Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2001. / Includes bibliographical references.

Cunila spicata Benth. é uma planta aromática e medicinal utilizada popularmente no sul do Brasil como béquica, peitoral e sudorífera, e que apresenta comprovada atividade antiviral e anticonvulsiva. C. spicata é uma das 12 espécies sul-americanas do gênero Cunila (Lamiaceae) sendo encontrada em banhados e borda de mata de galeria no sul do Brasil, Argentina e Uruguai. Dentro deste contexto, no presente trabalho foi avaliada a variabilidade genética e química de populações de C. spicata coletadas nas regiões nordeste e sudeste do Rio Grande do Sul, com vistas a formação de bancos de germoplasma, determinação de estratégias de preservação e uso sustentável. Os marcadores ISSR e RAPD mostraram-se eficientes na determinação de variabilidade genética desta espécie, permitindo a identificação de todas as populações e indivíduos avaliados. As populações de C. spicata caracterizam-se como grupos geneticamente estruturados. Entretanto, não foi constatada formação de agrupamentos dentro da espécie, nem relação entre as distâncias genéticas e geográficas, ou entre as populações originarias das duas regiões geográficas amostradas. Por outro lado, a análise da composição dos óleos essenciais das 10 populações permitiu separar as mesmas em dois quimiotipos caracterizados por elevada concentração de α-terpineol/limoneno, e linalol, respectivamente. As populações da região sudeste enquadraram-se dentro do quimiotipo linalol, enquanto as da região nordeste no quimiotipo α-terpineol/limoneno. A relação geográfica e química é indicativa da existência de pressão de seleção quanto ao tipo de óleo essencial da região de ocorrência. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-12-01T16:00:30Z No. of bitstreams: 1 Dissertacao Marcos Roberto Albuquerque.pdf: 1631570 bytes, checksum: d32cbb1d10de9a5f37eb7dd664ddc20d (MD5) / Made available in DSpace on 2016-12-01T16:00:30Z (GMT). No. of bitstreams: 1 Dissertacao Marcos Roberto Albuquerque.pdf: 1631570 bytes, checksum: d32cbb1d10de9a5f37eb7dd664ddc20d (MD5) Previous issue date: 2016-12-01 / Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq. / Cunila spicata Benth. is a medicinal and aromatic plant popularly used in South Brazil as bequic, expectorant and sudiriferous, and that has confirmed antiviral and anti-convulsive activities. C. spicata is one of the 12 South-American species of the genus Cunila( Lamiaceae) been currently found in swamps and borders of gallery forests in South Brazil, North Argentina and Uruguay. In this context, the present work aimed to evaluate the genetic and chemical variability of C. spicata populations collected at the northeast and southeast regions of Rio Grande do Sul, to subside the construction of a germplasm bank, to determine conservation strategies, and to develop a sustainable use of this species. ISSR and RAPD markers proved to be efficients for the determination of the genetic variability of this species, allowing the identification of all the populations and individuals. C. spicata populations were characterized as genetically structured groups. However, clusters within the species were not evident, and no relations were detected between geographic and genetic distances, or between populations of the two regions. Conversely, the analysis of essential oil composition allowed the populations in two chemotypes, characterized by high concentration of α-terpineol/limonene, and linalool, respectively. The populations of the southeast region belong to the linalool chemotype, and those from the northeast region to the a-terpineol/limonene chemotype. This geographical and chemical relation is indicative of different selection pressures in the two regions.

Cunila spicata Benth. é uma planta aromática e medicinal utilizada popularmente no sul do Brasil como béquica, peitoral e sudorífera, e que apresenta comprovada atividade antiviral e anticonvulsiva. C. spicata é uma das 12 espécies sul-americanas do gênero Cunila (Lamiaceae) sendo encontrada em banhados e borda de mata de galeria no sul do Brasil, Argentina e Uruguai. Dentro deste contexto, no presente trabalho foi avaliada a variabilidade genética e química de populações de C. spicata coletadas nas regiões nordeste e sudeste do Rio Grande do Sul, com vistas a formação de bancos de germoplasma, determinação de estratégias de preservação e uso sustentável. Os marcadores ISSR e RAPD mostraram-se eficientes na determinação de variabilidade genética desta espécie, permitindo a identificação de todas as populações e indivíduos avaliados. As populações de C. spicata caracterizam-se como grupos geneticamente estruturados. Entretanto, não foi constatada formação de agrupamentos dentro da espécie, nem relação entre as distâncias genéticas e geográficas, ou entre as populações originarias das duas regiões geográficas amostradas. Por outro lado, a análise da composição dos óleos essenciais das 10 populações permitiu separar as mesmas em dois quimiotipos caracterizados por elevada concentração de α-terpineol/limoneno, e linalol, respectivamente. As populações da região sudeste enquadraram-se dentro do quimiotipo linalol, enquanto as da região nordeste no quimiotipo α-terpineol/limoneno. A relação geográfica e química é indicativa da existência de pressão de seleção quanto ao tipo de óleo essencial da região de ocorrência. / Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq. / Cunila spicata Benth. is a medicinal and aromatic plant popularly used in South Brazil as bequic, expectorant and sudiriferous, and that has confirmed antiviral and anti-convulsive activities. C. spicata is one of the 12 South-American species of the genus Cunila( Lamiaceae) been currently found in swamps and borders of gallery forests in South Brazil, North Argentina and Uruguay. In this context, the present work aimed to evaluate the genetic and chemical variability of C. spicata populations collected at the northeast and southeast regions of Rio Grande do Sul, to subside the construction of a germplasm bank, to determine conservation strategies, and to develop a sustainable use of this species. ISSR and RAPD markers proved to be efficients for the determination of the genetic variability of this species, allowing the identification of all the populations and individuals. C. spicata populations were characterized as genetically structured groups. However, clusters within the species were not evident, and no relations were detected between geographic and genetic distances, or between populations of the two regions. Conversely, the analysis of essential oil composition allowed the populations in two chemotypes, characterized by high concentration of α-terpineol/limonene, and linalool, respectively. The populations of the southeast region belong to the linalool chemotype, and those from the northeast region to the a-terpineol/limonene chemotype. This geographical and chemical relation is indicative of different selection pressures in the two regions.

MSCAGR ( Plant Production) / Department of Plant Production / See the attached abstract below

Gray leaf spot (GLS) disease of maize (Zea mays L.), caused by the fungus Cercospora zeae-maydis, causes significant corn yield losses in Virginia and other mid-Atlantic states. A new greenhouse assay method with filter paper discs of C. zeaemaydis mycelia has been developed to evaluate corn germplasm for resistance to GLS. Mycelial inoculum obtained from cultures of mycelia in liquid malt media was pipetted at 100 ul samples onto each filter paper disc which was then adhered to the lower leaf surface by transparent tape. The inoculated corn seedlings were placed in a moist plastic chamber with high relative humidity provided by a humidifier. The first macroscopic symptoms induced by this inoculation method appeared 3 days after inoculation. This new inoculation method with mycelial discs was used on five corn genotypes (VA14, B68, PA875 , B73, and M017) to screen resistance to GLS disease. With this inoculation method, resistant and susceptible inbreds were easily differentiated based on lesion type. Resistant inbreds including VA14, B68, and P A875 were characterized by water-soaked appearance or small chlorotic flecks while susceptible inbreds like B73 and M017 were characterized by more extensive necrosis. Necrotic area under the mycelial disc was a good indicator for disease severity. However, the percent leaf area under discs affected by mycelia which reflected the total host responses was not appropriate to indicate disease severity. The effects of plant physiological factors on the expression of resistance to GLS was also investigated. Placing mycelial discs on lower leaf surfaces induced more responses than placing on upper leaf surfaces. Inoculation of lower older leaves induced more severe lesions than inoculation of upper leaves. The effect of cercosporin was investigated by inoculating corn seedlings with cercosporin-producing mycelia and with non-cercosporin containing mycelia. The former induced much more severe host response than the latter. Conidiation of C. zeae-maydis was examined with the mycelial inoculation method in the greenhouse. Conidiophores were found emerging from stomata as early as 15 days after inoculation in B73 and M017 and limited only to necrotic tissue. No conidiation was observed in resistant genotypes VA14, B68 and PA875. / Master of Science

MSCAGR (Plant Production) / Department of Plant Production / Tepary bean (Phaseolus acutifolius) is an important food legume originating from South America and the South-western parts of the United States. The crop is produced in many countries worldwide including South Africa. It is highly tolerant to drought and the seed contains a wide range of vitamins, minerals and protein of high nutritional quality. The genetic base of tepary bean is narrow but can be widened by chemical mutagenesis. However, there are no reports on the impact of chemical mutagenesis on the root nodulation and seed storage proteins in tepary bean. Therefore, this study was designed to examine root nodulation attributes and seed storage proteins of three tepary bean genotypes in the early mutagenic generations (M2 to M4) derived through treatment with varying doses (0.0, 0.5, 1.0, 1.5 and 2.0 v/v) of ethyl methanesulfonate (EMS). The experiment on root nodulation attributes was laid out as a 3 x 5 x 3 (genotypes x EMS doses x mutant generations) factorial design replicated three times. At harvest, shoot height (SHT), primary root length (PRL), dry weights (shoot, root and nodule), number of nodules per plant (NNP) and grain yield components such as the number of pods per plant (NPP) and number of seeds per pod (NSP) were measured. Highly significant (P≤0.01) dose effects were observed for SHT, PRL, shoot dry weight (SDW) and root dry weight (RDW). Highly significant (P≤0.01) interaction effects of mutant generation x genotype x dose were observed for NSP. A highly significant (P≤0.01) positive linear relationship was observed between the NNP and nodule dry weight (NDW). Increase in the PRL suggested that tepary bean mutants could be important in drought tolerance. EMS treatment led to an enhanced partitioning of dry matter (assimilates) to the shoots and roots. There was a three fold increase in most of the root nodulation traits at the 0.5% EMS dose.The Kjeldahl method was used for crude protein determination whereas the sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS PAGE) was utilized in determining the protein banding patterns of the bean. There were highly significant (P≤0.01) differences among the genotypes in crude protein accumulation. Highly significant (P≤0.01) mutant generation x genotype x dose were observed for seed protein accumulation. ‘Genotype 3’ attained the highest protein content (24.23%) at 1.5% EMS dose in the M4 generation. EMS doses ≥0.5% positively stimulated protein accumulation in all genotypes but high EMS doses (2.0%) depressed protein content. There were significant variations in seed storage protein profiles among the genotypes and mutant generations. ‘Genotype 6’ showed a distinct 15.0kDa protein fragment which was absent in the majority of the remaining genotypes. The presence of distinct protein subunits in the three genotypes could be used in varietal / NRF

Traditional peoples are often described as "stewards of agricultural diversity", yet little research has been conducted on the determinants of agrodiversity. This thesis focuses on agrodiversity and how peasant farmers build and maintain cultivated plant diversity in home gardens found in three distinct traditional communities along the Maranon river in the Peruvian Amazon---an upland mixed agricultural village, a lowland agricultural village, and a lowland fishing village. Data were gathered through household surveys (n = 192) and in-depth interviews (n = 112). Substantial variation in cultivated plant diversity was found among and within villages. Residents with the highest home garden agrodiversity tend to be among the wealthier households, and are more likely to have both established their own garden, and tended it for longer periods. Complex planting material exchange networks underlie the establishment and maintenance of home garden agrodiversity. The results underscore the importance of studying local variations in agricultural diversity, and exchange networks that bring agricultural planting stock to peasant farmers.

Agrobiodiversity constitutes an essential resource for traditional rural populations. Home gardens are "hotspots" of agrobiodiversity and important loci of in situ conservation efforts. This study seeks to understand the factors affecting gardeners' choices and to assess the accessibility of planting material in rural communities of the Peruvian Amazon. Household surveys and garden inventories conducted in 15 villages of the Corrientes river (n = 300), and case studies in three of these villages (n = 89), allowed to describe the local and regional patterns of garden agrobiodiversity and the structure of planting material exchange networks. Analyses reveal a strong link between species diversity and both household cultural and socioeconomic characteristics, and village ethnicity and size. Planting material flows primarily through matrilineal bonds, from advice-givers to advice-seekers, from old to young and from rich to poor. Farmers with exceptional species diversity, propensity to give and/or expertise are identified and their role in the conservation of cultivated plants is assessed. Expertise is not found to be as closely related to high species diversity as expected, but knowledge and planting stock dissemination go hand-in-hand.

No description available.

No description available.