Mestrado em Genética e Melhoramento de Plantas (EA)
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Navegando Mestrado em Genética e Melhoramento de Plantas (EA) por Por Orientador "Chaves, Lázaro José"
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Item Variabilidade morfoagronômica da coleção de germoplasma de mangabeira (Hancornia speciosa Gomes) da Universidade Federal de Goiás(Universidade Federal de Goiás, 2015-08-28) Almeida, Gabriella Queiroz de; Telles, Mariana P. Campos; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4707329E5; Chaves, Lázaro José; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783820E2; Chaves, Lázaro José; Peixoto, Nei; Coelho, Alexandre Siqueira GuedesThis study aimed to characterize the Mangaba (Hancornia speciosa Gomes) Germplasm Collection owned by the Universidade Federal de Goiás, by measuring 40 morpho-agronomic characters. The collection was designed in randomized blocks with 57 treatments (progenies) and four replications, totaling 192 individual accesses, which represent 29 natural populations and four botanical varieties. The variance components estimation was done using random model, and REML procedure, considering the effects of botanical varieties, populations within varieties, progenies within populations and individuals within progenies. Considering 40 morpho-agronomic characters, it was observed that there is significant genetic variability in seven characters among the progenies, 24 characters among the populations and 18 characters among botanical varieties. In addition, individual heritability was higher than 50% in 21 of them. The highest percentual individual selection gain was estimated for the character number of fruits produced by each plant. Significant correlation in some biometric characters between young and adult plants was noticed, including their productivity, which suggests the possibility of early selection. Among the 55 genetic correlations among the agronomic characters, 25 were significative. The fruit production peak occurred between June and October, H. speciosa var. cuyabensis being the most productive one. Multivariate analyses results showed that H. speciosa var. speciosa is the most genetically different in comparison with the others. The characters suggested as minimum quantitative descriptors for the Mangaba tree were: leaf length and width, petiole length and diameter, length between the knot, corolla diameter, flower peduncle diameter, fruit length and diameter, number of fruits, plant height and first branching heightItem Seleção de linhagens de milho a partir do esquema de topcrosses com testadores recíprocos intergrupos(Universidade Federal de Goiás, 2020-02-28) Costa, Nayana Valéria; Resende, Marcela Pedroso Mendes; http://lattes.cnpq.br/2080097211870591; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Chaves, Lázaro José; Resende, Marcela Pedroso Mendes; Oliveira, Bruna Mendes de; Corrêa, Luiza Vasconcelos TavaresThe method of topcrosses with reciprocal intergroup testers allows the estimation of genetic parameters and prediction of means of hybrids and synthetic varieties, without the need for diallel crossing, which causes a reduction in the number of evaluated genotypes. The objectives of the present study were: i) to evaluate heterosis components and combining ability of two groups of maize S1 inbred lines derived from the UFG-Samambaia population; ii) to improve the procedure for analyzing heterosis components based on the use of topcrosses with reciprocal testers, including S2 inbred lines; iii) to predict the performance of synthetic and hybrid that can be obtained from selected inbred lines. The experiment was carried out in the experimental area of the School of Agronomy of the Universidade Federal de Goiás, Goiânia-GO, with 60 S1 maize inbred lines derived from the UFG-Samambaia population, where 30 presented dent kernels (Group A) and 30 presented flint kernels (Group B). From the S1 inbred lines, 60 S2 inbred lines were obtained, 30 from group A and 30 from group B and 57 hybrids, where 27 were from group A inbred lines crossed with a mixture of group B inbred lines and 30 from group B inbred lines crossed with a mixture of group A inbred lines. The genotypes were divided into six trials and were included three common control treatments. A randomized block design with four replications was used and the variables analyzed were: male (FM) and female (FF) flowering, flowering interval (IF), plant height (AP) and ear height (AE), lodging and breaking (AQ), prolificacy (PROL), ears yield (PE) and grain yield (PG). Analysis of variance was performed for the individual trials and based on topcrosses. Parameter estimation and sum of squares of model effects were obtained from the least squares method. The general combining ability (CGC) and inbreeding depression (DP) were estimated from the effects of the model. The prediction of means for synthetics and hybrids was performed using the lines that presented higher estimates of general combining ability. The lines of the variety UFG-Samambaia presented genetic variability for the evaluated traits. The additive effects were decisive for the manifestation of all traits, which points to the possibility of genetic gain by recurrent selection. Most of the genotypes belonging to groups A (dent kernels) and B (flint kernels) showed potential for extracting inbred lines for later formation of hybrids. The dominance effects were more expressive for the traits related to productivity and had a strong influence on the components of heterosis and inbreeding depression. The inclusion of S2 inbred lines in the intergroup reciprocal topcrosses analysis model was effective for detailing the additive and dominance effects. Estimates of general combining ability pointed out the variability between inbred lines that can be used in the selection of hybrids. Prediction methods allowed the selection of superior inbred lines for the formation of synthetics with adequate productive potentials when crossed.Item Caracterização morfoagronômica da coleção de germoplasma de jatobá-do-cerrado (Hymenaea stigonocarpa Mart. ex Hayne) da UFG(Universidade Federal de Goiás, 2017-02-22) Gonzaga, Lamartine Nogueira; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Chaves, Lázaro José; Reis, Cristiane Aparecida Fioravante; Coelho, Alexandre Siqueira GuedesHymenaea stigonocarpa is classified as a priority for research and sustainable exploitation, with potential for fruit production. There is a phenotypic variation in the species that allows the distinction of three botanical varieties based on leaf characters. The present study aimed to characterize and evaluate the magnitude and distribution of the genetic variability of a germplasm collection of the species. The experimental material consisted of 336 accessions of 120 maternal families, from 24 subpopulations sampled in the Brazilian Cerrado. Plant height, stem diameter, number of branches and number of leaves were measured. Later, they were measured the morpho-agronomic variables: leaf length, leaf width, petiole length, petile diameter, leaf angle, leaflets angle and chlorophyll index. Growth dynamics and analysis of variance were performed to estimate genetic and statistical parameters and selection gain, for growth traits. Data from 113 progenies were used to estimate phenotypic and genetic correlation coefficients. It was also determined the relative importance of the variables for genetic divergence. The dynamics of growth were different in different periods, which is attributed to the formation of the root system in the initial phase of growth. The effects of progeny and subpopulation explain considerably part of the total variation, being significant between and, predominantly, not significant within subpopulations for the growth variables. The morpho-agronomic traits showed significant variation within subpopulations. The cluster analysis showed the formation of two distinct groups which corroborates a population study previously carried out with molecular markers. There is significant variation between subpopulations for growth trais, with possibility of selection for these variables. Based on morphological agronomic variables, the genetic variability is structured among subpopulations. Plants with high growth rates in height have a high growth rate of stem diameter. The variables petiole length (CP), petiole diameter (DP) and final stem diameter (DF) were the most determinant in the discrimination of accessions.Item Caracterização fenotípica e variação genética quantitativa em Dipteryx alata Vog. (Barueiro) do cerrado(Universidade Federal de Goiás, 2013-03-27) Mota, Elias Emanuel Silva; Soares, Thannya Nascimento; http://lattes.cnpq.br/5590256762396056; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Nabout, João Carlos; Ganga, Rita Maria Devós; Sano, Sueli Matiko; Chaves, Lázaro JoséThe Cerrado biome is the second largest in Brazil, occupying 23% of the national territory, has several vegetation types, and has the richest flora among the world's savannas. The baru tree, due to its wide geographic distribution, is a species with the ability to display high levels of genetic diversity, thus providing the ability to occupy different habitats. The species in question has a multitude of uses, constituting a key species for studying domestication and cultivation. This study aimed to obtain information about the patterns of phenotypic variation for some traits of fruits, seeds and seedlings of baru and to estimate the genotic variability among and within 25 natural subpopulations of Dipteryx alata Vog., based on quantitative data. Fruits were collected from plants of 25 regions in the Cerrado biome, sampling six plants per subpopulation and, at least, 25 fruits per plant. The data were submitted to descriptive analysis, analysis of variance and correlation between traits. There was significant variation for all variables at all levels evaluated; among fruits within plants, among plants within subpopulations and among subpopulations for the fruits and seed traits evaluated. There was variation among progeny within subpopulations and among subpopulations for initial and final height, number of leaves, total leaf size, number of internodes and root length of seedlings. A greater proportion of variability was observed between plants within subpopulations. Correlation analysis demonstrated significant correlations for most pairs of characters of fruit evaluated at different hierarchical levels. The heritability found for final height, fresh weight and dry weight of shoots indicates possibility of gains from selection for these characters.Item Potencial genético de genitores de cana-de-açúcar com base em cruzamentos biparentais(Universidade Federal de Goiás, 2013-08-28) Santana, Priscilla Neves de; Reis, Américo José dos Santos; http://lattes.cnpq.br/8061057395813231; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Chaves, Lázaro José; Coelho, Alexandre Siqueira Guedes; Oliveira, Ricardo Augusto deAn adequate choice of genitors to be crossed to generate genetic variability is essential to increase the efficiency of sugarcane breeding program. The combining ability of genotypes in crosses constitutes a good measure of genetic potential in future crosses. The aim of this study was to evaluate the genetic potential of sugarcane genotypes based on biparental crosses of sugarcane breeding programs from the Interuniversity Network for the Development of Sugarcane Trade (PMGCA / RIDESA). The basic variable used was the rate of selection of each cross population (full sib family) in the initial phase of the program (T1), resulting from the selection practiced evaluating variables of primary importance for the species. The average selection rate of each family was predicted using BLUP methodology. Data analysis was performed using Method IV proposed by Griffing (1956), adapted to the set of crosses available, detailing the effects of General Combining Ability (GCA) and Specific Combining Ability (SCA). The predicted effects of SCA were correlated with genetic similarity estimates obtained using the Dice coefficient from SSR markers and the Malécot coancestry coefficient. It was detected significant effects of GCA, showing the possibility of selection of parents based on this parameter. Although not statistically tested, SCA showed determination coefficient higher than CGC. The genetic similarity obtained by coancestry coefficient showed a significant correlation with SCA, although of low magnitude. There was no significance for the correlation between genetic distance based on SSR marker and SCA. It was concluded that the rate of selection is efficient to select potentially promising parents in the first stage of selection in sugarcane.