• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Análises genéticas em progênies de Pinus caribaea Morelet var. caribaea por caracteres quantitativos e marcadores moleculares /

Gonzaga, Janete Motta da Silva. January 2005 (has links)
Abstract: This work aimed: to estimate the genetic variability to growth characters and the wood density; to estimate the genetic value of superior trees; to characterize by molecular markers (RAPD e SSR), three groups of individuals - superiors, intermediates and inferiors, selected with multi-effects index; to verify the effect of thinning on progeny trial relating it to parameters genetics; to estimate the gain expected through the use of IME, aiming to turn the progeny trial in a seedling seed orchard and/or to supply material to establish a clonal seed orchard; to give subsidies to genetic breeding program of this species. The results were: a) a genetic variation verified on the traits was few expressive; b) the thinning showed perspectives to these progenies trial to be explored as a seed orchard by seedling and/or clonal; c) the heritability estimates had presented low magnitude and little variation through time; d) the correlations between characters dbh, height and volume was high, and low for wood density and form. The path analysis coefficient was useful to know to correlation among the studied trait, with volume being largely determined by height and little influence by dbh; e) the Mahalanobis generalized distance and the assemble of progenies by Tocher's method gave important information to future breeding programs about hybridization or backcross; f) the multi-effect index applied to dbh, on D situation, showed higher gains than the selection within and among progenies, and the best option the selection up to five plants per progenies because to permit higher gains and keep genetic diversity close to a selection within and among progenies; g) the characterization using molecular markers evidenced homogeneity between the groups of superiors, intermediates and inferiors individuals. / Orientador: Mario Luiz Teixeira de Moraes / Coorientador: Edson Seizo Mori / Alexandre Magno Sebbenn / Miguel Luiz Menezes Freitas / Mestre
2

Análises genéticas em progênies de Pinus caribaea Morelet var. caribaea por caracteres quantitativos e marcadores moleculares

Silva, Janete Motta da [UNESP] 26 July 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07-26Bitstream added on 2014-06-13T21:00:08Z : No. of bitstreams: 1 silva_jm_me_ilha.pdf: 744004 bytes, checksum: a46600146851ee56b85f98515c789195 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / This work aimed: to estimate the genetic variability to growth characters and the wood density; to estimate the genetic value of superior trees; to characterize by molecular markers (RAPD e SSR), three groups of individuals - superiors, intermediates and inferiors, selected with multi-effects index; to verify the effect of thinning on progeny trial relating it to parameters genetics; to estimate the gain expected through the use of IME, aiming to turn the progeny trial in a seedling seed orchard and/or to supply material to establish a clonal seed orchard; to give subsidies to genetic breeding program of this species. The results were: a) a genetic variation verified on the traits was few expressive; b) the thinning showed perspectives to these progenies trial to be explored as a seed orchard by seedling and/or clonal; c) the heritability estimates had presented low magnitude and little variation through time; d) the correlations between characters dbh, height and volume was high, and low for wood density and form. The path analysis coefficient was useful to know to correlation among the studied trait, with volume being largely determined by height and little influence by dbh; e) the Mahalanobis generalized distance and the assemble of progenies by Tocher's method gave important information to future breeding programs about hybridization or backcross; f) the multi-effect index applied to dbh, on D situation, showed higher gains than the selection within and among progenies, and the best option the selection up to five plants per progenies because to permit higher gains and keep genetic diversity close to a selection within and among progenies; g) the characterization using molecular markers evidenced homogeneity between the groups of superiors, intermediates and inferiors individuals.
3

Diversidade genética e sistema de reprodução progênies elites de Pupunheira Inerme (Bactris gasipaes KUNTH) com marcadores microssatélites: Implicações para o melhoramento do palmito.

Rodrigues, Doriane Picanço 28 September 2006 (has links)
Made available in DSpace on 2015-04-20T12:31:07Z (GMT). No. of bitstreams: 1 Doriane Picanco Rodrigues.pdf: 621795 bytes, checksum: eef07284526ed1e322db593a7fb7fd98 (MD5) Previous issue date: 2006-09-28 / Fundação de Amparo à Pesquisa do Estado do Amazonas / The peach palm (Bactris gasipaes Kunth var. gasipaes) is a domesticated Neotropical palm that is important as a cultivated source of heart-of-palm. The genetic base for this agribusiness is the Pampa Hermosa landrace, Yurimaguas, Peru, that supplies the absolute majority of the seeds used in the expansion of the agribusiness and the improvement programs in Brazil, because its plants are spineless and more productive than those of other landraces. The use of molecular markers will permit better discrimination among populations and progenies of the landrace, guiding the selection of elite individuals and the search for hybrid vigor via maximization of heterozygosity within the landrace. This study evaluated the genetic diversity, population structure, and genetic relations among progenies and populations in a progeny trial maintained at INPA, Manaus, Amazonas, as well as the mating system of the peach palm using eight microsatellite loci, to support the improvement programs that use these genetic resources. Samples from three populations of the Pampa Hermosa landrace and from the market of Yurimaguas were collected from 12 progenies from the Cuiparillo River (n=140), 12 from the Paranapura River (n=130), nine from the Shanusi River (n=130), and 17 from the market at Yurimaguas (n=168). The sampling concentrated on plants (121) selected for heart length, and included non-selected plants (447). High genetic variability exists in the progeny trail, with a mean of 15.1 alleles per locus and total diversity (HT) equal to 0.82. The eight loci had 12 common alleles and 26 intermediate-frequency alleles found in all the populations and the market, and 83 alleles scattered among populations, with 14 private alleles. The observed heterozygosity (Ho) in the trail was less than the He in the majority of the loci; in locus Bg02-08 Ho was very inferior, suggesting a strong excess of homozygotes in this locus. The Ho was lowest in Shanusi (0.64) and highest in Paranapura (0.74). The inbreeding coefficient f varied among populations and market, and was highest in Shanusi (0.190) and lowest in Paranapura (0.111). Genetic divergence among the populations and the market was low (formula), certainly due to high gene flow (9.8 migrants per generation). The AMOVA detected 82.8% of the total variation within the progenies, 16% among the progenies within the populations and market, and only 1.3% among the populations and the market, describing a weak genetic structure and suggesting that the populations and the market are highly related. This relationship was confirmed by the dendrograms of the DAS genetic distances among the populations, with a greater proximity between the populations of Paranapura and Cuiparillo, and between the Mercado and Shanusi. The dendrogram of the DAS genetic distances showed high genetic affinity among the progenies and the formation of groups independent of their geographic origin. The Ho and He were high for the majority of the progenies, confirming high genetic variability within the progenies. The inbreeding coefficient (f) for the progeny trial was not different from zero, confirming an excess of heterozygotes and confirming the high variability observed from the estimates of heterozygosity. The analysis of the mating system found that the species is predominantly allogamous. The high out-crossing rate demonstrates that the progenies are derived almost exclusively from individuals experiencing out-crossing, probably due to the harvest representing the peak of the flowering season and to the synchronism of flowering associated with the behavior of the pollinator. The estimates of crossing among relatives (tm - ts) were significant (0.101 to 0.202), suggesting some biparental inbreeding, probably due to the farmers practice of planting open-pollinated seeds of only a few seed sources in the same plot. The estimate of paternity correlation was low (varying from 0.051 to 0.112), suggesting a small number of full sibs within the progenies and large number of pollen sources (9 to 20) participating in the crosses. The progenies of the trial are composed mainly of half sibs with great genetic variability, enhanced by the large number of pollen sources, and suggests that selection for heart-of-palm production could be based on the classic models of quantitative genetics applied to exclusively allogamous species. This information will be used to guide the crosses among progenies/populations. Two improvement plans are feasible with this information: population improvement, with crosses among highly divergent plants and progenies; by reciprocal recurrent selection, with the creation of divergent populations based on morphometric and genetic information. / A pupunheira cultivada (Bactris gasipaes Kunth var. gasipaes) é uma palmeira domesticada que vem se destacando como produtora de palmito. A base genética para o agronegócio vem da raça primitiva Pampa Hermosa, Yurimáguas, Peru, que fornece a maioria absoluta das sementes usadas na expansão do agronegócio e nos programas de melhoramento no Brasil, devido a possuir plantas sem espinho que são mais produtivas que as de outras raças. O uso de marcadores moleculares possibilitará discriminar com maior confiabilidade entre populações e progênies, orientando a seleção de matrizes e a busca de vigor híbrido via maximização de heterozigosidade dentro da raça. Este trabalho avaliou a diversidade e a estrutura genética, as relações genéticas entre as progênies e o sistema de reprodução de pupunheira da raça Pampa Hermosa, usando oito loci microsatélites, para apoiar os programas de melhoramento que usam estes recursos genéticos. Foram coletadas amostras de três populações de pupunheira da raça Pampa Hermosa e do mercado de Yurimáguas mantidas no ensaio de progênies do INPA, sendo 12 progênies do rio Cuiparillo (n=140), nove do rio Shanusi (n=130), 12 do rio Paranapura (n=130) e 17 do mercado de Yurimáguas (n=168). A amostragem concentrou-se em plantas selecionadas (121) para comprimento do palmito e não selecionadas (447). Existe alta variabilidade genética nas progênies do ensaio, com média de 15,1 alelos por loci e diversidade total (HT) igual a 0,82. Os oito loci apresentaram 12 alelos comuns e 26 alelos intermediários presentes em todas as populações e o mercado, e 83 alelos raros, sendo 14 privados, 10 esporádicos e 62 difundidos. As heterozigosidades observadas (Ho) no conjunto de plantas foram inferiores a heterozigosidade esperada (He) na maioria dos loci; no lócus Bg02-08 Ho foi muito inferior, sugerindo forte excesso de homozigotos neste lócus. A Ho foi menor em Shanusi (0,64) e maior em Paranapura (0,74). Os coeficientes de endogamia variaram entre populações e mercado, sendo maior em Shanusi (0,190) e menor em Paranapura (0,111). Detectou-se baixa divergência genética entre as populações e o mercado (fórmula), certamente devido ao alto fluxo gênico (9,8 migrantes por geração). A AMOVA detectou 82,8% do total da variação dentro das progênies, 16% entre as progênies dentro das populações e o mercado, e somente 1,3% entre as populações e o mercado, confirmando uma estrutura genética mínima e sugerindo que as populações e o mercado são altamente relacionadas. Este relacionamento foi confirmado pelos dendrogramas de distâncias (DAS) das populações, o qual mostra maior proximidade entre as populações de Paranapura e Cuiparillo, e entre o mercado e Shanusi. O dendrograma das progênies mostra alta afinidade genética e formação de grupos independentes de sua área geográfica de origem. As heterozigosidades observadas (Ho) e esperadas (He) foram altas para a maioria das progênies, evidenciando alta variabilidade genética dentro das progênies. O coeficiente de endogamia (f) para o conjunto de progênies não foi diferente de zero, evidenciando excesso de heterozigotos e confirmando a alta variabilidade observada pelas estimativas de heterozigosidade. A análise do sistema de reprodução revela que a espécie é predominantemente alógama. As altas taxas de cruzamento demonstram que as progênies são oriundas quase que exclusivamente por indivíduos provenientes de exocruzamento, provavelmente devido ao estágio fenológico (pico da safra) e ao sincronismo de floração associado ao comportamento do polinizador. Porém, as estimativas (tm - ts) foram significativas (0,101 a 0,202), evidenciando endogamia biparental, provavelmente decorrente da prática agrícola de plantar sementes de polinização aberta de poucas matrizes na mesma roça. A estimativa da correlação de paternidade foi baixa (variando de 0,051 a 0,112), indicando pequena proporção de irmãos-completos dentro das progênies e grande número de doadores de pólen (9 a 20) participando dos cruzamentos individuais. Portanto, as progênies do ensaio são compostas em sua maioria por meios-irmãos com elevada variabilidade genética, evidenciada pelo alto número de doadores de pólen, e sugere que a seleção para produção de palmito poderá ser baseada nos modelos clássicos de genética quantitativa aplicados para espécies exclusivamente alógamas. Essas informações serão utilizadas para orientar os cruzamentos entre e dentro de progênies/populações. Dois planos de melhoramento são factíveis com essa informação: melhoramento populacional, com cruzamentos entre plantas e acessos altamente divergentes; melhoramento por meio de seleção recorrente recíproca, com a criação de populações divergentes em termos morfométricos e genéticos.

Page generated in 0.0703 seconds