Biblioteca do Café

URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1

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Resultados da Pesquisa

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    Partial map of Coffea arabica L. and recovery of the recurrent parent in backcross progenies
    (Crop Breeding and Applied Biotechnology, 2007-06-30) Oliveira, Antonio Carlos Baião de; Sakiyama, Ney Sussumu; Caixeta, Eveline Teixeira; Zambolim, Eunize Maciel; Rufino, Raphael José Nascif; Zambolim, Laércio
    A partial map of Coffea arabica L. was constructed based on a backcross population and RAPD markers. From a total of 178 markers evaluated, only 134 that segregated 1:1 (P>0.05) were used to develop the map. Seventeen markers were not linked, while 117 formed 11 linkage groups, covering a genome distance of 803.2 cM. The maximum distance between adjacent markers was 26.9 cM, and only seven intervals exceeded 20 cM. The markers were further used for assisted selection of the plants closest to the recurrent parent, to accelerate the introgression of rust resistance genes in the coffee breeding program. Three BC1 plants resistant to coffee leaf rust and with high genetic similarity to ?Catuaí? were selected and integrated in the following backcross cycles.
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    Genomic identification, gene expression and enzyme activity of CAZymes from biotrophic fungus Hemileia vastatrix during coffee leaf infection
    (Universidade Federal de Minas Gerais, 2021-02-25) Pereira, Júlia Santos; Mendes, Tiago Antônio de Oliveira
    Coffee leaf rust, caused by the fungus Hemileia vastatrix, is a major disease that affects many coffee producers around the world, causing a huge economic loss. H. vastatrix is a biotrophic fungus, hence, its growth and reproduction are totally dependent on the cells of the living host. Because of that, they infect the tissue without causing necrosis. Nevertheless, it is known that some fungi during plant interaction can express genes involved in the formation of infectious structures, as well as synthesize enzymes responsible for the degradation of the host cell wall. However, little is known about the importance of cell wall degrading enzymes (CWDE) for biotrophic phytopathogens. In this work, we performed genomic analysis to identify CAZymes (Carbohydrate Active EnZymes) from H. vastatrix and the analysis of expression and enzyme activity during experimental coffee infection. The first step was the ab initio prediction of H. vastatrix genome, using AUGUSTUS program, which was adjusted with H. vastatrix RNA-Seq for model determination. Functional annotation to identify CAZymes was performed using dbCAN2 meta server. Among the 345 CAZymes found, 162 belong to Glycoside Hydrolases (GH) including 34 endoglucanases, xylanases and polygalacturonases from families GH 5, 9, 10, 12 and 28 - which may act during fungal infection degrading the highest prevalent components of cell wall, represented by cellulose, xylan and pectin, respectively. Physico-chemical parameters of these enzymes were checked, including identification of catalytic residues and standard CAZymes motifs. The enzyme structures were also modelled. Moreover, analysis of expression of enzymes were performed using RNA-seq data from a genotype of C. arabica susceptible to infection, therefore presenting compatible interaction with the pathogen, after 0, 12, 24 and 96 hours after inoculation (hai). Enzyme activity assays were carried out in order to verify if these enzymes were also active during the fungal infection. The enzymes showed typical physico-chemical characteristics and structures of active enzymes including conservation of the catalytic sites. Genes encoding endoglucanases and xylanases were expressed during different times of H. vastatrix infection, being the first more expressed at 12 hai and the other at 24 hai. In agreement with expression data, endoglucanases started to be produced early, and were more active at 24 hai, whereas xylanases had greater activity at 96 hai. The results suggest that biotrophic fungus also use active enzymes on carbohydrates during the infection. In relation to H. vastatrix, these enzymes start being produced at the pre-haustorial phase of the fungal infection, but are more active at the post-haustorial phase, when the haustorium begins to be formed in the host membranes and in the plant cell wall.
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    MGS Aranãs: the new Arabica coffee cultivar developed by Epamig with wide adaptation
    (Editora UFLA, 2021) Botelho, Cesar Elias; Abrahão, Juliana Costa de Rezende; Pereira, Antônio Alves; Oliveira, Antônio Carlos Baião de; Carvalho, Gladyston Rodrigues; Ferreira, André Dominghetti
    This paper describes the MGS Aranãs cultivar (H32-11-17-4-2-MS-MS) resulting from a cross between the cultivars Icatu 3851-2 and Catimor. The MGS Aranãs cultivar is characterized by small size, ripe red fruits, large seeds, coffee leaf rust resistance, an architecture suitable for densification, production stability, and high beverage quality. This new cultivar is recommended for the Sul de Minas, Cerrado Mineiro and Vale do Jequitinhonha regions.
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    Receptor-Like Kinase (RLK) as a candidate gene conferring resistance to Hemileia vastatrix in coffee
    (Escola Superior de Agricultura "Luiz de Queiroz", 2021) Almeida, Dênia Pires de; Castro, Isabel Samila Lima; Mendes, Tiago Antônio de Oliveira; Alves, Danúbia Rodrigues; Barka, Geleta Dugassa; Barreiros, Pedro Ricardo Rossi Marques; Zambolim, Laércio; Sakiyama, Ney Sussumu; Caixeta, Eveline Teixeira
    The biotrophic fungus Hemileia vastatrix causes coffee leaf rust (CLR), one of the most devastating diseases in Coffea arabica. Coffee, like other plants, has developed effective mechanisms to recognize and respond to infections caused by pathogens. Plant resistance gene analogs (RGAs) have been identified in certain plants as candidates for resistance (R) genes or membrane receptors that activate the R genes. The RGAs identified in different plants possess conserved domains that play specific roles in the fight against pathogens. Despite the importance of RGAs, in coffee plants these genes and other molecular mechanisms of disease resistance are still unknown. This study aimed to sequence and characterize candidate genes from coffee plants with the potential for involvement in resistance to H. vastatrix. Sequencing was performed based on a library of bacterial artificial chromosomes (BAC) of the coffee clone ‘Híbrido de Timor’ (HdT) CIFC 832/2 and screened using a functional marker. Two RGAs, HdT_ LRR_RLK1 and HdT_LRR_RLK2, containing the motif of leucine-rich repeat-like kinase (LRR-RLK) were identified. Based on the presence or absence of the HdT_LRR_RLK2 RGA in a number of differential coffee clones containing different combinations of the rust resistance gene, these RGAs did not correspond to any resistance gene already characterized (SH1-9). These genes were also analyzed using qPCR and demonstrated a major expression peak at 24 h after inoculation in both the compatible and incompatible interactions between coffee and H. vastatrix. These results are valuable information for breeding programs aimed at developing CLR-resistant cultivars, in addition to enabling a better understanding of the interactions between coffee and H. vastatrix.
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    IPR 107 – Dwarf arabic coffee cultivar with resistance to coffee leaf rust
    (Crop Breeding and Applied Biotechnology, 2013-10) Sera, Tumoru; Sera, Gustavo Hiroshi
    ‘IPR 107’ was derived from a cross between ‘IAPAR 59’ and ‘Mundo Novo IAC 376-4’. ‘IPR 107’ is a dwarf medium size plant with medium precocity in ripening and with complete resistance to rust races in this time. This cultivar presents superior quality and high yield in many coffee regions.
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    IPR 99 - Dwarf arabica coffee cultivar resistant to coffee ringspot virus
    (Crop Breeding and Applied Biotechnology, 2013-03) Sera, Tumoru; Sera, Gustavo Hiroshi; Fazuoli, Luiz Carlos; Bettencourt, Aníbal Jardim
    ‘IPR 99’ was derived from a cross between “Villa Sarchi 971/10” and “Hibrido de Timor 832/2”. It is a dwarf cultivar, resistant to coffee ringspot virus, partially resistant to leaf rust with semi-late ripening. ‘IPR 99’ presents partial resistance to necrosis and mummification of young fruits on field conditions. It presents special cup quality and high yield in lower and higher temperature coffee regions in Paraná State.