Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2017-07-11T16:32:21Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Rafael Antonio Pasini.pdf: 2553408 bytes, checksum: 6b56b5a30a27d4c38a90cbaee22f20f3 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-07-17T20:26:26Z (GMT) No. of bitstreams: 2 Tese Rafael Antonio Pasini.pdf: 2553408 bytes, checksum: 6b56b5a30a27d4c38a90cbaee22f20f3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-17T20:26:26Z (GMT). No. of bitstreams: 2 Tese Rafael Antonio Pasini.pdf: 2553408 bytes, checksum: 6b56b5a30a27d4c38a90cbaee22f20f3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A cultura do trigo apresenta grande importância na alimentação humana e animal. Para que grandes produtividades sejam obtidas, faz-se necessário o controle de insetos, doenças e plantas daninhas. O controle químico é a principal medida utilizada pelos agricultores para o manejo dessas pragas. No entanto, esses agrotóxicos podem afetar de forma negativa os inimigos naturais presentes nesse cultivo. Chrysoperla externa e Eriopis connexa são dois predadores vorazes encontrados com frequência, predando insetos-praga presentes na cultura do trigo. Para que o controle químico e o controle biológico possam ser associados de forma harmoniosa nas lavouras de trigo é necessário que os produtos químicos utilizados sejam seletivos aos insetos benéficos. Nesse sentido, estudos de seletividade a inimigos naturais podem gerar uma grande quantidade de informações importantes para que a associação desses dois métodos de controle possa ser viabilizada, e com o mínimo impacto ao meio ambiente. Objetivou-se com este trabalho avaliar a seletividade de agrotóxicos utilizados na cultura do trigo aos predadores C. externa e E. connexa, utilizando como base a metodologia da “International Organization for Biological and Integrated Control of Noxious Animals and Plants” (IOBC), através de bioensaios em laboratório sobre larvas, ovos, pupas e adultos, além de testes de pesistência biológica em casa-de-vegetação sobre larvas e adultos. O inseticida diflubenzuron SC foi o único inseticida considerado levemente nocivo as larvas de E. connexa. Os inseticidas inibidores da biossíntese de quitina diflubenzuron SC, diflubenzuron WP, lufenuron e triflumuron apresentaram reduzida mortalidade aos adultos de C. externa e E. connexa. Para os ovos dos predadores, o inseticida etofenproxi foi classificado como levemente nocivo a C. externa, sendo que imidacloprido+beta-ciflutrina, diflubenzuron WP, tiametoxam+lambda-cialotrina A e B, gama-cialotrina e etofenproxi apresentaram a mesma classificação para E. connexa, tendo ainda metomil sendo classificado como moderadamente nocivo aos ovos do predador. Imidacloprido+beta-ciflutrina foi considerado como levemente nocivo as pupas de C. externa enquanto imidacloprido+beta-ciflutrina, tiametoxam+lambda-cialotrina A e B e lufenuron apresentaram efeito total superior a 30% e foram classificados como levemente nocivos as pupas do predador E. connexa. Quanto a persistência, com exceção de tiametoxam+lambda-cialotrina que 7 foi moderadamente persistente, gama-cialotrina, imidacloprido+beta-ciflutrina, metomil e tiametoxam foram persistentes as larvas de C. externa e E. connexa. Gama-cialotrina, imidacloprido+beta-ciflutrina e metomil foram persistentes a C. externa e imidacloprido+beta-ciflutrina e metomil aos adultos de E. connexa. Tiametoxam foi considerado moderadamente persistente a C. externa e gamacialotrina, tiametoxam e tiametoxam+lambda-cialotrina a E. connexa. O inseticida tiametoxam+lambda-cialotrina foi levemente persistente aos adultos de C. externa. O herbicida glufosinato de amônio foi classificado como moderadamente nocivo a fase larval de ambos os predadores. Quase todos os herbicidas foram classificados como inócuos aos ovos dos dois predadores, com exceção de metsulfuron-metil que foi classificado como levemente nocivo aos ovos de E. connexa. O herbicida 2,4-D amina foi classificado como levemente nocivo a pupas de C. externa e pirimidinadiona apresentou a mesma classificação a pupas de E. connexa. Os fungicidas piraclostrobina+epoxiconazole B e picoxistrobina+ciproconazole são nocivos as larvas de C. externa. Piraclostrobina+epoxiconazole A foi levemente nocivo a fase de ovo, e propiconazol foi levemente nocivo a fase de pupa de C. externa. O fungicida piraclostrobina+epoxiconazole A foi considerado nocivo as larvas de E. connexa. Piraclostrobina+epoxiconazole A e tebuconazole A foram levemente nocivos a fase de ovo, e piraclostrobina+epoxiconazole A e propiconazol foram levemente nocivos a fase de pupa do coccinelídeo. / The wheat crop hasp great importance in the human and animal nutrition. In order to obtain large yields, it is necessary the control of insects, diseases and weeds. The chemical control through the use of pesticides is the main measure used by farmers to manage these pests. However, these pesticides can negatively affect the natural enemies present in this crop. Chrysoperla externa and Eriopis connexa are two very voracious predators and are found often preying on aphids present in wheat crop. In order for chemical control and biological control to be harmoniously associated in the wheat crop, it is necessary that the chemicals used must be selective for beneficial insects. So, studies of selectivity to natural enemies can generate a large amount of important data for the association of these two control methods can be made feasible, with minimal impact to the environment. The objective of this work was to evaluate the selectivity of agrochemicals used in the wheat crop to the predators C. externa and E. connexa, based on the methodology of the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC) Through laboratory bioassays on larvae, eggs, pupae and adults, in addition to tests of biological persistence in greenhouse conditions on larvae and adults. The insecticide diflubenzuron SC was the only insecticide considered to be slightly harmful to E. connexa larvae. The chitin biosynthesis inhibitors diflubenzuron SC, diflubenzuron WP, lufenuron and triflumuron showed reduced mortality on adults of C. externa and E. connexa. For the eggs of the predators, the insecticide etofenproxi was classified as slightly harmful to C. externa, and imidacloprid+beta-cyfluthrin, diflubenzuron WP, thiamethoxam+lambda-cyhalothrin A and B, gamma-cyhalothrin and etofenproxi showed the same classification for E. connexa, being methomyl classified as moderately harmful to the predator eggs. Imidacloprid+beta-cyfluthrin was considered as slightly harmful the pupae of C. externa while imidacloprid+betacyfluthrin, thiamethoxam+lambda-cyhalothrin A and B and lufenuron had a total effect superior to 30% and were classified as slightly harmful to the pupae of the predator E. connexa. Regarding the insecticide persistence, with the exception of thiamethoxam+lambda-cyhalothrin that was moderately persistent, gammacyhalothrin, imidacloprid+beta-cyfluthrin, methomyl and thiamethoxam were persistent to C. externa and E. connexa larvae. Gamma-cyhalothrin, 9 imidacloprid+beta-cyfluthrin and methomyl were persistent to C. externa and imidacloprid+beta-cyfluthrin and methomyl to adults of E. connexa. Thiamethoxam was considered moderately persistent to C. externa and gamma-cyhalothrin, thiamethoxam and thiamethoxam+lambda-cyhalothrin to E. connexa. The insecticide thiamethoxam+lambda-cyhalothrin was slightly persistent to C. externa adults. The herbicide ammonium glufosinate was classified as moderately harmful to the larval phase of both predators. Almost all herbicides were classified as innocuous to the eggs of both predators, with the exception of metsulfuron-methyl which was classified as slightly deleterious to E. connexa eggs. The herbicide 2,4-D amine was classified as slightly harmful to pupae of C. externa and pyrimidinedione presented the same classification to E. connexa pupae. The fungicides pyraclostrobin +epoxiconazole B and picoxystrobin+ciproconazole are harmful to C. externa larvae. Piraclostrobin+epoxiconazole A was slightly harmful to the egg phase, and propiconazole was slightly harmful to the pupa phase of C. externa. The fungicide pyraclostrobin+epoxiconazole A was considered to be harmful to E. connexa larvae. Piraclostrobin+epoxiconazole A and tebuconazole A were slightly harmful to the egg phase, and pyraclostrobin+epoxiconazole A and propiconazole were slightly harmful to the pupal phase of the coccinellidae.

Made available in DSpace on 2017-07-10T17:36:58Z (GMT). No. of bitstreams: 1 2013_Diss_Luan_Fernando_Ormond_Sobreira_Rodrigues.pdf: 1586609 bytes, checksum: f7d3b9b64f94098b8a18d355548fb9ab (MD5) Previous issue date: 2013-06-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazil has a low contribution to the production of wheat in relation to world stage. Therefore, some techniques have been developed to increase the productivity of wheat grains in the country and reduce production costs. Among these techniques, we can highlight inoculation with plant growth promoting bacteria which contribute both to the biological nitrogen fixation in non-legumes, as with the release of plant growth regulator to the roots of the plants in which they associate. However, the biological nitrogen fixation by these bacteria is not sufficient for maximum yield of these crops and it is necessary, therefore, association with some other technique such as spraying organic material stabilized in humic acid, it may be a viable alternative in the process production of wheat. Given the above, the aim of this work was to verify the agronomic effectiveness of the combination of Azospirillum brasilense in relation to or associated with the use of humic acid and different levels of nitrogen fertilizer in wheat crop conditions in the greenhouse and field. Three experiments were conducted, two simultaneously in the agricultural year 2011/2012, in the greenhouse and in a field experiment in the agricultural year 2012/2013. Both experiments were carried out in experimental stations belonging to the core of experimental stations Unioeste, from Marechal Cândido Rondon, PR. The experimental design was randomized blocks in a 4x4 factorial with four replications. The first factor relates to plant growth promoters (Control; Ab-V5 strain of A. brasilense; organic material stabilized humic acid HA and Ab-V5+HA) and the second factor levels of nitrogen (0, 30 , 60 and, 90 kg ha-1 of N). Was used as plant material wheat cultivar CD 150, which evaluated the plant height, dry weight of leaves, stems and sheaths, reproductive structures and shoots, leaf area, leaf gas exchange measurements, SPAD , yield components and grain yield of the crop. In general, home vegetable was observed that the combined use of Ab-V5+AH, favored the increase in dry matter of shoots, the absorption of N and K, the leaves, and P and K, the grains wheat, number of ears per pot, the average length of the ears and the weight of one hundred grains. In the field experiment showed that Ab-V5+HA promoted increase in shoot dry matter, gas exchange, the K content of grain, and the number of ears per square meter. The grain yield of the crop was influenced by any of the treatments under greenhouse and only levels of nitrogen in field experiment. The conclusion of this work that the combined use of Ab-V5+AH favors the growth characteristics of wheat crop, but more studies are needed because grain yield is only influenced by nitrogen fertilizer rates / O Brasil apresenta uma baixa contribuição na produção de trigo, em relação ao panorama mundial. Diante disso, algumas técnicas foram desenvolvidas para aumentar a produtividade de grãos de trigo no país e diminuir os custos produtivos. Entre essas técnicas, pode-se destacar a inoculação com bactérias promotoras do crescimento vegetal, que contribuem tanto com a fixação biológica de nitrogênio em não leguminosas, quanto com a liberação de reguladores vegetais para as raízes das plantas em que se associam. Contudo, a fixação biológica de nitrogênio por essas bactérias, não é suficiente para máxima produção dessas culturas, sendo necessário, portanto, a associação com alguma outra técnica, como a pulverização de matéria orgânica estabilizada em ácido húmico, pode ser uma alternativa viável no processo produtivo do trigo. Face ao exposto, objetivou-se com este trabalho verificar a eficiência agronômica da combinação entre Azospirillum brasilense em relação ou associada à utilização de ácido húmico e diferentes níveis de adubação nitrogenada na cultura do trigo em condições de casa de vegetação e a campo. Foram conduzidos três experimentos, sendo dois simultaneamente, no ano agrícola 2011/2012, em casa de vegetação e, um experimento a campo, no ano agrícola 2012/2013. Ambos os experimentos foram instalados nas estações experimentais pertencentes ao núcleo de estações experimentais da Unioeste, do município de Marechal Cândido Rondon-PR. O delineamento experimental adotado foi em blocos casualizados em esquema fatorial 4x4, com quatro repetições. O primeiro fator refere-se aos promotores do crescimento vegetal (Controle; estirpe Ab-V5 de A. brasilense; matéria orgânica estabilizada em ácido húmico AH e; Ab-V5+AH) e o segundo fator aos níveis de nitrogênio (0; 30; 60 e; 90 kg ha-1 de N). Utilizou-se como material vegetal a cultivar de trigo CD 150, em que se avaliou altura de plantas, massa de matéria seca das folhas, colmo mais bainhas, das estruturas reprodutivas e da parte aérea, área foliar, medidas de trocas gasosas, índice SPAD, componentes de produção e a produtividade de grãos da cultura. De maneira geral, em casa de vegetal foi observado que o uso combinado de Ab-V5+AH, favoreceu o incremento em matéria seca da parte aérea, na absorção de N e K, pelas folhas, e de K e P, pelos grãos de trigo, no número de espigas por vaso, no comprimento médio das espigas e na massa de cem grãos. No experimento a campo observou-se que Ab-V5+AH promoveu incremento em matéria seca da parte aérea, nas trocas gasosas, no teor de K dos grãos, e no número de espigas por metro quadrado. A produtividade de grãos da cultura foi influenciada por nenhum dos tratamentos em casa de vegetação e somente pelas doses de nitrogênio no experimento a campo. Conclui-se com este trabalho que o uso combinado de Ab-V5+AH favorece nas características de desenvolvimento da cultura do trigo, porém mais estudos devem ser realizados pois a produtividade dos grãos é influenciada apenas pelas doses de nitrogênio utilizadas

Made available in DSpace on 2017-07-10T17:37:02Z (GMT). No. of bitstreams: 1 Luiz_Claudio_Offemann.pdf: 946925 bytes, checksum: 6e708b213cd6fa0ed040f9f73a3bc05e (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to evaluate the combined use of Azospirillum brasilense inoculation by seed and foliar application, associated to nitrogen fertilization on the agronomic characteristics of wheat. The experiment was installed in greenhouse on May 24th 2014, for this purpose, vases were used with capacity 15 dm3, in which were conducted 4 plants. The harvest proceeded on September 12th 2014, to 111 after emergence. The experimental design was a randomized block factorial 2 x 2 x 3, with four repetitions. The first factor was formed by the absence or presence of seed inoculation with A. brasilense. The second by nitrogen fertilization at doses of 70 and 140 Kg ha-1 (50 and 100% respectively). The third factor by application by foliar spraying of A. brasilense in the stages of tillering, booting and two applications, the first in the tillering and the second in booting. Were evaluated the biometric parameters of the culture at the end of the silking stage, the production components at the end of crop cycle. Were also evaluated gas exchange rates in the flag leaf and contents of macronutrients N, P and K in leaves and grains. It can be concluded that the use of A. brasilense, applied by foliar spraying, promotes increases in average internode length, average length of ears, dry leaves mass, ears and root, root volume and nitrogen content in leaves, besides maximize the effect of nitrogen fertilization. Gas exchange measurements and leaf nutrient content, were affected positively only by the higher nitrogen dose / Objetivou-se com este estudo avaliar o uso combinado de inoculação de Azospirillum brasilense, via semente e pulverização foliar, associada à adubação nitrogenada, nas características agronômicas da cultura do trigo. O experimento foi instalado em casa de vegetação no dia 24 de maio de 2014. Foram utilizados vasos com capacidade de 15 dm3, nos quais foram conduzidas 4 plantas. A colheita foi realizada no dia 12 de setembro de 2014, aos 111 dias após a emergência. O delineamento experimental adotado foi de blocos ao acaso em esquema fatorial 2 x 2 x 3, com quatro repetições. O primeiro fator foi formado pela ausência ou presença de inoculação das sementes com A. brasilense. O segundo pela fertilização nitrogenada nas doses de 70 e 140 kg ha-1 (50 e 100% respectivamente). O terceiro fator pela aplicação via pulverização foliar de A. brasilense nos estádios de perfilhamento, espigamento e duas aplicações, sendo a primeira no perfilhamento e a segunda no espigamento. Foram avaliados os parâmetros morfométricos ao final do estádio de espigamento, os componentes da produção ao final do ciclo. Também foram avaliadas as taxas de trocas gasosas na folha bandeira e teores dos macronutrientes N, P e K em folhas e grãos. Pode-se concluir que A. brasilense, aplicado via pulverização foliar, promove incrementos em comprimento médio de entrenós, comprimento médio de espigas, massa da matéria seca de folhas, espigas e raízes, volume de raízes e teor de nitrogênio nas folhas. As medidas de trocas gasosas e teor de nutrientes nas folhas foram influenciadas positivamente apenas pela maior dose de nitrogênio

Made available in DSpace on 2017-07-10T17:37:12Z (GMT). No. of bitstreams: 1 Aline Kelly Pomini de Souza.pdf: 1804826 bytes, checksum: d87df5227a66ab496298a79ceeb8b614 (MD5) Previous issue date: 2016-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Produce wheat competitive and sustainable manner is one of the main challenges of agriculture, because the culture demands a high amount of nitrogen, this element with high cost of obtaining. The objective of this study was to evaluate the ability to promote growth of plant growth promoting bacteria (PGPB) previously isolated from forest areas with different types of soil inoculated by seeds, in wheat plants and the effect of the use of nitrogen fertilizers in the plant-bacteria association. The experiment was been conducted in a randomized block design in a factorial 3 x 7 with four replications. The first factor was composed of 3 doses of nitrogen fertilizer 0; 45 and 90 kg ha-1. The second factor was been formed by the absence of inoculation (control), and inoculation by seeds with the isolates: UFPRPALT2-24, Pseudomonas chlororaphis, UFPRPALM1-131, Ensifer adhaerens, Burkholderia ambifaria and standard strain AbV5 (Azospirillum brasilense), registered in the Ministry of Agriculture. During the experiment were measured the length of plants and chlorophyll content (SPAD). At the flowering stage were measured morphometric and physiological variables (gas exchange and SPAD), and in the end of the crop cycle the production components. Data were been subjected to analysis of variance and regression analysis used for the length of plants and the SPAD index. For the other variables, the averages were been compared by Tukey test at 5% probability of error. For the averages of morphometric analyzes performed at the stage of flowering and maturity was conducted Pearson's correlation and generated groupings of treatments by the methods of Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and Tocher. The morphometric analyzes in the flowering stage was a significant difference in length of plants and number of viable tillers, to the isolated factor. Given the interaction of the factors tested, the significant interaction was observed for: mass of dry matter leaves, mass of dry matter stem, mass of dry matter ears, mass of dry matter of roots and length of ears. In the analysis of gas exchange there was a significant difference for internal CO2 concentration (Ci). Components of production, there was a significant interaction for: ear length, root - aerial part relationship, harvest index, number of grains and grain yield. Pearson's correlation were found 45 correlations, highlighting the relationship of SPAD index, ear length and harvest index, because the chlorophyll content be related to photosynthesis. The groups was observed that the treatments with no inoculation by both UPGMA, and Tocher remained in the same group, separate from treatments that stood out. Given the results exposed, it can being concluded that the bacteria used showed satisfactory results in the development of the wheat crop in combination with nitrogen and compared to Azospirillum brasilense, similar or higher behavior was observed / Produzir trigo de forma competitiva e sustentável tornou-se um dos principais desafios da agricultura, visto que a cultura demanda grande quantidade de nitrogênio, elemento este com alto custo de obtenção. O objetivo do presente estudo foi avaliar a capacidade de bactérias promotoras de crescimento de plantas (BPCP) previamente isoladas de áreas de mata com diferentes tipos de solo, inoculadas via sementes, em plantas de trigo e o efeito do uso de fertilizantes nitrogenados na associação planta-bactéria. O experimento foi conduzido em delineamento em blocos casualizados em esquema fatorial 3 x 7 com quatro repetições. O primeiro fator foi composto por 3 doses de fertilizante nitrogenado 0; 45 e 90 kg ha-1. O segundo fator foi formado pela ausência de inoculação (controle), e inoculação via sementes com os isolados: UFPRPALT2-24, Pseudomonas chlororaphis, UFPRPALM1-131, Ensifer adhaerens, Burkholderia ambifaria e a estirpe padrão AbV5 (Azospirillum brasilense), registrada no Ministério da Agricultura. Durante o experimento foram mensurados o comprimento de plantas e teor de clorofila (índice SPAD). No estádio de florescimento foram mensuradas variáveis morfométricas e fisiológicas (trocas gasosas e SPAD), e ao final do ciclo da cultura os componentes da produção. Os dados foram submetidos a análise de variância, sendo utilizada análise de regressão para o comprimento de plantas e índice SPAD. Para as demais variáveis, as médias foram comparadas pelo teste de Tukey a 5% de probabilidade de erro. Para as médias das análises morfométricas realizadas no estádio de florescimento e maturação foi realizada a correlação de Pearson e gerados agrupamentos dos tratamentos pelos métodos do Unweighted Pair Group Method with Arithmetic Mean (UPGMA) e Tocher. Das análises morfométricas realizadas no estádio de florescimento foi verificada diferença significativa para comprimento de plantas e número de perfilhos viáveis, para o fator isolado. Diante da interação dos fatores testados, a interação significativa foi verificada para: massa de matéria seca de folhas, massa de matéria seca de colmo, massa de matéria seca de espigas, massa de matéria seca de raízes e comprimento de espigas. Nas análises de trocas gasosas verificou-se diferença significativa para concentração interna de CO2 (Ci). Dos componentes da produção, houve interação significativa para: comprimento de espigas, relação raiz-parte aérea, índice de colheita, número de grãos e massa de grãos. Da correlação de Pearson foram verificadas 45 correlações, destacando a relação do índice SPAD, comprimento de espigas e índice de colheita, devido o teor de clorofila estar relacionado com a fotossíntese. Dos agrupamentos foi verificado que os tratamentos com ausência de inoculação tanto pelo UPGMA, quanto por Tocher permaneceram em um mesmo grupo, separados dos tratamentos que se destacaram. Diante dos resultados expostos, pode-se concluir que as bactérias utilizadas apresentaram resultados satisfatórios no desenvolvimento da cultura do trigo em associação com o nitrogênio e em comparação ao Azospirillum brasilense, foi verificado comportamento similar ou superior

Made available in DSpace on 2017-07-10T17:37:20Z (GMT). No. of bitstreams: 1 Paulo_Evandro_Jandrey.pdf: 921971 bytes, checksum: d3457f5f5270b5d9b9a7612a24091ca0 (MD5) Previous issue date: 2013-05-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Knowledge of the degree of seed germination in the ear is useful both for crop condition as for breeding in wheat. The results of the different tests used to identify cultivars with improved tolerance of sprouting indicate that there is possibility to keep the grains with suitable properties for industry, enabling decrease the amount of losses occurring on the wheat production areas. Accordingly, the aim of this study was to evaluate the tolerance to sprouting and grain yield in wheat grown at two sowing dates. The field experiment was conducted in the area of the Center of Research in COODETEC Palotina-PR using randomized blocks with 15 x 2 factorial arrangement with 3 replications. The first factor refers to genotypes, 3 cultivars (Mirante, CD 150 and Frontana) and 12 lineages resulting from the backcross of cultivars CD 150 with Frontana (CD 12901, CD 12902, CD 12903, CD 12904, CD 12905, CD12906 , CD 12907, CD 12908, CD12 909, CD12 910, CD12 911 and CD 12912). The second factor relates to the two sowing dates (31/03 and 05/03/2012). Plots consisted of 6 rows of 6 meters in length, 0.17 meters spacing between lines, being regarded as one boundary line on each side and 0.50 meters from each end. Evaluations of sprouting, the experiments were conducted in the laboratory, using a randomized block design in 15 x 2 factorial arrangement with 4 replications, each replication was composed of 10 spikes. In the evaluations of sprouting was evaluated for germination in two distinct metologias (immersion in water and rainfall simulator). The variable number of days to silking, plant height, thousand grain weight and number of grains per spike were the characteristics that have greater variability among genotypes, and the sowing in 03/05 was the one that led to the highest for plant height, test weight, number of spikelets per spike and number of grains per spike. The cultivar Frontana showed high resistance to germination of the grain in the ear, regardless of sowing and methodology. Genotypes CD 12901, CD 12905, CD 12907 showed tolerance to the germination of the grain in the ear when evaluated by the method of rainfall simulator in sowing on 31/03. Highest grain yield was obtained for genotypes CD 12902, CD 12905, CD 12909, CD 12910 and CD 12911 in sowing in 03/05. Already Frontana to cultivate, cultivate greater number of days to silking, the highest yield was obtained in sowing on 31/03 / O conhecimento do grau de germinação da semente na espiga é de utilidade tanto para condição de lavoura como para trabalhos de melhoramento na cultura do trigo. Resultados de diferentes testes utilizados para identificar as cultivares com melhor tolerância à germinação na espiga indicam que existe possibilidade de manter os grãos com as propriedades adequadas para a indústria, possibilitando diminuir a quantidade de perdas ocorrentes nas regiões produtoras de trigo. Nesse sentido, objetivou-se com este trabalho avaliar a tolerância a germinação na espiga e a produtividade de grãos em genótipos de trigo cultivados em duas épocas de semeadura. O experimento a campo, foi conduzido na área experimental do Centro de Pesquisa da COODETEC em Palotina-PR utilizando o delineamento em blocos ao acaso em esquema fatorial 15 x 2, com 3 repetições. O primeiro fator refere-se aos genótipos, sendo 3 cultivares (Mirante, CD 150 e Frontana) e 12 linhagens resultantes do retrocruzamento das cultivares CD 150 com Frontana (CD 12901, CD 12902, CD 12903, CD 12904, CD 12905, CD 12906, CD 12907, CD 12908, CD 12909, CD 12910, CD 12911 e CD 12912). O segundo fator refere-se as duas épocas de semeadura (31/03 e 03/05/2012). As parcelas foram constituídas de 6 linhas de 6 metros de comprimento, com espaçamento de 0,17 metros entre linhas, sendo considerado como bordadura 1 linha de cada lado e 0,50 metros de cada extremidade. Para as avaliações de germinação na espiga, os experimentos foram conduzidos em laboratório, utilizando o delineamento de blocos ao acaso em esquema fatorial 15 x 2 com 4 repetições, sendo que cada repetição foi composta de 10 espigas. Nas avaliações de germinação na espiga, foi avaliado o índice de germinação em duas metodologias distintas (imersão em água e simulador de chuva). As variáveis número de dias para o espigamento, altura de plantas, massa de mil grãos e numero de grãos por espiga foram as características que apresentaram maior variabilidade entre os genótipos estudados, sendo que a semeadura realizada em 03/05 foi a que proporcionou maiores valores para altura de plantas, peso do hectolitro, número de espiguetas por espiga e número de grãos por espiga. O cultivar Frontana apresentou alta resistência ao processo germinativo do grão na espiga, independente da época de semeadura e metodologia utilizada. Os genótipos CD 12901, CD 12905, CD 12907 apresentaram tolerância ao processo germinativo do grão na espiga quando avaliados pelo método de simulador de chuva em semeadura realizada em 31/03. Maior rendimento de grãos foi obtido para os genótipos CD 12902, CD 12905, CD 12909, CD 12910 e CD 12911 na semeadura realizada em 03/05. Já para o cultivar Frontana, cultivar de maior numero de dias para o espigamento, o maior rendimento foi obtido na semeadura realizada em 31/03

Made available in DSpace on 2017-07-10T17:37:44Z (GMT). No. of bitstreams: 1 Adeline Neiverth.pdf: 1649092 bytes, checksum: d7d182e371115519785a39ebe6e95aee (MD5) Previous issue date: 2011-07-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Wheat is the most important staple food of the world. The increase in grains productivity and protein content is correlated to increase inorganic nitrogen absorption. Usually, urea is the most convenient source of N2, but, it causes the increase in crops costs beyond injuries to the environment. The BNF realized by diazotrophics bacteria is an alternative to supplement or replace the nitrogen fertilizers and promote plant growth. The objective of this study was to evaluate the performance of Brazilian wheat genotypes for PCV( plant promoter growth) and BNF by association between diazotrophic bacteria (H. seropedicae SmR1) and wheat cultivars under in vitro and greenhouse conditions. In in vitro experiment, eight wheat plantlets of 8 genotypes were tested in tubes with liquid culture medium and these were co-cultured for 7 days with 107 cells.mL-1. As control plantlets without inoculum under the same conditions were used. The experimental design was completely randomized in a 2 x 8 factorial with 3 repetitions. We analyzed the fresh mass of roots, fresh and dry weight of shoots, total nitrogen (TN) content of NH4 +, microbial counting (CFU), glutamine synthetase activity (GS), the morphology of the roots by microscopy and molecular analysis of epiphytic and endophytic bacteria recovered after co-cultivation. In the greenhouse, it was planted five wheat genotypes. The seeds were placed in pots with 4.5 kg of soil under four treatments: 1 - Control 2 - Addition of N as urea (142 kg ha-1 of N) 3 - Addition of inoculum containing H. seropedicae (106 cells.mL-1) (Hs) and 4 - Addition of inoculum containing urea + H. seropedicae (N + Hs). The experimental design was completely randomized in a factorial 5 x 4 with 5 repetitions. The fresh mass of roots, fresh and dry weight of shoots, NT, NH4 + content and GS activity were evaluated. As agronomic parameters were evaluated the whole plant mass at the end of the phenological cycle, yield per plant and weight of 100 seeds.As results in vitro, it was observed the presence of epiphytic bacteria on the roots of all genotypes and the presence of endophytic bacteria in genotypes CD 105, CD 108, CD 111, CD 117, CD 120. There was a sharp increase of root hairs in the genotypes CD 105, CD 117, CD 119 and CD120. The cultivars CD 105 and CD 120 by the presence of endophytic bacteria showed an increase of root hairs, probably it may be the most promising for a response of BNF. The levels of NH4 +, NT and GS in the roots were not decisive for in vitro plant growth promotion. The results obtained in the greenhouse showed significant interactions among parameters, although there were were not crucial for the definition of a specific genotype which answers to the interaction. However, there was a contribution to be further studied, where the CD 120 cultivar showed evidence of association with response to the bacterium and possible occurrence of the BNF. There was no negative effect of inoculation to plants. Additional studies are needed to get answers about the interactions of these genotypes with diazotrophic bacteria related to BNF and plant growth promotion / Os fertilizantes nitrogenados são fontes convenientes de nitrogênio para a cultura de trigo, porém geram altos custos e podem ser poluentes. A fixação biológica de nitrogênio (FBN) é uma fonte alternativa de nitrogênio por meio das bactérias diazotráficas. Assim, o objetivo deste trabalho foi avaliar o desempenho de genótipos de trigo brasileiros para a FBN e promoção do crescimento vegetal (PCV) associados com a bactéria diazotrófica H. seropedicae SmR1, sob condições in vitro e em casa de vegetação. Nas condições in vitro, colocou-se plântulas de 8 genótipos de trigo em tubos de ensaio com meio de cultura líquido, co-cultivadas durante 7 dias com 107células de bactéria.mL-1. O mesmo número de plântulas foi mantido nas mesmas condições, porém sem inóculo. O delineamento experimental foi inteiramente casualizado, num esquema fatorial 8 x 2 com 3 repetições. Analisou-se a massa fresca de raízes, massa fresca e seca de parte aérea, o nitrogênio total (NT), conteúdo de amônio (NH4+), contagem microbiana (UFC), Glutamina sintetase (GS), a morfologia das raízes por microscopia e análise molecular das bactérias endofíticas e epifíticas recuperadas após co-cultivo. Em casa de vegetação, foram avaliados 5 genótipos de trigo, onde o delineamento experimental foi inteiramente casualizado num esquema fatorial 5 x 4 com 5 repetições, onde: 1 Testemunha; 2 Adição de N na forma de ureia, 142 kg ha-1 de N; 3 Adição de inóculo contendo H. seropedicae, 106 celulas por semente (Hs) e 4 Adição de ureia + inóculo (N+Hs). Avaliaram-se a massa fresca de raízes, massa fresca e seca de parte aérea, o NT, conteúdo de NH4+ e a atividade da GS. Como parâmetros agronômicos avaliaram-se a massa da planta inteira no final do ciclo fenológico, produção por planta e massa de 100 grãos. Como resultados, observou-se in vitro a presença de bactérias epifíticas nas raízes de todos os genótipos e presença de bactérias endofíticas não foi verificada nos genótipos CD 104, CD 119 e CD 150. Verificou-se um aumento acentuado de pêlos radiculares nos genótipos CD 105, CD 117, CD 119 e CD120. As cultivares CD 105 e CD 120 pela presença da bactéria endofiticamente associado com o aumento de pêlos radiculares, podem ser as mais promissoras para uma resposta da FBN. As plântulas inoculadas apresentaram senescência precoce. Os níveis de NH4+, GS e NT nas raízes não foram determinantes para a promoção do crescimento vegetal. Os resultados obtidos em casa de vegetação demonstram que, apesar de ter havido interações significativas, os parâmetros não foram determinantes para a definição de um genótipo que apresentasse uma resposta conclusiva a respeito da interação benéfica entre genótipo COODETEC e H. seropedicae. No entanto, observou-se uma contribuição a ser mais bem estudada, onde a cultivar CD 120 mostrou indícios de resposta à associação com a bactéria e possível ocorrência da FBN. Não foi observado nenhum efeito negativo da inoculação às plantas. Estudos complementares são necessários para obter respostas quanto às interações destes genótipos com estas bactérias diazotróficas, no processo de colonização, da FBN e da PCV

Des épisodes climatiques de sècheresse et/ou de hautes températures peuvent engendrer de fortes pertes de rendement pour les cultures de céréales au champ. Un QTL associé au rendement et à ses composantes a été détecté dans quatre populations de blé (Triticum aestivum L.) sur le bras long du chromosome 3B « qYDH.3BL ». Deux populations d’haploïdes doublés (RAC875/Kukri et Excalibur/Kukri) et deux populations de lignées recombinantes (RAC875/Kukri et Gladius/Drysdale) ont été utilisées pour cartographier finement le QTL, au même titre que l’identification de gènes candidats. Ces quatre populations ont été testées sous des conditions environnementales variées, incluant des périodes de sécheresse et/ou hautes températures en Australie et au Mexique. Des modèles statistiques mixtes et linéaires décomposant les variations génétiques et non-génétiques ont été utilisés pour la détection de QTL en considérant dans un premier temps chaque environnement unique, puis en considérant les environnements multiples dans une analyse commune. Les allèles de RAC875, Drysdale et Excalibur à ce locus ont montré une hausse du rendement de 5 à 12.5 % comparées à celles de Gladius ou Kukri. Un total de trente-sept marqueurs moléculaires a été cartographié dans la région du QTL. Les marqueurs moléculaires ont été sélectionnés (i) par comparaison avec une carte génétique publiée du chromosome 3B, ou (ii) en désignant de nouveaux marqueurs moléculaires sur les séquences de BAC-end, de contig ou de gènes provenant du projet de séquençage du chromosome 3B (3BSEQ, http://urgi.versailles.inra.fr/, cv. Chinese Spring). Ceci a permis la construction d’une carte génétique consensus du locus qYDH.3BL . A ce jour, aucun QTL associé au rendement ou ses composantes en condition de sécheresse et/ou de hautes températures n’a encore été cloné positionellement chez le blé tendre. Les marqueurs moléculaires de la région d’intérêt ont été utilisés pour cartographier physiquement des contigs, soit par PCR, soit par comparaison de séquences in silico. La région du QTL inclus un total de huit contigs physiques comprenant 85 gènes annotés. L’utilisation de base de données de transcris biologiques publiques ou internes ont été utilisées pour détecter la présence de ces gènes, réduisant la liste à soixante-cinq gènes. Sur les contigs ayant une confiance élevée, aucun des vingt gènes n’a été exprimé différentiellement entre RAC875 et Kukri. Cependant, un gène présentant du polymorphisme dans sa séquence ainsi qu’une délétion/insertion d’un segment portant 12 gènes ont été découvert permettant ainsi de continuer à affiner la liste de gènes candidats. Les trois lignées parentales (RAC875, Drysdale et Excalibur) qui ont l’allèle liée au haut rendement ont le même haplotype pour ce gène, et la même délétion/insertion en opposition au deux autres lignées parentales Gladius et Kukri. Ainsi, dans ce travail de thèse nous avons pu confirmer la présence d’un QTL répondant aux stresses environnementaux sur le chromosome 3BL dans différentes populations et différents environnements, identifier des gènes candidats sous le QTL, et proposer une liste restreinte pour de futures analyses sur la base de données d’expression et de polymorphismes entre les parents des populations de cartographie. / Drought and heat can occur during the growth cycle of crops and severely reduce yield. A QTL associated with yield and yield-related component was found in four wheat populations (Triticum aestivum L.) on the long arm of chromosome 3B “qYDH.3BL”. The four populations were grown under various climatic conditions including drought, heat and combinations of both in a number of different areas (Australia and Mexico). Linear mixed models that partition and account for genetic and non-genetic or extraneous variation were used to detect loci in single-environment and/or multi-environment QTL analysis using ASReml-R. The alleles carried by RAC875, Excalibur or Drysdale improved grain yield by between 5% and 12.5%. Two doubled haploid populations (RAC875/Kukri and Excalibur/Kukri) and two recombinant inbred line populations (RAC875/Kukri and Gladius/Drysdale) were used to fine map qYDH.3BL and identify candidate gene(s). A total of thirty-seven molecular markers were mapped on one or both genetic maps of chromosome 3B enabling development of a consensus genetic map of the qYDH.3BL region. The markers were selected based on comparisons with a published “neighbour map” of chromosome 3B or designed using either BAC-end, contig or gene sequences from the chromosome 3B sequencing project; 3BSEQ http://urgi.versailles.inra.fr/ (cv. Chinese Spring). A positional cloning approach was used to identify candidate genes for qYDH.3BL. Molecular markers from the targeted region were assigned to physical contigs by screening the chromosome 3B BAC library experimentally using PCR or in silico by sequence comparison. A total of eight physical contigs containing 85 genes, were anchored to the qYDH.3BL region. Public and in-house resources of wheat transcript sequences were used to restrict the gene list to 65 expressed genes. Based on comparison of the 65 gene sequences to gene probes in a drought transcriptomic database, three genes were found to be differentially expressed between RAC875 and Kukri under drought conditions. Short genomic sequence reads (10× coverage) from each of the five parental lines (RAC875, Kukri, Excalibur, Gladius and Drysdale) were mapped against the 65 genes for polymorphism discovery. One gene exhibited sequence polymorphism between the drought tolerant parents (RAC875, Excalibur and Drysdale) and the drought-sensitive parents (Gladius and Kukri). In addition, presence/absence polymorphisms were consistently detected throughout a region containing 12 genes, indicating that the drought tolerant parents may have a deletion (or alien introgression) in this region. Thus, in this work, we confirmed the genetic effect of qYDH.3BL in multiple environments and multiple populations, saturated the target region with new molecular markers and defined a preliminary list of genes located in the qYDH.3BL region and selected candidate genes for further investigations.

Dans le cadre d’étude de l’amélioration de la teneur en Mg dans le grain par la sélection du blé (Triticum aestivum) afin de renforcer l’apport alimentaire du Mg, les objectifs de cette thèse étaient (i) de mettre en évidence les caractéristiques agro-physiologiques de la plante associées à la teneur en Mg, (ii) d’étudier l’effet de variants génétiques affectant la dynamique du Mg dans la plante et l’accumulation du Mg dans le grain, (iii) d’identifier les éléments minéraux influençant l’absorption et la répartition du Mg, et (iv) d’étudier par approche protéomique le métabolisme associé au Mg influençant la quantité du Mg dans le grain. A travers trois séries d’essai multifactoriel au champ conduites dans le but de sélectionner des génotypes de blé à haut rendement en Mg des grains, les suivis agro-physiologiques ont permis de préciser l’effet négatif du rendement, du poids de mille grains et du nombre de grains par épi sur la teneur en Mg dans le grain. Une différence génétique dans la dynamique du Mg de la plante au cours du développement du grain a été montrée avec l’implication de la translocation du Mg des racines ainsi que de la remobilisation du Mg des tissus végétatifs aériens. La réserve du Mg à préfloraison dans les tissus végétatifs influe sur la quantité de Mg dans le grain. Enfin, l’absorption du Mg est positivement associée avec celle des éléments Mn, P et Zn, et la teneur en Mg est positivement associée avec celle des éléments Zn et P. L’étude protéomique sur les couches périphériques du grain a mis évidence que le Mg intervient dans la division cellulaire, le repliement des protéines et le métabolisme d’énergie, et donc influence l’accumulation de la matière sèche du grain en déterminant la taille potentielle et le remplissage du grain. En conclusion, l’accumulation du Mg dans la plante influence la matière sèche du grain qui a un effet négatif sur la teneur en Mg. / In order to increase the Mg content in the grain of wheat (Triticum aestivum) through plant breeding to improve the dietary Mg intake, the objectives of the present study is (i) to identify the plant traits which are associated with the grain Mg concentration, (ii) to study genotypic variation in Mg dynamic in plant and its effect on Mg accumulation in grain, (iii) identify the minerals interacted with Mg in absorption and distribution, and (iv) study the Mg-related metabolisms influencing the amount of Mg in grain by proteomic approach. The study of 22 genotypes in a multiple-sites and -years field trial showed that there was negative effect of yield, thousand grain weight and number of grains per spike on the grain Mg concentration. The genetic difference was observed in the Mg dynamic during grain development. Mg in the grain depended on both Mg translocation from roots and remobilization from aboveground vegetative tissues, and could be affected by the Mg reserve in vegetative tissues. The study of correlation among different minerals showed that the Mg concentration in grain was positively associated with those of Zn and P, and the Mg content in aboveground was positively associated with those of Mn, P and Zn. Proteomic study of grain peripheral layers showed that Mg is involved in cell division, protein folding and energy metabolism, and hence influenced the grain dry matter accumulation by determining the potential size and grain filling. In conclusion, the accumulation of Mg in the plant influences the grain dry matter which has a negative effect on the Mg content.

O trigo (Triticum aestivum L.) é uma importante cultura no Brasil. Poucas cultivares são recomendadas para produção do tipo sequeiro no Bioma Cerrado onde a escassez de água limita o rendimento de grãos. Aqui reportamos uma análise de transcriptoma do MGS1 Aliança (cultivar de trigo adaptada ao Cerrado) sob estresse de seca. Um grupo de 4.422 transcritos diferencialmente expressos foi encontrado em raízes e folhas. O número de transcritos reprimidos em raiz (1.102) foi menor que os transcritos induzidos (1.706), enquanto o oposto ocorreu em folhas (1,017 induzidos e 647 reprimidos). O número de transcritos comuns entre ambos órgaõs foi 1.249, enquanto 2.124 foram específicos para raíz e 1.049 específicos para folhas. Análises de RT-qPCR de 35 transcritos selecionados ao acaso revelou uma correlação de 0,78 com os dados de transcriptoma. Os transcritos diferencialmente expressos foram distribuídos por todos os cromossomos e componentes do genoma. O número de transcritos no genoma B foi maior do que nos genomas A e D. Ainda, um grande número de transcritos relacionados à seca foi mapeado nos cromossomos 3B, 5B e 2B. Quando consideramos ambos órgãos, 116 diferentes rotas metabólicas foram alteradas. Uma rota em comum, entre as três mais alteradas em ambos órgãos, foi o metabolismo do amido e da sacarose. A comparação de transcritos derivados de raiz e de folha permite a identificação de transcritos importantes relacionados à respota ao estresse de seca em cada um destes órgãos. Os dados obtidos, também, abrem caminho para o desenvolvimento de futuros marcadores e seleção de genes candidatos ligados à característica. Estes resultados são úteis para o entendimento de rotas metabólicas envolvidas na tolerância à seca em trigo. A informação gerada será usada, a mais longo prazo, para propósitos de transgenia. Para isto, a metodologia de duplo-haploides é desejável e uma primeira investigação sobre a eficiência de protocolo se mostrou necessária. Micrósporos são células gaméticas com capacidade de dar origem a uma nova planta via embriogênese in vitro. Plantas duplo-haploides geradas pela cultura de micrósporos isolados são completamente homozigotas e representam uma importante ferramenta para estudos genéticos e melhoramento de plantas O processo androgenético é desencadeado por diferentes pré-tratamentos de estresse, os quais são empregados para mudar os micrósporos da rota gametofítica para a rota esporofítica. Embora a cultura de micrósporos isolados tenha inúmeras vantagens, importantes limitações tem impedido sua apliação em larga escala. Diferenças genotípicas na resposta androgenética e na formação de plantas albinas ainda constituem desafios. Embora o albinismo seja principalmente uma característica genética, pré-tratamentos e meios de cultura apropriados podem evitar este fenômeno até certo ponto. A resposta androgenética de cinco genótipos de trigo brasileiro foi avaliada no presente estudo. Dois pré-tratamentos foram testados: frio (4°C) e ácido 2-hidroxinicotinico (100 mg/L). O frio foi melhor que o pré-tratamento químico, produzindo mais plantas verdes em quatro de cinco genótipos. Somente dois genótipos brasileiros tratados com ácido 2-hidroxinicotinico produziram plantas, e um deles apenas uma única planta albina. Nossos reultados mostram, também, que o meio semilíquido (contendo 10% de Ficoll) promoveu uma maior resposta androgenética que o meio líquido, aumentando o número de embriões e plantas regeneradas. / Wheat (Triticum aestivum L.) is an important crop cultivated in Brazil. Few cultivars are recommended for rainfed production in the Cerrado Biome where water scarcity limits grain yield. Here we report a transcriptome analysis of MGS1 Aliança (a wheat cultivar adapted to the Cerrado) under drought stress. A set of 4,422 differentially expressed transcripts was found in roots and leaves. The number of down-regulated transcripts in roots (1,102) was lower than the up-regulated transcripts (1,706), while the opposite occurred in leaves (1,017 induced and 647 repressed). The number of common transcripts between the two tissues was 1,249, while 2,124 were specific to roots and 1,049 specific to leaves. Quantitative RT-PCR analysis of 35 randomly selected transcripts revealed a 0.78 correlation with the transcriptome data. The differentially expressed transcripts were distributed across all chromosomes and component genomes. The number of transcripts on the B genome was greater than on the A and D genomes. Additionally, a greater number of drought related transcripts was mapped on chromosomes 3B, 5B and 5D. When considering both tissues, 116 different metabolic pathways were changed. One common pathway, among the top three changed pathways in both tissues, was starch and sucrose metabolism. The comparison of root- and leaf-derived transcripts allows the identification of important transcripts related to water stress response in each of these tissues. It also paves the way for future marker development and selection of candidate genes linked to that trait. These results are useful for understanding the metabolic pathways involved in wheat drought response. The information generated will be used for transgenic wheat purposes. For this the doubled-haploid method is desirable and an investigation about the protocol eficiency is needed. Microspores are gametic cells with capacity to give rise to a new plant via in vitro embryogenesis. Doubled haploid plants generated by isolated microspore culture are completely homozygous and represent an important tool for plant genetics and breeding research. This process is triggered by different stress pretreatments, which are employed to switch microspores from gametophytic to a sporophytic pathway. Although isolated microspore culture has innumerous advantages, important limitations have prevented its application on a large scale. Genotypic differences in androgenic response and the formation of albino plants remain great challenges. Although albinism is a major genetic characteristic, appropriated pretreatments and culture medium can avoid this phenomenon to some extent. The androgenic response of five Brazilian wheat genotypes was evaluated in the present study. Two pretreatments were tested: cold (4°C) and 2-hydroxynicotinic acid (100 mg/L). Cold was better than chemical pretreatment, producing more green plants in four out of five genotypes. Only two Brazilian genotypes treated with 2-hydroxynicotinic acid produced plants, and one of them produced a single albino plant. Our results also show that semi-liquid medium (containing 10% Ficoll) promoted a higher androgenic response than did liquid medium, increasing the number of embryos and regenerated plants.

Le rendement en grains (Rdt) et la teneur en protéines (%Prot) sont deux cibles majeures dans les programmes de sélection variétale chez le blé car ces caractères contribuent à la valeur économique de cette culture. Malheureusement, leur amélioration simultanée est empêchée par la relation négative %Prot-Rdt. Il a été montré que l’écart à cette relation (“Grain Protein Deviation”, GPD) est déterminé en partie génétiquement et serait utile pour modifier cette relation négative mais ses bases biologiques restent mal comprises à ce jour. Nous avons montré que le GPD est principalement relié à la variabilité génétique pour l’absorption d’azote post-floraison (ABSN) dans les conditions agro-climatiques du Nord-Ouest de l’Europe. Nous proposons que la variabilité génétique pour l’accès à l’azote du sol (architecture et fonctionnement racinaire) ou pour la régulation de ABSN par le statut azoté (transport et assimilation de l’azote) pourrait expliquer le GPD. Etant donné que le retardement de la sénescence durant la période post-floraison peut résulter en une augmentation de ABSN, nous avons analysé les déterminants génétique des relations entre durée de sénescence des feuilles après floraison et Rdt ou %Prot, observées au niveau phénotypique, en utilisant des données acquises sur une population de cartographie de blé cultivée au sein d’un large réseau expérimental. Une association positive entre durée de sénescence des feuilles après floraison et %Prot ou Rdt a été observée selon les environnements étudiés. Nous faisons l’hypothèse que l’impact d’un retardement de la sénescence des feuilles après floraison pourrait être modulé selon la disponibilité en azote durant cette période, ce qui conduirait à modifier la relation %Prot-Rdt selon les environnements étudiés. Enfin, des données obtenues sur trois populations de cartographie cultivées dans un large réseau expérimental ont permis de suggérer, après méta-analyse de QTL, des régions génomiques potentiellement utiles en sélection pour améliorer la %Prot sans diminuer le Rdt. Ceci a permis de mettre en avant des régions situées sur les chromosomes 2A et 3B. En particulier, la région située sur le 2A pourrait être reliée à la présence d’un gène codant pour une glutamine synthétase chloroplastique qui a été associée à la variabilité génétique pour %Prot chez le blé tendre dans une étude antérieure. / Grain yield (GY) and grain protein concentration (GPC) are two major targets in wheat breeding programs as these traits contribute to the economic value of the wheat crop. Unfortunately, their simultaneous improvement is hampered by the genetic negative GPC-GY relationship. It has been shown that the deviation to this relationship (“Grain Protein Deviation”, GPD) has a genetic basis and might be useful to shift this negative relationship but its biological bases remain unclear. GPD was shown to be mainly related to the genetic variability for post-anthesis nitrogen (N) uptake (PANU) in the North-West European agro-climatic conditions. We proposed that the genetic variability for the access to N in the soil (root architecture and functioning) or for the regulation of PANU by the plant N status (N transport and assimilation) could explain GPD. As delaying leaf senescence during the post-anthesis period might result in increasing PANU, we analysed the genetic determinants of the phenotypic relationships between leaf senescence duration after anthesis and GPC or GY using data obtained on a wheat mapping population grown in a large mutli-environment trial network. A positive association was found between leaf senescence duration and GPC or GY depending onthe environment. We suggested that the impact of delaying leaf senescence after anthesis on GY or GPC might be modulated by the N availability during the post-anthesis period and would lead to modify the GPC-GY relationship depending on the considered environments. Finally, data obtained on three connected mapping populations grown in a large mutli-environment trial network were used to suggest by meta-QTL analysis potential genomic regions possibly useful in wheat breeding to improve GPC without reducing GY. This put forward genomic regions located on the 2A and 3B chromosomes as potentially interesting targets to improve GPC. In particular, the region on the 2A might be related to a chloroplastic glutamine synthetase gene previously shown to be associated with genetic variability for GPC in bread wheat.