Thesis (Ph. D.)--University of Michigan, 1942. / Papers no. 777 and no. 801 from the Department of Botany, University of Michigan. Reprinted from the American journal of botany, v. 28, no. 8, October, 1941, and Proceedings of the American Society for Horticultural Science, v. 40, 1942. "Literature cited" at end of each part.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 67-71).

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13149号 / 論農博第2855号 / 新制||農||1056(附属図書館) / 学位論文||H30||N5096(農学部図書室) / (主査)教授 北島 宣, 教授 土井 元章, 教授 奥本 裕 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Negative impacts from intensifying agriculture have generated concerns that pollinator-dependent crop species, such as courgette Cucurbita pepo L., may be experiencing a pollination deficit. This thesis explores the extent to which pollination influences fruit set; how pollination could be improved; and how in doing so growers’ profits and agricultural resilience could increase, using UK field-grown courgettes as a model system. Inspired by evidence of parthenocarpy (fruit set in the absence of fertilisation) in courgette, a systematic review showed extensive use of parthenocarpy to circumvent the need for pollination in other ‘pollinator-dependent’ crop species across the globe. Nonetheless, pollination significantly increased yield and pollinators were abundant enough to fulfil the pollination requirements of courgette, which if extrapolated to the rest of the UK, equates to pollinators contributing approximately £2.7 million to annual UK courgette production. Furthermore, wild flowers within fields were shown to be effective at increasing the abundance of bumblebees and solitary bees. Further exploration of the mutualistic relationship between courgettes and pollinators showed that courgette can improve populations of Bombus terrestris (using the Bumble-BEEHAVE model), an important pollinator of courgette. This thesis concludes that pollination is a vital mechanism for ensuring optimal courgette yields and that whilst pollination levels were maximal at study sites, simple management, such as encouraging wild flowers within courgette fields could help to attract pollinators to courgette flowers and support bees’ nutritional requirements beyond the extensive, yet transient, resource provided by courgette. Understanding a crop’s requirement for pollinators can also aid growers in their decision making about what varieties and sites should be used which could increase their agricultural resilience and further their economic advantage. Further work is needed to understand how other environmental factors interact with pollination to influence fruit set so that growers can prioritise key regulating services in their management for optimal crop yields.

Parthenocarpy, or seedless fruit development, has an agronomic importance in many horticultural crops. In most fruit, fertilization or seed set usually determines whether fruit growth is sustained. Naturally occurring parthenocarpy results from a genetic lesion that permits fruit to develop in the absence of fertilization and seed development. Parthenocarpy can also be induced artificially with cytokinin, gibberellin or auxin plant growth regulators applied to anthesis pistils. This thesis describes genetic research using Arabidopsis as a model plant to identify integral mechanisms that control parthenocarpy and the initiation of fruit development. The growth and structure of the Arabidopsis pistil was determined post-fertilization. Experiments were designed to understand how plant growth regulators induce Arabidopsis silique (fruit) development in emasculated anthesis stage pistils. Exogenous gibberellin (GA3) induced growth and cellular differentiation most comparable to pollinated pistils. Dependencies on gibberellins during silique development were examined in mutants defective for gibberellin biosynthesis (ga1, ga4-1, ga5-1) or perception (spy-4, gai-1). Although exogenous GAs are effective at inducing parthenocarpy, mutant studies concluded that GAs are not the sole cue for fruit development in Arabidopsis. Mutants blocked in GA perception could develop siliques in response to pollination, auxin, cytokinin but not to exogenously applied gibberellins. Silique structure in pollinated gai-1 and ga5-1 provided strong evidence for a model supporting evidence of an auxin-like signal regulating structural development and that GAs limit anticlinal cellular division. A specialized function for GAI and related GRAS family members in controlling cellular division during fruit development was uncovered. A mutant that forms parthenocarpic siliques without fertilization (fwf), was also characterized. The presence of surrounding floral whorls reduced the extent of parthenocarpic silique formation in fwf. Silique growth in the fwf background was examined when hormone perception, ovule and carpel identity functions were removed genetically. This established that FWF functions independent of GAI-mediated GA perception. Carpel identity conferred by FUL was critical for parthenocarpic silique elongation and ovule development beyond integument initiation, nucellar specification and subsequent morphogenesis, was essential for parthenocarpic silique development in fwf. Silique elongation occurs over a four-day period post-pollination or post-anthesis. This coincides with a similar time period in which fwf ovules remained receptive to fertilization. These observations are congruent with the hypothesis that FWF potentially represses a signal transduction process initiated within the ovule that mediates subsequent transition from carpel to silique development. Further analysis revealed that aberrant testa shape (ats) a mutant defective in integument formation enhanced parthenocarpic development in fwf, indicating that an ovule located repressor other than fwf can function to affect silique formation. Other studies have shown that ethylene can modulate auxin-dependent growth in both aerial and root tissues by altering both polar and lateral auxin transport. The contribution of ethylene perception to signal transduction between ovule and carpel was also genetically assessed. Constitutive ethylene responses, conferred by ctr1-1, enhanced cellular expansion in fwf and also the autonomous silique development in fis-2, which develops autonomous endosperm. ats ctr1-1 and ino ctr1-1 double mutants were also found to be parthenocarpic. This indicates that ethylene perception and integumentary structure play an important role in autonomous silique development, conceivably by changing the polar and lateral movement of an auxin-like signal within the integumentary tissues of the ovule. fwf and ats were fine mapped on chromosome 5 of Arabidopsis. Candidate genes were identified corresponding to both mutations but only the identity of FWF was established. Auxin Response Factor 8 (ARF8) was cloned and sequenced from the fwf mutant background. The gene encodes a protein with a amino-terminal DNA binding domain and a carboxy-terminal protein binding domain which homo- and hetero- dimerizes with other ARF or Aux / IAA class proteins. ARF8 sequence from fwf mutants encoded a mutation in the translation start site. Complementation of fwf plants by the transformation of wild type copies of ARF8 into fwf plants was hampered by reduced transformation efficiency. However wild type L.er and No.O plants transformed with mutant copies of ARF8 were obtained in higher frequency, and these formed parthenocarpic siliques when primary transformants were emasculated. This indicated that an interfering protein is produced from the mutated ARF8 gene that has altered regulatory activity. Sequence analysis indicated this and found that interference resulted from functional activity of the Q-rich and carboxy-terminal domains of the ARF8 protein. This inference is consistent with other published molecular data, which has demonstrated that the carboxy-terminal domain, together with the Q-rich region of selected ARF members, can activate auxin-responses. Thus the FWF / ARF8 protein may have a dual role, repressing carpel growth development through the DNA binding domain and then ensuring activation of silique development through the carboxy-terminal domain. The combined molecular and genetic data has been used to construct models concerning the genetic control of silique development. The first model considers the role of plant hormones and how signals from floral whorls surrounding the carpel and from within the ovule control silique growth. A model is also presented for the control of adaxial growth and development of the outer integument by the INNER NO OUTER gene. Finally the role of FWF and SPY in controlling floral tissue identity and boundary tissue specification is considered in a third model. Modification of the FWF / ARF8 gene could be used as a tool to improve fruit set and retention in horticultural crops, in addition to creating seedless parthenocarpic fruit. / Thesis (Ph.D.)--Agriculture and Wine, 2001.

Submitted by EDER MARQUES DA SILVA null (biodida@yahoo.com.br) on 2016-05-23T19:54:50Z No. of bitstreams: 1 TESE_Eder30 04.pdf: 2779899 bytes, checksum: c45da4458d84767b126f9e3b3af87767 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-05-25T18:03:50Z (GMT) No. of bitstreams: 1 silva_em_dr_bot.pdf: 2779899 bytes, checksum: c45da4458d84767b126f9e3b3af87767 (MD5) / Made available in DSpace on 2016-05-25T18:03:50Z (GMT). No. of bitstreams: 1 silva_em_dr_bot.pdf: 2779899 bytes, checksum: c45da4458d84767b126f9e3b3af87767 (MD5) Previous issue date: 2016-05-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O processo de frutificação é definido como a transição de um ovário em estágio quiescente para estágio de iniciação de formação do fruto. Esta transição é iniciada em resposta aos eventos de polinização e fertilização, os quais induzem o início dos processos fisiológicos e moleculares, que, ao final, irão originar o fruto. A frutificação é fundamental para reprodução nas plantas com flores (Angiospermas). Já foi demonstrado que hormônios (tais como auxina e giberelina) podem atuar em paralelo com fatores de transcrição durante o desenvolvimento do fruto. Alguns desses fatores de transcrição são pós-transcricionalmente regulados por microRNAs. MicroRNAs, são pequenos RNAs (20-22 nt) que regulam pós-transcricionalmente a expressão de genes endógenos, modelando o transcriptoma e a produção de proteínas.Entretanto, vias genéticas orquestradas por microRNAs associadas com o desenvolvimento de ovário, e consequentemente, do fruto em tomateiro (Solanum lycopersicum L.), permanecem pouco exploradas. Neste trabalho, foi investigada a contribuição da via SlymiR159/GAMYB-like durante o processo de desenvolvimento do ovário e frutificação em tomateiro. O miR159 e seus alvos (SlyGAMYB1 e 2) são dinamicamente expressos durante os estágios de desenvolvimento do ovário e consequentemente do fruto. Eventos transgênicos de tomateiro (cv. Micro-Tom) apresentando super-expressão do precursor SlyMIR159 (denominados OE-159) exibiram frutificação precoce quando comparadas aos controles. Notavelmente, todos os eventos OE-159 apresentaram formação de frutos partenocárpicos. Tal alteração no padrão de frutificação pode estar correlacionada a repressão do gene SlyGAMYB1 em períodos pré-antese de desenvolvimento do ovário, é possível que a atividade do fator de transcrição SlyGAMYB1 seja importante para prevenir o início da frutificação antes da polinização. Além disso, a via regulada pelo miR167/SlyARF8A mostrou-se desregulada em ovários pré-antese de plantas transgênicas OE-159. Adicionalmente, mesmo com o fenótipo de partenocarpia e frutificação precoce, não houve alterações na quantidade de hormônios (e.g. giberelina, ácido abscisico e auxina) relacionados à formação de frutos nas plantas transgênicas OE-159. Contudo, a via miR159/GAMYB-like encontra-se reprimida nos primeiros estágios da frutificação (após polinização e fertilização) e a expressão do SlyARF8A (alvo do miR167) encontra-se induzida na presença de auxina. Em conjunto, nossos dados sugerem que o crosstalk entre as vias moduladas pelos microRNAs miR159 e miR167, integrados com a via de sinalização de auxina, é importante para a frutificação em tomateiro. / Fruit set, defined as the shift from quiescent ovary to a fast-growing young fruit, is a key process for fruit production in flowering plants. It has been shown that hormones (such as auxin and gibberellin) act in parallel with transcription factors during fruit set. Some of these are post-transcriptionally regulated by microRNAs (miRNAs). MiRNAs are a group of small non coding RNAs (21-22 nt) that act by regulating post-transcriptionally genes in plants and animals However, microRNA-regulated genetic pathways associated with tomato (Solanum lycopersicum L.) ovary development and fruit set remain poorly exploited. Here, we investigated the functional role of miRNA159/SlyGAMYBlike in tomato ovary development and fruit set. MiR159 and its targets were dynamically expressed in developing flowers, ovaries and fruit tissues. Transgenic tomato (cv. Micro-Tom) plants over-expressing the SlyMIR159 (termed OE-159) exhibited fruit set earlier when compared with control plants. Strikingly, all transgenic lines presented parthenocarpy fruits. Such developmental modification may be a result of the repression of SlyGAMYB1 in pre-anthesis ovaries, our data suggest that SlyGAMYB1 activity is important to prevent fruit set before pollination. In addition as a consequence of this repression, the miR167 node (miR167/SlyARF8 pathway) was mis-regulated in OE-159 ovaries. In addition, we observed that levels of auxin, gibberellin (GA) and abscisic acid (ABA) in pre-anthesis ovaries of several transgenic lines overexpressing the SlyMIR159 were similar to those of the control. Moreover, our experiments suggested that auxin and GA may act repressing the miR159 node during fruit set initiation, in order to release the miR167-targeted SlyARF8A expression during fruit set. Our data show how two microRNA nodes (miR159 and miR167) integrated with hormone signalling into a circuit that coordinates successive steps along ovary and fruit development.

Orientador: Fábio Tebaldi Silveira Nogueira / Resumo: O processo de frutificação é definido como a transição de um ovário em estágio quiescente para estágio de iniciação de formação do fruto. Esta transição é iniciada em resposta aos eventos de polinização e fertilização, os quais induzem o início dos processos fisiológicos e moleculares, que, ao final, irão originar o fruto. A frutificação é fundamental para reprodução nas plantas com flores (Angiospermas). Já foi demonstrado que hormônios (tais como auxina e giberelina) podem atuar em paralelo com fatores de transcrição durante o desenvolvimento do fruto. Alguns desses fatores de transcrição são pós-transcricionalmente regulados por microRNAs. MicroRNAs, são pequenos RNAs (20-22 nt) que regulam pós-transcricionalmente a expressão de genes endógenos, modelando o transcriptoma e a produção de proteínas.Entretanto, vias genéticas orquestradas por microRNAs associadas com o desenvolvimento de ovário, e consequentemente, do fruto em tomateiro (Solanum lycopersicum L.), permanecem pouco exploradas. Neste trabalho, foi investigada a contribuição da via SlymiR159/GAMYB-like durante o processo de desenvolvimento do ovário e frutificação em tomateiro. O miR159 e seus alvos (SlyGAMYB1 e 2) são dinamicamente expressos durante os estágios de desenvolvimento do ovário e consequentemente do fruto. Eventos transgênicos de tomateiro (cv. Micro-Tom) apresentando super-expressão do precursor SlyMIR159 (denominados OE-159) exibiram frutificação precoce quando comparadas aos controles. Notavelment... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fruit set, defined as the shift from quiescent ovary to a fast-growing young fruit, is a key process for fruit production in flowering plants. It has been shown that hormones (such as auxin and gibberellin) act in parallel with transcription factors during fruit set. Some of these are post-transcriptionally regulated by microRNAs (miRNAs). MiRNAs are a group of small non coding RNAs (21-22 nt) that act by regulating post-transcriptionally genes in plants and animals However, microRNA-regulated genetic pathways associated with tomato (Solanum lycopersicum L.) ovary development and fruit set remain poorly exploited. Here, we investigated the functional role of miRNA159/SlyGAMYBlike in tomato ovary development and fruit set. MiR159 and its targets were dynamically expressed in developing flowers, ovaries and fruit tissues. Transgenic tomato (cv. Micro-Tom) plants over-expressing the SlyMIR159 (termed OE-159) exhibited fruit set earlier when compared with control plants. Strikingly, all transgenic lines presented parthenocarpy fruits. Such developmental modification may be a result of the repression of SlyGAMYB1 in pre-anthesis ovaries, our data suggest that SlyGAMYB1 activity is important to prevent fruit set before pollination. In addition as a consequence of this repression, the miR167 node (miR167/SlyARF8 pathway) was mis-regulated in OE-159 ovaries. In addition, we observed that levels of auxin, gibberellin (GA) and abscisic acid (ABA) in pre-anthesis ovaries of several tran... (Complete abstract click electronic access below) / Doutor

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13345号 / 論農博第2888号 / 新制||農||1079(附属図書館) / 学位論文||R2||N5252(農学部図書室) / (主査)教授 奥本 裕, 教授 土井 元章, 教授 冨永 達 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Made available in DSpace on 2014-06-11T19:33:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-27Bitstream added on 2014-06-13T18:45:21Z : No. of bitstreams: 1 nicodemo_d_dr_jabo.pdf: 529924 bytes, checksum: 436115f2f4f07ab45288d9c5ed7c0e35 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O cultivo em estufas propicia a obtenção de produtos de excelente qualidade, porém, os agentes polinizadores que contribuem na maximização da produção não são adaptados a ambientes fechados. Utilizando três cultivares tipo Japonês e duas tipo Aodai de pepino (Cucumis sativus L.) foram realizados dois experimentos em três estufas localizadas na USP/Ribeirão Preto. Os objetivos foram estudar a biologia floral das cultivares no que se refere ao número de flores produzidas por planta, período de antese, porcentagem de açúcares do néctar, produção e viabilidade dos grãos de pólen, receptividade do estigma e atratividade de flores e, a importância das abelhas Jataí (Tetragonisca angustula), Iraí (Nannotrigona testaceicornis) e Africanizadas (Apis mellifera) quanto a freqüência das abelhas nas flores, tempo e tipo de coleta e produção de frutos quanto ao peso, comprimento e diâmetro. O manejo das abelhas africanizadas foi estudado e um modelo de núcleo com dois alvados desenvolvido. As flores das cultivares avaliadas têm antese de, aproximadamente, 10 horas. A viabilidade dos grãos de pólen e a receptividade do estigma não são limitantes na polinização de pepino Japonês e Aodai. Os índices de frutificação de pepino Japonês por partenocarpia são altos (78 %), porém há aumento de 19% quando ocorre polinização por abelhas. A cultivar Aodai depende dos insetos para produção de frutos, sendo que flores visitadas até às 10h30 originaram frutos mais pesados. As abelhas Africanizadas se adaptaram a colméia com dois alvados, visitando flores em parte do dia dentro da estufa, promovendo a polinização, e o restante fora, ambiente com maior oferta de recursos. / The cultivation in greenhouses allows obtaining products of excellent quality, however, the pollinators that contribute maximizing the production are not adapted to the indoor environment. Using three Japanese and two Aodai cultivars of cucumber (Cucumis sativus L.) were conducted two experiments in three greenhouses located in USP / Ribeirão Preto. The aims were to study the cultivars floral biology with regard to the number of flowers produced per plant, anthesis period, the percentage of sugars in nectar, production and viability of pollen grains, stigma receptivity and attractiveness of flowers, and the importance of Jataí (Tetragonisca angustula), Iraí (Nannotrigona testaceicornis) and Africanized honeybees (Apis mellifera) with regard to the frequency of bees in the flowers, time and type of collection and fruit weight, length and diameter. The management of Africanized bees has been studied and a hive with two entrances was developed. The anthesis period was approximately of 10 hours. The viability of pollen grains and the receptivity of stigma did not limit the pollination of Japanese cucumber and Aodai. The parthenocarpy fruit set of Japanese cucumber was high (78%), but there is an increase of 19% in fruit set when the flowers were pollinated by bees. The cultivar Aodai depends on the insects for production of fruits. Flowers visited until 10h30 originated the heaviest ones. Africanized bees adapted itself to the hive with two entrances, visiting flowers in part of the day inside the greenhouse, promoting pollination, and the rest outside, the environment with greater supply of resources.