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Search Results: 1 - 10 of 322255 matches for " Fernando Irajá Félix de;Vieira "
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Emprego de modelos gráficos na sele o de genitores de milho para hibridiza o e mapeamento genético
Vieira Eduardo Alano,Zimmer Paulo Dejalma,Oliveira Antonio Costa de,Carvalho Fernando Irajá Félix de
Ciência Rural , 2005,
Abstract: A dissimilaridade genética estimada por meio de marcadores moleculares, quando acompanhada de informa es fenotípicas, é importante para a sele o de genótipos para o melhoramento e o mapeamento genético. Desta forma, os objetivos deste estudo foram: i) estimar a dissimilaridade genética entre 30 linhagens de milho contrastantes para a tolerancia ao encharcamento; ii) selecionar genitores para mapeamento e melhoramento genético; iii) comparar diferentes métodos de visualiza o gráfica das distancias. Foram utilizados 21 iniciadores de RAPD. A dissimilaridade genética foi estimada por meio do complemento do coeficiente de similaridade de Dice, posteriormente foi construído um dendrograma pelo método de agrupamento da distancia média e calculado o coeficiente de correla o cofenética entre a matriz de dissimilaridade e o dendrograma gerado. O complemento da matriz de similaridade foi submetido também à análise de componentes principais e de escala multidimensional. Para ambas as análises, foi testada a eficiência das proje es, por meio da correla o entre as distancias originais e as representadas nos gráficos. As técnicas de agrupamento n o revelaram um bom ajuste entre as distancias apresentadas graficamente e a matriz original de distancias, com correla es de 0,70, 0,53 e 0,75 para o dendrograma, componentes principais e análise de escala multidimensional, respectivamente. Dentre as técnicas de agrupamento empregadas, a que atendeu de forma mais precisa aos objetivos do trabalho foi a análise multidimensional, uma vez que esta, além de apresentar a maior correla o com a matriz original de distancias, preservou as distancias entre todos os pares de genótipos. Além disso, esta técnica é a mais indicada quando o objetivo do trabalho é a defini o de cruzamentos, pois ela permite uma observa o mais fácil das distancias entre todos os pares de genótipos.
Emprego de modelos gráficos na sele??o de genitores de milho para hibridiza??o e mapeamento genético
Vieira, Eduardo Alano;Zimmer, Paulo Dejalma;Oliveira, Antonio Costa de;Carvalho, Fernando Irajá Félix de;Malone, Gaspar;Benin, Giovani;
Ciência Rural , 2005, DOI: 10.1590/S0103-84782005000500002
Abstract: associating phenotypic to molecular data can be a powerful tool for the selection of parental genotypes for breeding and mapping purposes. thus, the objectives of the study were: i) to estimate the genetic dissimilarity among 30 maize inbred lines (15 tolerant and 15 sensitive to flooding); ii) to select potential parents for mapping and breeding; iii) to compare the efficiency of different graphical models in displaying the calculated distances. a total of 21 rapd primers were used for the estimation of genetic dissimilarity. the genetic dissimilarity was obtained according to the complement of dice similarity coefficient, clustering procedure was performed by the average linkage method and the cophenetic coefficient was obtained. the complement of dice similarity coefficient was subjected to principal components and multidimensional scale analyses, and the output efficiency was tested by the correlation between the original distances and those presented in the graphs. the clustering techniques did not reveal a perfect agreement with the original matrix, with correlations of 0.70, 0.53 and 0.75 for the dendrogram, principal components and multidimensional scale analyses, respectively. among the tested techniques employed, multidimensional scale analyses gave more precise outputs, since this technique showed higher agreement with the original distance matrix, and preserved distances between all genotype pairs. besides, this technique is the most indicated when the objective is to plan crosses, since it displays the distances between genotype pairs.
Correla o de acamamento com rendimento de gr os e outros caracteres de interesse agron mico em plantas de trigo
Silva José Antonio Gonzalez da,Carvalho Fernando Irajá Félix de,Oliveira Antonio Costa de,Vieira Eduardo Alano
Ciência Rural , 2006,
Abstract: A sele o indireta visando ao incremento no rendimento de gr os pelos seus componentes primários bem como a resistência ao acamamento podem representar estratégias eficientes a serem adotadas para otimiza o do ganho genético em trigo. Nesse sentido, o objetivo do trabalho foi evidenciar caracteres que possibilitem identificar genótipos de elevado rendimento de gr os e resistentes ao acamamento através de sele o indireta. O experimento foi conduzido no Centro Agropecuário da Palma, em Cap o do Le o/RS, utilizando dezenove genótipos de trigo em delineamento de blocos ao acaso, com três repeti es. Nas condi es deste estudo, o peso hectolítrico pode ser empregado de maneira eficiente na sele o indireta, visando ao incremento no rendimento de gr os, no peso médio de gr os, número de gr os por espiga e no peso de espiga. O caráter peso de espiga evidenciou elevado efeito indireto sobre o rendimento de gr os, podendo ser empregado na sele o indireta pela facilidade de mensura o. A linhagem TB 951 é indicada como excelente fonte de resistência ao acamamento em trigo, podendo contribuir para elevar o comprimento de espiga, o número de espigueta por espiga, o peso de espiga e o número de gr os por espiga.
Heran a da resistência à ferrugem da folha da aveia (Puccinia coronata f. sp. avenae Fraser & Led.) em genótipos brasileiros de aveia branca
Vieira Eduardo Alano,Carvalho Fernando Irajá Félix de,Chaves Márcia Soares,Oliveira Antonio Costa de
Ciência Rural , 2006,
Abstract: A ferrugem da folha da aveia é a moléstia mais importante que ataca a cultura da aveia, ocorrendo em praticamente todas as áreas em que a aveia é cultivada. A forma mais indicada para o seu controle é a utiliza o de cultivares resistentes. Contudo, para que seja alcan ada a resistência durável ao patógeno, é necessário que se conhe a a genética da resistência à ferrugem da folha em aveia. O objetivo foi determinar a forma de heran a da resistência a três isolados de Puccinia coronata f. sp. avenae Fraser & Led., (coletados no sul do Brasil) em genótipos brasileiros de aveia branca. Para a determina o da heran a da resistência a cada um dos três isolados, foram utilizadas popula es F2 geradas por meio de cruzamentos artificiais, entre genótipos resistentes (R) e suscetíveis (S) e entre genótipos resistentes (R). Desta forma, foram utilizadas popula es F2 dos cruzamentos artificiais entre: i) URPEL 15 (R) x UFRGS 7 (S), UPF 16 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 16 (R), para a determina o da heran a da resistência ao isolado um (1); ii) URPEL 15 (R) x UFRGS 7 (S), UPF 18 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 18 (R), para a determina o da heran a da resistência ao isolado dois (2); iii) URPEL 15 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 18 (S), para a determina o da heran a da resistência ao isolado três (3). Os resultados obtidos evidenciaram que o genótipo URPEL 15 apresenta genes dominantes de resistência aos três isolados de ferrugem da folha da aveia avaliados, que o cultivar UPF 16 apresenta um gene recessivo de resistência ao isolado 1 e o cultivar UPF 18 apresenta um gene recessivo de resistência ao isolado 2. E que os genes de resistência apresentados pelos genótipos URPEL 15, UPF 16 e UPF 18, segregam de forma independente.
Genetic structure of annual ryegrass (Lolium multiflorum) populations estimated by RAPD
Vieira, Eduardo Alano;Castro, Caroline Marques;Oliveira, Ant?nio Costa de;Carvalho, Fernando Irajá Félix de;Zimmer, Paulo Dejalma;Martins, Luís Fernando;
Scientia Agricola , 2004, DOI: 10.1590/S0103-90162004000400009
Abstract: annual ryegrass is a temperate climate annual foraging grass, grown mostly in the south of brazil, especially in the state of rio grande do sul. despite its importance, little is known about its genetic diversity, both within and among the populations cultivated. this knowledge is of fundamental importance for developing breeding and conservation strategies. the aim of this study was to characterize the genetic diversity and structure of four populations of annual ryegrass. three of the populations were located in rio grande do sul and the fourth in uruguay. rapd markers were used to study the genetic diversity and structure of these populations. analysis of 375 individuals sampled from the populations, using six rapd primers, generated a total of 82 amplified bands. they included 73 polymorphic bands (89,02%). the value of the total genetic diversity index obtained, (0,71) was high, indicating the presence of wide genetic diversity in the four populations. genetic structure analysis revealed that 98% of total diversity is intrapopulational, whereas interpopulational genetic diversity was only 2%. these results suggest that before these populations separated, they had gone through a period of gene exchange and, even after the separation event, gene frequency stayed at levels similar to the original levels, with no differential selection for these genes in the different cultivation areas.
Qualidade de película de famílias clonais de batata
Silva, Giovani Olegario da;Pereira, Arione da Silva;Souza, Velci Queiroz de;Carvalho, Fernando Irajá Félix de;Vieira, Eduardo Alano;
Bragantia , 2008, DOI: 10.1590/S0006-87052008000300011
Abstract: tuber general appearance is a very important trait for potato breeding, once it affects consumer acceptance of in natura products. among appearance components the tuber coloration and smooth are very important. the objective of this work was to investigate the expected selection response for traits related to skin quality (smooth and coloration) and tuber appearance in three potato families. the experiments were performed in the experimental field of embrapa clima temperado during the spring of 2004 and 2005, using three families at second and third clonal generations, respectively. the traits smooth, skin coloration and tuber general appearance in the tubers were evaluated. data was analyzed statistically according to the model reml/blup, in way to distinguish fixed and aleatory effects and comparing values among the families, correlation between traits, heritability index and gain of selection. it can be verified that, for the development of superior potato populations regarding skin quality, the inclusion of parents bearing flat and clear skin is necessary. the traits smoothness and tuber coloration are correlated with the tuber general appearance, but this trait has lower heritability than its components.
Estimativa do desempenho de progênies F2 e F3 com base no comportamento dos genitores e dos híbridos F1 em aveia
Lorencetti, Claudir;Carvalho, Fernando Irajá Félix de;Oliveira, Ant?nio Costa de;Valério, Igor Pirez;Vieira, Eduardo Alano;Silva, José Ant?nio Gonzalez da;Ribeiro, Guilherme;
Bragantia , 2006, DOI: 10.1590/S0006-87052006000200003
Abstract: many techniques have been proposed to increase the probability of obtaining superior segregating populations, and major efforts have been invested by researchers worldwide. in this sense, the present work had as objective to verify the efficiency of using parental average, f1 heterosis and heterobeltiosis and the morphological and molecular genetic distance in the prediction of grain yield in oat. grain yield and its primary components, were measured in f2 and f3 generations originated from the diallel cross involving five parents. data were obtained from two experiments carried out in the centro agropecuário da palma, in cap?o do le?o county, rs, brazil, in 2002 and 2003. the results indicate that the performance f2 and f3 populations can not be adequately predicted on the basis of the performance of f1 generation. grain yield of f2 and f3 populations could not be predicted by the genetic distance calculated by morphology or molecular markers. crosses of high-yielding genotypes did not always yield offsprings with positive transgressive segregation.
Estimativas de correla??es genotípicas e de ambiente em gera??es com elevada freqüência de heterozigotos
Benin, Giovani;Carvalho, Fernando Irajá Félix de;Oliveira, Antonio Costa de;Hartwig, Irineu;Schmidt, Douglas;Vieira, Eduardo Alano;Valério, Igor Pires;Silva, José Gonzáles da;
Ciência Rural , 2005, DOI: 10.1590/S0103-84782005000300006
Abstract: the use of genotypic correlation helps evaluating the magnitude and direction of associations between characters facilitating the application of indirect selection, leading to faster and larger genetic gains in oat (avena sativa l.) breeding programs. this study aimed to test a modification of petr & freys? (1996) formula, to obtain genotypic, phenotypic and environmental correlation estimates through the analyses of four f2 oat segregant populations: or 2 x upf 18, upf 7 x ctc 5, or 2 x upf 7 and upf 18 x ctc 5. the estimates of genetic correlations indicated that plants of superior grain productivity could be selected indirectly through the characters: number of panicles per plant, panicle weight, number of grains per panicle and average grain weight. however, the opposite direction and the difference of magnitude of correlation estimates between many pairs of characters on the four studied populations did not allow any generalization of selection strategies. this is probably due to the imposed limitations caused by the differences on the genetic background of parents and populations. in this way, it is advisable to test the combining ability of major genotypes used in artificial crossings in brazil, to establish more effective criteria for superior genotype selection.
Retrocruzamento como uma estratégia de identificar genótipos e desenvolver popula??es segregantes promissoras em aveia
Lorencetti, Claudir;Carvalho, Fernando Irajá Félix de;Oliveira, Antonio Costa de;Valério, Igor Pirez;Hartwig, Irineu;Marchioro, Volmir Sérgio;Vieira, Eduardo Alano;
Ciência Rural , 2006, DOI: 10.1590/S0103-84782006000400012
Abstract: the objective of this work was to develop the use of backcrosses among elite parental lines and to identify the parents with higher probability of developing superior progenies when used in crossing blocks. the following traits were analyzed: number of panicles per plant and plant grain yield in kg. ha-1. five oat genotypes (upf 16, upf 18, ufrgs 7, ufrgs 17 and urpel 95/015) were crossed on a diallel design not considering reciprocal crosses. f1 populations were obtained from the cross of parental lines. these populations were either backcrossed to obtain the populations bc1p1, bc1p2, bc1p1f2, bc1p2f2, bc2p1 and bc2p2, or selfed to obtain f2 and f3 generations. the f1 hybrids, the f3 populations and the backcrosses were field evaluated during a 2003 winter season. a cross dependent superiority was observed for backcrosses, when compared to the f3 population. an improvement in progeny superiority was observed when the background was increased for the genotypes upf 16, ufrgs 7 and ufrgs 17. these results were observed in 75% of the crosses, in which those genotypes were present as parental lines upf 18 and urpel 95/015 presented less favorable genes to increase grain yield, showing a tendency to reduce the performance of progenies when of their genetic background was increased in the tested combinations.
Capacidade de combina??o multivariada para caracteres de tubérculo em gera??es iniciais de sele??o em batata
Silva, Giovani Olegario da;Pereira, Arione da Silva;Souza, Velci Queiroz de;Carvalho, Fernando Irajá Félix de;Vieira, Eduardo Alano;
Ciência Rural , 2008, DOI: 10.1590/S0103-84782008000200004
Abstract: the diallel analysis provides estimates of useful parameters to parent selection and to the understanding of the genetic effects involved in a trait control. this research was aimed at estimating multivariate combining ability of potato parents in the initial generations of selection. twenty potato clonal families (5*4) of nine genotypes in a partial diallel design were evaluated for two successive generations. the experiments were conducted at the embrapa clima temperado, in pelotas, rs (31° s, 52° w), in the spring of 2005 and autumn of 2006. fourteen morphological tuber traits were evaluated and the six more stable, or those that were best repeated in the generations were selected for further analysis. the analysis of variance revealed significant differences for all traits. the diallel multivariate analysis, using principal components, showed "2cri-1149-1-78", "eliza", "c-1786-6-96" and "white lady" genotypes with higher general combining ability for tuber appearance, smoothness, eye brown, pointing, curving and flatness, contributing with additive effects for crossings. the "c-1750-15-95"/"agria", "c-1786-6-96"/"asterix" and "eliza"/"asterix" cross combinations were outstanding for specific combing ability for tuber eye brown, pointing, curving and flatness, and "2cri-1149-1-78"/"vivaldi", "eliza"/"bp1" and "eliza"/"agria" for tuber appearance, smoothness and eye brown.
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