 18 days. Growth and anatomical parameters, leaf water potential and gas exchanges were measured. Under irrigated conditions and prolonged drought (18 days), the divergence among the genotypes was determined mainly by morphological traits, such as leaf area, stem diameter and, consequently, shoot dry mass. Under moderate drought (14 days), parameters such as water potential, cuticle thickness, stomatal density, number of xylem vessels and water-use efficiency were important for the divergence of the group with the highest ability to maintain its water status. The genotypes 1, 2, 4, 11 and 12 have characteristics that contributed to the maintenance of water status, such as greater cuticle thickness, stomatal density, smaller number of xylem vessels and phloem thickness, bigger root length and greater water-use efficiency. The functional divergence combining morphological, anatomical and physiological analyses in response to the moderate drought indicated the early selection of the genotypes 1, 2,4, 11 and 12 as more drought tolerant during the seedling stage.Item Adaptations to the drought season and impacts on the yield of ‘Híbrido de Timor’ coffee tree in the Minas Gerais State Cerrado (Brazilian Savanna)(Escola de Agronomia - UFG, 2022-09-02) Santos, Cyntia Stephânia dos; Freitas, Ana Flávia de; Silva, Glauber Henrique Barbosa da; Carvalho, Milene Alves de Figueiredo; Santos, Meline de Oliveira; Carvalho, Gladyston Rodrigues; Silva, Vânia AparecidaClimate change threatens the survival of commercial crops due to their narrow genetic base. One of the alternatives is the identification of plants with potential for abiotic stress tolerance. This study aimed to verify the physiological and anatomical adaptations to the drought period and the impacts on the yield of ‘Híbrido de Timor’ coffee tree accessions. The experimental design was randomized blocks, in a 7 x 2 factorial arrangement, being seven genotypes (UFV 377-21, UFV 377-21, UFV 442-42, BE 5 Wush-Wush x UFV 366-08, UFV 428-02, UFV 376-31 and UFV 427-55) and two seasonal periods (dry and rainy), with two replications. The stomatal conductance; predawn water potential; levels of hydrogen peroxide and malondialdehyde; activity of the enzymes catalase, superoxide dismutase and ascorbate oxidase; ascorbate content; cuticle thickness of the adaxial surface and leaf lamina; stomatal density; ratio between polar and equatorial diameter; phloem area; area, diameter and frequency of xylem vessels; relative hydraulic conductivity; vulnerability index; and yield were evaluated. The results showed acclimatization of the accessions to the dry period, with some of them maintaining higher water potential values in the predawn; induction of the antioxidant system with the increase in the activity of the superoxide dismutase enzyme and ascorbate levels; increase in the cuticle and leaf lamina thickness; and a higher ratio between polar and equatorial diameters. Most of the evaluated accessions showed a good productive performance, especially the ‘UFV 377-21’, ‘UFV 442-42’ and ‘UFV 376-31’, with adaptations to the dry period and yield potential.Item Resposta fisiológica de clone de café Conilon sensível à deficiência hídrica enxertado em porta‐enxerto tolerante(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2010-05) Silva, Vânia Aparecida; Antunes, Werner Camargos; Guimarães, Breno Lourenzzo Salgado; Paiva, Rita Márcia Cardoso; Silva, Vanisse de Fátima; Ferrão, Maria Amélia Gava; DaMatta, Fábio Murilo; Loureiro, Marcelo EhlersO objetivo deste trabalho foi determinar alterações fisiológicas e de tolerância à seca em clones de café Conilon (Coffea canephora) contrastantes quanto à sensibilidade ao deficit hídrico. Foram avaliadas as enxertias recíprocas entre os clones 109A, sensível ao deficit hídrico, e 120, tolerante – 120/109A, 120/120, 109A/120, 109A/109A –, além de seus respectivos pés‐francos. As plantas foram cultivadas em vasos de 12 L em casa de vegetação. Após seis meses, metade das plantas foi submetida ao deficit hídrico por meio da suspensão da irrigação, até que as folhas atingissem o potencial hídrico de antemanhã de ‐3,0 MPa. Quando o clone 120 foi usado como porta‐enxerto, as plantas apresentaram sistema radicular mais profundo, mas com menor massa, retardaram por mais tempo a desidratação celular das folhas e apresentaram maior eficiência no uso da água. Sob seca severa, os teores de amido e sacarose decresceram em todos os tratamentos, enquanto os teores de glicose, frutose, aminoácidos totais e prolina aumentaram, particularmente nos tratamentos 109A pé‐franco, 109A/109A e 120/109A. Essas plantas apresentaram menor eficiência no uso da água. O acúmulo de solutos não foi associado à tolerância à seca. O uso de porta‐enxertos tolerantes à seca contribui para a maior tolerância das plantas ao deficit hídrico.