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  • 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

Estudo Fitoquímico e Biológico das folhas da dioscorea alata (DIOSCOREACEAE)

Paulino Machado Magalhães, Luciméri January 2004 (has links)
Made available in DSpace on 2014-06-12T15:50:25Z (GMT). No. of bitstreams: 2 arquivo4452_1.pdf: 567437 bytes, checksum: 687a30913ef93cfdd5ad5f0dd5efa7d1 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2004 / Paulino Machado Magalhães, Luciméri; Ferreira Cavalcanti de Albuquerque, Julianna. Estudo Fitoquímico e Biológico das folhas da dioscorea alata (DIOSCOREACEAE). 2004. Dissertação (Mestrado). Programa de Pós-Graduação em Biotecnologia de Produtos Bioativos, Universidade Federal de Pernambuco, Recife, 2004.
2

Molecular systematics of the neotropical tuberous legume Pachyrhizus Rich. ex DC, the yam bean

Engelmann, Jaime Eduardo Estrella January 1998 (has links)
The Neotropical genus Pachyrhizus Rich, ex DC. (the yam beans) is one of the few legume genera with edible tuberous roots. Two of its five species (P. ahipa and P. tuberosus) are cultivated by rural communities in the Andean and Amazonian regions, while a third species (P. erosus) is grown on a large scale in Central America for the domestic and international market. Current breeding work in Costa Rica, Ecuador, Denmark, Portugal and Tonga is aimed at increasing the potential use of the genus as a crop. The objective of this research was to construct a phylogeny for the genus based on molecular variation, and to establish relationships and levels of genetic diversity among Pachyrhizus species. A phylogeny based on chloroplast (cp) DNA variation separated the genus into two evolutionary branches, i.e. a Mesoamerican and a South American branch, reflecting a consistent phylogeographic pattern of species distribution and dispersal. The wild species P. ferrugineus (resolved as the most primitive within the genus) together with wild and cultivated P. erosus represented the Mesoamerican branch. Materials of Andean and Amazonian distribution, namely P. panamensis, the P. tuberosus complex and the highly derived species P. ahipa made up the South American evolutionary branch of the genus. P. panamensis was the most primitive taxon in this group. A phylogeny constructed from sequence variation of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA complemented the cpDNA phylogeny to a broad extent, separating Pachyrhizus species into similar clades and reflecting a congruent phylogeographical distribution. The ITS phylogeny also indicated that P. panamensis and wild taxa of P. tuberosus and P. erosus probably originated after rapid radiation from a continuously distributed early ancestor (i.e. ecotypes of P. ferrugineus). Subsequently, speciation may have accompanied divergent adaptation to dissimilar ecological niches in two directions: to areas with conspicuous annual dry seasons and deciduous forests in Mesoamerica, which in turn resulted in the origin and specialisation of P. erosus and its several primitive landraces and cultivars; and, to the tropical and subtropical rainforests and Andean valleys, giving rise to the different aided by domestication and man-made selection. Phenograms produced from RAPD variation were congruent to a broad extent with the phylogenies obtained from cpDNA and ITS variation, confirming the affinity between P. ahipa and P. tuberosus, and revealing the existence of three gene pools in Mesoamerica and Mexico. P. tuberosus appears to have played a significant role in the evolution of the genus. Multiple lines of molecular evidence suggest that this species might also be ancestral to P. erosus, as a separate lineage. Moreover, an early, wild ancestor of P. tuberosus was also closely related to other wild species (i.e. P. panamensis and P. ferrugineus); and, some of the cultigen types of the P. tuberosus complex encompass the early ancestry of the highly advanced species P. ahipa. Finally, a broad range of potentially exploitable genetic diversity was identified in this study, enabling both the implementation (or continuation) of in situ/ex situ conservation strategies, and a more efficient progress towards genetic breeding of yam beans.
3

Phylogeny and taxonomic reexamination of the genus Dioscorea (Dioscoreaceae) / ヤマノイモ属(ヤマノイモ科)の系統と分類学的再検討

Noda, Hiroshi 25 May 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22631号 / 理博第4620号 / 新制||理||1664(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 田村 実, 教授 工藤 洋, 教授 永益 英敏 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
4

Agrodiversidade e cadeia produtiva do cará (Dioscorea spp.) na agricultura familiar: um estudo etnográfico no município de Caapiranga-AM

Castro, Albejamere Pereira de 12 May 2011 (has links)
Made available in DSpace on 2015-04-20T12:22:50Z (GMT). No. of bitstreams: 1 Albejamere.pdf: 5701790 bytes, checksum: c07cf3ee46eb8494340bc2f8ca159726 (MD5) Previous issue date: 2011-05-12 / Fundação de Amparo à Pesquisa do Estado do Amazonas / Aiming to achieve a comprehensive agronomic study on the agro-biodiversity conservation and the supply chain of or yam (Dioscorea spp.) originated from family farms in the municipality of Caapiranga in Amazonas State, an ethnographic research was conducted with contributions from approaches of ethnobotany, participatory analysis of four-cell, qualitative analysis and rapid diagnosis of supply chains, through the use of proper tools such as surveys, interviews, participant observation, soil analysis, chemical analysis and botanical identification. In the localities surveyed, the cultivation of yam revealed itself not just as an important commercial activity, but also as a cultural symbol that makes Caapiranga´s farming communities and their territories full of feelings for the place and the cultivation of yam. In order to achieve sufficient production and their sustainability, family farmers carry out the practice of mutual aid such as: mutirão , troca-de-dia or parceiria/meia , but what stands out is the itinerant ajuri . It was found that the whole family participates in the production units and tasks performed in the houselholds. Depending on the work and the financial condition of the farmer, it is often necessary external force identified as a temporary appointment, called diária "avulso" and / or "acessório" work. The research on yam agro-biodiversity revealed that farmers recognize fifteen varieties, however, grow only eleven of these. The varieties still grown are: Roxão , Macaxeira , Pata-de-onça , Ovo-de-cavalo , Durão , Inhame , Rabo-de-mucura , Miguel e Cará-do-ar . It is believed that all these belong to species D. trifida except cará-do-ar that belongs to the species D. bulbifera. As for varieties that are no longer cultivated: Cará-alemão , Cará-creme , Cará-sucuriju and Cará-espinho , the first two may be D. trifida, in accordance with the ethnobotanical descriptors, while the latter two need accurate botanical identification. Slash and burning of natural vegetation are done in the implementation of yam cultivated plots. The cultivation system follows a rotational system of soil management, i.e., the fields where yam is grown are used for a maximum of three years, and then left to fallow. For planting, high holes are made, with 0.80 m in diameter and 0.40 m high and 0.20 m deep, the spacing used by 42% of farmers is 1x1m between the pits. There is no standardized spacing between rows and final arrangement of plants in gardens is dense. In crop management, there is a consortium with cassava which serves as a support for the yam. Due to diversification in yam plots, pests and diseases do not cause economic damage. The harvest of the tubers is performed at different times in relation to age of plantation crop cycle, allowing offseason. Although the acidic soil with pH 4.5 in average and low in nutrients, and non-use of conventional inputs and mechanization, the production of 15 ton.ha-1 is considered good by the local agricultural agencies. Due to its positive social and environmental characteristics, the cultivation of yam is presented as a promising economic activity for the region, mainly in the municipality of Caapiranga. For developing such potential, actions are required to fortify family production systems based on expansion of technical-scientific research to promote the unity of knowledges for the conservation of agricultural biodiversity and the promotion of the productive chain of the culture of character for the Amazon region. / Com o objetivo de realizar um amplo estudo agronômico sobre a conservação da agrodiversidade e cadeia produtiva de cará (Dioscorea spp.) com origem na agricultura familiar do município de Caapiranga no Amazonas, realizou-se uma pesquisa etnográfica com contribuições de abordagens da etnobotânica, da análise participativa de quatro-células, da análise qualitativa e do diagnóstico rápido dos circuitos de comercialização, com emprego de ferramentas tais como: questionário, entrevista, observação participativa, análise de solo, análise química e identificação botânica. Nas localidades pesquisadas, o cultivo do cará se revelou não apenas como uma importante atividade comercial, mas também, como um símbolo cultural que faz de Caapiranga e de suas comunidades agrícolas territórios carregados de sentimentos pelo lugar e pelo o cultivo de cará. Visando alcançar produção suficiente para a sustentabilidade da família, os agricultores realizam as práticas de ajuda mútua, tais como: mutirão, troca-de-dia ou parceria-meia, no entanto, o que se destaca é o ajuri itinerante. Verificou-se que toda a família participa nas unidades produtivas e nas tarefas realizadas nos lares. Dependendo do trabalho e da condição financeira do agricultor, muitas vezes é necessária a força externa identificada como contratação temporária, denominada de diária, trabalho avulso e/ou acessório . A pesquisa sobre a agrodiversidade de cará revelou que os agricultores reconhecem quinze variedades, no entanto, cultivam apenas onze destas. As variedades ainda cultivadas são: Roxão , Macaxeira , Pata-de-onça , Ovo-de-cavalo , Durão , Inhame , Rabo-de-mucura , Miguel e Cará-do-ar . Acredita-se que todas estas pertençam à espécie D. trifida exceto o Cará-do-ar, que pertence à espécie D. bulbifera. Quanto às variedades que não são mais cultivadas como Cará-alemão, Cará-creme, Cará-sucuriju e Cará-espinho, as duas primeiras podem, de acordo com os descritores etnobotânicos, ser D. trifida, enquanto que as duas últimas é preciso identificação botânica. Na implantação da cultura do cará são realizados o corte e a queima da vegetação espontânea. O sistema de cultivo segue sistema rotacional de manejo do solo, ou seja, a roça onde são cultivados os carazais é utilizada por, no máximo três anos e depois é deixada, em pousio. Para o plantio, são feitas covas altas, de 0,80m de diâmetro por 0,40 m de altura e 0,20 m de profundidade. O espaçamento utilizado por 42% dos agricultores é de 1x1m entre as covas, não há espaçamento padronizado entre linhas e o arranjo final das plantas nas roças é de forma adensada. No manejo da cultura, há o consórcio com a mandioca que serve como tutor para o cará. Devido à diversificação nos carazais, as pragas e doenças não causam danos econômicos. A colheita dos tubérculos é realizada em épocas diferentes em relação à idade dos plantios e ciclo da cultura, possibilitando entressafra. Apesar do solo ácido com pH 4,5, em média, pobre em nutrientes, o não uso de insumos convencionais e mecanização, a produção em média de 15 ton.ha-1 é considerada boa pelos órgãos de produção local. Por suas características socioambientais favoráveis, o cultivo do cará se apresenta como uma atividade econômica promissora para região, principalmente para o município de Caapiranga. Para o desenvolvimento desse potencial são necessárias ações que fortaleçam os sistemas de produção familiar, com base na ampliação de pesquisas técnico - cientificas que promovam a união dos saberes para a conservação da agrobiodiversidade e da dinamização da cadeia produtiva da cultura do cará para região amazônica.
5

Extractives of three southern African medicinal plants.

Page, Bronwen Ann. January 1998 (has links)
In this investigation the chemistry of three southern African plants used for medicinal purposes was investigated. The plants were Dioscorea dregeana, Avonia rhodesica and Equisetum ramossisimum. Extracts of all three of these plants have been found to be active on the central nervous system. The structures of the compounds isolated were determined by using 1H and 13C n.m.r., i.f., UV-VIS, - mass spectroscopy and chemical methods. D. dregeana yielded two alkaloids and three aromatic compounds. A. rhodesica contained a large amount of wax which was analysed by GC-MS and its distribution and physical nature on the surface of the leaves was determined by SEM (scanning electron microscopy). This plant also contained two sterols. Equisetum ramossisimum extracts contained a carotenoid and several porphyrins, as well as large amounts of silica. A DTSA X-ray microanalysis system (which was a component of the scanning electron microscope) was used to determine the distribution of silica in the stem. / Thesis (M.Sc.)-University of Natal, Durban, 1998.

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