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Resultados da Pesquisa
Item Large-scale gene expression analysis reveals the role of primary metabolism regulation in resistance to Brazilian Pseudomonas coronafaciens pv. garcae in coffee(Instituto Agronômico (IAC), 2024-12-20) Schenk, Juliana Camargo Martinati; Rodrigues, Lucas Mateus Rivero; Arruda, Natália; Guimarães, Paula de Souza; Diniz, Leandro Cardamone; Rezende, Antonio Mauro; Destéfano, Suzete Aparecida Lanza; Padilha, Lilian; Maluf, Mirian Perez; Guerreiro Filho, OliveiroThis study investigated the response of arabica coffee plants to the pathogen Pseudomonas coronafaciens pv. garcae using RNA-seq technology. Susceptible and resistant coffee plants were inoculated with the bacteria, and leaf samples were collected at different time points for RNA sequencing. Seven genes related to different defense pathways were chosen for expression quantification in time-course experiments using infected leaves from resistant and susceptible plants, as well as non-infiltrated and water-infiltrated leaves as controls. The results obtained revealed that response mechanisms differ between genotypes and provide insights into the genetic basis of early defense in coffee plants against P. coronafaciens pv. garcae, offering potential strategies for genetic breeding.Item Sample size estimation of fruit maturation for Arabica’s coffee(Instituto Agronômico (IAC), 2025-01-31) Botega, Gustavo Pucci; Abrahão, Juliana Costa de Rezende; Botelho, Thiago Tavares; Botelho, Cesar Elias; Salvador, Guilherme Soares; Gonçalves, Flávia Maria AvelarThis study aimed at establishing the ideal sample size for evaluating the maturation cycle in Coffea arabica, and investigating the errors associated with different sample sizes, in addition to verifying the possibility of using the clustering method to separate genotypes according to the maturation stage. Two experiments were analyzed: one with F2:3 progenies using visual maturation assessment through fruit counting, and another with cultivars using image processing for maturation assessment. To determine the ideal sample size for this trait, we used the estimation of the errors associated with maturation, using the bootstrap technique. Subsequently, the K-means algorithm was tested as an alternative for clustering genotypes into maturation classes. The application of the bootstrap technique in order to estimate the error associated with maturation revealed that the adoption of a 450-mL sample size resulted in an associated error of approximately 5%, indicating that it is an adequate size for character assessment. The implementation of K-means as a clustering tool offers a promising perspective for Arabica coffee plant breeding programs. A more comprehensive analysis, which not only assesses the proportion of ripe fruits, but also considers the distribution of different maturation stages, provides a more accurate understanding of the maturation process. This allows a more precise identification of genotypes with the most suitable performance for different growing conditions, as well as enabling adjustments in harvest management and post-harvest processing, optimizing coffee quality.Item Contribution of mycorrhiza and phosphate-solubilizing fungi in coffee seedling growth in four soils with different fertility conditions(Instituto Agronômico (IAC), 2025-01-17) González-Osorio, Hernan; Sadeghian, Siavosh; Mira, Beatriz EugeniaPhosphorus (P) is a limiting nutrient for coffee seedlings. To meet this requirement, coffee growers usually apply di-ammonium phosphate (DAP), which is highly sensitive to local price fluctuations. The use of arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing fungi (PSF) has been recommended, but the results derived from their application are inconsistent and uncertain, depending on soil fertility status. The response of AMF and PSF application in the plant growth of coffee seedlings during the nursery stage was evaluated in four non-sterile soils, which represent the most abundant type of soils in the coffee regions of Colombia: Eutropept, Dystropept, Fulvudand, and Ultisol. The treatments included a commercial AMF inoculum, PSF-Phlebia subserialis-CH4, and a consortium of AMF+PSF, at four P levels (0, 0.5, 1, and 2 g.plant-1 P2O5) using DAP fertilizer. Shoot dry weight (SDW) was affected by P applications in Fulvudand. In the other soils, a P-response occurred with 0.5 g.plant-1 , whereas 1 and 2 g.plant-1 of P2O5 caused a significant reduction in SDW. AMF increased SDW by 40% in Eutropept. The negative effect of higher P amounts was mitigated (> 70%) through PSF and AMF+PSF in Ultisol and Eutropept, respectively. In plants in which microorganisms increased SDW, the P concentration was 0.17 to 0.22%. The plant growth promotion of coffee seedlings during the nursery stage with AMF and/or PSF applications varied according to soil type and P amounts applied.Item Arbuscular mycorrhizal fungi inoculation for coffee seedling production with commercial and conventional substrates(Instituto Agronômico (IAC), 2023-05-22) Silveira, Adriana Parada Dias; Tristão, Fabrício Sales Massafera; Fernandes, Ana Olívia; Andrade, Sara Adrian Lopez; Cipriano, Mateus Aparecido PereiraCoffee seedlings are commonly produced on substrate composed of a mixture of soil and cattle manure, supplemented with chemical fertilizers. Alternatives to reduce production costs and produce seedlings of greater quality and health include the use of commercial organic substrates, which require less handling. The use of beneficial microorganisms such as arbuscular mycorrhizal fungi (AMF) can be considered a good alternative for production of more vigorous coffee seedlings. The main goal of this study was to evaluate the effect of the inoculation of AMF isolates on coffee seedlings development in a commercial organic substrate (based on coconut fiber) and conventional substrate (mixture composed of soil and cattle manure compost). Ten AMF were tested: Rhizophagus irregularis, Glomus macrocarpum, Claroideoglomus etunicatum, Rhizophagus clarus, Glomus spp., Gigaspora margarita, Acaulospora morrowiae, Acaulospora scrobiculata, Acaulospora spp., and Dentiscutata heterogamma. Plant growth, shoot P content, mycorrhizal colonization, extraradical mycelium length, phosphatase activity, and photosynthetic pigments were evaluated. The effects of mycorrhization depended on both the inoculated fungal species and the substrate for seedling cultivation. Inoculation of G. margarita, Acaulospora spp., and Glomus spp. in the conventional substrate conferred the best growth plant responses, increasing shoot biomass by 160 to 320%. In the commercial substrate, the most efficient AMF were R. clarus, Glomus spp, A. morrowiae and A. scrobiculata, with up to 149% of shoot biomass increase. The commercial organic substrate and the inoculation of some of the AMF isolates were highly beneficial to coffee seedlings development and can replace the use of the conventional substrate. These results open new opportunities for the use of AMF as an inoculant to improve coffee seedling production in commercial organic substrates.