Programa de Pós-graduação em Agronomia

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Caracterização genética de populações naturais de Palicourea coriacea (Cham) K. Schum utilizando marcadores moleculares
(Universidade Federal de Goiás, 2006-08-24) BARBOSA, Taryana Coelho Sales; SIBOV, Sérgio Tadeu; http://lattes.cnpq.br/4627553641870284
The Species Palicourea coriacea (Cham) K,Shum is a species little know, it is belonging to the Rubiaceae family, popularly known as douradinha. The popular use medicine in the therapy of kidneys illnesses. The popular name douradinha is associated with the color of the bracts and of the stem and the species occurs in Cerrado s Bioma, however in different environments. Studies about the genetic diversity and its distribution in natural populations of P. coriacea are of extreme importance for the definition of adequate strategies of handling and cultivation, however they do not exist in literature, studies of this nature. This work had as objective to evaluate the genetic structure from nine natural populations of P. coriacea, collected in States of Goiás and Bahia and to evaluate the genetic diversity of these populations through markers RAPD. The P. coriacea species presented one high level of genetic diversity, or heterozygosity waited by Nei (1972) that it varied between 0,259 and 0,338 in the populations, with equal on average value the 0,296. The AMOVA disclosed that 23% of the total variability is meeting each other between populations. Although the estimates of apparent gene flow (Nm) have disclosed values inferior to one, on the other hand, equal the 0,83. The analyses of Bayesian Statistics had disclosed to a value of f (FIS) equal the 0,98 suggesting the possibility of this species has behavior like autogamous species. The analyses of grouping of the populations using Bayesian and AMOVA statistics disclosed that it does not exist a correlation between geographic distance and genetic distance all the nine populations they grouping, eventually, not obeying its geographic origin. Then, the hypothesis previously formulated of that geographically next populations would be genetic next, was discarded for the results gotten for the Mantel test where it got a correlation of 0,155. In addition, this relatively high inter populations differentiation allows to recommend to a strategy ex situ of the genetic variability using the biggest possible number of populations. In what, the conservation says respect in situ must be taken in account characteristic genetic and demographic of this species considering that this fact implies in the possibility of a continuous evolution and in the development of new adaptable strategies. It is necessary to have conscience on the distribution of the genetic diversity of these areas with intention to not only promote polities for preservation of found natural populations in national parks, but yes to private preservation of the legal reserves and properties.
Caracterização genética de populações naturais de araticunzeiro (Annona crassiflora Mart.) pela análise de cpDNA
(Universidade Federal de Goiás, 2005-08-30) BLANCO, Angel José Vieira; COELHO, Alexandre Siqueira Guedes; http://lattes.cnpq.br/0840926305216925
The araticunzeiro (Annona crassiflora Mart.) is a tropical fruit tree species from the Cerrado (Brazilian Savannah) with high economic potential. The strong degradation of the Cerrado, allied to the predatory extractivism that threatens the species, points out to the necessity of development of research to support future conservation programs. With the aim to furnish information about the genetic status of this species and to guide future conservation strategies, 82 individuals from 11 natural populations were submitted to genetic analysis. The coalescent based analysis of the polymorphism present in the trn-L cpDNA allowed the detection of high levels of genetic diversity in the species. In spite of the high level of genetic similarity among different populations the results produced suggested that, , there is an incipient, but statistically significant, increasing differentiation process taking place due to current status of geographical isolation and genetic drift. The genetic differentiation coefficient estimated was equal to 7.3%. The spatial genetic divergence analyses suggested that the genetic distances are not associated to geographical distances between populations, evidencing the absence of current gene flow between adjacent populations. The coalescent based approach allowed the identification of different evolutionary scenes to the investigated populations. Among sampled populations cases from well conserved status to dangerous low levels of genetic diversity were detected. Results obtained by the use of coalescent models to infer the divergence time between populations suggested that natural populations of A. crassiflora were, until recently, part of a great regional continuum. These findings suggest that the low levels of genetic diversity among different populations must be due to the small time since isolation.
Caracterização agronômica e molecular da coleção nuclear de arroz da Embrapa
(Universidade Federal de Goiás, 2010-08-31) BUENO, Luíce Gomes; OLIVEIRA, Jaison Pereira de; http://lattes.cnpq.br/7342298421214478; BRONDANI, Claudio; http://lattes.cnpq.br/4775600104554147
The plant genetic resources stored ex situ are considered as a genetic repository, and are raw material for the development of the world agriculture. In rice, despite its high genetic variability, the lack of information of accessions to compose a databank prevents its use to help the choice of genitors for the breeding programs. The Embrapa Rice Core Collection (ERiCC) was developed from 10,000 accessions from Embrapa GeneBank, and it was set up by 550 accessions, divided in three subsets: 1) 94 lines and cultivars from Brazil (LCB); 2) 148 lines and cultivars from abroad (LCI); and 3) 308 traditional varieties (VT), obtained from germplasm collection expeditions in Brazil. This work aimed: 1) to evaluate the extension of genetic variability of 550 accessions from ERiCC by means of agronomic traits characterization using mixed models and multivariate statistics; 2) to perform a comparative analysis of the genetic divergence considering the agronomical and SSR markers characterizations; and 3) to identify the genotypes with higher genetic diversity and with the best agronomic performances, aiming to promote the most efficient use of such germplasm in breeding programs. The agronomic characterization of 550 accessions was performed in nine field experiments, evaluating 18 phenological-agronomic traits. The data were analyzed using the mixed linear and AMMI models. There was wide variation range of genotypical values for most evaluated traits. In different environments, it was observed VT accessions among the high-yielding materials, demonstrating the potential of this group of germplasm, particularly important due to its high genetic variability, to contribute to the development of cultivars regionally adapted. The AMMI approach allowed a good discrimination of ERiCC rice genotypes in relation to the adaptive performance, identifying the accessions CA880078, CA990001, CA870071 (subset VT), and CNA0009113 (LCI) as having good yield and broad adaptation to distinct environments. The comparative analysis of genetic diversity between agronomic and molecular data was performed using the 242 lines and cultivars accessions from ERiCC, which were characterized by 86 fluorescent SSR markers, and five agronomic traits with genotypic values predicted (values without from the effects of interaction genotypes x environment, from a joint analysis of nine experiments. The genetic divergence among accessions was estimated by the average Euclidian distance for phenotypical data, and by the Rogers modified by Wright (RW) genetic distance. The datasets were jointly analyzed by descriptive and multivariate statistics, using correlation analyses from hierarchical grouping of Ward and UPGMA methods. The phenotypical and molecular data showed a broad distribution of dissimilarity indexes, despite they showed different patterns of variation between them. Low molecular distances were associated to low phenotypical distances, however to high molecular distances, occurred a high broad range of phenotypical variation. The correlation between genetical and phenotypical dissimilarities was significant for both lowland and upland accessions, despite with different values (r=0.156 and r=0.409, respectively). Due to the low relation between phenotypical and molecular data, the analysis of genotypes to be used in breeding programs must include both evaluations to a better accession characterization. Considering the high yielding accessions, the higher molecular distances were identified among the accessions from lowland system of cultivation, among which BR IRGA 413 and CNA0005014, BR IRGA 413 and CNA0005853, and CNA0004552 and CNA0005014. Considering the upland accessions, maximum genetic distances were identified in CNA0000482 and CNA0006422, CNA0001006 and CNA0006422, and CNA0001006 and CNA0003490. The molecular analysis was able to identify accessions with reduced genetic relationship, that if used as genitors, will result in a progeny with a high probability to find new allelic combinations. On the other hand, the phenotypical characterization is important to identify accessions not just genetically divergent, but with superior agronomic trait performances for breeding programs. The results of this work will permit to increase the activities related to the characterization of accessions from rice Genebank, giving support of breeding programs to choose the best accessions to obtain new cultivars, with favorable traits, and broad genetic basis. In addition, a continuous program of phenotypical and molecular characterization of germplasm will be able to identify accessions to increase the genetic variability of ERiCC.
Variabilidade de plantas e progênies de populações naturais de Hancornia speciosa Gomes do Cerrado
(Universidade Federal de Goiás, 2008-07-30) GANGA, Rita Maria Devós; NAVES, Ronaldo Veloso; http://lattes.cnpq.br/2740049203016314; CHAVES, Lázaro José; http://lattes.cnpq.br/9990967290797379
The mangaba tree (Hancornia speciosa Gomes) is a fruit tree native from Brazil with potential for domestication, due to its excellent smell, flavor and texture. However, genetic conservation and breeding programs of these species are in an initial developmental phase. This way, this research aimed to characterize trees and fruits of natural populations of H. speciosa, as well as evaluate the distribution of phenotypic variability among them; evaluate progenies of mangaba trees that compose the Escola de Agronomia e Engenharia de Alimentos of Universidade Federal de Goiás (EA/UFG) germplasm collection and estimate genetic parameters for the initial development of plants in the field. Mangaba trees populations have been sampled in different locations of the Brazilian Cerrado, including the states of Goiás, Tocantins, Mato Grosso, Mato Grosso do Sul, and Bahia, totaling 109 mother plants of 35 populations of the botanic varieties pubescens, gardneri, speciosa and cuyabensis. In relation to the trees, plant height, stem perimeter, and number of fruits per plant were taken. From a sample of five fruits per plant, individual measures have been taken, such as: length, diameter, weight, total weight of seeds, average seed weight, pulp plus peel weight, seed number per fruit, pulp plus peel yield, fruit shape and color and estimated production. Seeds from these mother plants were used to install the EA/UFG mangaba germplasm collection in December 2005, in a randomized complete block design with 57 treatments, four replications and one plant per plot in a 5 m x 6 m spacing. The treatments were open pollination progenies, originated from 28 natural populations. The characteristics plant height and stem basal diameter were evaluated in all plants from January 2006 to August 2007, which resulted in 20 data readings. Data from each plant has been transformed into growth rate. The analyses of variance and the genetic parameter estimates were obtained to the growth rate and to the data of latest reading of stem diameter and plant height. The progress was estimated by simulating genetic selection in both sexes and maternal selection. In Cerrado conditions, the results showed that H. speciosa mother plants show high levels of phenotypic variation in fruit characters and most of this variation is among populations. There is a large phenotypic variability in the varieties too. H. speciosa var. gardneri and H. speciosa var. pubescens fruits are larger and heavier. The botanic variety gardneri shows gait more high than the others varieties. In the varieties gardneri and pubescens predominate round shape and light green color, while in speciosa and cuyabensis predominate oblong shape and dark yellow and dark green colors, respectively. The varieties gardneri and pubescens stand out as the most promising for selection based on fruit size and fruit weight. The mangaba tree progenies of the germplasm collection of EA/UFG present high levels of genetic variation in stem diameter and plant height and to their growth rates. Most of the genetic variation in stem diameter is within populations and to plant height is among populations. H. speciosa var. cuyabensis and H. speciosa var. gardneri show greater growth in stem diameter and plant height. On account of the expected progress of selection, the collection can be used as seed orchard or clonal garden, without plant thinning, collecting seeds or buds of superior plants. The maternal selection is recommended to maintain greater variability in future breeding cycles, permitting progress from selection and maintaining the germoplasm collection intact.
Desempenho de famílias s0:2 da população CNA9 do programa de melhoramento de arroz de terras altas para a agricultura familiar
(Universidade Federal de Goiás, 2012-03-15) GUEDES, Janine Magalhães; MORAIS, Orlando Peixoto de; http://lattes.cnpq.br/2175152793170778; MELO, Patrícia Guimarães Santos; http://lattes.cnpq.br/1508679345970114
Rice (Oryza sativa) stands out in Brazil for its economic and social importance, being an important source of protein and energy. Selecting lines of upland rice adapted to different environments is critical to the success of breeding programs targeted to family farmers in the state of Goiás, The objective of this work was to evaluate S0:2 families drawn from CNA9 population of the upland rice breeding program in greenhouse and in the field, aiming to select families for recombination and obtainment of a new selecting cycle. 50 families from CNA9 population from recurrent selection were used, in four experiments, with N, P, and inoculant combinations, in a randomized bloc design arrangement with two replicates in greenhouse. Traits evaluated were: plant height, chlorophyll content, canopy dry matter, roots dry matter and volume. The field experiment was arranged in a 14 X 14 square lattice, with 194 families, two controls, and three replicates. Traits evaluated were: plant height, flowering and yield, besides the following diseases: leaf and neck blast, scald, brown spot, grain spot, and narrow leaf spot. Results obtained from greenhouse indicate that families studied performed similarly in the absence of the inoculant, but responded differently for plant height, dry matter, and root volume, regarding nitrogen and phosphorus combinations. Field data showed that the families drawn from CNA9 population showed superior performance when compared to controls and to the original population, especially regarding neck blast and yield. It was possible to select 48 families from the field to recombine in the next breeding cycle.
Caracterização genética e morfoagronômica de germoplasma de Stylosanthes guianensis (Aubl.) Sw.
(Universidade Federal de Goiás, 2008-08-21) KARIA, Cláudio Takao; COELHO, Alexandre Siqueira Guedes; http://lattes.cnpq.br/0840926305216925; DUARTE, João Batista; http://lattes.cnpq.br/4117228759548186
Plant genetic resources maintained ex situ, in germplasm banks, are few used in agricultural systems and genetic plant breeding programs. One of the main reasons of this incipient use is the difficulty to obtain information about stored accessions, especially the characterization and preliminary evaluation data. Stylosanthes guianensis is a predominantly self-pollinated and diploid species, which has a great number of this stored accessions and potential for use in agricultural systems. There are approximately one thousand accessions of the S. guianensis in Embrapa‟s germplasm bank. Moreover, only one genotype of this species is now available to commercial growers in Brazil, the cultivar Mineirão. To promote the use of these resources, this study aimed to characterize accessions of S. guianensis, stored in the germplasm bank of Embrapa, using morpho-agronomic traits and microstellites markers (SSR). In morpho-agronomic characterization 535 accessions were evaluated using 23 quantitative traits. The data were analyzed by a principal component analysis (PCA), the Ward's agglomerative hierarchical clustering method, and by univariate analysis of variance, associated to a Tukey test for comparisons among means of the established groups. Thirteen similarity accession groups were established, five of them were considered the ones with the highest potential use in agricultural systems. Regarding these potential groups, it is possible to reduce from 535 to 126 accessions to be thoroughly evaluated. The molecular characterization was made in 437 accessions, using seven microsatellites fluorescent primers, and the detection of the DNA fragments generated by PCR (Polimerase Chain Reaction) was accomplished by a capillary electrophoresis. The seven loci provided 45 alleles (6.43 alleles/locus), of which four were private alleles. Both, principal coordinates analysis and cluster analysis, in this case, by UPGMA agglomerative method, showed a tendency to group accessions together by botanical varieties (canescens, guianensis and pauciflora), except for the microcephala variety. The correlation between the genetic and morpho-agronomic dissimilarities was highly significant, however, it was of low magnitude (r = 0.23, P ≤ 0.0001). This indicates that both evaluations are important and should be performed to achieve a more complete characterization of these accessions and, possibly, of the species. Taking account the germplasm accessions with agronomic potential, selected based on the morpho-agronomic evaluation, several of them presented significant genetic dissimilarities to the Mineirão cultivar. These accessions should be better assessed for agronomic traits, and crossed with this cultivar in breeding programs of the species. The results of this research will allow increasing the efficiency and effectiveness of the germplasm bank activities, helping the choice of genotypes to be tested in agronomic evaluations, and stimulating further researches with these genetic resources.
Distribuição de taxas de recombinação ao longo do cromossomo 4 de Arabidopsis thaliana e sua associação com elementos genômicos
(Universidade Federal de Goiás, 2010-03-29) MARTINS, Adilson Santos; COELHO, Alexandre Siqueira Guedes; http://lattes.cnpq.br/0840926305216925
Recombination is one of the most important factors in the evolution of genome organization. It provides the links between homologous chromosomes that ensure their proper segregation during the first meiotic division. It is responsible for the creation of novel allele combinations and yields genetic diversity on which evolutionary selection can act. Double-strand DNA breaks (DSB) initiate meiotic recombination and when the 3 terminus of one of the broken strands invades the unbroken DNA molecule and primes DNA synthesis a double Holliday junction must be resolved through some alternative pathways. When homologous chromosomes exchange genetic material with each other, an event of recombination or a crossover takes place, which may be seen through chiasma. Citological, genetics, and molecular studies in many organisms have demonstrated that crossovers have a non homogeneous distribution across chromosomes, and rather concentrated in relative small DNA fragments usually called recombination hotspots. In searching for genomic features associated with recombination hotspots a model fitted to human genome data explained 42% of recombination rate variation in a 5 mega base pairs scale. Despite the fact that genomes of some plant species have been already sequenced, up to this moment, no research has been published concerning a high resolution characterization of recombination rate variation across a plant s genome. This study used OH- radical cleavage intensity estimates and sequence data of chromosome 4 of A. thaliana and population genetic data from a public set of 250 thousand SNP genotypes obtained for 362 A. thaliana accessions to: i) characterize the recombination rate and linkage disequilibrium (LD) distributions across the chromosome 4 in different scales; ii) search for recombination hotspots; iii) evaluate probable associations between sequence motifs and genomic features with recombination hotspots. The results have shown that the distribution of recombination events across chromosome 4 of A. thaliana is very concentrated: 50% to 60% of all recombination events spans in only 13% to 20% of the total length of the chromosome. Genomic features as G+C percent (G+C%) and OHradical cleavage intensity showed important associations with LD estimates in several scales. The mean OH- radical cleavage intensity and G+C% showed redundancy in correlation analysis with LD and recombination rates. Artificial strong and statistically significant correlations arose from the usage of sliding windows. DNA fragments considered as hotspots lay preferentially in the middle third of the chromosome, while those characterized for having long range LD decay are most localized in the two distal thirds of the chromosome.
Determinação da variabilidade genética nas populações de seleção recorrente de arroz CNA-IRAT 4 e CNA 12 utilizando marcadores microssatélites
(Universidade Federal de Goiás, 2008-03-07) PINHEIRO, Letícia da Silveira; BRONDANI, Claudio; http://lattes.cnpq.br/4775600104554147
Recurrent Selection is a population inbreed method that is not traditionally used in autogamous species as rice. However, it is still an interesting methodology to the implementation of recurrent selection populations, due to the possibility of obtaining genotypes with wide genetic base and adequate agronomical traits. It is even more attractive when a great genetic variability is easily available, as it is for rice and could be largely used in the development of more productive elite cultivars and with a better production stability even under low input agricultural systems. Two recurrent selection irrigated rice populations, developed by Embrapa Arroz e Feijão, were synthetized using different recombination methods. The CNA-IRAT 4 population was developed in field conditions using male-sterelity, while the CNA 12 population originated from manual crosses in a circulant partial diallel scheme. The aim of this work was the evaluation of the genetic variability among cycles of the two recurrent selection populations using fourteen SSR markers. Hundred and eighty genotypes of the cycles 1, 2 and 5 of CNA-IRAT 4 population and cycles 1 and 2 of CNA 12, were evaluated. The AMOVA did not indicate any genetic structure among the cycles of selection, meaning that the greater variation was attributed between individuals within cycles, in both studied populations. Unexpected alleles, which means alleles that not belong to the genetic pool of the genitors, were identified in both populations and in all cycles evaluated, mostly of these alleles were observed on CNA-IRAT 4 population. These alleles were probably a result of undesired crosses of genotypes which did not belong to both populations. Parameters Fis and Fit of Wright s statistics indicated that the genetic variability of the manually conducted population (CNA 12) were increased while the population using male-sterelity recombination (CNA-IRAT 4) were reduced. The mean reason for this particular situation was due to the directionally crosses that promoted a greater combination between the alleles of all genitors, while male-sterelity methodology pollination the alleles from plants with major height and more capable of producing more pollen were privileged. To avoid the genetic drift in CNA-IRAT 4, genotypes genetically divergent, with more General Capacity of Combination and with good agronomic attributes, should be introduced on this population.
Eficiência de métodos de condução de população segregante de feijoeiro comum para teor de proteína.
(Universidade Federal de Goiás, 2007-07-05) SILVA, Gláucio Freitas Oliveira e; MELO, Leonardo Cunha; http://lattes.cnpq.br/9132553601896172; BASSINELLO, Priscila Zaczuk; http://lattes.cnpq.br/7932216023958412; MELO, Patrícia Guimarães Santos; http://lattes.cnpq.br/1508679345970114
The common bean (Phaseolus vulgaris L.) is part of the daily diet of more than 300 million people worldwide, being an essential food for low income human populations, since it is a cheaper protein source. The beans protein content can be improved by breeding programs since the existence of genetic variability for this character can be explored. It is important to have the relative efficiency of the available methods evaluated. The objective of this research was to evaluate the genetic potential for protein content of segregant populations of common beans submitted to different breeding methods and evaluate the potential of the populations of the bulk method inside F2 families for the traits yield and flowering. The parental utilized in this study was from the bean group carioca , CNFC 7812 with 23% of total protein content and CNFC 8056 with 23% of total protein content. Starting with the F1 generation, was obtained the segregant population F2, witch were selected 150 plants wich families was utilized to produce the populations by three methods: Bulk, Bulk within of F2 and SSD method until the F5 generation. The average protein content of the families obtained by this cross was 16,58% for the method SSD, 20,37% for the method Bulk e 20,44% for the Bulk F2:5. Based on the results, it could be concluded that the best method for protein content was the Bulk method, on account of its easiness and its generation of a larger number of families superior than the best parental and the average of the genitors. Among the evaluated families there is enough genetic variability to be explored for the characters protein, grain yield and flowering.

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