Through the pruning type 'esqueletamento' it was developed a technology for the management of trees called "Zero Yield" in order to keep the size of the crop and eliminate the harvesting in a low yield season, which usually compromises the earnings of the coffee grower. With this technology, the harvest takes place every two years, always in years of high yield season. This technology is highly dependent on climate, and genotype. Given this, the objective of the study was to select genotypes of Coffea arabica L. responsive to pruning type 'esqueletamento', with high productivity and high potential for quality of drink for specialty coffee production. The experiment was deployed in the Coffee Sector at the Universidade Federal de Lavras (UFLA) in December 2005 and after six crops, it has undergone the pruning type 'esqueletamento' in August 2014. 20 genotypes were evaluated, being 18 progenies in F 5 generation, derived from the cross between cultivars of the Catuaí Group with coffees of germplasm Icatu and germplasm "Hibrido de Timor" and two commercial cultivars as witnesses. (Tupi IAC 1669-33 and Obatã IAC 1669-20). The following characteristics were evaluated: productivity (before and after pruning), vegetative vigor, the incidence of leaf rust, dull fruits, sieve No.16 and above, grain type mocha, aspect, and quality of drink. The genotypes 9 (H516-2-1-1-18-1-1), 12 (H516-2-1-1-18-1-4), 16 (H419-3-4-5-2-1-3), 18 (H419-3-4-5-2-1-5) and the cultivar Tupi IAC 1669-33 were responsive to the 'esqueletamento', with productivity after pruning higher than the maximum reached before the adoption of the pruning. All genotypes with the exception of Catucaí Amarelo 24/137 showed potential for the production of specialty coffees.

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.

ABSTRACT. Mutagenic and antimutagenic activities of the medicinal plant Duguetia furfuracea were assessed using SMART/ wing and ring-X-loss tests. For the ring-X-loss test, 2-to 3-day-old Drosophila melanogaster ring-X-lineage males and virgin ywsn

Nutritional efficiency is a term used to characterize plants in their capacity to uptake and use nutrients, being related to the efficiency of uptake, translocation, and utilization of nutrients. Different coffee genotypes are expected to exhibit variability in their nutritional efficiency. This work aimed to evaluate the phosphorus nutritional efficiency in arabica coffee genotypes. The experiment was carried out in a greenhouse of the Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG), located in the municipality of Lavras-Minas Gerais, Brazil. The experimental design was a randomized complete block design, in a 10x2 factorial scheme (10 arabica coffee genotypes and two dosages of phosphate fertilization), with four replicates. Each experimental plot consisted of one pot with ten liters of soil, with one plant. The cultivars Catiguá MG2, MGS Ametista and Sarchimor MG 8840 are neither efficient nor responsive to phosphate fertilization. Progeny H 6-47-10 pl. 3 and the cultivar Catuaí Vermelho IAC 144 are not efficient but are responsive to phosphate fertilization. The cultivars Paraíso MG H 419-1, Topázio MG 1190 and MGS Paraíso 2 are efficient but are not responsive to phosphate fertilization. The cultivars Bourbon Amarelo IAC J10 and MGS Aranãs are efficient and responsive to phosphate fertilization.

The objective of this work was to select genotypes of Coffea arabica with good yield and potential tolerance to water deficit, as well as to try to understand the physiological and anatomical mechanisms involved in the adaptability of these genotypes to water stress. The physiological, anatomical, and agronomic traits of 19 genotypes of C. arabica were evaluated under the two following water conditions: regular irrigation and no irrigation (soil water deficit). The 'IPR 100', 2, 5, and 7 genotypes showed agronomic, physiological, and anatomical traits that contributed to a better water status maintenance in the initial development of coffee plants. Based on these results, these genotypes are potentially tolerant to water deficit. The 4, 10, 11, 14, 15, and 'Bourbon Amarelo IAC J10' genotypes show a lower adaptability of the anatomical structures under soil-water deficit conditions. The coffee tree genotypes display leaf plasticity, such as the thickness of palisade and spongy parenchyma, and the number, position, dimensions, and mobility of stomata under water deficit conditions.