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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

Avaliação do condicionamento fisiológico e aplicação de fósforo em sementes de milheto / Physiological conditioning and phosphorous application on pearl millet seeds

Peske, Fabrício Becker 17 November 2011 (has links)
Apesar das diversas aptidões de uso do milheto (Pennisetum glaucum (L.) R. Br.), como forragem para pastoreio ou silagem, cobertura do solo e alimentação humana, alguns fatores são limitantes para a expansão do cultivo dessa espécie no Brasil e um dos agravantes é a qualidade física e fisiológica das sementes comercializadas. Assim, este trabalho visou aplicar as técnicas de condicionamento fisiológico, peletização e incorporação de fósforo às sementes para favorecer a implementação e o desenvolvimento da cultura em campo. O experimento envolveu sementes do cultivar BRS 1501, representadas por três lotes, com condicionamento envolvendo água e soluções de PEG6000, enquanto que a peletização foi testada inicialmente com adesivos (PVA, PVP k30, bentonita e Metil celulose) e diferentes produtos em pó com base inerte ou fosforada. As avaliações consistiram de testes físicos iniciais, testes fisiológicos por seis meses de armazenamento, desenvolvimento das plantas em campos com diferentes disponibilidades de fósforo no solo e avaliações químicas de fósforo total e fosfatase ácida em plântulas e plantas de milheto. Não há diferemça significativa na germinação das sementes e emergência das plântulas originadas de sementes pré condicionadas. A peletização das sementes é uma alternativa viável para alteração do volume das sementes sem alterar seu desempenho fisiológico. Em relação à incorporação de fósforo ao pélete das sementes, há efeito significativo no desenvolvimento das plântulas, assim como para a absorção deste macronutriente. Por outro lado, há impacto significativo de materiais e doses específicas sobre a qualidade fisiológica das sementes, principalmente do fosfato bicálcico. / Beside the many aptitudes of the pearl millet (stock feeding, hay, soil layer protection and food in general), some factors limit its expansion in Brazil, being generally, the low physical and physiological seed quality on the market as one of the harshest problems. Thus, this study aimed at applying physiologic conditioning techniques, pelleting and phosphorus application on seeds to improve seedling emergence and crop development in the fields. The experiment used 3 seed lots of BRS 1501 cv, with water and osmotic solution conditioning, while pelleting was tested with 4 different binders (PVA, PVP k30, bentonite and Methil celulose) and different inert and phosphorate powder products. The evaluations consisted of initial phisical tests, followed by physiological tests for 6 months of storage, Field development under 2 different phosphorus soil content and, chemical evaluations as total P content and acid phosphate on pearl millet seedlings and plants. The results show no significant difference on the seedling emergence and germination of physiological conditioned seeds. The seed pelleting was effective on improving seeds volume without harming seed physiologic performance. Regarding phosphorous incorporation through seed pellet, the results show significant effects on the seedling development, as well as it´s absorption. However, with significant impact of specific materials and quantities on the seeds physiologic performance, especially with Bicalcic phosphate.
2

Avaliação do condicionamento fisiológico e aplicação de fósforo em sementes de milheto / Physiological conditioning and phosphorous application on pearl millet seeds

Fabrício Becker Peske 17 November 2011 (has links)
Apesar das diversas aptidões de uso do milheto (Pennisetum glaucum (L.) R. Br.), como forragem para pastoreio ou silagem, cobertura do solo e alimentação humana, alguns fatores são limitantes para a expansão do cultivo dessa espécie no Brasil e um dos agravantes é a qualidade física e fisiológica das sementes comercializadas. Assim, este trabalho visou aplicar as técnicas de condicionamento fisiológico, peletização e incorporação de fósforo às sementes para favorecer a implementação e o desenvolvimento da cultura em campo. O experimento envolveu sementes do cultivar BRS 1501, representadas por três lotes, com condicionamento envolvendo água e soluções de PEG6000, enquanto que a peletização foi testada inicialmente com adesivos (PVA, PVP k30, bentonita e Metil celulose) e diferentes produtos em pó com base inerte ou fosforada. As avaliações consistiram de testes físicos iniciais, testes fisiológicos por seis meses de armazenamento, desenvolvimento das plantas em campos com diferentes disponibilidades de fósforo no solo e avaliações químicas de fósforo total e fosfatase ácida em plântulas e plantas de milheto. Não há diferemça significativa na germinação das sementes e emergência das plântulas originadas de sementes pré condicionadas. A peletização das sementes é uma alternativa viável para alteração do volume das sementes sem alterar seu desempenho fisiológico. Em relação à incorporação de fósforo ao pélete das sementes, há efeito significativo no desenvolvimento das plântulas, assim como para a absorção deste macronutriente. Por outro lado, há impacto significativo de materiais e doses específicas sobre a qualidade fisiológica das sementes, principalmente do fosfato bicálcico. / Beside the many aptitudes of the pearl millet (stock feeding, hay, soil layer protection and food in general), some factors limit its expansion in Brazil, being generally, the low physical and physiological seed quality on the market as one of the harshest problems. Thus, this study aimed at applying physiologic conditioning techniques, pelleting and phosphorus application on seeds to improve seedling emergence and crop development in the fields. The experiment used 3 seed lots of BRS 1501 cv, with water and osmotic solution conditioning, while pelleting was tested with 4 different binders (PVA, PVP k30, bentonite and Methil celulose) and different inert and phosphorate powder products. The evaluations consisted of initial phisical tests, followed by physiological tests for 6 months of storage, Field development under 2 different phosphorus soil content and, chemical evaluations as total P content and acid phosphate on pearl millet seedlings and plants. The results show no significant difference on the seedling emergence and germination of physiological conditioned seeds. The seed pelleting was effective on improving seeds volume without harming seed physiologic performance. Regarding phosphorous incorporation through seed pellet, the results show significant effects on the seedling development, as well as it´s absorption. However, with significant impact of specific materials and quantities on the seeds physiologic performance, especially with Bicalcic phosphate.
3

An evaluation of the germination and establishment of three selected coated grass species in different soil types for rehabilitation / Marguerite Westcott

Westcott, Marguerite January 2011 (has links)
The primary impacts of mining on the environment include the deterioration of soil properties and the loss of vegetation cover and density, often leading to increased erosion. In order to encumber further degeneration of such ecosystems and all subsequent other negative environmental impacts, active rehabilitation practices are often implemented. Active rehabilitation involves the introduction of species by different re–seeding (re–vegetation) methodologies. A higher vegetation cover and density is needed to increase soil quality, combat erosion and contribute to species richness, diversity and ground cover. Several Acts regarding environmental legislation and the conservation of the natural resource in South Africa are used to ensure that sustainable development, rehabilitation and effective environmental management of disturbed areas are enforced. Legislation therefore provides a measure to prevent pollution and ecological degradation, promotes conservation, secure ecologically sustainable development and the use of natural resources, while promoting justifiable economic and social development. Legislation also enforces and regulates the remediation of disturbed ecosystems, such as the rehabilitation of mine tailing areas. Some of this legislation mentioned above is described in the thesis. Species selected for the compilation of seed mixtures for re–seeding and re–vegetation purposes should comply with the standards determined by the regional biodiversity framework where the disturbed area is situated. Only seed of species with non–invasive potential, that are adapted to the specific environmental conditions and have specific genetic traits, should be included in the seed mixture for rehabilitation. Since seed from local ecotype species are often not available, seed companies use seed from especially grass species that might be adapted to the environmental conditions and type of disturbance or degradation to help remediate the poor soil conditions and improve the vegetation cover. The problem is that if the morphological and physiological aspects of the seed type have not been researched properly, it may lead to poor germination and establishment results when used for the rehabilitation of certain degraded and disturbed areas, such as rangelands or mine tailings. Advance Seed Company tries to enhance seed by adding a coating around the caryopsis (grass seed) for better germination and establishment rates. Such seeds are then referred to as “enhanced” or “coated” seed. The term “seed” will be used throughout the dissertation to describe the whole, intact caryopsis (e.g. Anthephora pubescens). The coatings normally refer to the physical enhancements of the seeds by the application of a water–soluble lime–based coating, which may contain nutrients, fungicides, pesticides and other polymers. This study focused on the evaluation of the germination– and establishment rates in four soil types (growth mediums), as well as the activity of three growth enzymes on coated seed of three grass species, namely Anthephora pubescens, Cynodon dactylon and Panicum maximum. Advanced Seed Company provided the seeds for the three selected grass species that were coated with their newly developed certified formulae. Experimental trails were carried out in the laboratory and greenhouses (controlled conditions) at the North West University and in the field (uncontrolled conditions) at the four locations representing the different soil types, namely the clayey and sandy soils at Taaibosbult near Potchefstroom and the platinum (alkaline growth medium) and gold mine tailings (acidic growth medium) near Rustenburg and Stilfontein respectively. Detailed soil analysis was carried out by certified soil laboratories in Potchefstroom and seed purity, viability and quality determined by the Plant Protection Institute in Pretoria. The results from the greenhouse and the field trials differed significantly for all seed types (coated and uncoated) of the three grass species in the four soil types. The germination and establishment rates in both the greenhouse (controlled conditions) and field (uncontrolled conditions) trials were overall very low. The latter can also be ascribed to the competition with other weed species that were present in the soil seed bank before re–seeding, as well as the predation by ants and guinea fowls in especially the field trials of the sandy and clayey soils. Due to the absence of competition in the field trials on the mine tailings, the germination and establishment rates were higher for most grass species. The quality of the seed batches as supplied by Advance Seed Company was not very good. Although the purity was high, many dead seeds were found, especially for Panicum maximum. The germination and establishment rates of Antephora pubescens of the uncoated seed was higher in the sandy, platinum and gold mine tailings soil types in both the uncontrolled field and controlled greenhouse trials and low for both seed types (coated and uncoated) in the clayey soils. Cynodon dactylon had higher germination and establishment rates for especially the gold mine tailings soil in the field trials for both seed types, as well as the sandy soils under controlled conditions in the greenhouse. Both rates were lower in the sand– and clayey soils field trials. The germination rates for Panicum maximum for both seed types were similar for the clay and sandy soil types, but very low in the soils from the mine tailings, especially under controlled conditions in the greenhouse trials. The germination and establishment rates for both seed types of this species were however much higher in the field trials at both the gold and platinum mine tailings, mainly due to the absence of competition. No results for Panicum maximum were obtained from the field trials on the clay soils due to management and maintenance problems. The peroxidise enzyme activity was higher in the coated seed of Antephora pubescens, but lower in both seed types of Cynodon dactylon and Panicum maximum. The alpha amylase enzyme activity was high in the coated seed of Antephora pubescens and both seed types of Panicum maximum, but low in both seed types of Cynodon dactylon. The activity of the lipoxygenase enzyme was higher in all the coated seed of all three grass species that were used in this study. It also appears as if the storage period played a significant role in the germination of the species, especially after and during the seed coating process, as it had a negative effect on the physiology of the seed. In all species, a higher rate of gaseous exchange was observed in the uncoated seed types. However, the water content of the seed types differed between the seed types. Depending on the size and the genetic characteristics of the species, the longevity of the enzyme proteins differed. This is especially observed in the enzyme activity of three enzymes tested, i.e. lipoxygenase, peroxidase and alpha–amylase. The germination rate only improved shortly after being coated and then declined steadily. The germination capacity therefore depends on the length of the storage period. The genetic adaptation of the different species coincided with the four soil types. It is therefore recommended that only species that are adapted to a certain soil type is used in rehabilitation and if the seed is coated, it should be sown shortly after the coating process and not be stored for long periods. It is also recommended to first treat the area with herbicide before any re–seeding takes place, especially if low concentrations of seeds are used. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.
4

An evaluation of the germination and establishment of three selected coated grass species in different soil types for rehabilitation / Marguerite Westcott

Westcott, Marguerite January 2011 (has links)
The primary impacts of mining on the environment include the deterioration of soil properties and the loss of vegetation cover and density, often leading to increased erosion. In order to encumber further degeneration of such ecosystems and all subsequent other negative environmental impacts, active rehabilitation practices are often implemented. Active rehabilitation involves the introduction of species by different re–seeding (re–vegetation) methodologies. A higher vegetation cover and density is needed to increase soil quality, combat erosion and contribute to species richness, diversity and ground cover. Several Acts regarding environmental legislation and the conservation of the natural resource in South Africa are used to ensure that sustainable development, rehabilitation and effective environmental management of disturbed areas are enforced. Legislation therefore provides a measure to prevent pollution and ecological degradation, promotes conservation, secure ecologically sustainable development and the use of natural resources, while promoting justifiable economic and social development. Legislation also enforces and regulates the remediation of disturbed ecosystems, such as the rehabilitation of mine tailing areas. Some of this legislation mentioned above is described in the thesis. Species selected for the compilation of seed mixtures for re–seeding and re–vegetation purposes should comply with the standards determined by the regional biodiversity framework where the disturbed area is situated. Only seed of species with non–invasive potential, that are adapted to the specific environmental conditions and have specific genetic traits, should be included in the seed mixture for rehabilitation. Since seed from local ecotype species are often not available, seed companies use seed from especially grass species that might be adapted to the environmental conditions and type of disturbance or degradation to help remediate the poor soil conditions and improve the vegetation cover. The problem is that if the morphological and physiological aspects of the seed type have not been researched properly, it may lead to poor germination and establishment results when used for the rehabilitation of certain degraded and disturbed areas, such as rangelands or mine tailings. Advance Seed Company tries to enhance seed by adding a coating around the caryopsis (grass seed) for better germination and establishment rates. Such seeds are then referred to as “enhanced” or “coated” seed. The term “seed” will be used throughout the dissertation to describe the whole, intact caryopsis (e.g. Anthephora pubescens). The coatings normally refer to the physical enhancements of the seeds by the application of a water–soluble lime–based coating, which may contain nutrients, fungicides, pesticides and other polymers. This study focused on the evaluation of the germination– and establishment rates in four soil types (growth mediums), as well as the activity of three growth enzymes on coated seed of three grass species, namely Anthephora pubescens, Cynodon dactylon and Panicum maximum. Advanced Seed Company provided the seeds for the three selected grass species that were coated with their newly developed certified formulae. Experimental trails were carried out in the laboratory and greenhouses (controlled conditions) at the North West University and in the field (uncontrolled conditions) at the four locations representing the different soil types, namely the clayey and sandy soils at Taaibosbult near Potchefstroom and the platinum (alkaline growth medium) and gold mine tailings (acidic growth medium) near Rustenburg and Stilfontein respectively. Detailed soil analysis was carried out by certified soil laboratories in Potchefstroom and seed purity, viability and quality determined by the Plant Protection Institute in Pretoria. The results from the greenhouse and the field trials differed significantly for all seed types (coated and uncoated) of the three grass species in the four soil types. The germination and establishment rates in both the greenhouse (controlled conditions) and field (uncontrolled conditions) trials were overall very low. The latter can also be ascribed to the competition with other weed species that were present in the soil seed bank before re–seeding, as well as the predation by ants and guinea fowls in especially the field trials of the sandy and clayey soils. Due to the absence of competition in the field trials on the mine tailings, the germination and establishment rates were higher for most grass species. The quality of the seed batches as supplied by Advance Seed Company was not very good. Although the purity was high, many dead seeds were found, especially for Panicum maximum. The germination and establishment rates of Antephora pubescens of the uncoated seed was higher in the sandy, platinum and gold mine tailings soil types in both the uncontrolled field and controlled greenhouse trials and low for both seed types (coated and uncoated) in the clayey soils. Cynodon dactylon had higher germination and establishment rates for especially the gold mine tailings soil in the field trials for both seed types, as well as the sandy soils under controlled conditions in the greenhouse. Both rates were lower in the sand– and clayey soils field trials. The germination rates for Panicum maximum for both seed types were similar for the clay and sandy soil types, but very low in the soils from the mine tailings, especially under controlled conditions in the greenhouse trials. The germination and establishment rates for both seed types of this species were however much higher in the field trials at both the gold and platinum mine tailings, mainly due to the absence of competition. No results for Panicum maximum were obtained from the field trials on the clay soils due to management and maintenance problems. The peroxidise enzyme activity was higher in the coated seed of Antephora pubescens, but lower in both seed types of Cynodon dactylon and Panicum maximum. The alpha amylase enzyme activity was high in the coated seed of Antephora pubescens and both seed types of Panicum maximum, but low in both seed types of Cynodon dactylon. The activity of the lipoxygenase enzyme was higher in all the coated seed of all three grass species that were used in this study. It also appears as if the storage period played a significant role in the germination of the species, especially after and during the seed coating process, as it had a negative effect on the physiology of the seed. In all species, a higher rate of gaseous exchange was observed in the uncoated seed types. However, the water content of the seed types differed between the seed types. Depending on the size and the genetic characteristics of the species, the longevity of the enzyme proteins differed. This is especially observed in the enzyme activity of three enzymes tested, i.e. lipoxygenase, peroxidase and alpha–amylase. The germination rate only improved shortly after being coated and then declined steadily. The germination capacity therefore depends on the length of the storage period. The genetic adaptation of the different species coincided with the four soil types. It is therefore recommended that only species that are adapted to a certain soil type is used in rehabilitation and if the seed is coated, it should be sown shortly after the coating process and not be stored for long periods. It is also recommended to first treat the area with herbicide before any re–seeding takes place, especially if low concentrations of seeds are used. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.
5

Physiological and molecular studies during acquisition of longevity in soybean (Glycine max (L.) Merrill) seeds / Estudos fisiológicos e moleculares durante a aquisição da longevidade em sementes de soja (Glycine max)

Lima, Juliana Joice Pereira [UNESP] 29 April 2016 (has links)
Submitted by JULIANA JOICE PEREIRA LIMA null (julianajoicelima@yahoo.com.br) on 2016-06-28T20:01:19Z No. of bitstreams: 1 Final_version_UNESP com ficha.pdf: 2890371 bytes, checksum: 99c3a37a64a79be1ed5e60fb7720deb9 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-29T18:48:22Z (GMT) No. of bitstreams: 1 lima_jjp_dr_bot_par.pdf: 731237 bytes, checksum: 6b7a35a2397a27e5b7522bcee2cf6435 (MD5) / Made available in DSpace on 2016-06-29T18:48:22Z (GMT). No. of bitstreams: 1 lima_jjp_dr_bot_par.pdf: 731237 bytes, checksum: 6b7a35a2397a27e5b7522bcee2cf6435 (MD5) Previous issue date: 2016-04-29 / Item withdrawn by Maria Lucia Martins Frederico null (mlucia@fca.unesp.br) on 2018-10-09T12:55:09Z Item was in collections: Teses - Agronomia (Agricultura) - FCA (ID: 320) No. of bitstreams: 3 lima_jjp_dr_bot_par.pdf.jpg: 3708 bytes, checksum: f4776b7545f49e0381732de6fe127643 (MD5) lima_jjp_dr_bot_par.pdf.txt: 70796 bytes, checksum: a8b790348c0cd59ac464aff1569d634a (MD5) lima_jjp_dr_botfca.pdf: 2807174 bytes, checksum: 00e8dea3c713cb320435c39d6d97bae6 (MD5) / Item reinstated by Vivian Rosa Storti null (vstorti@reitoria.unesp.br) on 2018-10-10T14:33:51Z Item was in collections: Teses - Agronomia (Agricultura) - FCA (ID: 320) No. of bitstreams: 3 lima_jjp_dr_bot_par.pdf.jpg: 3708 bytes, checksum: f4776b7545f49e0381732de6fe127643 (MD5) lima_jjp_dr_bot_par.pdf.txt: 70796 bytes, checksum: a8b790348c0cd59ac464aff1569d634a (MD5) lima_jjp_dr_botfca.pdf: 2807174 bytes, checksum: 00e8dea3c713cb320435c39d6d97bae6 (MD5) / Item reinstated by Vítor Silvério Rodrigues (vitor.s.rodrigues@unesp.br) on 2018-11-06T19:07:52Z Item was in collections: Teses - Agronomia (Agricultura) - FCA (ID: 320) No. of bitstreams: 5 lima_jjp_dr_bot_par.pdf.jpg: 3708 bytes, checksum: f4776b7545f49e0381732de6fe127643 (MD5) lima_jjp_dr_botfca.pdf.jpg: 4544 bytes, checksum: af481a0bb7992130d84da3a17c3b7c0d (MD5) lima_jjp_dr_bot_par.pdf.txt: 70796 bytes, checksum: a8b790348c0cd59ac464aff1569d634a (MD5) lima_jjp_dr_botfca.pdf.txt: 211012 bytes, checksum: 72d4f897af91998bbeca736aa4fc7e7f (MD5) lima_jjp_dr_botfca.pdf: 2807174 bytes, checksum: 00e8dea3c713cb320435c39d6d97bae6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Le soja est l'une des plus importantes espèces de cultures d'huile utilisée aussi bien en nourriture que dans diverses gammes d'applications industrielles. C'est pourquoi produire des graines vigoureuses est un levier essentiel pour augmenter efficacement de la production de la récolte. La qualité de graine physiologiquement faible, qui est plus à même de se produire sous un environnement tropical, mène à un pauvre établissement des plantes ainsi qu'à une diminution du rendement. La longévité d'une graine est la capacité de celle-ci à survivre à la sécheresse durant de longues périodes et représente une caractéristique importante sur la qualité d'une graine. Ici, l'objectif était d'obtenir une idée sur les mécanismes en régulant l'acquisition progressive de la longévité. En utilisant le séquençage à haut-débit, ARN a été séquencé en sept différentes étapes durant l'acquisition de longévité, générant entre 14 et 38 millions de reads. Ces reads ont été alignés sur les modeles de gene de Glycine max Wm82.a2.v1. Les transcripts différentiellement exprimés (DET) sont corrélée avec l'augmentation de la longévité de la graine. L’analise d’enrichissement via GO de ces DET ont révélé une importante surreprésentation des termes associés à la réponse au stress et traitement et modification de l'ARN. Le processu biologique Photosynthèse était liée à une faible longévité des semences. HSF (heat shock factor) et plusieurs facteurs de transcription associés à la défense biotique (WRKY 3 et NLFX1) sont des gènes candidats dont putative rôle dans la longévité des graines et méritent une caractérisation plus poussée. Nous avons également effectué la détermination de la teneur en sucres solubles non réducteurs, et nous avons observé que l'accumulation de sucres solubles non réducteurs sont liés à l'acquisition de la longévité, mais seulement l’accumulation d’eux ne suffit pas à expliquer la croissance de la longevité. / Soja é uma das mais culturas oleaginosas usadas para alimentação animal e humana bem como para uma larga aplicação industrial. Dada a sua capacidade de fixar nitrogênio atmsférico, é fundamental para o desenvolvimento de uma agricultura sustentável. Produzir sementes altamente vigorosas é a chave para aumentar a eficiência da produção da cultura. Longevidade de semente é a capacidade de sobreviver no estado seco por períodos prolongados e representa uma importante característica de qualidade da semente. Nesta pesquisa o objetivo foi obter insights sobre processos moleculares que regulam a aquisição de longevidade em sementes de soja. Com o sequenciamento de nova geração da Illumina, o RNA foi sequenciado a partir de sete estágios diferentes durante a aquisição de longevidade, gerando entre 14 e 38 milhões de reads. Estes reads foram alinhados com os modelos de genes de Glycine max Wm82.a2.v1 preditos no genoma de soja. Transcritos diferencialmente expressos (DET) foram correlacionados com o aumento da longevidade. Análise de enriquecimento da ontologia do gene daqueles DET revelaram uma siginificante sobre representação de termos associados com resposta a estresse e processamento e modificação de RNA. Processo biológico fotossíntese foi relacionado à baixa longevidade. Heat Shock Factors (HSF) e vários fatores de transcrição associados com resposta a estresse biótico (WRKY e NFXL1) são genes candidatos com possíveis papéis na longevidade de semente e merecem uma caracterização. Também foi determinado o conteúdo de açúcares solúveis não redutores. Foi observado que o acúmulo desses açúcares estão relacionados à aquisição da longevidade, porém somente eles não são suficientes para explicar o ganho da longevidade. / Soybean is one of the most important oil crop species used for food and feed as well as a range of industrial applications. However, producing highly vigorous seeds is a key lever to increase crop production efficiency. Low physiological seed quality, which is more prone to occur under tropical environment, leads to poor stand establishment and decreased in yields. Seed longevity is the ability to survive the dry state for prolonged periods of time and represents an important trait for seed quality. Here, the objective was to obtain insights into the mechanisms regulating the progressive acquisition of longevity. Using Illumina high-throughput sequencing, RNA was sequenced from seven different stages during the acquisition of longevity, generating between 14 and 38 million of reads. These reads were aligned to the Glycine max Wm82.a2.v1 gene model. Differentially expressed transcripts (DET) were correlated with the increase in seed longevity. Transcriptome and GO enrichment analyses of these DET revealed a significant over-representation of terms associated with response to stress and RNA processing and modification. Photosynthesis biological process was related to low seed longevity. HSF and several TF associated with biotic defense (WRKY3 and NLFX1) are candidate genes whose putative role in seed longevity deserve further characterization. We also performed the determination of the content of non-reducing soluble sugars, and we observed that the accumulation of non-reducing soluble sugars are related to acquisition of longevity but only the accumulation of them is not enough to explain the increase in longevity.
6

Tecnologia de sementes de Pachira aquatica Aubl

LIMA, Amanda de Araujo 30 September 2014 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-03-29T12:49:53Z No. of bitstreams: 1 Amanda de Araujo Lima.pdf: 855538 bytes, checksum: 59a4fcb96a7f2232a19479da3c2f4cd6 (MD5) / Made available in DSpace on 2017-03-29T12:49:53Z (GMT). No. of bitstreams: 1 Amanda de Araujo Lima.pdf: 855538 bytes, checksum: 59a4fcb96a7f2232a19479da3c2f4cd6 (MD5) Previous issue date: 2014-09-30 / The experiments were carried out at the Laboratory of Seed Analysis - (LSA) of the Universidade Federal Rural de Pernambuco/Unidade Acadêmica de Garanhuns UFRPE/UAG in Garanhuns-Pernambuco. The fruits and the stakes of Pachira aquatica Aubl. were collected from five mother trees located on the campus of UFRPE/UAG, aiming to evaluate the physiological quality of seeds of P. aquatica subjected to drying, and salt stress, and the influence of plant extracts the rooting of P. aquatica to contribute to scientific and technical knowledge to deploy this new oilseed areas in the state of Pernambuco. The first experiment was conducted with seed drying at temperature of 35 ºC, the following exposure periods of 0 (without drying), 24, 48, 72 and 96 hours; and evaluated the water content, germination, first count and rate of germination rate, length and dry weight of roots and shoots of seedlings. Data were subjected to analysis of variance and regression. The second experiment simulation of salt stress was performed using as solute sodium chloride (NaCl) at concentrations of 0,0 (control); 3,0; 6,0; 9,0; 12,0 and 15,0 dS.m-1 diluted in distilled and deionized water, then the seeds were germinated at temperatures of 25 ºC and 30 ºC. The experimental design was completely randomized, and evaluated the germination percentage, speed of germination, seedling length (root and shoot) and dry mass of shoots. In the third experiment the rooting of P. aquatica immersed in water, immersion in commercial fertilizer Forth®, immersion extract of Salix babylonica (10, 25, 50 and 100%) and immersion in extract of Cyperus rotundus was performed (10, 25, 50 and 100%). Treatments were arranged in completely randomized design, and 60 days after planting the cuttings were conducted evaluations of rooting percentage, number of roots/cuttings, number of shoots, number of leaves, number of cuttings with shoots and dry weight leaves. The seeds of Pachira aquatica species are scattered with very high water content (55%), and a small reduction in value commits physiological quality, allowing the characterization of the seeds of this species as recalcitrant. Increasing the salt concentration in the substrate reduces the germination and seed vigor P. aquatica, especially when the seeds are subjected to a temperature of 25 ºC. P. aquatica seeds are tolerant to salinity, temperature under 30 ºC, with a reduction in seed germination at concentrations above the concentration of 6.0 dS.m-1. The P. aquatica is an easy to root species, the use of commercial fertilizer and phytohormone Forth® not necessary. The application of leaf extracts of Cyperus rotundus and Salix babylonica not a viable alternative in the production of seedlings of P. aquatica. / Os experimentos foram realizados no Laboratório de Análise de Sementes - (LAS) da Universidade Federal Rural de Pernambuco/Unidade Acadêmica de Garanhuns UFRPE/UAG, em Garanhuns-PE. Os frutos e as estacas de Pachira aquatica Aubl. foram coletados de cinco árvores matrizes localizadas na UFRPE/UAG, com o objetivo de avaliar a qualidade fisiológica das sementes de P. aquatica submetidas à secagem, ao estresse salino, e a influência de extratos vegetais no enraizamento das estacas. No primeiro experimento foi realizado à secagem das sementes sob temperatura de 35 ºC, pelos seguintes períodos de exposição: 0 (sem secagem), 24, 48, 72 e 96 horas; e avaliados o teor de água, germinação, primeira contagem e índice de velocidade de germinação (IVG), comprimento e massa seca da raiz e parte aérea das plântulas. No segundo experimento foi realizada a simulação do estresse salino utilizando-se como soluto o cloreto de sódio (NaCl), nas concentrações de 0,0 (controle); 3,0; 6,0; 9,0; 12,0 e 15,0 dS.m-1 diluídas em água destilada e deionizada, posteriormente as sementes foram postas para germinar nas temperaturas de 25 ºC e 30 ºC. O delineamento experimental utilizado foi o inteiramente ao acaso, e foram avaliadas a porcentagem de germinação, IVG, comprimento de plântulas (raiz e parte aérea) e massa seca da parte aérea. O terceiro experimento foi realizado o enraizamento de estacas de P. aquatica imersas em extrato de Salix babylonica e Cyperus rotundus nas concentrações de 0, 10, 25, 50 e 100%, cada, e imersão em fertilizante comercial Forth®. Após 60 dias do plantio das estacas foram realizadas as avaliações de porcentagem de estacas enraizadas, número de raízes/estaca, número de brotações, número de folhas, número de estacas com brotações e massa seca das folhas. As sementes da espécie Pachira aquatica são dispersas com teor de água muito elevado (55%), e uma pequena redução nesse valor compromete sua qualidade fisiológica, permitindo caracterizar as sementes desta espécie como recalcitrantes. O aumento da concentração salina no substrato reduz a germinação e o vigor das sementes de P. aquatica, principalmente quando as sementes são submetidas a temperatura de 25 ºC. As sementes de P. aquatica são tolerantes a salinidade, sob temperatura de 30 ºC, com redução na germinação das sementes em concentrações acima da concentração de 6,0 dS.m-1. A P. aquatica é uma espécie de fácil enraizamento, não sendo necessário o uso de fitohormônio e fertilizante comercial Forth®. A aplicação de extratos de folhas de Cyperus rotundus e de Salix babylonica não se constitui uma alternativa viável na produção de mudas de P. aquatica.
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Ocorrência de populações naturais de Ampelozizyphus amazonicus ducke. e Piper peltatum l. ao longo dos rios Solimões e Amazonas e estratégias de conservação ex situ de germoplasma por técnicas in vitro, temperaturas sub zero e criogênicas

Siqueira, Aldecinei Bastos 11 June 2010 (has links)
Submitted by Alisson Mota (alisson.davidbeckam@gmail.com) on 2015-07-13T18:33:56Z No. of bitstreams: 1 Tese - Aldecinei Bastos Siqueira.pdf: 11876927 bytes, checksum: cf4e6b319286981a71942bf8cef68bc4 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-16T17:25:00Z (GMT) No. of bitstreams: 1 Tese - Aldecinei Bastos Siqueira.pdf: 11876927 bytes, checksum: cf4e6b319286981a71942bf8cef68bc4 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-16T17:33:31Z (GMT) No. of bitstreams: 1 Tese - Aldecinei Bastos Siqueira.pdf: 11876927 bytes, checksum: cf4e6b319286981a71942bf8cef68bc4 (MD5) / Made available in DSpace on 2015-07-16T17:33:32Z (GMT). No. of bitstreams: 1 Tese - Aldecinei Bastos Siqueira.pdf: 11876927 bytes, checksum: cf4e6b319286981a71942bf8cef68bc4 (MD5) Previous issue date: 2010-06-11 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Piper peltatum (Piperaceae) and Ampelozizyphus amazonicus (Rhamnaceae) are species that have important medicinal features proven, for example, the action against malaria. Both are used as medicinal by the Amazonian peoples, and are obtained exclusively by the practice of extraction. These species are not scientifically well-known, and, due to their potential, studies about methodologies for the conservation of genetic resources and the domestication of these species are necessary. The objectives of this study were to locate and characterize, based on field observation and environmental data base, the natural populations of these species along the Amazon River, and developing strategies for conservation of Ampelozizyphus amazonicus and Piper peltatum germplasm by minimum growth techniques and sub-zero and cryogenic temperatures. For in vitro conservation minimum growth techniques were used. The maintenance of P. peltatum microshoots was evaluated under different temperatures (10 °C, 20 °C and 25 °C) and different salts concentrations in MS medium. Microshoots of P. peltatum and Ampelozizyphus amazonicus were subjected to different concentrations of sucrose, mannitol and sorbitol (1%, 2% and 3%). Microshots of P. peltatum were also subjected to culture media with different concentrations of sucrose, mannitol and sorbitol (1%, 2% and 3%) with or without salicylic acid (SA). Seeds conservation of Piper peltatum were evaluated under sub-zero (-20 °C) and cryogenic (-196 °C) temperatures. For seeds preservation under sub-zero temperatures, the seeds were desiccated for 0h, 24h and 48h and maintained for 0, 90 and 180 days in temperature of -20 °C. For cryopreservation, seeds were immersed in liquid Nitrogen for 24h, and stored with or without other cryoprotectors. Field observation and the data base demonstrate that most of sampling areas visited are under anthropic deforestation. The In vitro maintenance of P. peltatum microshoots was more efficient in the temperature of 20 °C. The use of mannitol for conservation in vitro resulted in high mortality rates of the microshoots of both species. In vitro conservation of P. peltatum in function of sucrose, mannitol e sorbitol and different concentrations of SA, the best results are obtained in the absence of AS. Germination rates were satisfactory when the seeds of Piper peltatum were dried for up to 48 hours and stored for up to 180 days at -20 ° C. The seeds were also tolerant to cryopreservation, regardless of the use of cryoprotectants. It is possible the conservation of the species in vitro for up to 180 days by reducing the growth temperature. The addition of mannitol and sorbitol, for the concentrations tested, are inadequate for in vitro conservation of A. amazonicus microshoots. Sorbitol may be used in P. peltatum conservation in concentrations between 1% and 2% in MS medium. Piper peltatum seeds are tolerant to desiccation and exposure to subzero and cryogenic temperatures, suggesting that Piper peltatum seeds are orthodox. / Ampelozizyphus amazonicus Ducke (Rhamnaceae) e Piper peltatum L. (Piperaceae) são espécies que possuem características medicinais importantes comprovadas cientificamente, dentre essas a ação contra a malária. Ambas são usadas como medicinais pelas populações da Amazônia, que as obtêm exclusivamente pela prática do extrativismo. As espécies são pouco conhecidas sob o ponto de vista científico e devido ao potencial que estas apresentam, são necessários estudos a respeito de metodologias para a conservação dos recursos genéticos e domesticação destas espécies. Este trabalho teve por objetivo localizar populações naturais de Ampelozizyphus amazonicus e Piper peltatum ao longo dos rios Solimões e Amazonas, caracterizar por meio de observações nas áreas de coleta e informações de bases de dados as condições ambientais das populações, e desenvolver estratégias para a conservação de germoplasma por técnicas de crescimento mínimo, temperaturas sub zero e criogênicas. Para a conservação in vitro utilizaram-se técnicas de conservação in vitro por crescimento mínimo. Foi avaliada a manutenção de microestacas de Piper peltatum sob diferentes temperaturas (10 °C, 20 °C e 25 °C) e o cultivo em diferentes concentrações dos sais do meio de cultura MS. Microestacas de Ampelozizyphus amazonicus e Piper peltatum foram submetidas a diferentes concentrações de sacarose, manitol e sorbitol (1%, 2% e 3%). Em outro ensaio microestacas de Piper peltatum foram cultivadas em meio de cultura com diferentes concentrações de sacarose, manitol e sorbitol (1%, 2% e 3%) adicionado ou não de ácido salicílico (AS). Foram realizados ensaios de conservação de sementes de Piper peltatum, estas foram submetidas a conservação por temperaturas sub zero (-20 oC) e criogênicas (-196 oC). Para a conservação de sementes sob temperatura sub zero, inicialmente as sementes foram dessecadas por 0h, 24h e 48h e conservadas por 0, 90 e 180 dias, a -20 °C de temperatura. Para a criopreservação, as sementes foram testadas quanto à tolerância a imersão por 24 horas em Nitrogênio líquido (NL) e quanto ao uso ou não de diferentes tipos de crioprotetores. As observações ambientais realizadas e as informações das bases de dados demonstram que a maior parte das áreas de coleta visitadas está sob ação antrópica de desmatamento. A manutenção in vitro de microestacas de Piper peltatum a 20 °C de temperatura foi a mais eficiente na conservação in vitro sob diferentes temperaturas. O uso do manitol para a conservação in vitro resultou no aumento das taxas de mortalidade das microestacas de ambas as espécies estudadas. Para a conservação in vitro de P. peltatum em função da sacarose, manitol e sorbitol e diferentes concentrações de AS, os melhores resultados das culturas sobreviventes são obtidos na ausência de AS. A conservação de sementes de Piper peltatum apresentou taxa de germinação satisfatória quando dessecadas por até 48 horas e conservadas por até 180 dias à -20 °C de temperatura. As sementes foram tolerantes à criopreservação independentemente do uso de crioprotetores. Conclui-se que é possível a conservação in vitro de P. peltatum por até 180 dias pela redução da temperatura de crescimento. A adição de manitol e sorbitol, nas concentrações testadas, são inadequadas para a conservação in vitro de microestacas de A. amazonicus. O sorbitol pode ser usado na conservação de P. peltatum em intervalo de 1% a 2% da concentração adicionado ao meio de cultura de MS. As sementes de Piper peltatum são tolerantes à dessecação e à exposição às temperaturas sub zero e criogênicas, sugerindo que se trata de semente do tipo ortodoxa.

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