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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.
31

Automation of molecular markers in practical breeding of spring barley (Hordeum vulgare L.) /

Dayteg, Christophe, January 2008 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.
32

Produtividade e qualidade fisiológica de sementes de cevada em função da adubação nitrogenada / Productivity and physiological quality of barley seeds as a function of nitrogen fertilization

Jaques, Lanes Beatriz Acosta 27 July 2018 (has links)
Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-10-23T13:16:55Z No. of bitstreams: 1 ok_Dissertação. LANES - Copia.pdf: 1393368 bytes, checksum: 299b1e106186f2d856ee38215a776507 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-11-06T18:51:10Z (GMT) No. of bitstreams: 1 ok_Dissertação. LANES - Copia.pdf: 1393368 bytes, checksum: 299b1e106186f2d856ee38215a776507 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-11-13T15:50:18Z (GMT) No. of bitstreams: 1 ok_Dissertação. LANES - Copia.pdf: 1393368 bytes, checksum: 299b1e106186f2d856ee38215a776507 (MD5) / Made available in DSpace on 2018-11-13T15:50:29Z (GMT). No. of bitstreams: 1 ok_Dissertação. LANES - Copia.pdf: 1393368 bytes, checksum: 299b1e106186f2d856ee38215a776507 (MD5) Previous issue date: 2018-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Na cultura da cevada o nitrogênio é um dos principais nutrientes que influência a qualidade e a produtividade de sementes, pois, participa de inúmeras rotas metabólicas. É um fator limitante da produção, a falta ou o excesso pode trazer consequência a cultura. Este trabalho teve como objetivo avaliar o uso de diferentes doses de adubação nitrogenada, nos parâmetros produtivos e de qualidade fisiológica de duas cultivares de cevada a BRS Brau e BRS Cauê. O experimento foi realizado no município de Alegrete-RS e de Pelotas-RS, no estado do Rio Grande do Sul. O delineamento experimental foi de blocos ao acaso, organizado em esquema fatorial, sendo, 2 x 2 x 4 (ambiente de cultivo x cultivares x doses de nitrogênio), dispostas em quatro repetições, totalizando 32 unidades experimentais. O capítulo I compreendeu a análise de componentes da produtividade de sementes, compostas pelas variáveis de altura da planta, número de perfilhos por planta, número de espigas por metro quadrado, número de sementes por planta, massa de mil sementes e rendimento das sementes. O capítulo II compreendeu a avalição da qualidade fisiológica das sementes por meio dos testes de germinação, primeira contagem da germinação, envelhecimento acelerado, emergência a campo, comprimento da parte aérea e raiz de plântulas, massa seca da parte aérea e de raiz de plântulas, condutividade elétrica (3, 6 e 24 horas) e isoenzimas. No capítulo I os componentes de produtividades foram influenciados pela dose nitrogenada e o ambiente de cultivo, o incremento da dose traz aumentos na produtividade final, a cultivar BRS Cauê produzida em Pelotas-RS obteve o máximo rendimento de sementes, alcançado na dose de 200 kg ha-1. Para a qualidade das sementes no capítulo II o ambiente de cultivo promoveu diferenciação na qualidade fisiológica, comparando-se os locais, o ambiente de Pelotas-RS, resultou na produção de sementes mais vigorosas, resistentes a adversidades climáticas. A utilização de adubação nitrogenada na dose de 120 kg ha-1 resultou na melhor qualidade fisiológica, aliada a cultivar BRS Cauê, em ambos os ambientes estudados. / In barley, nitrogen is one of the main nutrients that influences the quality and productivity of seeds, since it participates in numerous metabolic routes. It is a limiting factor of the production, the lack or the excess can bring consequence to the culture. The objective of this work was to evaluate the use of different doses of nitrogen fertilization in the productive and physiological quality parameters of two barley cultivars BRS Brau and BRS Cauê. The experimental design was a randomized block design, organized in a factorial scheme, being 2 x 2 x 4 (cultivation environment x). The experiment was carried out in the city of Alegrete-RS and Pelotas-RS, state of Rio Grande do Sul. cultivars x doses of nitrogen), arranged in four replicates, totalizing 32 experimental units. Chapter I comprised the analysis of components of seed productivity, composed of plant height, number of tillers per plant, number of ears per square meter, number of seeds per plant, mass of one thousand seeds and seed yield. Chapter II included the evaluation of the physiological quality of the seeds by germination tests, first counting of germination, accelerated aging, field emergence, shoot length and seedling root, dry mass of shoot and root of seedlings, electrical conductivity (3, 6 and 24 hours) and isoenzymes. In chapter I the components of productivities were influenced by the nitrogen dose and the growing environment, the increment of the dose brings increases in the final productivity, the cultivar BRS Cauê produced in Pelotas-RS obtained the maximum yield of seeds, reached in the dose of 200 kg ha-1. For the quality of the seeds in chapter II, the culture environment promoted differentiation in the physiological quality, comparing the locations, the environment of Pelotas-RS, resulted in the production of more vigorous seeds, resistant to climatic adversities. The use of nitrogen fertilization at the dose of 120 kg ha-1 resulted in the best physiological quality, allied to the cultivar BRS Cauê, in both environments studied.
33

Caracterização de proteínas de reserva, perfil de aminoácidos e enzimas envolvidas no metabolismo de lisina em cevada (Hordeum vulgare L.) geneticamente modificada / Characterization of storage proteins, amino acid profile and enzymes involved in lysine metabolism in genetic modified barley (Hordeum vulgare L.)

Daiana Schmidt 16 May 2011 (has links)
Os cereais representam importantes fontes de proteína para alimentação humana e animal. Entretanto, são caracterizados pela baixa qualidade nutricional de suas proteínas devido à composição desbalanceada de aminoácidos, causada pelo excesso dos aminoácidos prolina e glutamina e deficiência de lisina, treonina e triptofano. As proteínas de reserva prolaminas constituem 50% do conteúdo total de proteínas no endosperma e são as principais responsáveis por tais características nos cereais. As informações sobre o metabolismo de lisina e o acúmulo de proteínas de reserva no endosperma vêm sendo utilizadas para desenvolver e aplicar estratégias em programas de melhoramento de plantas que visam suprir a deficiência de lisina encontrada nos cereais. Lange e colaboradores (2007) relataram a produção de linhagens transgênicas de cevada com padrão de proteínas de reserva alterado e que apresentaram incremento no teor de lisina e outros aminoácidos essenciais. O presente trabalho teve como objetivo identificar os mecanismos responsáveis pelas alterações observadas. Para tanto, avaliou-se a atividade das enzimas envolvidas na síntese e degradação de lisina, além da caracterização das proteínas de reserva e sua composição de aminoácidos. Observou-se redução na fração protéica das prolaminas (5,91 a 18,34%) e incrementos compensatórios na fração protéica das glutelinas (2,16 a 6,52%). As demais frações apresentaram respostas variáveis dependendo do evento avaliado. Além disso, a composição de aminoácidos foi alterada nas diferentes frações protéicas. As prolaminas exibiram incrementos nos teores de lisina (1,79 a 49,13%), treonina (5,04 a 22,60%) e metionina (13,57 a 45,38%), enquanto que as globulinas aumentaram principalmente o conteúdo de metionina (32,30 a 142,56%). Para os aminoácidos solúveis, foram observados incrementos na ordem de duas a três vezes de histidina, lisina, fenilalanina e metionina. A análise das enzimas envolvidas no metabolismo de lisina revelou que ocorreram alterações nas três principais enzimas da via do ácido aspártico. A enzima aspartato quinase (AK) apresentou aumentos na atividade (4,44 a 47,27%), entretanto, foi mais sensível a inibição causada por lisina. A enzima dihidrodipicolinato sintase (DHDPS) também apresentou incremento na atividade (1,50 a 66,32%), mas diferente da AK, foi menos sensível à inibição causada por lisina. A enzima homoserina desidrogenase (HSDH), a qual compete o substrato ASA com a enzima DHDPS, exibiu redução na atividade (3,36% a 28,80%) (exceto um evento de transformação) e foi menos sensível a inibição causada por treonina. Embora as enzimas envolvidas na degradação de lisina também foram alteradas, os resultados foram variáveis para os diferentes eventos. Para aqueles que foram observados redução na atividade da enzima lisina cetoglutarato redutase (LOR), foi também verificado para enzima sacaropina desidrogenase (SDH), mas na ordem de duas vezes, sendo válido para aqueles que apresentaram incremento. Este trabalho mostrou que a alteração no padrão de proteínas de reserva ocasionou mudanças no metabolismo de aminoácidos, neste caso a lisina, para suprir a demanda necessária para incorporação em proteínas de reserva / Cereals represent an important source of protein to human food and animal feed. However, they are characterized by low nutritional quality of proteins due to the unbalanced composition of amino acids, caused by the excess of the amino acids proline and glutamine and deficiency of lysine, threonine and tryptophan. The prolamin storage proteins constitute 50% of the total protein content in the endosperm and is primarily responsible for these characteristics in cereals. Information on the metabolism of lysine and accumulation of storage proteins in endosperm have been used to develop and implement strategies in plant breeding programs that aim to address the deficiencies found in cereals. Lange and coworkers (2007) reported the production of transgenic lines of barley with a pattern of storage proteins that showed altered and increase in the levels of lysine and other amino acids. This study aimed to identify what were the mechanisms responsible for observed changes. For this, we evaluated the activity of enzymes involved in synthesis and degradation of lysine, besides the characterization of storage proteins and their amino acid composition. There was a reduction in the prolamin protein fraction (5.91 to 18.34%) and compensatory increases in the glutelin fractions (2.16 to 6.52%). The other fractions had variable responses depending on the event evaluated. Moreover, the amino acid composition was changed in the different protein fractions. Prolamins exhibited increases in levels of lysine (1.79 to 49.13%), threonine (5.04 to 22.60%) and methionine (13.57 to 45.38%), whereas increases were mainly globulins content of methionine (32.30 to 142.56%). With respect to soluble amino acids, increases were observed in the order of 2-3 fold of histidine, lysine, phenylalanine and methionine. Analysis of enzymes involved in lysine metabolism showed that changes in three key enzymes of the pathway of aspartic acid. The enzyme aspartate kinase (AK) showed increase in activity (4.44 to 47.27%), however, was more sensitive to inhibition by lysine. The enzyme dihydrodipicolinate synthase (DHDPS) also showed increased activity (from 1.50 to 66.32%), but unlike the AK, was less sensitive to inhibition by lysine. The enzyme homoserine dehydrogenase (HSDH) that competes for the substrate ASA with the DHDPS, exhibited reduced activity (3.36% to 28.80%) (an exception one transgenic line) and was less sensitive to inhibition by threonine. The enzymes involved in degradation of lysine were also changed, though the results varied for different events. Those who observed decreased activity of the enzyme lysine ketoglutarate reductase (LOR) was also found for enzyme saccharopine dehydrogenase (SDH), but the order of twice, which was valid for those who had increased. This study showed that the change in the pattern of storage proteins produced changes in amino acid metabolism, in this case lysine, to supply the demand needed for incorporation into storage proteins.
34

Quantitative Trait Loci for Resistance to Fusarium Head Blight in the Hulless Winter Barley Cultivar Eve

Ullrich, Jordan Elizabeth 23 May 2017 (has links)
Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is a devastating fungal disease that affects barley production worldwide through damaged kernels, low yields, and production of mycotoxins. The most effective means of control is through the use of FHB resistant cultivars that are developed through gene pyramiding and incorporation of various sources of resistance. Resistance identified in winter barley cultivar Eve has been identified in Virginia Tech's Small Grains Breeding Program. The objectives of this study are to validate resistance and identify additional resistance QTL, and identify tightly linked and diagnostic markers for use in MAS programs. A population of F5:7 RILs derived from the cross Eve/Doyce were evaluated for FHB resistance. FHB incidence (Inc), FHB severity (Sev), Fusarium damaged kernels (FDK), and deoxynivalenol (DON) were assessed over 2014-15 and 2015-16 at Blacksburg, VA, Mount Holly, VA, Kinston, NC, and Lexington, KY. A QTL on chromosome 6H associated with FHB Sev, FDK, and DON was identified. The QTL accounted for as high as 14.5% of the phenotypic variation for DON accumulation, 8.3% for FHB Sev, and 11.87% to 17.63% for FDK. The QTL marker region spans 56.5 to 66.6 cM with flanking markers SCRI_RS_147342 and Bmag0613. QTL for morphological traits, heading date and height, were found in the same region as the FHB resistance traits. Diagnostic SNP makers associated with the FHB resistance QTL identified can be used for FHB resistance identification in MAS breeding programs to incorporate and pyramid resistance QTL and genes into other plant material. / Master of Science
35

Characterization of Hulled and Hulless Winter Barley, Hordeum vulgare L., Through Traditional Breeding and Molecular Techniques

Berger, Gregory Lawrence 28 November 2012 (has links)
Phenotypic and genotypic characterization of hulled and hulless winter barley (Hordeum vulgare L.) is necessary for improvement using traditional and molecular breeding techniques.  Identification of genomic regions conferring resistance to Fusarium head blight (caused by Fusarium graminearum), leaf rust (caused by Puccinia hordei G. Otth), powdery mildew [caused by Blumeria graminis (DC.) E.O. Speer f. sp. hordei Em. Marchal], net blotch (caused by Pyrenophora teres) and spot blotch [caused by Cochliobolus sativus (Ito & Kuribayashi) Drechsler ex Dastur] will greatly aid in breeding for improved resistance.  Determining factors that contribute to yield differences between hulled and hulless genotypes, and identification of markers associated with yield and yield related traits will greatly aid in improvement of hulled and hulless genotypes.  The hulled cultivar Nomini, hulless cultivar Eve, and hulless line VA06H-48 were consistently resistant to Fusarium head blight (FHB) and had low deoxynivalenol (DON) accumulation.  Screening with molecular markers on chromosomes 2H and 6H for FHB and DON identified quantitative trait loci (QTL) which may confer resistance in Virginia Tech germplasm.  Evaluation of hulled and hulless full-sibs from four populations indicated  that  grain volume weight and protein concentration were significantly (P d 0.05) higher for hulless genotypes, while seedling emergence and grain ash concentration were significantly (P d 0.05) higher for hulled genotypes.  In linear regression analysis, none of the assessed traits explained yield variation in all populations and environments.  Identification of hulless genotypes having yield potentials similar to those of their hulled sibs should be possible after adjusting for hull weight.  A genome wide association study was used to identify chromosome regions governing traits of importance in six-rowed winter barley germplasm and to identify single nucleotide polymorphisms (SNPs) markers for use in a marker-assisted breeding program. Significant SNPs associated with previously described QTL or genes were identified for heading date, test weight, yield, grain protein, polyphenol oxidase activity, and resistance to leaf rust, powdery mildew, net blotch, and spot blotch.  Novel QTL also were identified for agronomic, quality, and disease resistance traits.  These SNP-trait associations provide the opportunity to directly select for QTL contributing to multiple traits in breeding programs. / Ph. D.
36

Danos e controle químico da mancha marrom e do oídio da cevada / Damage and chemical control of brown spot and powdery mildew of barley

Agostinetto, Lenita 08 February 2011 (has links)
Made available in DSpace on 2016-12-08T16:44:42Z (GMT). No. of bitstreams: 1 PGPV11MA101.pdf: 1302742 bytes, checksum: b7efc06d336ca4a49c0225d1d0b03cfb (MD5) Previous issue date: 2011-02-08 / The objectives of the work were: a) to obtain the damage function equations for multiple pathosystem to calculate the EDT to time fungicides application; b) to quantify the control and damage of the yield components, and c) To relate the brown spot incidence and severity in different growth stages. The experiments were carry out at the NBN Seeds Company during the 2009 and 2010 crop seasons, located in Muitos Capões county, Rio Grande do Sul state, Brazil and in the Agro science Center at Santa Catarina State University only in 2010. The cultivar BRS Cauê was used as susceptible cultivar to brown spot and powdery mildew. The experiments design was in randomized block with four replications. The nine treatments consisting of different rates (half and recommended rates) and fungicide applications number (one, two, three and four) of mixture strobilurin and triazole fungicides, generating the disease gradients intensity. The total area of 5.0 x 2.5 m was the experimental unit in both experiments. The fungicide applications and incidence and severity assessment were done at EC 22, EC 31, EC 39, EC 45 and EC 56 plant development stages. Plants from central rows of each plot were manually harvested and grain yield (GY), one-thousand grain weight (TGW) and granulometry (G) were evaluated. In the first chapter, the damage function equations between disease intensity and GY for each plant development stages, obtained by regression analysis, in both 2009-10 crop growing seasons were significant and negative indicative that increasing disease severity lead into decreasing grain yield. The damage coefficients of these equations can be used to calculate the economic damage threshold. In the second chapter, the values of disease intensity were used to calculate the area under disease progress curve (AUDPC). The GY, TGW, G and AUDPC values were tested using the mean comparison between treatments and the percentage of damage and disease control were determinated. The largest 2009 crop damage was 45.87%, 15.47% and 25.84% for GY, G and TGW, respectively. The ultimate control was 68.11% when considered the severity and four foliar applications, independent of the used dose. In 2010, the greatest damage were 31.16%, 14.02% and 10.76% in Muitos Capões and 39.44%, 23.59% and 45.88%, in Lages, for GY, 10 TGW and G, respectively. The highest percentage of control, based on the leaf severity were 71.63% and 73.96% for Muitos Capões and Lages, respectively. The greater control, independent of used dose were obtained with three and four applications in Muitos Capões and four applications in Lages. In the third chapter, brown spot incidence and severity data were subjected to regression analysis and correlation and the obtained values were significant and positive. The brown spot and powdery mildew diseases incidence and severity recommended by the Technique Indication of crop (TIC) to initiate fungicide applications is 20% and 5% respectively. The severity average values for initiating chemical control are 0.77% and 0.34% respectively for 2009 and 2010 crop seasons when the incidence diseases were substituted in the equations. These values are lower than TIC recommended values / Os objetivos do trabalho foram: a) obter equações de função de dano para patossistema múltiplo para calcular o LDE servindo como critério indicador de aplicação de fungicidas; b) quantificar controle e dano nos componentes de rendimento; e c) relacionar incidência e severidade foliar da mancha marrom em diferentes estádios fenológicos. Os experimentos foram conduzidos nas safras agrícolas 2009 e 2010 na NBN Sementes no município de Muitos Capões, RS; e, na safra de 2010 no Centro de Ciências Agroveterinárias no município de Lages, SC. Em todos os experimentos foi utilizada a cultivar BRS Cauê suscetível à mancha marrom e oídio. O delineamento foi blocos casualisados, com quatro repetições e nove tratamentos constituídos de diferentes doses (meia dose e dose indicada) e número (uma, duas, três e quatro) de aplicações de fungicidas triazóis e estrobilurinas para gerar os gradientes de intensidade das doenças. A área de cada unidade experimental correspondeu a 5,0 x 2,5 m. As aplicações e as avaliações da incidência e severidade foliar ocorreram nos estádios de crescimento (EC) EC 22, EC 31, EC 39, EC 45 e EC 56. A colheita foi manual cortando as plantas das linhas centrais de cada parcela. Foram avaliados rendimento de grãos (RG), massa de mil grãos (MMG) e granulometria (G). No primeiro capítulo, as equações de função de dano entre intensidade de doença e RG para cada EC, obtidas por análise de regressão, em ambas as safras agrícolas, foram significativas e negativas, ou seja, à medida que aumentou a intensidade de doença, diminuiu o RG. Os coeficientes de dano obtidos podem ser utilizados no cálculo do limiar de dano econômico. No segundo capítulo, os valores de intensidade das doenças foram usados para o cálculo da área abaixo da curva de progresso da doença (AACPD). Os valores de RG, MMG, G e AACPD foram submetidos ao teste de comparação de médias. Foram determinados o percentual de dano e de controle das doenças. Na safra 2009, os maiores danos foram 45,87%, 15,47% e 25,84% para RG, MMG e G, respectivamente. O controle máximo foi 68,11% considerando a severidade foliar e quatro aplicações, independente da dose usada. Em 2010, os maiores danos foram 31,16%, 14,02% e 10,76% em Muitos Capões e 39,44%, 23,59% e 8 45,88% em Lages, respectivamente para R, MMG e G. Com base na severidade obteve-se controle de 71,63% e 73,96% em Muitos Capões e Lages, respectivamente. Em Muitos Capões três e quatro aplicações e em Lages quatro aplicações, independente da dose, apresentaram maior percentual de controle. No terceiro capítulo, os dados de incidência e severidade foliar de mancha marrom foram submetidos à análise de regressão e correlação. As equações obtidas foram significativas e positivas. A incidência e a severidade foliar recomendado pela Indicação Técnica da cultura (ITC) para iniciar as aplicações de fungicidas é de 20% e 5%, respectivamente. Substituindo esse valor de incidência nas equações obtidas têm-se valores médios de severidade para iniciar o controle químico de 0,77% e 0,34% respectivamente para 2009 e 2010, inferior ao recomendado pela ITC
37

Atributos fisiológicos de qualidade de sementes de cevada sobre diferentes épocas de colheita e durante o armazenamento / Physiologic attributes of quality of barley seeds about different harvest periods and during the storage

Tunes, Lílian Vanussa Madruga de 17 January 2009 (has links)
Made available in DSpace on 2014-08-20T13:44:42Z (GMT). No. of bitstreams: 1 dissertacao_lilian_tunes.pdf: 3629520 bytes, checksum: c63e3ee7e985806eda7edeb195ebba76 (MD5) Previous issue date: 2009-01-17 / The barley culture (Hordeum vulgare L.) for the beer production it is constituting in one of the more promising and safe agricultural businesses of the country, because it already comes linked to the commercialization process, by previous contract between the producer and the malt industry. In view of this and of the economical answer in relation to other winter cultures, many producers show interest in the inclusion of the barley in their production systems. The objective of this work was to evaluate physiologic attribute of quality about different harvesting periods of barley seeds and during the storage. The seeds used were of the cultivars MN 721 and Scarlett. Harvesting was accomplished when the plants were with 118, 129 and 140 days after the seeding. The seeds were dried in an oven with forced air circulation, until reaching 13% of moisture and then, stored in a cold room and out of the room. After harvesting different methods were tested for overcoming dormancy. The seeds were put for the germination tests, seedling length, mass dry weight, tetrazolium, accelerated aging, seed emergence, electrical conductivity, weight of a thousand seeds, hectolitric weight and also isoenzimatic diferentitation [malato desidrogenase (MDH), alcohol desidrogenase (ADH), acid fosfatase (FAC), glutamate oxalacetato transaminase (GOT) and esterase (EST)]. The results obtained showed that the intensity of dormancy and harvest periods interferes, directly, in the efficiency of the treatments used for overcoming dormancy. Harvesting should be accomplished when the seeds reach the humidity between 26 and 18%. The weight of a thousand seeds influences in a positive way, demonstrating that heavier seeds presented better quality than the light ones. The hectolitric weight, germination and viability tend to decrease as the harvesting period is delayed. There are variations in the pattern of expression of the enzymes EST, ACP, MDH, ADH and GOT between the seeds and seedlings. In the germination process the enzyme EST showed difference between cultivars MN 721 and Scarlett, however it had small variation in the different harvesting periods. In the germination process the enzyme GOT showed variation in the intensity of bands in the different moisture percentages. During storage it was evaluated the physiologic quality of the seeds, at the 3rd and the 6th months, analyzing two atmospheres (cold room and natural conditions). The results were that, the capacity of conservation of barley seeds it is just according to its initial quality. / A cultura de cevada (Hordeum vulgare L.) para a produção de cerveja vem se constituindo em um dos negócios agrícolas mais promissores e seguros do país, pois já vem vinculado ao processo de comercialização, mediante contrato prévio entre o produtor e a indústria de malte. Em vista disto e da resposta econômica em relação a outras culturas de inverno, muitos produtores mostram interesse na inclusão da cevada em seus sistemas de produção. O objetivo do trabalho foi avaliar atributos fisiológicos de qualidade de sementes de cevada sobre diferentes épocas de colheita e durante o armazenamento. Foram utilizadas sementes das cultivares MN 721 e Scarlett. As sementes foram secadas em estufa com circulação de ar forçado, até atingir 13% de umidade e então, armazenadas em câmara fria e seca e ambiente natural. Após a colheita foram testados diferentes métodos para a superação de dormência. As sementes foram avaliadas pelos testes de germinação, comprimento de plântulas, massa seca, tetrazólio, envelhecimento acelerado, emergência de plântulas, condutividade elétrica, peso de mil sementes, peso hectolítrico e também diferenciação isoenzimática [malato desidrogenase (MDH), álcool desidrogenase (ADH), fosfatase ácida (FAC), glutamato oxalacetato transaminase (GOT) e esterase (EST)]. Dos resultados obtidos, a intensidade da dormência e época de colheita das sementes de cevada interfere, diretamente, na eficiência dos tratamentos utilizados para sua superação. A colheita da cevada deve ser realizada quando as sementes atingirem a umidade entre 26 e 18%. O peso de mil das sementes influi de maneira positiva, demonstrando que sementes mais pesadas apresentaram melhor desempenho que as leves. O peso hectolítrico, a germinação e a viabilidade tendem a decrescer com o processo de retardamento da colheita. Há variações no padrão de expressão das enzimas EST, ACP, MDH, ADH e GOT entre as sementes e as plântulas. No processo de germinação a enzima EST apresentaram diferença entre as cultivares MN 721 e a Scarlett, no entanto teve pequena variação nos diferentes períodos de colheita. No processo de germinação a enzima GOT apresentou variação na intensidade de bandas nas diferentes percentagens de umidade. Durante o armazenamento foram avaliados a qualidade fisiológicas das sementes, por um período de 3 e seis meses, analisando dois ambientes (câmara fria e seca e ambiente em condições naturais). Os resultados encontrados foram que, a capacidade de conservação de sementes de cevada relaciona-se com a sua qualidade inicial.
38

Uso da argila silicatada como fonte de silício na produção de sementes de cereais / Use of silicate clay as a source of silicon in the production of cereal seed

Lima, Bento Alvenir Dornelles de 21 December 2010 (has links)
Made available in DSpace on 2014-08-20T13:44:45Z (GMT). No. of bitstreams: 1 tese_bento_lima.pdf: 352277 bytes, checksum: 068b6ef57c8c5363bd38978cd428f6fa (MD5) Previous issue date: 2010-12-21 / Rio Grande do Sul, which produces a variety of crops being the important cereal rice sown in spring / summer and wheat and barley with high potential for cultivation in the autumn / winter. The state accounts for the increased production of rice (Oryza sativa L.) in Brazil, with an acreage of about one million hectares per year. The wheat (Triticum aestivum L.) is intended for grain production, which are processed into flour for the bakery and pasta, the culture of barley (Hordeum vulgare L.) is intended for grain production, which are transformed malt in the brewing industry. The use of silicon has the potential to reduce the use of agrochemicals and increase productivity through balanced nutrition and physiologically more efficient. Silicate clay is a whitish powder contains 77.9% SiO2 at pH 5.5. This study aimed to evaluate the physiological quality, seed yield in the field of grain treated with silicate clay as a source of silicon. We used two foliar treatments with four applications and on the ground with three doses were: T1 360 kg ha ˉ ¹, T2 720 kg ha ˉ ¹ in four foliar applications on vegetative stages V4, V9 and reproductive R2 and R6 and at sowing T3 360 kg ha ˉ ¹, 720 kg ha T4 and T5 ˉ ¹ zero. We conclude that the use of silicate clay had no interference in the physiological quality and productivity of rice seeds and the response was different for genotypes of wheat and barley. / O Rio Grande do Sul, estado que produz uma diversidade de culturas sendo o arroz o importante cereal semeado na primavera/verão e o trigo e a cevada com grande potencial de cultivo no outono/inverno. O estado responde pela maior produção de arroz (Oryza sativa L.) do Brasil, com uma área cultivada de aproximadamente um milhão de hectares por ano. A cultura do trigo (Triticum aestivum L.) se destina a produção de grãos, que são transformados em farinha para a indústria de panificação e massas, a cultura da cevada (Hordeum vulgare L.) se destina a produção de grãos, que são transformados em malte na indústria cervejeira. O uso do elemento silício tem potencial para diminuir o uso de agro-químicos e aumentar a produtividade por meio de uma nutrição equilibrada e fisiologicamente mais eficiente. argila silicatada é um pó esbranquiçado contém 77.9% de SiO2 com pH 5,5. Este estudo teve como objetivo avaliar a qualidade fisiológica, produtividade em sementes destes cereais tratados a campo com argila silicatada como fonte de silício. Utilizou-se dois tratamentos foliares com quatro aplicações e no solo com três doses que foram: T1 360 kg haˉ¹, T2 720 kg haˉ¹, em quatro aplicações foliares nos estádios vegetativos, V4, V9 e reprodutivos R2 e R6 e no sulco de semeadura T3 360 kg haˉ¹, T4 720 kg haˉ¹ e T5 zero. Conclui-se que o uso de argila silicatada não teve interferência na qualidade fisiológica e produtividade de sementes de arroz e a resposta foi diferente para genótipos de trigo e cevada.
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Analysis of physical and chemical properties of fractionated grains and seeds with an emphasis on barley /

Elfverson, Cajsa, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.
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Cell death and defence gene responses in plant-fungal interactions /

Persson, Mattias, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 4 uppsatser.

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