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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.
11

Influence des jeunes sur le comportement maternel et conséquences développementales chez la caille japonaise (Coturnix c. japonica) / Chicks' influence on maternal behaviour and developmental consequences in quail (Coturnix c. japonica)

Aigueperse, Nadège 28 February 2017 (has links)
Le développement comportemental de l’individu est particulièrement sensible aux influences sociales précoces. La mère, en tant que partenaire privilégié des jeunes dès la naissance, joue un rôle primordial dans leur survie et leur développement. Chez l’oiseau précoce, s’il est bien établi que le comportement maternel varie en fonction des caractéristiques personnelles de la mère, en revanche le rôle des jeunes dans ces variations et les conséquences sur leur développement restent encore méconnus. Chez la caille japonaise (Coturnix coturnix japonica), nous nous sommes, dans un premier temps, intéressés à l’influence d’un lien de parenté entre la mère et tous ses cailleteaux. Nous avons montré que ce facteur n’induisait pas de variation de son comportement maternel, permettant de poser l’hypothèse d’une faible sélectivité parentale chez cette espèce. Nous avons montré qu’en revanche un changement de comportement des cailleteaux suite à une modification de l’environnement prénatale pouvait améliorer le comportement maternel en diminuant l’agressivité maternelle. Nous avons ensuite démontré qu’un nombre de cailleteaux plus important induisait une amélioration des premières interactions mais amenait un rejet émancipatoire plus précoce de la part de la mère. Enfin nous avons exploré l’influence de la composition sexuée de la fratrie. Il apparait que les mères s’investissaient plus auprès de leurs petits mâles mais que cela était dépendant du sexe des autres membres de la fratrie. L’ensemble de nos travaux montre que les variations du comportement maternel ont une influence certaine sur le développement comportemental des jeunes dont le sexe détermine leur sensibilité aux différents traits maternels. / The behavioural development of the individual is particularly sensitive to early social influences. The mother, as a privileged partner of the young from the birth, plays a primordial role in their survival and their development. In the precocial bird, although it is well established that maternal behavior varies according to the mother's personal characteristics, the role of the young in these variations and the consequences on their development remain unknown. In the Japanese quail (Coturnix coturnix japonica), we were initially interested in the influence of a relatedness between the mother and all her chicks. We showed that this factor did not induce any variation in its maternal behaviour, allowing us to place the hypothese of a weak parental selectivity in this species. We showed that, on the other hand, a change in the chicks’ behaviour following a modification of the prenatal environment improved the maternal behaviour, decreasing maternal aggressivity. We then demonstrated that a greater number of chicks induced an improvement of the first interactions but induced an emancipatory rejection earlier by the mother. Finally, we explored the influence of the sexual brood composition. It appears that mothers were more involved in their male chicks but that it was dependent on the sex of the other members of the brood. All of our work shows that these variations in maternal behaviour have a sure influence on the behavioural development of chicks whose sex determines their sensitivity to different maternal traits.
12

Genética dos teores de fósforo e de zinco em sementes de feijão / Genetic of the phosphorus and zinc contents in common bean seeds

Rosa, Simone Saydelles da 24 August 2009 (has links)
The common bean (Phaseolus vulgaris L.) stands out as an important source of phosphorus and zinc in for human consumption. Therefore, the legume can be used to reduce the risk of deficiency of phosphorus and zinc and to reduce the number of cases of malnutrition. The objectives of this research were: (1) investigate the presence of maternal effect for phosphorus and zinc contents in common bean; (2) obtain estimates of heritability in early generations. The crossings were performed among cultivars Pérola x Guapo Brilhante and TPS Nobre x Guapo Brilhante. The F1, F1 reciprocal, F2, F2 reciprocal and backcross (RCP1 and RCP2) were obtained. The phosphorus and zinc contents were ascertained by nitric-perchloric digestion and determination on the UV-VIS spectrophotometer (phosphorus) and the atomic absorption spectrophotometer (zinc). The results showed presence of genetic variability for the phosphorus and zinc contents in common bean seeds. No was observed effect maternal significant for phosphorus and zinc contents in common bean seeds. For phosphorus, in the narrow sense heritability of high (65.54%) and low (21.37%) magnitude was obtained. For zinc, estimates of heritability in the narrow sense, high (77.84%) and moderate (57.46%) magnitude were obtained. Transgressive segregation was observed and an increase of 19.17% for the phosphorus content and of 37.26% for the zinc content in common beans seeds was obtained by crop breeding. The selection performed in the early generation may be effective for development of common bean germplasm with higher minerals content. / O feijão (Phaseolus vulgaris L.) destaca-se como uma importante fonte de fósforo e de zinco para a alimentação humana. Portanto, essa leguminosa pode ser utilizada para diminuir os riscos de deficiência de fósforo e de zinco e para reduzir o número de casos de má nutrição. Sendo assim, esse trabalho foi conduzido com os objetivos de: (1) investigar a presença de efeito materno para os teores de fósforo e de zinco em sementes de feijão; (2) obter estimativas de herdabilidade em gerações precoces. Os cruzamentos dirigidos foram realizados entre as cultivares Pérola x Guapo Brilhante e TPS Nobre x Guapo Brilhante e obtiveram-se as gerações F1, F1 recíproco, F2, F2 recíproco e retrocruzamentos (RCP1 e RCP2). Os teores de fósforo e de zinco foram quantificados por meio de digestão nítrica-perclórica e leitura em espectrofotômetro UV-VIS (fósforo) e em espectrofotômetro de absorção atômica (zinco). Os resultados obtidos revelaram presença de variabilidade genética para os teores de fósforo e de zinco em sementes de feijão. Esses minerais não apresentaram expressão de efeito materno significativo. Para o fósforo, herdabilidade em sentido restrito de alta (65,54%) a baixa magnitude (21,37%) foi obtida. Para o zinco, estimativas de herdabilidade, em sentido restrito, de alta (77,84%) a moderada magnitude (57,46%) foram constatadas. Segregação transgressiva foi verificada e um aumento de 19,17% para o teor de fósforo e de 37,26% foi obtido por melhoramento genético. A seleção precoce poderá ser efetiva no desenvolvimento de germoplasma de feijão com maior teor de minerais.
13

Distribuição de minerais e genética dos teores de potássio e de cobre em sementes de feijão / Distribution of minerals and genetic potassium and copper content in common bean seeds

Poersch, Nerison Luís 19 February 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The common bean (Phaseolus vulgaris L.), besides having high protein food, is also an excellent source of minerals for consuming. However, genetic variability for minerals contents has been observed and the accumulation of minerals occurs differently in the embryo and seed coat of bean seeds. It was not found studies on the genetics levels of potassium and copper in common bean seeds and a little about the potential of genetic improvement to increase in these minerals. Therefore, the aims of this study were: (1) investigate the accumulation of potassium, calcium, copper, iron and zinc in the seed coat and embryo of beans seeds; (2) examine the occurrence of maternal effect in the expression levels of potassium and copper in common bean seeds; (3) to estimate heritability and gain by selection for potassium and copper contents in early generations. Thus, the seed coats of two cultivars BRS Expedito and Carioca were separated from the embryo and minerals were determined in each fraction. Also, crosses were made between IAPAR 44 x Guapo Brilhante and BRS Expedito x BRS Valente, to study the genetics of potassium, and between IAPAR 44 x IAPAR 31 and Diamante Negro x TPS Bonito, to study copper amount. In the embryo was concentrated more than 80% of potassium, 64% copper and 68% zinc and the tegument has accumulated more than 94% of calcium and 51.06% to 60.12% of iron in the seeds of BRS Expedito and Carioca cultivars. There was no significant maternal effect on the expression levels of potassium and copper in common bean seeds. Estimates of broad sense heritability of 44.08% and 79.97%, and in the narrow sense of 33.26% and 43.05% were obtained for potassium content in IAPAR 44 x Guapo Brilhante and BRS Expedito x BRS Valente crossing, respectively. For copper content was observed estimates of heritability in the broad sense of 71.90% and 79.65%, and in the narrow sense of 51.98% and 61.99% for IAPAR 44 x IAPAR 31 and Diamante Negro x TPS Bonito crossing, respectively. The increase in potassium content, for breeding, may be difficult due to the significant effect of the environment variance. For copper content, it was possible an increased of 46.78% for breeding. / O feijão (Phaseolus vulgaris L.), além de ser um alimento altamente protéico, também é uma excelente fonte de minerais para a utilização na alimentação humana. Todavia, variabilidade genética para os teores de minerais tem sido constatada e a acumulação dos minerais pode ocorrer de maneira diferenciada no tegumento e no embrião das sementes de feijão. Não foram encontrados estudos sobre a genética dos teores de potássio e de cobre em sementes de feijão e sobre o potencial do melhoramento genético para o aumento desses minerais. Sendo assim, os objetivos desse trabalho foram: (1) investigar a acumulação de potássio, cálcio, cobre, ferro e zinco no tegumento e no embrião das sementes de feijão; (2) verificar a ocorrência de efeito materno na expressão dos teores de potássio e de cobre em sementes de feijão; (3) obter estimativas de herdabilidade e de ganho por seleção para os teores de potássio e de cobre em gerações precoces. Para tanto, o tegumento foi separado do embrião das sementes de duas cultivares de feijão BRS Expedito e Carioca e os minerais foram determinados em cada fração. Também, foram realizados cruzamentos dirigidos entre as cultivares IAPAR 44 x Guapo Brilhante e BRS Expedito x BRS Valente, para o estudo da genética do teor de potássio, e entre as cultivares IAPAR 44 x IAPAR 31 e Diamante Negro x TPS Bonito, para o estudo da genética do teor de cobre. No embrião se concentraram mais de 80% do potássio, 64% do cobre e 68% do zinco e no tegumento acumularam-se mais de 94% do cálcio e de 51,06% a 60,12% do ferro nas sementes de feijão das cultivares BRS Expedito e Carioca. Não foi observado efeito materno significativo na expressão dos teores de potássio e de cobre em sementes de feijão. Estimativas de herdabilidade em sentido amplo de 44,08% e de 79,97% e em sentido restrito de 33,26% e de 43,05% foram obtidas para o teor de potássio, nos cruzamentos IAPAR 44 x Guapo Brilhante e BRS Expedito x BRS Valente, respectivamente. Para o teor de cobre, foram observadas estimativas de herdabilidade em sentido amplo de 71,90% e de 79,65% e em sentido restrito de 51,98% e de 61,99% para os cruzamentos IAPAR 44 x IAPAR 31 e Diamante Negro x TPS Bonito, respectivamente. O aumento do teor de potássio, por melhoramento genético, poderá ser dificultado em função do expressivo efeito da variância do ambiente. Para o teor de cobre foi possível um aumento de 46,78%, por melhoramento genético.
14

Técnicas multivariadas e predição de genitores em trigo / Multivariate techniques and prediction of parents in wheat

Toigo, Marcelo de Carli 30 September 2015 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-21T12:40:45Z No. of bitstreams: 1 PGPV15MA182.pdf: 576083 bytes, checksum: 30203f1600225b3bef1ac5a58e2caece (MD5) / Made available in DSpace on 2018-02-21T12:40:45Z (GMT). No. of bitstreams: 1 PGPV15MA182.pdf: 576083 bytes, checksum: 30203f1600225b3bef1ac5a58e2caece (MD5) Previous issue date: 2015-09-30 / Embrapa / To continue moving forward in terms of getting new wheat cultivars, more productive and more stable, it is necessary to increase the genetic variability made available to the breeder and increase the frequency of favorable alleles in new cultivars. As a contribution to these goals it studied the selection of parents possessing combining ability and superior genetic potential. In this sense the work was divided into two chapters. The first objective was to evaluate the performance of the parent wheat using multivariate techniques in order to obtain genotypes that approximate a ideotype. 16 genotypes were sown. Four commercial cultivars (BRS 331, CD 124, BRS Parrudo and Marfim). Six F1 hybrids obtained by artificial crosses between cultivars, forming a complete diallel without reciprocals. Six progenies of these crossings in the F2 generation. The treatments were arranged in a randomized complete block design with three replications. Were measured in all plants of the plots, five phenotypic variables: days from emergence to heading, plant height, peduncle length, number of ears per plant and grain yield per plant. Through multivariate contrasts, there were comparisons of interest which were significant. Standardized canonical coefficients were used to determine the importance of each variable on the significance of employed to Mahalanobis distance as dissimilarity measure contrasts. Among the evaluated intersections BRS 331 x CD 124 and BRS Parrudo x Marfim show the greatest genetic variability and Marfim x CD 124 does not have genetic dissimilarity to the set of characters studied. Cross only elite genotypes is not recommended for the provision of genetic variability. In the second chapter the objectives of this study were: i) estimate general and specific combining abilities through diallel analysis in order to identify crossings most likely to generate segregating populations with superior performance; ii) verify the existence of reciprocal effect on the evaluated hibrids. Were evaluated four varieties, Marfim, BRS Parrudo, BRS 331 and CD 124, using the the method 1 (p2 all combinations with reciprocal) of Griffing (1956). Five phenotypic variables were observed. Days from emergence to heading (DEE). Plant height (EST), measured in centimeters from the ground to the top of the ear, without considering the awn. Peduncle length (PED), measured in centimeters, distance from the last internode to the base of the main stem spike. Number of ears per plant (NEP), counting the spikes that formed grains. Grain yield per plant (MGP), measured in grams. They were estimated the general combining ability (GCA), specific combining ability (SCA) and the reciprocol effects (REC) of the traits of interest. The following conclusions were obtained: a) the assessed parents are contrasting and there is genetic variability for the studied characters; b) is greater the importance of the GCC and additive effects in the genetic control of observed variables, c) the effect of CGC's parent Marfim is increased NEP and MGP, the BRS Parrudo is to increase DEE, CD 124 is to decrease DEE, the BRS 331 is to reduce all traits; e) the CD 124 x BRS 331 crossing has reciprocal effect increasing DEE when CD 124 is used as a female / Para continuar avançando em termos de obtenção de novos cultivares de trigo, mais produtivos e mais estáveis, torna-se necessário aumentar a variabilidade genética posta à disposição do melhorista e aumentar a frequência de alelos favoráveis nas novas cultivares. Como forma de contribuir para estes objetivos foi estudada a seleção de genitores que possuam capacidade combinatória e potencial genético superior. Nesse sentido o trabalho foi dividido em dois capítulos. No primeiro o objetivo foi avaliar o desempenho de genitores em trigo através de técnicas multivariadas com o intuito de obter genótipos que se aproximem de um ideotipo. Foram semeados 16 genótipos. Quatro cultivares comerciais (BRS 331, CD 124, BRS Parrudo e Marfim). Seis híbridos F1 obtidos por cruzamentos artificiais entre os cultivares, formando um dialelo completo, sem os recíprocos. Seis progênies destes cruzamentos na geração F2. Os tratamentos foram dispostos em blocos completos casualizados, com três repetições. Foram mensuradas, em todas as plantas das parcelas, cinco variáveis fenotípicas: dias da emergência ao espigamento, estatura da planta, comprimento do pedúnculo, número de espigas por planta e massa de grãos por planta. Através de contrastes multivariados, verificaram-se quais comparações de interesse foram significativas. Foram utilizados coeficientes canônicos padronizados para determinar a importância de cada variável na significância dos contrastes Empregou-se a distância generalizada de mahalanobis como medida de dissimilaridade. Entre os cruzamentos avaliados BRS 331 x CD 124 e BRS Parrudo x Marfim apresentam a maior variabilidade genética e Marfim x CD 124 não apresentam dissimilaridade genética para o conjunto de caracteres estudados. O cruzamento apenas de genótipos elite não é recomendado para a disponibilização de variabilidade genética. No segundo capítulo os objetivos deste trabalho foram: i) estimar capacidades gerais e específicas de combinação através de análise dialélica com o intuito de identificar cruzamentos com maior possibilidade de gerar populações segregantes com desempenho superior; ii) verificar a existência de efeito recíproco nos cruzamentos avaliados. Foram avaliados quatro cultivares, Marfim, BRS Parrudo, BRS 331 e CD 124, utilizando-se o o método 1 (todas as p2 combinações com os recíprocos) de Griffing (1956). Foram observadas cinco variáveis fenotípicas. Dias da emergência ao espigamento (DEE). Estatura da planta (EST), medida em centímetros, do solo até o topo da espiga, sem considerar as aristas. Comprimento do pedúnculo (PED), medido em centímetros, distância do último entrenó até a base da espiga do colmo principal. Número de espigas por planta (NEP), contagem das espigas que formaram grãos. Massa de grãos por planta (MGP), medido em gramas. Foram estimadas a capacidade geral de combinação (CGC), a capacidade específica de combinação (CEC) e o efeito recíproco (REC) dos caracteres de interesse. Foram obtidas as seguintes conclusões: a) os genitores avaliados são contrastantes e existe variabilidade genética para os caracteres estudados; b) é maior a importância da CGC e dos efeitos aditivos no controle genético das variáveis observadas, c) o efeito da CGC do genitor Marfim é de aumento do NEP e MGP, do BRS Parrudo é de aumentar DEE, do CD 124 é de diminuir DEE, do BRS 331 é de diminuir todos os caracteres avaliados; d) o cruzamento CD 124 x BRS 331 apresenta efeito recíproco diminuindo DEE quando CD 124 é utilizado como fêmea
15

Genética dos teores de cálcio e de ferro em grãos de feijão comum / Genetic of the calcium and iron contents in common bean grains

Jost, Evandro 15 February 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The common bean has significant levels of calcium and iron in grains, providing that this legume is used in human food controlling minerals deficiency. Furthermore, genetic variability for these minerals were observed, allowing the development of nutraceutics germplasm. As knowledge about the genetics of calcium levels and iron content are essential for increasing their concentration in grain, and this information is not available in the literature, were objectives of this work: (1) to investigate the occurrence of maternal effect to the levels of calcium and iron in common bean grains (2) to estimate heritability and gain from selection in early generations to the levels of calcium and iron in common bean grains. Therefore, controlled crossings were made between cultivars Pérola x TPS Bonito and TPS Bonito x BRS Expedito, for the study of genetics of calcium, and between cultivars Minuano x Diamante Negro and Diamante Negro x Iapar 44 for the study of genetics of iron. Maternal effect was observed in the expression levels of calcium and iron content common bean grains. For calcium, estimates of heritability, in the broad sense, of 66.75% and 74.65%, and in the narrow sense of 47.00% and 63.61% were obtained for the crossings between Pérola x TPS Bonito and TPS Bonito x BRS Expedito respectively. F2 plant with 33.64% more calcium (1.47 g kg-1 DM) than the genitor with greater value of this mineral, was obtained. For the content of iron, the estimative of heritability, in the broad sense in 76.36% and, in the narrow sense in 50.60% it was observed, from crossing between Minuano x Diamante Negro. It was possible to increase by 94% the iron content, for the genitor of higher mineral content of this because a plant F2 with 161.20 mg kg-1 DM was obtained. The selection of plants in the F2 generation obtained from these crossings can be made effective in the development of common bean germplasm with higher levels of calcium and iron content in grains because of the moderate to high estimates of heritability and gain from selection. / O feijão possui teores significativos de cálcio e de ferro nos grãos, proporcionando que essa leguminosa seja utilizada na alimentação humana para o controle da deficiência de minerais. Além disso, variabilidade genética para estes minerais foi observada, o que possibilita o desenvolvimento de germoplasma nutracêutico. Como o conhecimento sobre a genética dos teores de cálcio e de ferro são fundamentais para aumentar sua concentração nos grãos, e estas informações não foram encontradas na literatura, foram objetivos desse trabalho: (1) investigar a ocorrência de efeito materno para os teores de cálcio e de ferro em grãos de feijão; (2) obter estimativas de herdabilidade e de ganho por seleção em gerações precoces para os teores de cálcio e de ferro em grãos de feijão. Por isso, cruzamentos controlados foram realizados entre as cultivares Pérola x TPS Bonito e TPS Bonito x BRS Expedito, para o estudo da genética do cálcio, e entre as cultivares Minuano x Diamante Negro e Diamante Negro x Iapar 44, para o estudo da genética do ferro. Efeito materno foi observado na expressão dos teores de cálcio e de ferro em grãos de feijão. Para o cálcio, estimativas de herdabilidade, em sentido amplo, de 66,75% e de 74,65% e, em sentido restrito, de 47,00% e 63,61% foram obtidas para os cruzamentos entre Pérola x TPS Bonito e TPS Bonito x BRS Expedito, respectivamente. Uma planta F2 com 33,64% a mais de cálcio (1,47 g kg-1 de MS) do que o genitor com maior valor desse mineral, foi obtida. Para o teor de ferro, estimativas de herdabilidade, em sentido amplo, de 76,36% e, em sentido restrito de 50,60% foram observadas, a partir do cruzamento entre Minuano x Diamante Negro. Foi possível aumentar em 94% o teor de ferro em grãos de feijão, em relação ao genitor de maior teor desse mineral, pois uma planta F2 com 161,20 mg kg-1 de MS foi obtida. A seleção de plantas F2 nas gerações segregantes obtidas a partir destes cruzamentos realizados poderá ser efetiva no desenvolvimento de germoplasma de feijão com maiores teores de cálcio e de ferro nos grãos devido às estimativas de herdabilidade e de ganho por seleção moderadas a altas constatadas.
16

Parâmetros genéticos da concentração de ferro e de zinco em sementes de feijão andino / Genetic parameters of the iron and zinc concentrations in andean bean seeds

Zemolin, Allan Emanoel Mezzomo 23 February 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this work was to investigate if occurs maternal effect for iron and zinc concentrations in Andean bean seeds, to obtain genetic parameters estimates for these minerals, and to select recombinants for the bean biofortification program. For this, crosses were performed between the parents IAC Boreal x Light Red Kidney, and Ouro Branco x Light Red Kidney, to produce F1, F1 reciprocal, F2, F2 reciprocal and backcrossed RC11 (F1 x P1) and RC12 (F1 x P2) generations. Parents and the other generations obtained were evaluated at a field experiment conducted at 2014 dry season, in Santa Maria, RS. In the bean seeds of the segregating populations obtained, the iron concentration range from 24.70 to 102.40 mg kg-1 of dry matter DM and the seed zinc concentration range from 10.70 to 37.50 mg kg-1 of DM, without that the expression of maternal effect was observed. The broad-sense heritability estimates for the seed iron concentration in the Andean beans range from 52.36 to 67.83%, and for zinc, the range was from 63.36 to 72.22%. The narrow-sense heritability estimates for seed iron concentration ranged from 19.04 to 45.29%, and, for zinc, from 31.04 to 63.60%. The selection gains for the seed iron and zinc concentrations ranged from 18.58 and 17.21%, respectively. Therefore, from the tested crosses, it is possible to obtain recombinants with high iron and zinc concentrations in Andean bean seeds. / Os objetivos desse trabalho foram investigar se ocorre efeito materno para a concentração de ferro e de zinco em sementes de feijão Andino, obter estimativas de parâmetros genéticos para esses minerais e selecionar recombinantes para o programa de biofortificação de feijão. Para tanto, hibridações controladas foram realizadas entre os parentais IAC Boreal x Light Red Kidney e Ouro Branco x Light Red Kidney para a obtenção das gerações F1, F1 recíproco, F2, F2 recíproco e retrocruzamentos RC11 (F1 x P1) e RC12 (F1 x P2). As gerações obtidas foram avaliadas em um experimento de campo conduzido no período de safrinha de 2014 em Santa Maria, RS. Nas sementes de feijão das populações segregantes obtidas a concentração de ferro variou de 24,70 a 102,40 mg kg-1 de matéria seca MS e a concentração de zinco foi de 10,70 a 37,50 mg kg-1 de MS, sem que a expressão de efeito materno tenha sido observada. A herdabilidade em sentido amplo estimada para a concentração de ferro nas sementes de feijão Andino variou de 52,36 a 67,83% e para zinco, a amplitude foi de 63,36 a 72,22%. A herdabilidade em sentido restrito para a concentração de ferro variou de 19,04 a 45,29% e para zinco, de 31,04 a 63,60%. Os ganhos de seleção obtidos para a concentração de ferro e de zinco nas sementes de feijão Andino foram de 18,58% e de 17,21%, respectivamente. Assim, a partir dos cruzamentos testados é possível obter recombinantes com alta concentração de ferro e de zinco nas sementes de feijão Andino.
17

Dynamics of the aphid-ant mutualism

Tegelaar, Karolina January 2015 (has links)
An appreciation of the role of mutualism is essential when studying ecology and evolution in most ecosystems. Information covering aspects of mutualistic interactions can serve as a complement to the somewhat one-sided perspective from the 1950’s and 60’s that is used when teaching biology. In this thesis I applied an in-depth approach in which variation in the interspecific interaction between Aphis fabae aphids and Lasius niger ants was studied both in the field and in the laboratory. An emphasis was put on studies spanning several consecutive aphid generations. This approach revealed important differences between ant tended aphids and those without ants. In the lab, I found an initial decrease in aphid adult size and reproductive investment in the first generations after the start of ant tending, which was followed by a recovery to the pre-tending situation after about four generations. Another laboratory experiment showed an increase in alate (winged aphid) production from exposure to aphid alarm pheromones, and an even stronger decrease in alate production from ant attendance, suggesting that ants have gained the upper hand in an evolutionary conflict over aphid dispersal. Results from a field experiment further emphasized the possibility of negative effects of ants on aphids, showing that ant-tended aphid colonies experienced a higher rate of parasitoid attacks, produced fewer alates and embryos in adult aphids. The thesis highlights the scope for variation in the net effect of the interaction for aphids, and argues that, depending on the environmental circumstances, the interaction may sometimes and perhaps even often not really be a case of mutualism. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>
18

Impact of the age on early embryonic mortality (EEM) and embryo quality in the honey bee (Apis mellifera L.)

Al-Lawati, Hassan 09 December 2009 (has links)
Die vorliegende Studie über den Alterseinfluß bei der Honigbiene (Apis mellifera) besteht aus drei Hauptteilen. Der erste Teil befasst sich mit den Charakteristiken des Spermathekeninhalts alter und junger Bienenköniginnen. Im zweiten Teil geht es um die Auswirkungen des maternalen Alters auf die embryonale Mortalität und die juvenile Entwicklung der Brut. Im dritten Studienteil werden die Auswirkungen der Verweildauer in der Spermatheca auf die embryonale Mortalität, Embryonenqualität und Larvenentwicklung der Nachkommen untersucht. Der Samen aus den Spermatheken älterer Bienen weist andere Bewegungsmuster, eine geringere Geschwindigkeit und eine anderen Enzymaktivität auf als der Samen, der aus den Spermatheken junger Königinnen gewonnen wurde. Ein altersbedingtes Nachlassen der Fertlität ist daraus zu erklären. Im Laufe von zwei Jahren wurde die embryonale Entwicklung und das Larvenwachstum von Nachkommen unterschiedlich alter Königinnen untersucht (2-jährige bis frisch begattete Königinnen). Ältere Königinnen legten kleinere Eier und deren Nachkommen zeigten eine signifikant höhere Mortalitätsrate und kleinere Entwicklungsstadien als die Nachkommen jüngerer Königinnen. In einer weiteren Studie wurde die embryonale Mortalität und die Embryonalentwicklung von Nachkommen, die aus älteren Samen entstanden, untersucht. Dabei wurde der Samen aus den Spermatheken von alten und jungen begatteten Königin entnommen und jungfräuliche Königinnen übertragen. um das Alter der Königin auszugleichen. Bei der Untersuchung wurde eine höhere embryonale Mortalität und generell, zu gewissen Entwicklungszeiten signifikant, kleine Entwicklungsstadien bei den Königinnen festgestellt, die mit dem älteren Samen befruchtet wurden. Der relative Anteil an früher und später embryonaler Mortalität war auch zwischen den beiden Spermien-Alterlassen signifikant unterschiedlich. Die insgesamt hohe embryonale Mortalität auch in der Kontrollgruppe (Königinnen besamt mit Sperma aus den Spermathecen junger Königinnen) belegt, dass die Methode der Samenextraktion und Reinsemination einen großen Einfluß auf die Embryonalentwicklung hatte. Auch das Phänomen „leerer Eier“, welches in beiden Gruppen in gleicher Frequenz vorgefunden wurde, ist möglicherweise durch diese Methode bedingt. / This study on the honey bee, Apis mellifera, consists of three major parts. The first involves the characteristics of the spermathecal content of old and young honey bee queen. The second examines maternal age effects on embryonic mortality and juvenile development of offspring in the honey bee. The third investigates on the impact of semen age on early embryonic mortality, embryo quality and larvae development in the honey bee. Semen collected from the spermatheca of old queen bees show different sperm movement patterns and slower speed than sperm from the spermathecae of young queens. This ability is possibly related to different enzyme activities and metabolisms found in the spermathecal contents of differently aged queens. The embryonic development and larval growth rate have been examined with regard to queen honey bees of different ages (2-year-old to freshly mated queens) during two years (2005 and 2006). Early embryonic mortality “EEM” has been found to be higher within the eggs from old queens than in those from younger queens. Egg volume, consequently embryo size, reduces as queen’s age. A further investigates embryonic mortality in offspring originating from older semen. This has been carried out by extracting the semen from the spermatheca of an old or/and young mated queen and re-inseminating it into a virgin queen, in order to adjust for queen age. The investigation show higher embryonic mortality in the offspring from virgin queens inseminated with semen extracted from older queens than with semen from younger queens. The relative percentage of early and late embryonic mortality within the groups was different between queens re-inseminated with aged semen. High embryonic mortality in the control semen ages may be affected by the method of extracting from semen out of the spermatheca and re-inseminating it into a virgin queen. Empty egg phenomenon, which has been found in both groups, may be related to this technique
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THE VISUALIZATION, QUANTIFICATION AND MODELING OF GENOMIC INSTABILITY IN THE MOUSE AND IN CULTURED CELLS

LARSON, JON SCOTT January 2006 (has links)
No description available.
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Accelerated evolution of tissue-specific modulation of gene expression in sibling species Drosophila simulans and D. sechellia

Loomer, Madeline H. 10 1900 (has links)
<p><strong> </strong>Comparison of tissue-specific gene expression profiles between sibling species and their F1 interspecific hybrids are expected to reveal important information about the mechanisms involved in speciation and species divergence. In the present study, the expression of 40 candidate genes were analyzed using qRT-PCR in the testis, ovary and head tissues (both male and female) among the hybrids and their parental species. The expression patterns of these genes were profiled via quantification of misexpression (both over- and under-expression) relative to that of their parents as well as across tissues. We set out to answer several questions as well as test the following hypotheses: (1) Do <em>Drosophila</em> sibling species differ in tissue-specific distribution of gene expression? (2) Do males and females differ in tissue specific distribution of expression? (3) Do reciprocal crosses differ in patterns of gene misexpression suggesting X-effect? (4) Do sex and non-sex genes differ in extent of gene misexpression? The results of this study gave rise to two important findings. First, it was found that while the majority of genes showed head and testis expression in <em>Drosophila melanogaster</em>, more genes showed head and ovary expression in <em>D. sechellia</em>. Second, we observed differences in gene misexpression between reciprocal <em>D. simulans </em>and <em>D. sechellia</em> hybrid females, suggesting the role of maternal effect. Thus, these findings supply a wealth of data regarding tissue-specific expression in both fertile females and sterile male hybrids, the former of which have largely been ignored, as well as advance our understanding of the process of species divergence and speciation. Ultimately, this thesis will provide a contribution to the field of gene regulatory evolution.</p> / Master of Science (MSc)

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