Desenvolvimento, produtividade e genes de referência de genótipos de coffea ssp. sob temperaturas adversas

• Autor(a) principal: Martins, Madlles Queiroz
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7857
• topic: Acclimation; Antioxidants; Coffee; Chloroplast; Climate change; Enhanced [CO2]; Global warming; Heat stress; Melhoramento Vegetal; Plantas - Melhoramento genético; Café; Aquecimento global; Expressão gênica; Interação genótipo-ambiente; 631.523

Global warming may promote changes in Agroclimatic zoning of the coffee, and consequêntimente in the global coffee scene. The general objective of this work was to evaluate the development, productivity and reference genes of Coffea spp genotypes. Under adverse temperatures. The work was divided in 5 chapters: Chapters 1 and 2: Increasing the atmospheric CO2 level and the high temperatures, can promote changes in the plants. This fact is of concern to mankind as regards the maintenance of food production, especially the world coffee industry. In this case the objectives of this study were: the occurrence of PSII photoinhibition (as photodegradation marker), followed by a characterization of the protection mechanisms, including the dynamics of photosynthetic pigments, enzymatic and non-enzymatic antioxidant systems, and the quantification of the raffinose family Oligosaccharides RFOs) and heat shock protein, in addition, detailed study of reference genes to evaluate the expression of selected genes with potential roles in heat acclimatization. The experiment was carried out using a simple factorial arrangement, in a completely randomized design, using two factors, the first one was composed of two levels of CO2 and the second factor was composed of four temperature levels. For the experimentation, two C. arabica genotypes (cv. Icatu and IPR 108) and one C. canephora (cv. Conilon clone 153) were grown in 80 L pots. The experiment was carried out in two growth chambers (Model 10000 EHHF, Mark Aralab, Portugal), with controlled climate conditions. The first chamber was controlled to maintain at constant 380 ppm of CO2 and the second chamber at 700 ppm of CO2. In these chambers the temperature was gradually increased every 30 days, taken day / night: 25/20°C; 31/25°C; 37/30°C at 40/34°C. The two growth chambers were submitted to 75% relative humidity, photosynthetically active radiation of ca. 750- 800 micromol m-2 s -1 and photoperiod of 12 h, continuously throughout the experiment. According to results obtained in this study, relevant heat tolerance was observed up to 37/30ºC for both [CO2], considering all the genotypes evaluated in this study. This tolerance was achieved with support of several protective molecules (neoxanthin, lutein, carotenes, TOC, HSP70, raffinose), changes in antioxidant enzyme activities (SOD, APX, QR, CAT) and upregulated expression of some genes (ELIP, Chape 20). At 42/34ºC the photoinhibition was manifested, especially in plans cultivated the 380 ppm and in the Icatu genotype. At this temperature an overall reinforcement of the antioxidative system was not observed, however, there was a positive regulation of protection mechanisms (HSP70, chaperonins, ELIP and APX Cyt) as well as raffinose content, which together constituted a common line For all genotypes evaluated in this study. A consistently higher expression in CL153 was observed at the highest temperature, according to its better tolerance at elevated temperatures. TOC and HSP70 appeared to be particularly relevant in C. arabica genotypes. The presence of RFOs, lutein, ß-carotene, TOC and HSP70, as well as upregulated expression of protective protein-related genes (ELIPS, HSP70, Chape 20 and 60) and antioxidant enzymes (CAT, CuSOD2, APX Cyt, APX Chl), Probably acted together to control the formation and elimination of ROS, induced by the increase in temperature. Overall, the results showed that the high [CO2] attenuated the impact of heat through higher photosynthetic performance, upregulation of protective molecules, as well as higher activity of some antioxidant enzymes. The expression stability varied according to the type of stress for most genes. The final ranking obtained with RefFinder ranked MDH as the most stable gene for a global use, regardless of the assessed stress. Chapters 3, 4 and 5: Taking into account the temperature rise predicted by the IPCC, one can imagine that some agricultural areas producing Coffea arabica may become unsuitable for cultivation. In this sense, plants of Coffea canephora may possibly occupy these areas, since they are plants that better adapt to the stressful conditions promoted by heat and possibly positive cold temperatures. In this context, it is necessary to experiment with Coffea canephora genotypes in regions that have the risk of shifting agricultural zoning from Coffea arabica to Coffea canephora, as is the case in this study. (a) To evaluate the productive capacity of 28 different genotypes of Coffea canephora grown in high altitude climate. (b) Characterize the growth rate of Coffea canephora genotypes grown at high altitude. (c) To identify genotypes with potential to be cultivated in the southern region of the cerrado of Goiás. The experiment was carried out at the Federal Institute of Education, Science and Technology Goiano Campus Morrinhos, Goiás. Using 28 genotypes of Coffea canephora, multiplied by clones and Seeds. The design was a randomized block design, with four replications, each replicate being composed of five plants. The following characteristics were evaluated: productivity/ ha of the 28 genotypes of Coffea canephora in 4 seasons, growth rate and quantification of accumulated nutrients in leaves collected in winter and summer. The results showed a significant genetic variability among the genotypes evaluated in this study, a condition that favors the gain of clonal selection. In addition, a high heritability was observed among the genotypes, a result that indicates the high precision regarding the selection of superior genotypes. The genotypes that stood out in terms of productivity stability and adaptability were: the 3V genotype of the "Vitória" variety; NV2; NV8; P1; VERDIM TA and A1, It should be considered that of the six genotypes considered superior there are different degrees of similarity depending on the characteristic in question. The growth rates of plagiotropic and orthotropic branches of the C. canephora genetic material were negatively affected during a period when the minimum temperatures were below 17ºC. For most of the nutrients, it is observed higher average values in leaves collected in the winter. Principal components analysis indicates that the genotype groups of C. canephora alter the relationships between objects (genotypes) and descriptors (nutrient content) according to the season of leaves collected (winter and summer)