Doutorado em Genética e Melhoramento de Plantas (EA)
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Navegando Doutorado em Genética e Melhoramento de Plantas (EA) por Assunto "Cerrado"
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Item Pré-melhoramento genético, floração in vitro e criopreservação de orquídeas nativas do cerrado(Universidade Federal de Goiás, 2014-11-27) Carneiro, Luciano Lajovic; Faria, Ricardo Tadeu de; Sibov, Sérgio Tadeu; http://lattes.cnpq.br/4627553641870284; Sibov, Sérgio Tadeu; Carvalho, Virgínia Silva; Galdiano Junior, Renato Fernandes; Ferreira, Wagner de Melo; Santos, Izulmé Rita ImaculadaThe vast majority of orchids species are pollinated by insects, mainly bees, butterflies and moths. The orchid family is generally considered allogamic, but information about the type of reproduction are unknown for most species. Little information exist about orchids of Cerrado, which hinders plant breeding of these species and postpones their use in developing new varieties for the ornamental market. Recent methods of plant biotechnology can assist both plant breeding and conservation of these species, such as induction of early in vitro flowering as important technique particularly for species with a long cycle, and cryopreservation as a tool for the conservation of genetic variability. This study aims to contribute to the improvement and conservation of orchids with distribution in the Brazilian Cerrado. Selfcompatibility was evaluated for seven species: Cohniella cepula, Cyrtopodium eugenii, C. saintlegerianum, Epidendrum densiflorum, Epidendrum nocturnum, Epidendrum secundum e Lockhartia goyazensis. Only three were autocompatible: Epidendrum nocturnum, Epidendrum secundum and Lockhartia goyazensis. Interspecific compatibility was assessed for Cyrtopodium and Epidendrum genera, using reciprocal crosses. Just E. nocturnum and C. eugenii produced viable seeds. For early in vitro floral induction 20 different treatments were used through nutritional changes and use of cytokinin (BAP) in modified MS medium. Only C. cepula showed positive responses to treatment with formation of 46% floral stems. The effect of BAP was evident in the results. Cryopreservation was tested by vitrification of seeds of seven species of orchids, obtained from outcrossing. The responses to cryopreservation were partially different for each species. Most seeds tested showed any significant differences between freezing in liquid nitrogen without cryoprotectants and control without freezing. The freezing without cryoprotectant was successful to maintaining seed viability for all species, C. cepula 63%, C. eugenii 59%, C. sainttlegerianum 70%, E. densiflorum 42%, E. nocturnum 31%, E. secundum 69% and L. goyazensis 52%. Only E .nocturnum and C. cepula showed a significant reduction in viability when submitted to freezing in liquid nitrogen. The results presented here are useful for the development of breeding programs for orchids and conservation of these species.Item Variação genética quantitativa e estrutura populacional de Hymenaea stigonocarpa (Mart. Ex Hayne) no cerrado(Universidade Federal de Goiás, 2016-05-30) Castro, Rodrigo Soares de; Telles, Mariana Pires de Campos; http://lattes.cnpq.br/4648436798023532; Diniz Filho, José Alexandre Felizola; http://lattes.cnpq.br/0706396442417351; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Chaves, Lázaro José; http://lattes.cnpq.br/9990967290797379; Novaes, Evandro; Rodrigues, Flávia Melo; Moura, Nara Fernandes; Soares, Thannya NascimentoThis study aimed to analyze the quantitative genetic variation within and between natural subpopulations of Hymenaea stigonocarpa (Mart. Ex Hayne), fruit tree from the Cerrado region. Six mother trees were sampled in each of the 25 subpopulations from the states of Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais and Bahia, covering a large area of the Cerrado biome. In each tree they were collected twenty fruits, which served for evaluation of biometric data of fruits and seeds. Twenty seeds of each mother tree were sown in a nursery, with five seeds per plot in four randomized blocks, constituting a test of provenances and progenies of half sibs. Analysis of variance were performed using the hierarchical model for the characters of initial development. With the produced seedlings it was planted a germplasm collection in vivo in Escola de Agronomia of Universidade Federal de Goias.The major phenotypic variation coefficients in fruits and seeds were found in the characters number of seed (47,87%) weight of the pulp (47.74%) and fruit weight (44.06%). The analysis of variance of the physical characteristics of the fruits and seeds revealed the existence of significant variation for all characters in all levels analyzed: among subpopulations, between mother trees within subpopulations and between fruit within mother tree. Of the ten characters analyzed in six the greatest variation was found between fruit within mother tree. Significant variability was found between subpopulations and between progenies within subpopulations for most quantitative traits studied, showing a great genetic variability of the sampled material, which is important for sustainability of the species and future breeding program. The heritability estimates of traits were also high, indicating success in the selection of desirable traits in a breeding program for the species. The comparative analysis between the estimated value of the QST and FST index showed no significant difference for eight of ten characters analyzed, demonstrating that there is no evidence of the action of natural selection in the differentiation between the studied subpopulations and that the differentiation found can be explained by the action of genetic drift combined with gene flow restriction between subpopulations. The value of correlation coefficient between phenotypic and geographical matrix was 0.164 (p <0.05) by Mantel test, indicating a weak correlation between the phenotypic subpopulations means and the distances between them.Item Filogeografia de populações naturais do buriti (Mauritia flexuosa L. f., Arecaceae) do Brasil Central(Universidade Federal de Goiás, 2012-04-23) Lima, Natácia Evangelista de; Collevatti, Rosane Garcia; http://lattes.cnpq.br/9979596352166630; Collevatti, Rosane Garcia; Coelho, Alexandre Siqueira Guedes; Figueiredo, Lúcio Flávio de AlencarMauritia flexuosa, popularly known as buriti, is a large palm that occurs especially in association with wetlands (veredas) in South America. It is distinguished because of its economic importance for local populations from Central Brazil, and as source of food, breeding site and haven for the terrestrial and aquatic fauna. The effect of historical demographic events and climatic fluctuations in the current distribution of buriti can provide clues about the responses of this species to anthropic pressures and to future climatic changes. For this purpose we studied the phylogeography of M. flexuosa. The results were based on the differences of sequences from the following chloroplast intergenic regions: psbA-trnH, trnC-ycf6 and trnS-trnG. We sampled 170 individuals from 14 localities throughout Central Brazil, including populations in the Amazon, Araguaia/Tocantins, Paraná and São Francisco Basins. Since the distribution of M. flexuosa is restricted to wetlands, which are surrounded by large areas of dry lands that may act as barriers to gene flow, we hypothesized that populations are highly differentiated and that River Basins act as phylogeographic breaks. The combined data from the three sequence regions generated a fragment of 1205bp, with 11 haplotypes. Nucleotide diversity was low (π = 0.005314 +/- 0.002800) and haplotipic diversity was high (h =0,791) for the combined data. The population parameter θ, and nucleotide and haplotype diversity per population, shows a pattern where populations from different geographic regions have a relative genetic uniformity, separated by steep losses on the diversity; what characterizes colonization by sectors. Differentiation among populations was significant (P< 0.001), but no sign of recent bottleneck on population size followed by expansion was found (D Tajima=-1.955 p = 0.00210; Mismatch Distribution=0.034 p=0.7467 and growth parameter g=402. 402, 95% = -334.961 ICredi, ICreds 95% = 999.91). We could group populations by location in the phylogenetic analysis (Network software), but they do not support the initial hypothesis that the major basins act as important phylogeographic breaks for the distribution of maternal lineages of M. flexuosa. The studied populations showed ancient time of coalescence. This research provided more details on the dynamics and genetic structure of the remnant of buriti populations, helping to elucidate the evolutionary history of this neotropical palm.Item Filogeografia de Pterodon emarginatus e Pterodon pubescens (Leguminosae)(Universidade Federal de Goiás, 2019-12-06) Lima, Stefany Lorrayny; Soares, Thannya Nascimento; http://lattes.cnpq.br/5590256762396056; Soares, Thannya Nascimento; Telles, Mariana Pires De Campos; Rocha, Dulce Maria Sucena da; Mansano, Vidal de Freitas; Jardim, Tatianne Piza Ferrari AbreuThe species Pterodon emarginatus and P. pubescens, known as sucupira, occur in the Cerrado and have potential for medicinal and wood use. The comparative phylogeography of these species can help in understanding the historical pattern of distribution of genetic diversity, generating information for use and conservation. The objective of this work was to identify the phylogeographic structure of P. emarginatus and P. pubescens, and the comparative phylogeography of these species. The sample consisted of eleven populations for P. emarginatus and nineteen for P. pubescens, distributed in the states of Goiás, Tocantins, Bahia, Mato Grosso and Minas Gerais. The chloroplast regions sequenced were trnLE-trnLF and psbA-trnH, and the nuclear ribosomal was ITS101-102. In P. emarginatus, haplotypic and nucleotide diversity are high in chloroplast, as there is a high polymorphism in this region, with a high number of indels. The population structure is relatively low (FST = 0.10). In this species the populations Alvorada do Norte-GO, Cariri-TO, Luiz Eduardo Magalhães-BA and Monte Alegre de Goiás-GO stand out for genetic diversity and are located in an area of climate stability, influencing the evolutionary dynamics of the Cerrado. The dispersal has long distance potential (500 km). The demographic pattern has shown population growth for less than 150 a thousand years. In P. pubescens the haplotypic and nucleotide diversity are high in chloroplast and nucleus, with a high number of haplotypes. The population genetic structure is considerable (FST = 0.24), with a phylogeographic pattern marked by the divergence of populations of the Araguaia basin region, an area of influence on the Cerrado evolutionary dynamics, mainly Araguapaz-GO and Araguaiana-MT. Demographic history has shown population growth from 1.67 million years ago. Finally, P. emarginatus showed a higher diversity pattern in chloroplast, while in P. pubescens there was a high complexity of the phylogeographic pattern, and the population of Araguaiana-MT showed a high genetic distance. Despite the species separation, there is a highlight for populations that exhibit high haplotype sharing, mainly Araguaiana-MT and Araguapaz-GO. The species tree showed no distinction between species, corroborating the hypothesis of recent diversification. Comparative analysis of species suggests ancestral introgression or polymorphism, considering the high sharing of haplotypes. These species are possibly in the process of recent separation, and P. emarginatus is the species in the process of speciation.Item Variabilidade e divergência genética de caracteres quantitativos e marcadores neutros em populações de Eugenia dysenterica DC(Universidade Federal de Goiás, 2014-10-16) Novaes, Carolina Ribeiro Diniz Boaventura; Telles, Mariana Pires de Campos; http://lattes.cnpq.br/4648436798023532; Chaves , Lázaro José; http://lattes.cnpq.br/9990967290797379; Chaves, Lázaro José; Zucchi, Maria Imaculada; Grattapaglia, Dario; Coelho, Alexandre Siqueira Guedes; Ganga, Rita Maria DevósGenotypic variations knowledge is an important tool that can point to the best approach for genetic resources maintenance, for both conservation and breeding purposes. To analyze and compare the phenotypic and genetic variation of wild subpopulations of Eugenia dysenterica DC., a fruity tree, 25 subpopulations were sampled in five states of the Brazilian Cerrado. Within each subpopulation, six trees were sampled and twenty fruits (maternal siblings) collected. Five fruits of each family were evaluated for morphometric variables of fruits and seeds. Twenty seeds of each family were randomly sown in each one of four blocks, five seeds per plot, established in a common garden experiment. Hierarchical model analysis of variance and variance components estimation were performed for fruit, seeds and early development traits and QST were estimated for early development traits. Four individuals per family were genotyped using nine microsatellite loci. Significant phenotypic and genotypic variations were observed both between subpopulations and between families within subpopulations. The highest proportion of the variance was found among families. Heritability estimates were 0.23 and 0.27 for growth rate and number of leaves and greater than 0.34 for other traits, indicating high potential for selective gain. Rapid early development is important for seedlings commercial production. Above ground biomass represented 15% of total biomass. Subpopulations are significantly structured for root length, height and diameter growth rates (QST 0.34, 0.23 and 0.20), but weak structure was establish for biomass and seedling emergence (QST <0.04). It has high genetic diversity, with average expected heterozigosity of 0.642. The mating system was mainly outcrossing (ta = 0.73), with high genetic differentiation between subpopulations (θP = 0.198), similar to previous studies. QST - FST contrasts were not significant for sixteen out of eighteen traits, suggesting genetic drift as the main source of phenotypic differentiation. Even though seedling emergence average time and root system fresh mass genetic similarity is granted to uniform selection. Quantitative and genetic distances clustered two distinct groups spatially structured, with respect to the Corumbá and São Bartolomeu river valley, in addition to the Chapada dos Veadeiros and Vão do Paranã region. Subpopulation 21 (Cocalinho-MT) quantitatively diverged from the two clusters. An in vivo collection of E. dysenterica was established for ex situ conservation. Genetic characterization and sampling extent suggest that the collection portrays well the cagaiteira’s wild population for selection purposes.