Submitted by (edna.saturno@ufrpe.br) on 2017-03-17T15:56:06Z No. of bitstreams: 1 Amanda Ferreira de Lima.pdf: 377887 bytes, checksum: fd40358a75475fdcdaedd3f5aa3cd8bc (MD5) / Made available in DSpace on 2017-03-17T15:56:06Z (GMT). No. of bitstreams: 1 Amanda Ferreira de Lima.pdf: 377887 bytes, checksum: fd40358a75475fdcdaedd3f5aa3cd8bc (MD5) Previous issue date: 2009-07-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The morphogenic characteristics of Panicum maximum Jacq. clones were evaluated during the regrowth period under water stress. The experiment was carried out in a greenhouse at the Animal Science Department - UFRPE, from March to September 2008. Samples collected in the of Sergipe state, municipalities of Pernambuco (São José da Coroa Grande, São Bento do Una and Itambé) and the Mombaça, Tanzania and Massai cultivars were evaluated. The seedlings were transplanted to experimental pots and fertilized with limestone and nitrogen. Two standardization cuts were performed and 27 days after the 2nd cut the clones were submitted to water stress. The establishment period until the application of water stress lasted 27 days. The experimental treatments were of 7, 14, 21 and 28 days without irrigation in order to evaluate the morphogenic characteristics in the regrowth period at 2, 4, 6, 8, 10, 12 and 14 days. A completely randomized design as a 4 x 7 (four periods of water stress x seven clones) factorial arrangement was used. Seven evaluations were performed in alternated days during the regrowth period. Estimates of plant height, leaf blade length, number of emerging green leaves, number of dead leaves and total number of tiller were the morphogenic characteristics evaluated during the regrowth period. Clone means were submitted to Tukey test at 5% of probability. Number of tillers, leaf blade length, plant height, number of dead leaves and number of green leaves were submitted to the analysis of variance in a repeated measure model within each stress period. No significant effect on clone regrowth under water stress from 7 to 28 days was detected. The highest water stress level favor the plant development after cutting. / Objetivou-se avaliar as características morfogênicas de clones de Panicum maximum Jacq. durante o período de rebrote após períodos de suspensão hídrica. O experimento foi realizado no Telado do Departamento de Zootecnia da UFRPE, no período de março a setembro de 2008. Foram avaliados materiais coletados nos municípios de Sergipe, São José da Coroa Grande, São Bento do Una e Itambé e os cultivares Mombaça, Tanzânia e Massai. As mudas foram transplantadas para vasos com capacidade para 7,5kg, preenchidos com solo previamente destorroado e corrigido, na proporção de 2 t/ha, fevereiro de 2008. Realizou-se adubação nitrogenada, na proporção de 50 kg/ha, em abril de 2008. Após o período de estabelecimento foram aplicados os períodos de suspensão hídrica. Foram realizados dois cortes de uniformização e 27 dias após o 2o corte os clones foram submetidos à suspensão hídrica. O período de estabelecimento até a aplicação dos períodos de estresse durou 37 dias. Os tratamentos experimentais constaram de submeter os clones a períodos de suspensão hídrica (sete, quatorze, vinte e um e vinte e oito dias sem irrigação) e avaliar as características morfogênicas no período de rebrota. O delineamento experimental utilizado foi o inteiramente casualizado, em um arranjo fatorial quatro x sete. Foram realizadas sete avaliações em dias alternados no período de rebrote. As variáveis estudadas foram altura da planta, comprimento da lâmina foliar, número de folhas verdes em expansão, número de folhas mortas e número total de perfilhos. Para comparação entre médias de clones utilizou-se o teste Tukey, a 5% de probabilidade. A rebrota dos clones avaliados pouco diferenciam após níveis de suspensão hídrica de 7 a 28 dias. O maior nível de suspensão hídrica avaliado favorece o desenvolvimento da planta após o corte.

Orientadores: Anete Pereira de Souza, Liana Jank / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T03:40:20Z (GMT). No. of bitstreams: 1 Toledo-Silva_Guilherme_D.pdf: 25638879 bytes, checksum: 40fca686426836cea01016a242b64c84 (MD5) Previous issue date: 2013 / Resumo: No Brasil, a pecuária bovina é baseada principalmente na utilização de pastagens cultivadas para alimentação animal. A espécie Panicum maximum Jacq., popularmente conhecida no Brasil como capim colonião, encontra-se entre as espécies mais utilizadas na alimentação do gado de corte. Grande parte das áreas destinadas a pastagens encontra-se estabelecida com cultivares exóticas e de reprodução clonal. O monocultivo representa sério risco para todos os sistemas de produção baseados no uso de pastagens. Nesse sentido, o melhoramento genético de forrageiras e o lançamento de novas cultivares de P. maximum surgem como alternativa para a diversificação das pastagens. O presente trabalho teve como objetivo principal contribuir para o conhecimento básico sobre a genética e a biologia molecular de P. maximum. Primeiramente, foi realizada a montagem de novo e análise do transcriptoma da espécie utilizando a metodologia de sequenciamento massivo paralelo de cDNA (RNA-seq), resultando em 38.192 unigenes, os quais foram anotados em diferentes bancos de dados. A maioria dos genes relacionados as vias de fixação de carbono C4 e de síntese de lignocelulose foram identificados. Ainda, foram identificados 5.035 marcadores microssatélites (SSR) e 346.456 marcadores do tipo single nucleotide polymorphism (SNP) em todo o transcriptoma. Na segunda parte deste trabalho, foram desenvolvidos 131 novos marcadores moleculares do tipo microssatélite para P. maximum. Estes marcadores foram utilizados juntamente a 43 marcadores SSR obtidos da literatura, para construção de mapas genético-moleculares, através da genotipagem dos híbridos F1 resultantes de cruzamento intraespecífico. Os mapas de ligação cobriram 672,2 cM e 802,2 cM dos genomas dos genitores S10 e Mombaça. Estes resultados contribuem para a pesquisa associada a P. maximum e forrageiras tropicais, assim como para os programas de melhoramento genético / Abstract: In Brazil, livestock feeding is mainly based on cultivated pastures. Panicum maximum Jacq., also known as capim-colonião, figures among the most cultivated tropical forage plants in brazilian pastures, which are established with exotic cultivars of clonal reproduction, leading to monoculture, and consequently offering serious risks to associated production systems. One possible solution to monoculture falls on new cultivars releases, throught breeding programs, diversificating livestock pastures in Brazil. The work presented here had an objective of elucidate some basic aspects regarding the genetics and molecular biology of P. maximum. First, we conducted a de novo assembly and analysis of leaf transcriptome, throught massive parallel cDNA sequencing (RNA-seq), resulting in 38.192 unigenes, which were annotated in different databases. Genes related to C4 metabolism and lignocellulose synthesis are valuable resource to breeding programs and were identified among assembled transcripts. Thus, several putative molecular markers were located in unigenes: 5.035 microsatellites (SSR) motifs and 346.456 single nucleotide polymorphism (SNP) positions. Also, we developed 131 new genomic and expressed SSR markers for P. maximum. These markers were used with 43 published SSR markers to develop a genetic map. A segregating F1 population were used for such, hybrids of S10 (sexual genotype) and Mombaça (apomictic genotype) crossing. Linkage maps covered 672,2 cM and 802,2 cM of parentals genomes respectively, using 88 and 96 markers each. Results presented in this work contributes to P. maximum and tropical grasses related research and breeding programs / Doutorado / Genetica Vegetal e Melhoramento / Doutor em Genetica e Biologia Molecular

The population in the high mountains of the northwest provinces of Vietnam belongs to the poorest population in the country. Among the reasons behind this are the high frequency of minority groups in the region and the infertile soils of the steep slopes. As a result of the diversified elevation in northwest Vietnam, farmers are forced to cultivate fields with a gradient of more than 25 %. Additionally, the heavy rainfall events in the region increase the runoff, which is the main mechanism in erosion. Erosion leads to loss of bulk soil, and large losses of plant nutrients. In addition to erosion, nutrient leakage also occurs especially where a surplus of nutrients is applied. This is often the case when fertilizers are not applied with care. Nutrients are a limiting factor within agriculture, and with better nutrient management, the yield, and thus the farmers' economy, increases.The overall aim of this study was to locate and quantify sources and sinks of nutrients within the ten chosen farms. To achieve this aim, two specific objectives were researched. The first objective was to quantify the farm gate balance to get an overall idea of nutrient surplus and deficit and environmental risks. The second objective was to quantify and map out the internal flows i.e the field balances and the nutrients lost during manure storage. This will help locate sources and sinks of nutrients within each farm. Additionally, it will show if the grass strips help absorb nutrients lost through erosion.The study was carried out in Mai Son District in Son La Province in northwest Vietnam. The data was mainly collected through interviews with farmers on ten farms in the study area, as well as observations made during the field visit. Five farms with cows were chosen, while five farms had no cows. The farms mainly grew maize, longan, mango, and forage grass. Additionally, analyses were made on the nitrogen, phosphorous and potassium concentration in the compost, and the nitrogen concentration of the Guinea grass (Panicum maximum Jacq) which made up the grass-strips in the sloping land. The analysis of Guinea leaves was made to calibrate the SPAD-meter used in the field to gather nitrogen-values of the grass strips in the fields.The calculated balances indicated that the elements N, P and K on each farm varied between 32 to 580 kg/ha/year for N, -680 (16) to 53 kg/ha/year for P and -130 to 220 kg/ha/year for K. It also showed that Guinea grass, when grown along the contour lines, did as anticipated; absorb excess nutrients from the soil. However, the result shows that the forage grass mines the soil from potassium. Finally, the result showed that the farmers seem to over fertilize the plants. When estimating the nutrient lost from manure storage, the calculation showed significant losses of both nitrogen, phosphorus, and potassium during storage.The result of the study shows that the handling of manure, choice of compost or mineral fertilizer and fodder and use of grass strips on the farms affects the nutrient loss within the farm. It also shows that a system with forage grass on the contour is, above all, effective when used on farms with grass eating animals as the farmers otherwise don’t harvest the grass.