Revista Ceres
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Item Resilience to water deficit of coffee seedlings produced through cuttings and somatic embryogenesis(Universidade Federal de Viçosa, 2024-12-16) Dominghetti, Anderson William; Freitas, Tainah; Silveira, Helbert Rezende de Oliveira; Guimarães, Rubens JoséInformation on Coffea arabica L. vegetatively propagated during crop establishment is still scarce. Knowledge on the anatomical and physiological adaptation of these types of plants in the crop formation phase, in conditions of water deficit is important. The objective of this work was to understand the anatomical and physiological adaptations of plants derived from cuttings and somatic embryogenesis as resilience to water deficit in the implantation phase of the crop. Both types of plants were submitted to 20%, 40%, 60%, 80% and 100% of water available in the soil, in a controlled environment, for 153 days. The design used in this experiment was the randomized blocks with five replications. Physiological characteristics (photosynthetic activity, stomatal conductance, transpiration and instantaneous carboxylation efficiency) and anatomical characteristics (palisade parenchyma thickness and stomatal density) were evaluated. Both types of plants are resilient to water deficit in the planting phase of the crop. Cutting plants have greater photosynthetic activity and palisade parenchyma thickness with greater growth potential. In general, somatic embryogenesis plants have higher stomatal density. Plants of both types of seedlings have lower values of transpiration, stomatal conductance and CO2 assimilation under water deficit conditions, but with higher stomatal densities, as an adaptation response.Item Variability of photosynthetic performance among improved genotypes of Coffea canephora(Universidade Federal de Viçosa, 2025-05-09) Colodetti, Tafarel Victor; Tomaz, Marcelo Antonio; Rodrigues, Wagner Nunes; Christo, Bruno Fardim; Martins, Lima Deleon; Cavatte, Paulo CezarThis study evaluated the variability of photosynthetic performance of 27 improved genotypes of Conilon coffee, cultivated in the Southern of the Espírito Santo State. The photosynthetic performance was based on the measurement of gas exchange rates and chlorophyll in the period most favorable to the photosynthetic activity and in different stages of the reproductive cycle: flowering, fruit initiation, grain formation and fruit maturation; being expressed as the average (weighted by the number of days) along the phenological stages of the third reproductive cycle of the plants. It was possible to verify the existence of sufficient variability to differentiate the photosynthetic performance among the 27 genotypes throughout the reproductive cycle, even starting from a group of already improved genotypes. Among the physiological parameters, the rate of carbon assimilation, stomatal conductance and the transpiration rate stood out as parameters for the study of variability, mainly due to their contributions to the clustering of genotypes. The genotype 108 is highlighted due to its high photosynthetic rate, associated with higher relative content of chlorophyll, as well as reasonable water use efficiency. The genotypes 205, 206 and 305 stood out in terms of water use and carbon assimilation.