Phenotypic Plasticity Index as a Strategy for Selecting Water-Stress-Adapted Coffee Genotypes.

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.

Photochemical efficiency correlated with candidate gene expression promote coffee drought tolerance.

The aim of this study was to identify the correlation between photochemical efficiency and candidate genes expression to elucidate the drought tolerance mechanisms in coffee progenies (Icatu Vermelho IAC 3851-2 × Catimor UFV 1602-215) previously identified as tolerant in field conditions. Four progenies (2, 5, 12 and 15) were evaluated under water-deficit conditions (water deficit imposed 8 months after transplanting seedlings to the pots) and under irrigated system. Evaluations of physiological parameters and expression of candidate genes for drought tolerance were performed. Progeny 5 showed capacity to maintain water potential, which contributed to lower qP variation between irrigated and deficit conditions. However, the increases of qN and NPQ in response to stress indicate that this progeny is photochemically responsive to small variations of Ψam protecting the photosystem and maintaining qP. Data obtained for progeny 12 indicated a lower water status maintenance capacity, but with increased qN and NPQ providing maintenance of the ɸPSII and ETR parameters. A PCA analysis revealed that the genes coding regulatory proteins, ABA-synthesis, cellular protectors, isoforms of ascorbate peroxidase clearly displayed a major response to drought stress and discriminated the progenies 5 and 12 which showed a better photochemical response. The genes CaMYB1, CaERF017, CaEDR2, CaNCED, CaAPX1, CaAPX5, CaGolS3, CaDHN1 and CaPYL8a were up-regulated in the arabica coffee progenies with greater photochemical efficiency under deficit and therefore contributing to efficiency of the photosynthesis in drought tolerant progenies.

Discrimination of genotypes coffee by chemical composition of the beans: Potential markers in natural coffees.

The chemical composition of coffee beans varies according to the cultivar used, but there is little information about the differences among them resulting in different sensory profiles. The purpose was to find potential chemical markers to discriminate genealogical groups of coffee using regression analysis by partial least squares. Twenty-two accessions of C. arabica were used with two repetitions each. There were chromatographic and physical-chemical analyses to determine the composition of raw beans and chemometric analysis as the PCA and the PLS-DA. The analysis of PCA did not showed detailed information about the differences between the groups. The model PLS-DA identified the most important variables in the discrimination of the genealogical groups. Arachidic acid and stearic acid the markers for the Bourbon group; the myristic and linoleic acids and sucrose for the Exotic group; and lauric, palmitoleic and oleic acids, and the protein content to the Timor Hybrid group.

Potential of rust-resistant arabica coffee cultivars for specialty coffee production

Rust is the main disease affecting Coffea arabica, the most economically important coffee species. The objective of this study was to analyze C. arabicacultivars with different levels of rust resistance, including bean size, raw bean appearance, finalsensory scores (FSS), and aromaand taste nuances of the coffee cup. The experiment was designed in randomized blocks (RBD) with three replications and 20 treatments (cultivars), totaling 60 experimental plots. The rust-susceptible cultivars IPR 100, Rubi MG 1192, and Topázio MG 1190 were compared with 17 rust-resistant cultivars.Cultivars IPR 103, MGS Aranãs, and SaíraII presented the highest percentages of high sieves, highest scores of raw bean appearance, and low percentages of mocha-type beans. All cultivars had FSS above 82 and were classified as specialty coffees. The cultivars with the highest FSS (Arara and Catiguá MG2) showed a greater diversity of coffee cup aroma and flavor nuances. Rust-resistant Arabica coffee cultivars are promising for the physical quality of beans and have potential for the specialty coffee market.

Agronomic traits of coffee tree progenies from Timor Hybrid x Catuaí crossing / Características agronômicas de progênies de cafeeiro oriundas do cruzamento de Híbrido de Timor x Catuaí

The objective of this work was to evaluate the agronomic traits of coffee tree progenies. The experiment was set in Ouro Verde Farm, located at Campos Altos County, MG. Twenty three coffee progenies and seven control cultivars were used. These progenies are from the fourth generation of crossing between Timor Hybrid and Catuaí. The experiment was set in a randomized block design with four replicates, a total of 120 plots with 8 plants per plot. The yield of processed coffee sacks ha-1 was evaluated in eight crop years from the 2003 to the 2011 harvests. The percentage of fruits at the cherry stage, floating fruits, coffee classification (sieve above 17), income and plant vigor were evaluated in the 2010 and in the 2011 harvests. It was concluded that the progenies showed a great variability for the agronomic traits. Progenies 514-7-4-C130, 493-1-2-C134 and 518-2-10-C408 had the highest yield in the four two-year periods. The progenies 436-1-4-C26, 516-8-2-C109, 493-1-2-C134, 518-2-10-C408, 514-7-16-C211 and 514-7-16-C208 presented the highest values for plant vigor. Progeny 493-1-2-C134 stood out in all analyzed traits, showing to be promising for the advance of the generations.

Objetivou-se com este trabalho avaliar o comportamento agronômico de progênies de cafeeiro. O experimento foi instalado na Fazenda Ouro Verde, situada no Município de Campos Altos-MG, compreendendo vinte e três progênies e sete cultivares utilizadas como testemunhas. Essas progênies referem-se à quarta geração do cruzamento entre Híbrido de Timor e Catuaí. Foi utilizado o delineamento de blocos ao acaso, com quatro repetições, totalizando 120 parcelas, sendo cada parcela constituída por oito plantas. A produtividade em sacas de café beneficiado ha-1 foi avaliada em oito colheitas, de 2003 a 2011. Nas colheitas de 2010 e 2011 foram avaliadas a porcentagem de frutos no estádio cereja e de frutos chochos, a classificação do café (peneira 17 acima), renda e vigor vegetativo. Conclui-se que as progênies apresentaram grande variabilidade para as características agronômicas estudadas. As progênies 514-7-4-C130, 493-1-2-C134 e 518-2-10-C408 apresentaram os maiores valores de produtividade na média dos quatro biênios avaliados. As progênies 436-1-4-C26, 516-8-2-C109, 493-1-2-C134, 518-2-10-C408, 514-7-16-C211 e 514-7-16-C208 apresentaram as maiores notas de vigor vegetativo. A progênie 493-1-2-C134 se destacou em todas as características analisadas, mostrando-se promissora para o avanço de gerações.

Comportamento de progênies F4 obtidas por cruzamentos de 'Icatu' com 'Catimor' / Behavior of F4 progenies obtained from crossing of Icatu with Catimor

Conduziu-se este trabalho com o objetivo de avaliar progênies de cafeeiro resultantes do cruzamento entre 'Icatu' x 'Catimor', quanto à produtividade e vigor vegetativo e selecionar progênies superiores para avançar no programa de melhoramento dessa população. O delineamento utilizado foi em blocos casualizados com quatro repetições, 30 tratamentos (29 progênies do cruzamento mais a cultivar Rubi MG 1192, utilizada como testemunha). Para análise de variância dos dados adotou-se o esquema de parcela subdividida no tempo. Foram analisados a produção em sacas beneficiadas.ha-1 de seis colheitas 2001/2002 a 2006/2007 e o vigor vegetativo avaliado após a colheita 2006/2007. Os resultados obtidos permitem verificar a presença da variabilidade genética para produção entre as progênies avaliadas, fato confirmado pela alta estimativa da maioria das progênies estudadas, demonstraram que é possível selecionar progênies superiores na população estudada.

The objective of this research was to evaluate coffee progenies resulted from the crossing of 'Icatu' with 'Catimor' in relation to their production and plant vigor and to select higher quality progenies to advance the breeding program of this population. For this purpose, a randomized complete block design was carried out with four replications and for the analysis of variance, the Split plot temporal arrangement was adopted. Twenty nine progenies plus the Rubi MG 1192 cultivar, used as a control, were evaluated. The yield of beans in bags.ha-1 of six harvests from 2001/2002 to 2006/2007 was evaluated and the plant vigor after the harvest was assessed. The results indicated that the evaluated progenies showed variability mainly for grain yield confirmed by heritability. This condition associated to high bean yields, which reached 62.0 bags.ha-1 and high plant vigor, showed the possibility of selecting outstanding progenies in the studied population.