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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Bee pollination of strawberries on different spatial scales – from crop varieties and fields to landscapes

Klatt, Björn Kristian 14 March 2013 (has links)
No description available.
2

Use of honey bees (Apis mellifera L.) in the pollination and the gain in productivity of grains in variety of soybean (Glycine max (L.) Merril.)adapted to Brazilian Northeastern climatic conditions / Uso da abelha melÃfera (Apis mellifera L.) na polinizaÃÃo e aumento de produtividade de grÃos em variedade de soja (Glycine max. (L.)Merril.) adaptada Ãs condiÃÃes climÃticas do nordeste brasileiro

Marcelo de Oliveira Milfont 28 February 2012 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The research was carried out between July and December 2009 using tropical soya bean (Glycine max (L.) Merril) cultivars irrigated by center pivots in the irrigation district of Jaguaribe-Apodi, belonging to the agribusiness Faedo Sementes situated at the Apodi plateau, Limoeiro do Norte, CearÃ, Brazil. The study aimed to investigate the use of Apis mellifera L. for pollination and productivity increment in the soya bean cultivars Monsoy 9144RR, BRS-CarnaÃba, BRS-SambaÃba, adapted for the tropical conditions of N and NE Brazil. The following aspects were investigated: floral biology, pollination requirements, pollination efficiency of A. mellifera ; behavior and pattern of foraging; use of A. mellifera to augment productivity per Ãrea, per plant, in oil and protein content; and potential for honey production in soya bean crops and risks of pesticide contamination of the honey. Results showed that the cultivars are attractive to honey bees and they concentrate their foraging for nectar collection in the morning shift. The varieties were capable of autopollination, however there were significant (p<0.05) increments of productivity when flowers were visited by biotic agents. A single honey bee visit raised productivity to equivalent (p>0.05) levels of those flowers open for pollination. Regarding absolute production, it differed significantly (p<0.05) from the areas where honey bees were introduced in the center or along the sideline of the plantation to that where flowers did not receive flower visits. The mean number of pods per plant was 49.64  2.64, 57.16  2.41 and 59.60  2.71; the mean number of seeds per plant was 104.68  5.13, 121.46  3.98 and 127.42  5.95; and the percentage of pods bearing three seeds was 18.65%, 20.43% and 23.72% for the caged, open and open + honey bees treatments, respectively. Oil and protein contents of seeds did not differ (p>0.05) among treatments. All colonies produced honey and by the end of the blooming period (30 days) total production reached 81.7 kg, with a mean production of 10.1  0.86 kg per hive and no pesticide residue was found. It was concluded that the soya bean cultivars adapted to N and NE Brazil can be used for honey production and the foraging behavior of A. mellifera visiting flowers only in the morning allows to recommend spraying the crop only in the late afternoon and early evening when bees are no longer in the crop to produce residue-free honey and prevent poisioning risks to the bees; also, introducing A. mellifera for pollination purpose can increase production over 25% especially due to augment in the percentage of three-seeded pods. / A pesquisa foi conduzida entre julho e dezembro de 2009 usando cultivares tropicais de soja (Glycine max (L.) Merril) irrigadas por pivà central no distrito de irrigaÃÃo Jaguaribe-Apodi, sendo o plantio pertencente à agroempresa Faedo Sementes situada na Chapada do Apodi, Limoeiro do Norte, CearÃ. O estudo teve por objetivo investigar o uso de Apis mellifera L. para polinizaÃÃo e incrementos de produtividade nas cultivares de soja Monsoy 9144RR, BRS-CarnaÃba, BRS-SambaÃba, adaptadas Ãs condiÃÃes tropicais do Norte e Nordeste brasileiro. Os seguintes aspectos foram investigados: biologia floral, requerimentos de polinizaÃÃo, eficiÃncia de polinizaÃÃo de A. mellifera; comportamento e padrÃo de forrageamento; uso de A. mellifera para elevar a produtividade por Ãrea, por planta, em conteÃdo de Ãleo e proteÃna dos grÃos; potencial para a produÃÃo de mel e os riscos de contaminaÃÃo deste mel. Os resultados mostraram que as cultivares estudadas sÃo atrativas para as abelhas melÃferas e elas concentram seu forrageio na coleta de nÃctar no turno da manhÃ. As variedades sÃo capazes de se autopolinizarem, contudo houve incrementos de produtividade significativos (p<0,05) quando as flores foram visitadas por agentes biÃticos. Uma Ãnica visita da abelha melÃfera elevou a produtividade para nÃveis equivalentes (p>0.05) ao das flores abertas para polinizaÃÃo. No que se refere à produÃÃo total, observou-se diferenÃas significativas (p<0,05) das Ãreas onde as abelhas foram introduzidas no centro ou ao longo da linha lateral do plantio para a Ãrea cujas flores nÃo receberam visitas. O nÃmero mÃdio de vagens por planta foi 49,64  2,64, 57,16  2,41 e 59,60  2,71; o nÃmero mÃdio de grÃos por planta foi 104,68  5,13, 121,46  3,98 e 127,42  5,95; e o percentual de vagens com trÃs grÃos foi 18,65%, 20,43% e 23,72% para os tratamentos onde as plantas foram engaioladas para nÃo receberem visitantes florais, deixadas abertas para receberem visitantes florais e aberta + a introduÃÃo de colÃnias de abelhas melÃferas, respectivamente. Os conteÃdos de Ãleo e proteÃna nÃo diferiram (p>0,05) entre os tratamentos. Todas as colÃnias produziram mel e ao final do florescimento (30 dias) a produÃÃo total alcanÃou 81,7 kg, com uma produÃÃo mÃdia por colmÃia de 10,1  0,86 kg e nenhum resÃduo de pesticida foi identificado no mel. Concluiu-se que as cultivares de soja adaptadas ao Norte e Nordeste do Brasil podem ser usadas para a produÃÃo de mel e o comportamento de forrageio de A. mellifera visitando flores somente no perÃodo da manhà permite recomendar a aplicaÃÃo de defensivos apenas no final da tarde ou cedo da noite, quando as abelhas nÃo se encontram no plantio para produzir mel livre de resÃduos de pesticidas e prevenir riscos de envenenamento das abelhas; tambÃm, a introduÃÃo de A. mellifera para polinizaÃÃo pode elevar a produtividade em mais de 25%, principalmente devido ao aumento no percentual de vagens com trÃs grÃos.
3

The africanized honey bee (Apis mellifera L.) for pollination and seed oil production in Jatropha curcas (L.) / A abelha melÃfera africanizada (Apis mellifera L.) na polinizaÃÃo e produÃÃo de Ãleo das sementes do pinhÃo manso (Jatropha curcas L.)

RÃmulo Augusto Guedes Rizzardo 27 February 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / The purpose of this thesis was to investigate the feasibility of using the honey bee (Apis mellifera L.) for pollination and yield increment in Jatropha curcas L. crops. Therefore, the floral biology and pollination process of J. curcas were studied as well as the foraging behavior and pollination efficiency of A. mellifera in this crop by the introduction of four colonies in a hectare. The work was carried out in a five years-old commercial plantation comprising 10ha, in the state of PiauÃ, (08Â32â19,0âS and 43Â56â19,7âW, 220 meters above sea level), Brazil, from March to July, 2009. Flowers were presented in protogynous inflorescences and the anthesis and most of pollen presentation took place mainly in the morning shift. Inflorescences last, in average, 20 days, with female flowers concentrating in the first third of the period and male flowers predominating in the second third, in a relation of 18.1:1 male/ female flower. Although this may favor xenogamy, the stigma receptivity lasts for, at least, five days ensuring the flower to reach the period of most pollen release in its own inflorescence, facilitating the occurrence of geitonogamy. Flowers pollinated up to four days after anthesis did not differ (p>0.05) in fruit setting to those pollinated in the first, second or third day after anthesis. Foraging by A. mellifera occurs throughout the day and peaks between 13h00min and 15h00min and is characteristic of nectar harvesting both in male and female flowers. Only one visit by A. mellifera to J. curcas flowers set 100% producing results similar (p>0,05) to those from manual xenogamy (96%), manual geitonogamy (94%) and open pollination (93%). However, only one visit by a bee was not enough to maximize the oil content per seed (213mg) in comparison to the open pollination and geitonogamy treatments (both 250mg). Besides that, it was possible to observe that geitonogamy led to greater oil production than xenogamy (237mg). It is concluded that A. mellifera is an efficient pollinator of this crop. The introduction of four honey bee colonies per hectare maximize oil production and produce the best results for all parameters studied. Furthermore, only one visit by the honey bee to J. curcas flowers was enough to prevent pollination deficit in this crop. / O objetivo desta tese foi investigar a possibilidade da utilizaÃÃo de Apis mellifera L. na polinizaÃÃo e incremento de produtividade da cultura do pinhÃo manso (Jatropha curcas L.). Para tanto, foi estudado a biologia floral e a polinizaÃÃo do pinhÃo manso bem como o comportamento forrageiro e a eficiÃncia polinizadora de Apis mellifera. O trabalho foi realizado em 10ha de plantio comercial jà estabelecido, com cinco anos de idade, no estado do PiauÃ, (08Â32â19,0âS e 43Â56â19,7âW e 220 metros de altitude), entre os meses de marÃo e julho de 2009. A antese das flores do pinhÃo manso, distribuÃdas em cimos com carÃter protogÃnico, ocorre basicamente no perÃodo matinal, bem como a maior oferta de pÃlen. As inflorescÃncias duram, em mÃdia, 20 dias, com maior concentraÃÃo de flores femininas no terÃo inicial e de masculinas, no terÃo mÃdio, com relaÃÃo de 18,1 flores masculinas para cada feminina. Embora esse fato favoreÃa a xenogamia, a receptividade do estigma por, pelo menos, cinco dias, garante a flor alcanÃar o perÃodo de maior oferta de pÃlen no prÃprio cimo, oportunizando a geitonogamia. As flores polinizadas atà o quarto dia frutificam da mesma forma que aquelas polinizadas no primeiro, segundo e terceiro dias apÃs antese, nÃo havendo diferenÃas significativas. O forrageamento por A. mellifera ocorre durante todo o dia, com maior pico entre 13h00m e 15h00m e à tÃpico de coleta de nÃctar, tanto nas flores masculinas quanto nas femininas. Apenas uma visita da abelha Ãs flores acarreta em 100% de vingamento, mostrando resultado semelhante, (p>0,05), aos tratamentos de xenogamia manual (96%), geitonogamia manual (94%), e polinizaÃÃo aberta (93%). PorÃm, uma visita apenas, nÃo à suficiente para produzir maior quantidade de Ãleo por semente (213mg), em comparaÃÃo com o tratamento de polinizaÃÃo aberta, e por geitonogamia (250mg). AlÃm disto, foi possÃvel constatar que hà maior produÃÃo de Ãleo por geitonogamia e nÃo por xenogamia (237mg). Conclui-se que a Apis mellifera à um polinizador eficiente da cultura. Sua introduÃÃo, com quatro colÃnias por hectare, maximiza a produÃÃo de Ãleo e produz os melhores resultados para todos os parÃmetros avaliados. AlÃm disso, apenas uma visita da abelha melÃfera Ãs flores do pinhÃo manso à suficiente para prevenir dÃficit de polinizaÃÃo.
4

Floral symmetry genes elucidate the development and evolution of oil-bee pollinated flowers of Malpighiaceae and Krameriaceae

Khojayori, Farahnoz N 01 January 2018 (has links)
Specialization on insect and animal pollinators is thought to be the driving force for the evolution of floral traits. Specifically in the New World (NW), the oil-bee pollination syndrome has led to the convergence of floral characters in two distantly related families of core eudicots, Malpighiaceae and Krameriaceae. Both families display a flag-like structure that establishes a zygomorphic flower and floral oil rewards in epithelial elaiophores. These traits work concomitantly to attract and reward female oil-bees that help fertilize these flowers and in return receive oils. The underlying genetics of floral zygomorphy were studied in several clades of core eudicots, which implicated CYCLOIDEA2-(CYC2-)like genes of the TCP gene family to play a role in the establishment and maintenance of this trait. In Malpighiaceae, previous work demonstrated that two CYC2-like genes, CYC2A and CYC2B, are expressed during development correlated with establishing zygomorphy in flowers of NW Malpighiaceae. In this thesis work, I investigated the underlying developmental and genetic basis for the establishment of non-homologous and yet functionally similar traits in the oil-bee pollinated flowers of Malpighiaceae and Krameriaceae. In Chapter 1, I investigated the modification of a conserved CYC2 genetic program in the Old World (OW) acridocarpoids of Malpighiaceae following a major biogeographic disjunction. And in Chapter 2, I studied the floral ontogeny and genetic basis of floral zygomorphy development in Krameria lanceolata Torrey of Krameriaceae. This thesis work sheds light on the significance of the interdisciplinary study of floral symmetry evolution through comparative pollination ecology, development, and genetics.

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