Programa de Pós-graduação em Agronomia
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Item Caracterização de germoplasma de soja quanto aos teores de proteína, óleo e ácidos graxos(Universidade Federal de Goiás, 2011-04-26) RIBEIRO, Keyla de Oliveira; OLIVEIRA, Jaison Pereira de; http://lattes.cnpq.br/7342298421214478; DUARTE, João Batista; http://lattes.cnpq.br/4117228759548186Soybean is currently the most prominent crop in the Brazilian production of grains. Its main products include oil and meal, which have been used for the production of food and animal feed. The high protein contents represent the main attraction of soybean use in diet. Furthermore, soybean oil has also been used in the production of biodiesel. These industrial segments demands cultivars with similar profiles of fatty acids, in which case the oil guarantees a better oxidative stability. This profile corresponds to oils with low polyunsaturated acids contents, associated to high contents of monounsaturated fatty acids. For that, it becomes essential the chemical characterization of grains in cultivars, which could be extended to the genetic resources preserved in germplasm collections, with the purpose of breeding soybean in these traits. Nowadays the characterization of these resources is still deficient, mainly regarding special traits such as those previously mentioned. In this context, the objective of this study was to characterize a sub-collection of 527 accessions of soybean from the germplasm bank of Secretaria de Agricultura, Pecuária e Abastecimento do Estado Goiás (SEAGRO-GO), based on the physicochemical traits of the grain, including protein and oil contents in the meal, and the main fatty acids contents of the oil. The grains were obtained through a field trial carried out at the experimental unit of SEAGRO-GO (16°43 S; 49°7 W; 765 m), county of Senador Canedo - GO, in the 2007-2008 growing season. The experimental design was augmented blocks (blocks of Federer), with two check cultivars (Conquista and Monsoy 6101). The plots were constituted by one row of plants (5.0 m x 0.5 m). The protein contents were quantified by the Kjeldahl method, the oil by the Soxhlet method, and the fatty acids (palmitic, stearic, oleic, linoleic and linolenic) by FAME method (Fatty Acid Methyl Esters). To assess the genetic divergence among accessions the multivariate analyses used were: canonical variables, principal components and cluster analysis. The last one was performed by the hierarchical clustering method using UPGMA criteria. Canonical discriminant analysis was also performed on established similarity groups and on maturity groups of the accessions (early, intermediate and late). In the principal components analysis it was needed three components to retain 78% of the total variance, whereas in the canonical variables analysis only two of these variables captured 81.2% of this variation. About the phenotypic variation, it was observed that the studied sub-collection presents a relatively lowl variability among its accessions, in protein content (from 35.7% to 44.0%) and oil content (from 14.8% to 18.5%). For fatty acids, the germplasm showed a relatively wide variation, although characteristics of industrial interest such as high contents of oleic acid (greater than 40%) and low contents of polyunsaturated acids (less than 40%) are restricted to few accessions. Regarding the polyunsaturated acids, the germplasm presents satisfactory variability to the linoleic oil (omega-6), however, low variability to the linolenic acid (omega-3), especially in its upper limit. By cluster analysis they were established five similarity groups (A, B, C, D, and E) with the formation of subgroups in some them. The accessions of groups A and B present the largest oil and protein contents, respectively. The accessions of group C outstood with the best profile of oil quality (oxidative stability), and they were followed by the accessions of E and B groups. Among the germplasm with the best profiles of oil oxidative stability, it was still possible to identify in this collection five divergent groups of accessions with significant differences in fatty acids contents. The polyunsaturated and saturated fatty acids are the most relevant variables in the structuring of genetic diversity of this germplasm.Item Escolha de descritores mínimos e estabelecimento de coleções nucleares em Capsicum spp.(Universidade Federal de Goiás, 2008-03-05) SILVA, Waldir Camargos Júnior e; DUARTE, João Batista; http://lattes.cnpq.br/4117228759548186The plant genetic diversity is a valuable guarantee for possible adversities that can be risking the survival of biological species. Brazil is one of the richest countries in biodiversity of plants, with about 20% of all the existing biodiversity on Earth and around 19% of the agricultural lands in the world. Genetic resources are studied in well-defined stages, such as collecting or introduction, multiplication, preservation/conservation, evaluation/characterization and use. In Brazil, the Empresa Brasileira de Pesquisa Agropecuária manages a national system of curatorship of genetic resources in which more than 250 thousand samples of plants, animals and microorganisms are preserved. The plants of the genus Capsicum (chilli and sweet peppers) are found throughout the national territory, presenting countless kinds, with a great phenotypic and genotypic diversity. Practically all the brazilian states have their own cultivars, but some of them, can be in fact, considered a mere duplicate because, sometimes, the same cultivar is known under different names. Thus, the morphological characterization is a task of great importance to this plant genus so, it is possible to avoid the conservation and maintenance of accessions of similar genomic patterns in germplasm banks. Embrapa Hortaliças has a collection of germplasm of sweet and chilli peppers (Capsicum spp.), which amounts to about 2,500 accessions. These mainly belong to the species C. annuum, C. baccatum, C. chinense and C. frutescens. The morphological characterization of most of these acessions (893) have been carried out in recent years for a series of characters (descriptors) which allow the investigation of the structure of their genetic variability and, from then the proposition of strategies to handle the collection. Considering the need of studies aiming to know, value and use the accessions of the Capsicum spp. Embrapa Hortaliças collection, this research was developed with the objective of describing the accessions and the descriptors available in this collection, in order to search for minimum descriptors and propose core collections for this germplasm bank. The study demonstrated that it is possible to reduce around 50% the number of descriptors currently used in the characterization of the accessions, without significant harm to the representation of the genetic variability of the collection. The factorial correspondence analysis showed to be appropriate for the selection of minimum descriptors, as well as to the proposition of core collections from germplasm banks, characterized, predominantly, by qualitative data. Variables related to the fruit showed great variability in all the germplasm collection, demonstrating that these attributes are important in the genetic discrimination among the accessions. The study also showed that the geographical origin, regardless of the species, is directly associated with the genetic divergence among the accessions in Capsicum spp.