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2021 - 20253

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Assunto: search.filters.subject.Genetic breeding

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    Physiological and nutritional parameters of drought resistance in coffee seedlings genotypes
    (Editora da Universidade Estadual de Maringá - EDUEM, 2025-06-02) Andreazi, Elder; Sousa, Bruno Teixeira de; Oliveira, Halley Caixeta; Fonseca, Inês Cristina de Batista; Mariucci Junior, Valdir; Shigueoka, Luciana Harumi; Sera, Gustavo Hiroshi
    Drought is an environmental condition that compromises the development of coffee plants. New coffee genotypes that are resistant to drought must be selected quickly and practically. The objectives of this study were to evaluate the resistance of five genotypes of Coffea arabica, including three new genotypes with introgression of genes from Coffea racemosa (H0113-40-26-1, H0113-40-26-19, and H0113-40-26-10), to water restriction and relate the intensity of plant wilting with physiological responses and nutrient accumulation. The experiment was conducted using 45 coffee seedlings obtained from seeds with six pairs of leaves cultivated in tubes. Some seedlings were subjected to two water restriction periods, whereas the remainder were kept under irrigation. The photosynthesis rate, transpiration rate, and wilting intensity were evaluated after each restriction period. Nutrient content was also evaluated after two periods of water restriction. The evaluation of wilting intensity corroborated the physiological parameters. There was a reduction in photosynthesis and transpiration rates under water restriction and nutrient accumulation in coffee seedlings H0113-40-26-1, H0113-40-26-19, and H0113-40-26-10 increased under these conditions. C. arabica genotypes carrying the genes of C. racemosa presented good drought resistance, with H0113-40-26-10 being the most resistant and showing the lowest wilt intensity.
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    Assessment of leaf anatomic and physiological characteristics and genetic divergence among Coffea arabica L. cultivars in the Brazilian Savanna
    (Escola de Agronomia - UFG, 2022-01-16) Santos, Cyntia Stephânia dos; Pereira, Fernanda Aparecida Castro; Mauri, Janaína; Viana, Mariana Thereza Rodrigues; Rodrigues, Gustavo Costa; Veiga, Adriano Delly; Bartholo, Gabriel Ferreira; Carvalho, Milene Alves de Figueiredo
    The knowledge on cultivars is essential for parental choosing on breeding programs. This research aimed to study the genetic divergence of Coffea arabica L. cultivars from a germoplasm bank of the Embrapa Cerrados, Brazil, for leaf anatomic and physiological characteristics. A total of 23 cultivars were evaluated: Acaiá Cerrado MG1474, Araponga MG1, Catiguá MG1, Catiguá MG2, Catiguá MG3, Catiguá MG3 P4, Catiguá MG3 P5, Catiguá MG3 P7, Catiguá MG3 P9, Catiguá MG3 P23, Catiguá MG3 P51, Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 15, Catuaí Vermelho IAC 81, Catuaí Vermelho IAC 99, Caturra Vermelho MG0187, Guatenano Colis MG0207, Mundo Novo IAC 379-19, Paraíso MG1, Pau Brasil MG1, Sacramento MG1, San Ramon MG0198 and Topázio MG1190. In addition to the genetic divergence, the broad sense heritability and coefficient of genetic and environmental variation were also evaluated. All characteristics showed high coefficients of genetic variation and heritability values greater than 70 %, indicating a predominance of genetic over environmental factors, and that these are characteristics likely to obtain genetic gain. Catiguá MG1, Catiguá MG3 P51 and Topázio MG1190 stood out, with superior gas exchange characteristics. Attributes related to gas exchange were important for cultivar differentiation, demonstrating that they can be used in the early selection of Coffea arabica L. genotypes.
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    Physiological aspects and yield in coffee progenies with large beans
    (Editora UFLA, 2021) Pavan, João Paulo Silva; Santos, Cyntia Stephânia dos; Freitas, Ana Flávia de; Carvalho, Samuel Pereira de; Carvalho, Gladyston Rodrigues
    Genetic coffee breeding is aimed at increasing yield associated with tolerance or resistance to biotic and abiotic factors, besides providing a better beverage quality and supplying the demand for bigger beans. The efficiency in photosynthetic activity can limit produce and diversify genotypes, mainly under adverse environmental conditions. Consequently, the importance of selection of Coffea arabica L. regarding these characteristics stands out. Therefore, the objective of this paper was to measure the physiological characterization and yield of Coffea arabica L. progenies with large beans “Big Coffee VL”. Twelve productive progenies were selected and classified according to fruit size (“small”, “medium” and “large”), which were: S14, S23, S34, S36, M4, M5, M14, M20, L10, L12, L17 and L31. Net photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), internal carbon (Ci), intercellular CO2 concentration in the mesophyll were evaluated on the current external CO2 concentration (Ci/Ca), besides vapor pressure deficit (VPD), leaf temperature (Tleaf), indirect determination of the relative levels of chlorophylls a, b and total, in addition to bean yield in two crops. The Tocher grouping resulted in the formation of 4 groups, and progenies M4, L10 and S34 remained in isolated groups.Progeny L10 stood out for higher mean values of A, gs and Ci; the opposite behavior was observed in progeny S34. Progeny M4 is noteworthy as the one with the highest yield in the two years considered, in addition to presenting high photosynthetic rate and chlorophyll indexes. It is concluded that the progenies of “Big Coffee VL” show variability for physiological parameters and productivity. Progenies S14, M4 and L10 stood out, and S14 was more efficient in the use of water; M4 was the most productive and L10 stood out in terms of gas exchange.