ABSTRACT Climate 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.
RESUMO As mudanças climáticas ameaçam a sobrevivência das culturas comercias com sua base genética estreita. Uma das alternativas é a identificação de plantas com potencial para a tolerância a estresses abióticos. Objetivou-se verificar as adaptações fisiológicas e anatômicas ao período seco e os impactos sobre a produtividade de acessos de cafeeiro Híbrido de Timor. O delineamento experimental foi em blocos casualizados, em esquema fatorial 7 x 2, sendo sete genótipos (UFV 377-21, UFV 377-21, UFV 442-42, BE 5 Wush-Wush x UFV 366-08, UFV 428-02, UFV 376-31 e UFV 427-55) e dois períodos sazonais (seco e chuvoso), com duas repetições. Foram avaliados a condutância estomática; potencial hídrico na antemanhã; níveis de peróxido de hidrogênio e malondialdeído; atividade das enzimas catalase, superóxido dismutase e ascorbato peroxidase; conteúdo de ascorbato; espessura da cutícula da face adaxial e limbo foliar; densidade estomática; relação entre diâmetro polar e equatorial; área do floema; área, diâmetro e frequência de vasos do xilema; condutividade hidráulica relativa; índice de vulnerabilidade; e produtividade. Observaram-se aclimatações dos acessos ao período seco, sendo que alguns mantiveram maiores valores de potencial hídrico na antemanhã; indução do sistema antioxidante com o aumento da atividade da enzima superóxido dismutase e de níveis de ascorbato; aumento da espessura da cutícula e do limbo foliar; e maior relação entre diâmetro polar e equatorial. A maioria dos acessos avaliados apresentou bom desempenho produtivo, com destaque para UFV 377-21, UFV 442-42 e UFV 376-31, com adaptações ao período seco e potencial produtivo.
Abstract Light quality is an important factor for the adequacy of plant production through plant tissue culture, as it directly interferes with morphogenesis and photosynthetic capacity of explants. ...The objective of this study was to analyze the impact of monochromatic lights such as light emitting diode (LED) on the in vitro development of Cattleya walkeriana G. and their effects on acclimatization. The plants were developed in vitro under the colors of green, blue, yellow, red, 2 red:1 blue, and white LED lights. For in vitro cultivation, Knudson medium was used, supplemented with 20 mg L-1 sucrose, 5.5 mg L-1 agar, 2% activated charcoal, 100 mL coconut water, and pH 6.0. For ex vitro cultivation, the plants were acclimatized in styrofoam trays containing sphagnum as a substrate. In general, the supplied light lengths impactedin vitro growth and acclimatization analyses. There was influence on the cuticle thickness of plants in vitro. Chlorophyll and carotenoid contents were not significant. We can conclude that light lengths formed by 2 red:1 blue, red and yellow LEDs can be indicated for better performance in the production of C. walkeriana. The 2 red:1 blue and red LEDs provide superior in vitro development than the others, with gains for the species in acclimatization. The yellow LED provided a possible in vitro hardening, which ensured the greatest success of the seedlings during acclimatization.
Resumo A qualidade luminosa é um fator importante para a adequação da produção de plantas através da cultura de tecidos vegetais, pois interfere diretamente nos processos de morfogênese e na capacidade fotossintéticas dos explantes. O objetivo deste estudo foi analisar o impacto de luzes monocromática do tipo diodo emissor de luz (light-emittingdiode - LED) no desenvolvimento in vitro de Cattleya walkeriana G. e os efeitos na fase aclimatização. As plantas foram desenvolvidas in vitro sob as cores de luzes do tipo LED verde, azul, amarelo, vermelho, 2 vermelhos: 1 azul, e branco. Para cultivo in vitro foi utilizado o meio Knudson acrescido de 20 mg L-1 de sacarose, 5,5 mg L-1 de ágar, 2% de carvão ativado, 100 mL de água de coco, e pH 6,0. Para o cultivo ex vitro as plantas foram aclimatizadas em bandejas de isopor contendo esfagno como substrato. De maneira geral, os comprimentos luminosos fornecidos apresentaram impactos nas análises de crescimento in vitro e na de aclimatização. Houve influência na espessura da cutícula das plantas in vitro. Os teores de clorofilas e carotenoides não foram significativos. Podemos concluir, que comprimentos luminosos formados pelos LEDs 2 vermelhos: 1 azul, vermelho e amarelo podem ser indicados para melhor desempenho na produção de C. walkeriana. Os LEDs 2 vermelhos: 1 azul, e o LED vermelho propiciam desenvolvimento in vitro superior ao demais com ganhos na fase de aclimatização para espécie. O LED amarelo propiciou um possível processo de rustificação in vitro o que garantiu o maior sucesso das mudas no período de aclimatização.
ABSTRACT 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.
RESUMO O conhecimento das cultivares é essencial para a escolha dos pais em programas de melhoramento. Objetivou-se estudar a divergência genética de cultivares de Coffea arabica L. de um banco de germoplasma da Embrapa Cerrados, quanto às características anatômicas foliares e fisiológicas. Foram avaliadas 23 cultivares: 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 e Topázio MG1190. Além da divergência genética, foram avaliados a herdabilidade de sentido amplo, coeficiente de variação genética e ambiental. Todas as características apresentaram altos coeficientes de variação genética e valores de herdabilidade superiores a 70 %, indicando predominância de fatores genéticos sobre ambientais, e que essas são características passíveis de se obter ganho genético. Catiguá MG1, Catiguá MG3 P51 e Topázio MG1190 se destacaram com características de trocas gasosas superiores. Atributos relacionados às trocas gasosas foram importantes para a discriminação das cultivares, o que demonstra que podem ser utilizados na seleção precoce de genótipos de Coffea arabica L.
A qualidade luminosa é um fator importante para a adequação da produção de plantas através da cultura de tecidos vegetais, pois interfere diretamente nos processos de morfogênese e na capacidade ...fotossintéticas dos explantes. O objetivo deste estudo foi analisar o impacto de luzes monocromática do tipo diodo emissor de luz (light-emitting diode - LED) no desenvolvimento in vitro de Cattleya walkeriana G. e os efeitos na fase aclimatização. As plantas foram desenvolvidas in vitro sob as cores de luzes do tipo LED verde, azul, amarelo, vermelho, 2 vermelhos : 1 azul, e branco. Para cultivo in vitro foi utilizado o meio Knudson acrescido de 20 mg L-1 de sacarose, 5,5 mg L-1 de ágar, 2% de carvão ativado, 100 mL de água de coco, e pH 6,0. Para o cultivo ex vitro as plantas foram aclimatizadas em bandejas de isopor contendo esfagno como substrato. De maneira geral, os comprimentos luminosos fornecidos apresentaram impactos nas análises de crescimento in vitro e na de aclimatização. Houve influência na espessura da cutícula das plantas in vitro. Os teores de clorofilas e carotenoides não foram significativos. Podemos concluir, que comprimentos luminosos formados pelos LEDs 2 vermelhos : 1 azul, vermelho e amarelo podem ser indicados para melhor desempenho na produção de C. walkeriana. Os LEDs 2 vermelhos : 1 azul, e o LED vermelho propiciam desenvolvimento in vitro superior ao demais com ganhos na fase de aclimatização para espécie. O LED amarelo propiciou um possível processo de rustificação in vitro o que garantiu o maior sucesso das mudas no período de aclimatização.
The adaptive potential of plants is commonly used as an indicator of genotypes with higher breeding program potential. However, the complexity and interaction of plant metabolic parameters pose a ...challenge to selection strategies. In this context, this study aimed to explore phenotypic plasticity within the germplasm of Hybrid Timor coffee. Additionally, we assessed the utility of the multivariate phenotypic plasticity index (MVPi) as a promising tool to predict genotype performance across diverse climatic conditions. To achieve this, we evaluated the performance of seven accessions from the Hybrid Timor germplasm in comparison to the Rubi and IPR 100 cultivars, known for their susceptibility and resistance to drought, respectively. The experiment took place in a greenhouse under two conditions: one with normal soil moisture levels near maximum capacity, and the other with a water deficit scenario involving a period of no irrigation followed by rehydration. Data on physiological and biochemical factors were collected at three stages: before applying the water deficit, during its imposition, and after rehydration. Growth data were obtained by the difference between the beginning and end of the experimental period Furthermore, field evaluations of the productivity of the same genotypes were carried out over two consecutive seasons. Based on physiological and biochemical assessments, the MVPi was computed, employing Euclidean distance between principal component multivariate analysis scores. Subsequently, this index was correlated with growth and productivity data through linear regressions. Our findings reveal that the plastic genotypes that are capable of significantly altering physiological and biochemical parameters in response to environmental stimuli exhibited reduced biomass loss in both aerial and root parts. As a result, this positively influenced their productivity. Enhanced plasticity was particularly prominent in accessions from the MG Germplasm Collection: MG 311-Hybrid Timor UFV 428-02, MG 270-Hybrid Timor UFV 377-21, and MG 279-Hybrid Timor UFV 376-31, alongside the Rubi MG 1192 cultivar. The MVPi emerged as a valuable instrument to assess genotype adaptability and predict their performance under varying climatic scenarios.
The present study combined qualitative and quantitative approaches to obtain a better understanding of the sensory quality of beverages made from Arabica coffee genotypes subjected to different ...processing methods. Over three consecutive years, 270 accessions of arabica coffee from the Germplasm Collection of Minas Gerais State, Brazil, were sensorially characterized after dry postharvest processing. At the end of this period, the 26 genotypes with the greatest potential for the production of specialty coffees were subjected to dry and wet processing. Granulometry and sensory quality were evaluated by scoring and describing the sensory profile of the samples.
Adequate management during all postharvest stages maintained the potential coffee quality, regardless of processing. All of the coffees studied were classified as special. There was variation in the perceived nuances of the sensory attributes among the groups of genotypes and as a function of postharvest processing, with emphasis on the increased frequency of high sweetness in wet processing. Among the aroma/flavor sensory attributes, the caramel subcategory, as a long and pleasant aftertaste, were predominant in all of the genotypes studied, regardless of the type of processing.
The differences in the perceptions of aroma/flavor and aftertaste in different processes were easier to identify in the commercial cultivars studied, as well as in the Bourbon accessions of Timor Hybrid and their derivatives. The access MG 0159 Maragogipe Hybrid F1 stood out in terms of all of the evaluated characteristics, regardless of the processing method used. This article is protected by copyright. All rights reserved.
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