Coffee Science
URI permanente desta seção${dspace.url}/handle/123456789/3355
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Item Histochemical approach of the mobilization of reserve compounds in germinating coffee seeds(Editora UFLA, 2020) Oliveira, Leonardo Araujo; Souza, Genaina Aparecida de; Silva, Bruno Tavares; Rocha, Antônio Augusto Gomes; Picoli, Edgard Augusto de Toledo; Pereira, Diego de Sousa; Donzeles, Sérgio Maurício Lopes; Ribeiro, Marcelo de Freitas; Ferreira, Williams Pinto MarquesThe endosperm of coffee beans is an important structure which is composed of different reserve compounds. In the present study, we followed anatomical features during the reserve mobilization of Coffea arabica L. cv ‘Catuaí’ seed samples, harvested at 20 different sites, after 0, 3, 6, 12, 24, 30 and 45 days of imbibition. Seed samples were properly stored for enzyme activity assessment and fixed in FAA solution (formaldehyde, acetic acid and ethanol, 1; 1; 18) and kept in ethanol 70% solution, for histochemical analysis. Alternatively, samples for phenolic compounds histochemical test were fixed in Ferrous sulfate in formalin. Fixed samples were cross-sectioned for detection of starch, lipids, essential oils, oleoresins, proteins, phenolic compounds, neutral polysaccharides, alkaloids, β-1,3 and β-1,4 glucans, and lignin. Overall, based on histochemical tests and enzyme activity, seed reserve mobilization was similar among the evaluated altitudes and mountainsides. During soaking, there is an intense consumption of reserve compounds, starting at the region close to the embryo. Reserve mobilization intensifies after root protrusion, from 12 days of soaking. The intensification of the reserve consumption concomitant with an increased activity of MDH is observed at the first 12 days, whereas SOD showed higher expression after 30 days of soaking. At the 30th day, little reserve is observed in the endosperm. At 45th day, cotyledon leaves are expanded, and the root system, constituted by the taproot and lateral roots, is well established.Item Impact of drying methods over the germinative potenti al of conilon coffee of late maturation(Editora UFLA, 2019-10) Posse, Sheila Cristina Prucoli; Rodrigues, Wagner Nunes; Comério, Marcone; Volpi, Paulo Sérgio; Verdin Filho, Abraão Carlos; Posse, Robson Prucoli; Oliveira, Vinicius de Souza; Arantes, Sara DousseauThis study aimed to evaluate the effect of different drying methods (regarding temperature and drying time) over the seed moisture and germination of seeds of Coffea canephora, harvested from genotypes of late maturation. For this end, seeds from selected genotypes were harvested and dried using two different methods: drying at 25 ˚C with natural circulation of air and drying at 35 ˚C with artificial circulation of air. The seeds were evaluated to quantify the loss of moisture content, and their germinative potential was assessed by parameters of germination speed, and the proportion of seedlings with healthy germination originated from them. The results show it is possible to apply different drying methods; using different systems, temperatures and times of exposure; to decrease the moisture content of seeds of C. canephora, from 50% (freshly harvested seeds from genotypes of late maturation, in July) to under 18% (dried seeds). Even if the initial stages of the drying process, while the seeds still present high moisture content, are similar for both methods, the method with artificial circulation of air at 35 ˚C promotes the drying speed and is able to achieve the lower levels of seed moisture using less than half of the time required by method with natural circulation of air at 25 ˚C. This faster moisture removal, however, has negative impacts over the germinative potential of the seeds, which are not observed for seeds subjected to the slow natural drying.