Brazilian Journal of Biology
URI permanente para esta coleção${dspace.url}/handle/123456789/13321
Navegar
2 resultados
Resultados da Pesquisa
Item Physiological quality of seeds of arabic coffee cultivars stored for a period of two years(Instituto Internacional de Ecologia, 2024-11-08) Alixandre, R. D.; Lima, P. A. M.; Alixandre, F. T.; Krohling, C. A.; Fornazier, M. J.; Guarçoni, R. C.; Almeida, T. F. R.; Dias, R. S.; Anastácio, A. S.; Alexandre, R. S.; Ferreira, A.; Lopes, J. C.The rapid loss of viability, coupled with the difficulties and limitations in conserving coffee seeds, are some of the challenges that nurseries are currently facing. Thus, the objective of this work was to analyze the physiological quality of stored Arabica coffee seeds from cultivars recommended for planting in Brazilian mountainous regions. Seeds from 10 Arabica coffee cultivars were used: Catucaí-785/15, Catucaí-2SL, Catucaí-24/137, Japan, Arara, Acauã, Catuaí IAC-81, Mundo Novo IAC-379/19, Catuaí IAC-62, and Caturra IAC-479. The seeds were collected in the Arabica coffee seed production field, in the municipality of Marechal Floriano-ES. They were subsequently processed and dried in the shade, at room temperature, until reaching a humidity of 35 ± 1%, analyzed and stored in a natural laboratory environment (25 ± 2 °C), for 24 months. The following were analyzed: seed water content, germination, germination speed index, electrical conductivity and potassium leaching. The experimental design used was completely randomized, with ten cultivars, two storage times, with four replications of 25 seeds. Storing arabica coffee seeds for 24 months results in a drop in the germination percentage. Stored seeds of the Catucai 24/137 and Arara cultivars showed germination percentages similar to those of newly harvested seeds. Seeds of the Catuai IAC-62 cultivar maintain vigor during storage. The stored seeds of the Caturra IAC-476 and Japi cultivars showed a reduction in physiological quality. Electrical conductivity and potassium leaching tests are efficient in identifying seeds in an advanced state of deterioration. Seeds of Arabica coffee cultivars stored for 24 months, under the conditions of the present study, produce abnormal seedlings.Item 16S metabarcoding analysis reveals the influence of organic and conventional farming practices on bacterial communities from the rhizospheric of Coffea arabica L.(Instituto Internacional de Ecologia, 2023-11-03) Andrade, P. H. M.; Machado, P. C.; Paula, A. F.; Paganin, A. C. L.; Rezende, G. S.; Matheucci Jr., E.; Carvalho, L. M.; Freire, C. C. M.; Cunha, A. F.; Lacava, P. T.Coffea sp. is cultivated in many tropical countries. Brazil has always adopted intensive agricultural practices, but organic coffee farming is an alternative system based on the non-use of agrochemicals and the rational management of soils. Metabarcoding 16S analysis using next-generation sequencing has been developed to identify and compare the diversity of the Coffea arabica L. rhizospheric bacterial community in two farming areas in São Paulo, Brazil. Dourado uses conventional farming, while Ribeirão Corrente uses organic. We found broad taxonomic composition, with sequences from 24 phyla, 55 classes, 61 orders, 146 families, and 337genus. The three most abundant phyla were Proteobacteria (38.27%), Actinobacteria (15.56%), and Acidobacteria (16.10%). In organic farming, the top 3 were the family Sphingomonadaceae, order Rhizobiales, genus Nocardioides, and Gp6. The genus Gp2 and the phylum Candidatus Saccharibacteria were the most abundant OTUs exclusively present in conventional farming. In the organic farming practice, Proteobacteria, Actinobacteria, and Acidobacteria were also present among the exclusive OTUs; we also found OTUs belonging to Bacteroidetes, Firmicutes, and Verrucomicrobia. Our study indicates a positive effect of organic farming on microbial communities. Fertilization may directly affect soil microbiota, suggesting that a large and active microbial community low in functional diversity might not adapt to new climatic conditions. A diverse community could provide better resilience to environmental changes, improving the productivity of this important crop.