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Search Results: 1 - 10 of 85312 matches for " Giovani Olegário da Silva "
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Componentes genéticos e fenotípicos para caracteres de importancia agron?mica em popula??o de cenoura sob sele??o recorrente
Silva, Giovani Olegário da;Vieira, Jairo Vidal;
Horticultura Brasileira , 2008, DOI: 10.1590/S0102-05362008000400011
Abstract: the objective of this work was to estimate the genotypic and phenotypic parameters for traits of carrot populations among characters in carrot populations, in order to guide the choice of selection strategies. the experiments were performed at two locations (lap?o, bahia state and brasília, brazil) in the summer of 2004. nine carrot hybrid populations were evaluated in randomized complete block design with 4 replications and 2 m2 treatments. 90 days after sowing, 15 competitive plants per plot were harvested and evaluated individually for the characters yield, root length, green shoulder length, tip type, shoulder type, root diameter, xylem root diameter, relationship among xylem diameter/root diameter, and both xylem and phloem a* color (color parameter determined by colorimetry, varying from green to red). the data were submitted to variance analyses and the heritability in the wide sense of plot average was estimated by medium square and the correlation among the characters. according to the heritability values, for the characters xylem diameter (0.92 and 0.87), color of a* xylem (0.96 and 0.95) and ratio among xylem diameter and root diameter (0.87 and 0.91), strong selection pressure can be applied in the two evaluation places. larger root yield was associated with larger root diameter and larger xylem diameter, as well as by larger values of the ratio among xylem diameter and root diameter. thicker roots are associated with smaller a* (content of β-carotene), mainly in relation to the part constituted by the xylem. therefore, through the correlation values, there exist an indication that selection for larger carotene content cannot be carried out without considering the characters of root diameter, which are important yield components.
Ganhos realizados com a sele??o para caracteres de importancia agron?mica em cenoura
Silva, Giovani Olegário da;Vieira, Jairo V;
Horticultura Brasileira , 2009, DOI: 10.1590/S0102-05362009000400009
Abstract: the genetic progress estimative is an important aspect in breeding programs, in order to evaluate the breeding selection methods efficiency for the characteristics of interest in the populations under selection. in this research, the gains obtained from the selection of agronomic traits were evaluated in a carrot population through successive generations. the experiment was performed at embrapa hortali?as, brasília, brazil. a carrot population was selected every summer during six consecutive generations from 1999 to 2004. in the summer of 2005, samples of seeds harvested in the previous years were sown in plots of 1 m2 in randomized blocks design with five replications. the plants were evaluated for severity of leaf blight at 60 and 90 days after sowing and harvested at 90 days after sowing when each plot was evaluated for the characters of number and mass of waste roots, number and mass of marketable roots with green shoulder, number and mass of marketable roots without green shoulder, number, mass and average mass of total roots and number, mass and average mass of marketable roots. the data were submitted to analyses of variance, and comparisons of treatment means by scott-knott, and the gain obtained with selection was calculated. superior gains occurred only in the first cycles of selection towards the decrease of refused roots and increase of resistance to leaf blight. the selection for leaf blight resistance was efficient only when performed at 90 days after sowing, because the disease severity was low at 60 days. the amount of roots classified as marketable with and without green shoulder increased during all the selection cycles, although the gains were higher for the roots without green shoulder.
Tamanho mínimo de parcela para avalia??o de caracteres de raiz em cenoura
Vieira, Jairo Vidal;Silva, Giovani Olegário da;
Bragantia , 2008, DOI: 10.1590/S0006-87052008000400029
Abstract: the estimate of the optimal number of plants per plot for the evaluation of carrot populations is important in order to reduce the experimental error and to enhance the accuracy of the information obtained in breeding experiments. additionally, it contributes to reduce the research costs. the objective of the present work was to estimate the minimum number of plants per plot for evaluation of root characters in carrot populations using the modified maximum curvature and the stabilization of the average and genetic variance methods. the essays were conducted in the summer of 2004 at three representative areas for carrot production in brazil, respectively: brasília, df; s?o gotardo, mg and lap?o, ba, in randomized blocks design with four replications, and plots with 2 m2. harvesting took place 90 days after sowing. in each plot of nine populations, 15 competitive plants were harvest and roots evaluated for mass, length, green shoulder length, tip shape, shoulder shape, diameter, xylem diameter, relationship among xylem diameter / root diameter and the l* a* b* color caracters for the xylem and phloem. the procedures of re-sampling and the modified maximum curvature method were used to estimate the minimum plant number to represent each plot. the results obtained for each procedure indicated that a sample of 13 plants per plot is enough to guarantee an appropriate evaluation of carrot populations for the group of studied characters.
Rela??es entre caracteres de cenoura para sistemas de cultivos organico e convencional
Silva, Giovani Olegário da;Vieira, Jairo Vidal;
Revista Ceres , 2010, DOI: 10.1590/S0034-737X2010000500016
Abstract: the selection strategy and the gain that it will provide allow, in a more efficient way, to direct a breeding program and to predict the success of the chosen selective scheme. the aim of this work was to evaluate the stability of the relationships among phenotypic characteristics of carrot populations cultivated in organic and conventional production systems. the experiments were conducted at embrapa vegetables, df, brazil. two breeding lines and four commercial cultivars were planted in november 2007 in both production systems, in a randomized block design with four replications and plots of 1m2. ninety days after planting, twenty roots per plot were harvested and evaluated for phenotypic characteristics. the analysis of variance was performed to determine the interaction between treatments and production systems, as well as phenotypic correlations and path analysis. the direct and correlated selection gains were also determined. almost all of the median correlations above 0.30 and the largest direct effects of path analysis and direct and indirect gains estimated were repeated in both systems, indicating that the systems are very similar in the expression of the relationship among the characteristics. thus, breeding for these traits do not need to be carried out in areas of both organic and conventional systems.
Ganhos genéticos após seis ciclos de sele??o em três popula??es de cenoura
Silva, Giovani Olegário da;Vieira, Jairo Vidal;
Revista Ceres , 2010, DOI: 10.1590/S0034-737X2010000600011
Abstract: the objective of this work was to evaluate the genetic gain with selection for root traits in three carrot populations. the experiment was conducted at embrapa hortali?as, brasília -df, brazil. three carrot populations derived from cultivar brasília and of common origin until 2001, were selected in six consecutive generations in the summers of 1998 to 2003. in the summer of 2004, seed samples of each year were sowed in the field in a randomized block design with five replications and plots of 1m2. ninety days after sowing, 25 roots per plot were harvested and evaluated for: length, xylem and phloem diameter, green shoulder length, mass, presence of halo, shape of tip and shoulder, and l* a* b* parameters of xylem and phloem. analysis of variance, comparisons among treatment means and estimation of genetic gain with selection were performed. in the last six years of selection, visual selection for color traits was not successful, probably due the low genetic variability, because the roots of these populations are already deep in color, indicating higher β-carotene content. increase in mass and root length was seen in both populations, with a proportional decrease in mean diameter of root and phloem.
Sele??o e número mínimo de famílias para avalia??o de parametros de cor em uma popula??o meio-irm? de cenoura
Silva, Giovani Olegário da;Vieira, Jairo Vidal;
Revista Ceres , 2010, DOI: 10.1590/S0034-737X2010000100012
Abstract: the use of the number of families not superior to what may be considered as sufficient for a good representation of a certain crossing is recommended, but taking into account the relationship between cost of experiment implementation and the progress obtained from the breeding program. thus, the aim of this work was to estimate the minimum number of half-sibling families of carrot necessary to represent the genetic characteristics of a population, as well as to identify the best families and the best plants inside families as to color features. the experiment was carried out at embrapa vegetable crops, gama-df, during the summer of 2004. a hybrid population with 71 half-sibling families of carrot plus two standard cultivars were evaluated in a experiment arranged in a complete randomized block design with 2 replications, with plots measuring 2,0 m2. ninety days after planting, 10 plants per plot were harvested and evaluated as to xylem and phloem l* a* b* parameters. the analysis of variance was performed and the minimum number of families to represent the population as well as the gains from the selection of 10% of the best families and plants inside families were estimated. it was observed that the selection among and inside families provided similar βcarotene level increases for faboth root parts. higher gains with the selection were obtained for the xylem characteristics. for xylem l* a* b*, both standard cultivars were surpassed by the selected families. only families 71, 7, 61 and 20 should be selected for phloem l* a* b*. for the evaluation of xylem and phloem color parameters, 52 and 42 families are necessary, respectively.
NOTE-Estimate of cross efficiency of potato parents
Roberto Fritsche Neto,Velci Queiroz de Souza,Arione da Silva Pereira,Giovani Olegário da Silva
Crop Breeding and Applied Biotechnology , 2006,
Abstract: The objective of this study was to estimate the cross efficiency of 43 genotypes frequently used as parents in thepotato breeding program of Embrapa Clima Temperado. The study was conducted under greenhouse conditions in theseasons autumn and winter/spring, from 2000 to 2004, in Pelotas, RS, Brazil. For each cross, the number of pollinated flowerbuds, the fruit-set and the number of seeds were recorded. Each season, in which the genotype was crossed, was considereda replication. The data were analyzed using the REML/BLUE statistic model. Male parents adapted to the ecological conditionsof the southern regions of Brazil presented higher efficiency in crosses than female parents. Genotypes used as male parentsinfluenced the number of seeds per flower bud more than female parents.
Genetic distances of potato genotypes based upon using morphological, genealogical, and molecular data / Distancias genéticas entre genótipos de batata a partir de dados morfológicos, moleculares e genealógicos
Giovani Olegário da Silva,Arione da Silva Pereira,Velci Queiroz de Souza,Caroline Marques Castro
Semina : Ciências Agrárias , 2009,
Abstract: The objective of this work was to compare estimates of genetic distances of potato genotypes using genealogical, morphological and molecular data, and jointed data (morphological and molecular). The work was carried on at Embrapa Clima Temperado and UFPel/FAEM/Laboratório de Gen mica e Fitomelhoramento. The evaluaton was with a set of 13 potato cultivars and elite clones of the Embrapa Clima Temperado Active Germoplasm Bank of Potatoes. The field experiments were grown in springs of 1999, 2000, 2001, 2002 and 2003, in single 20 plant plots, spaced at 0.30m between plants and 0.80m between rows. The genotypes were evaluated morphologically for 33 plant and tuber traits and for AFLP markers. The analysis of variance, considering year as replication, revealed no significant differences only for leaflet width, flowers frequency, stalk pigmentation e apex aspect. Correlations between dissimilarity matrices were significant only for jointed (morphologic and molecular) and molecular matrix. Therefore, all estimates of genetic distance between potato genitors should be considered in planning crosses. O objetivo do trabalho foi comparar estimativas de distancia genética entre genótipos de batata usando dados genealógicos, morfológicos, moleculares e conjuntamente, dados morfológicos e moleculares. Os trabalhos foram realizados na Embrapa Clima Temperado e na UFPel/FAEM/Laboratório de Gen mica e Fitomelhoramento. Foi avaliado um conjunto de 13 cultivares e clones elite, componentes do Banco Ativo de Germoplasma de Batata da Embrapa Clima Temperado. Os experimentos de campo foram realizados nas primaveras de 1999, 2000, 2001, 2002 e 2003, em parcelas únicas de 20 plantas, espa adas 0,30m entre plantas e 0,80m entre fileiras. Os genótipos foram avaliados em rela o a 33 caracteres morfológicos de planta e tubérculo e analisados molecularmente usando marcadores AFLP. A análise de variancia, considerando ano como repeti o, n o revelou diferen as significativas somente em rela o à largura dos folíolos, frequência de flores, pigmenta o do pedúnculo e aspecto do ápice. Apenas a correla o entre matrizes de dissimilaridade conjunta (morfológico e molecular) e molecular foi significativa. Portanto, todas as estimativas de distancia genética entre genitores de batata deveriam ser consideradas no plano de cruzamentos.
Adaptabilidade e estabilidade de cultivares de trigo em diferentes épocas de semeadura, no Paraná
Silva, Raphael Rossi;Benin, Giovani;Silva, Giovani Olegário da;Marchioro, Volmir Sérgio;Almeida, Juliano Luiz de;Matei, Gilvani;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011001100004
Abstract: the objective of this work was to identify the best sowing dates and to evaluate the adaptability and stability of wheat cultivars in two wheat growing regions of the state of paraná, brazil. seven cultivars were evaluated at guarapuava and nine at palotina as to grain yield, at four sowing seasons, in 2006, 2007 and 2008. the experimental design was a randomized complete block design, with four and three replicates, for guarapuava and palotina, respectively. the methodologies reml/blup and genotype main effect and genotype x environment interaction (gge biplot) were used for adaptability and stability analysis, and the ammi model was used to identify the best sowing dates. sowing in july, at guarapuava, and in april, at palotina, maximized grain yield. the cultivars safira, at guarapuava, and cd 113, at palotina, are stable, highly adapted and show high grain yield.
Estratégias de sele??o para germina??o de sementes de cenoura em condi??es de temperaturas elevadas
Silva, Giovani Olegário da;Vieira, Jairo Vidal;Nascimento, Warley Marcos;Boiteux, Leonardo Silva;
Revista Ceres , 2011, DOI: 10.1590/S0034-737X2011000100018
Abstract: the objective of this work was to determine the best selection strategy to improve seed germination rate and assess their effectiveness at two temperatures (20oc and 35oc). first count (vigor) and germination rate at 20oc and 35oc were used as evaluation criteria. seeds of 27 carrot breeding populations derived from cultivar brasília and three commercial standard cultivars were used in a randomized block design with three replications of 50 seeds for each accession. the correlation pattern among traits was estimated and treatment means were compared. first count (vigor) and germination were significant among populations. no correlation was observed between first count and germination rate at the two temperatures. this result suggests that selection for increasing seed germination should be carried out at both temperatures in order to avoid potential loss of adaptation to one of them. first count and seed germination rate had high correlations at each temperature, indicating that a single character could be used in the evaluation.
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