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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Biossistematica das especies do complexo Anemopaegma arvense (Vell.) Stellf. ex de Souza (Bignoniaceae, Bignonieae) = aspectos anatomicos, citologicos, moleculares, morfologicos e reprodutivos / Biossystematics of the Anemopaegma arvense (Vell.) Stellf. ex de Souza complex (Bignoniaceae, Bignonieae) : anatomical, cytological, molecular, morphological and reproductive aspects

Firetti-Leggieri, Fabiana 15 August 2018 (has links)
Orientadores: João Semir, Lucia Garcez Lohmann / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T14:46:18Z (GMT). No. of bitstreams: 1 Firetti-Leggieri_Fabiana_D.pdf: 148843515 bytes, checksum: bfb6fa893bb9997ed92b1d321acb5e7a (MD5) Previous issue date: 2009 / Resumo: O complexo Anemopaegma arvense é constituído por espécies e variedades de difícil delimitação. As opiniões dos taxonomistas, baseadas em caracteres morfológicos, são controversas em considerálas uma única espécie altamente polimórfica ou separá-las. Com o intuito de auxiliar na circunscrição de tais táxons, realizou-se um estudo biossistemático que englobou os seguintes assuntos: morfologia e morfometria de caracteres vegetativos e reprodutivos, anatomia da lâmina foliolar, contagem cromossômica, aplicação de marcadores AFLP para a delimitação genética, fenologia, biologia floral e polinização, sistema reprodutivo e hibridação e, poliembrionia em espécies do gênero com distintos níveis de ploidia. As morfoespécies do complexo diferem principalmente na morfologia foliar, sendo os táxons de Anemopaegma acutifolium caracterizados por folíolos elípticos a estreitamente oblanceolados com razão comprimento/largura do folíolo 3,5 a 18,5, os de A. arvense por folíolos lineares a estreitamente oblanceolados (razão 22,2 a 45,5) e, A. glaucum por folíolos largamente oblanceolados, oblongos a obovados (razão entre 1,69 e 3,9). A partir de caracteres morfológicos, como crescimento indeterminado dos ramos, exclui-se A. scabriusculum do complexo. O estudo morfométrico de caracteres foliares se mostrou útil para a separação das espécies. Já a morfometria de caracteres reprodutivos não foi informativa para a delimitação de tais táxons. Anatomicamente, as espécies e morfoespécies do complexo diferem quanto à disposição dos estômatos, tipo de epiderme constituição do sistema vascular da nervura mediana e composição da bainha dos feixes vasculares das nervuras laterais. Dentre as morfoespécies de A. acutifolium, A. acutifolium "típica" difere das demais por possuir folíolos anfiestomáticos e A. acutifolium "sarmentosa" por apresentar epiderme da face adaxial com desdobramentos pontuais. Já A. arvense é caracterizada pela ausência de cordões floemáticos no sistema vascular da nervura mediana e por possuir a margem destituída de parênquima fundamental subepidérmico. As morfoespécies de A. glaucum, "típica" da Bahia e "não glauca", são diferenciadas das demais pela ausência de calotas de fibras sobre o xilema nas nervuras laterais de grande e médio calibre. A. scabriusculum difere das outras espécies por possuir extensão de bainha nos feixes vasculares de grande e médio calibre e estômatos agrupados nas regiões internervurais com câmaras subestomáticas unidas. A contagem cromossômica revelou a condição poliplóide das espécies e morfoespécies do complexo, tendo estas 2n = 80. Os marcadores AFLP, apesar de serem bastante utilizados para a separação de táxons em nível infra-específico, não se mostraram eficientes para a delimitação das espécies do complexo Anemopaegma arvense. Quanto ao comportamento fenológico, A. acutifolium, A. arvense e A. glaucum apresentaram eventos anuais de brotamento, floração e frutificação. Já os indivíduos de A. scabriusculum têm dois a três eventos de floração e frutificação por ano. As flores das espécies são bastante semelhantes quanto à morfologia e recursos produzidos e são polinizadas pelas mesmas espécies de abelhas. Através de polinizações controladas constatou-se que tais espécies são auto-compatíveis e interférteis, havendo, portanto, alta probabilidade de formação de híbridos em populações simpátricas destas espécies. Notou-se uma relação positiva entre poliploidia e poliembrionia nas espécies do gênero aqui abordadas, tendo as sementes das espécies poliplóides mais de um embrião e as da espécie diplóide, A. album, somente um embrião. / Abstract: Anemopaegma arvense complex is constituted by species and varieties of difficult delimiting. Taxonomists opinions based upon morphologic features are controversial as to considering them either an only highly polymorphic species or separating them into different taxa. In order to help with the circumscription of such taxa, a biosystematic study was conducted which included the following subjects: morphology and morphometry of vegetative and reproductive features, leaflet blade anatomy, chromosome counting, AFLP markers application for genetic delimitation, phenology , floral biology and pollination, reproductive system and hybridization and polyembryony of the genus species with different ploidy levels .The morphs of the complex differ mainly in leaf morphology where the Anemopaegma acutifolium taxa are characterized by elliptical leaflets with the lengh / width ratio of leaflet falling within the range 3,5 to 18,5; A. arvense characterized by linear leaflets to narrowly oblanceolate (ratio between 22,2 and 45,5) and, A. glaucum by leaflets broadly oblanceolate, from oblong to obovate (ratio between 1,69 and 3,9).Taking into account morphologic features such as undetermined growth of the branches, A. scabriusculum may be excluded off the complex. The morphometric study of the leaf features has been found useful for species separation. However, the morphometry of reproductive features were not informative enough for the delimitation of such taxa. Anatomically, the species and morphs of the complex differ from one another as to the stomata disposition, epidermis type, vascular system constitution of the midrib and, composition of the vascular bundle of the lateral veins. Among the A. acutifolium morphs, A. acutifolium "típica" differs from the others for possessing anphistomatic leaflets and, A. acutifolium "sarmentosa" for presenting the adaxial face epidermis with punctual unfoldings. As for A. arvense, it is characterized by the absence of phloematic strings in the midrib vascular system and parenchyma absent in the marginal region. As for the two morphs, A. glaucum "típica" of Bahia and "não glauca", they are differentiated from the others by the absence of fibers caps on the xilem on the lateral ribs of large and medium caliber. A. scabriusculum differs from the other species for possessing extension sheath in the vascular bundles of large and medium caliber and, stomata grouped between vascular bundles presenting substomatic cameras linked to one another. The chromosome counting revealed polyploidy condition of the species and the morphs of the complex, those presenting 2n = 80. The AFLP markers, in spite of being quite utilized for taxa separation in an infraspecific level, were not found efficient for the species delimitation of Anemopaegma arvense complex. With relation to the phenologic behavior, A. acutifolium, A. arvense and A. glaucum presented annual events of sprouting, blooming and fructification. However, A. scabriusculumindividuals presented two to three blooming and fructification events a year. The flowers of the species are very similar to one another as to their morphology and to the resources provided by them and are pollinated by the same species of bees. Through controlled pollinations, it could be verified, that such species are self- ompatible and inter fertile, bearing, therefore, high probability of hybrid formation in sympatric populations of those species. A positive relationship between polyploidy and polyembryony in the species of the genus studied here was observed, as well as the fact that more than one embryo were found for polyploidy species seeds whereas for diploid species, A. album, only one embryo has been registered. / Doutorado / Doutor em Biologia Vegetal
32

Walking through the flower fields = the role of time and space on the evolution of pollination strategies / Caminhando entre flores : o papel de variações no tempo e espaço na evolução de estratégias de polinização

Rech, André Rodrigo, 1985- 24 August 2018 (has links)
Orientadores: Marlies Sazima, Jeff Ollerton / Texto em português e inglês / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T19:39:30Z (GMT). No. of bitstreams: 1 Rech_AndreRodrigo_D.pdf: 2738650 bytes, checksum: 6bf617833a57ef7d0a29fdcd8d4cd53b (MD5) Previous issue date: 2014 / Resumo: Os padrões encontrados em ecologia são resultado de processos contemporâneos interagindo com uma longa história de contingência. No entanto, poucos estudos têm buscado entender o papel relativo de fatores contemporâneos e pretéritos sobre padrões reprodutivos de plantas. No decorrer dessa tese foram consideradas essas duas dimensões (temporal e espacial) em estudos sobre polinização. A amplitude do estudo em relação ao tempo foi de horas até milênios, da mesma forma que para o espaço, para o qual se considerou desde metros até variações entre diferentes continentes na escala planetária. Os capítulos estão organizados em uma escala crescente de tempo e espaço. No primeiro capítulo foi considerada a variação fina de horas e metros no estudo sobre a polinização de algumas espécies de Davilla; nesse capítulo também são apresentados outros aspectos da história natural na família Dilleniaceae e uma abordagem filogenética para a evolução de algumas características florais. No capítulo 2, ao longo de vários anos, foi verificada a habilidade de visitantes florais depositar pólen, sua frequência e a importância de cada grupo de visitante nas flores de Knautia arvensis nesse período. O capítulo 3 demonstra variações no espaço tanto na morfologia floral e foliar como no crescimento do tubo polínico em diferentes testes de polinização, utilizando Curatella americana com populações distribuídas no Cerrado Brasileiro. No capítulo 4 é apresentada a variação espacial no sistema reprodutivo e a relação dos polinizadores com o nível de polinização cruzada e do passado climático com o nível de autopolinização espontânea, também tratando de C. americana. Para finalizar o capítulo 5 considera 50 inventários distribuidos ao redor do planeta categorizando as plantas em anemófilas ou zoófilas e demonstra o papel da precipitação (presente e passada) e da riqueza de espécies vegetais na prevalência de cada um dos modos de polinização. Como conclusão geral, fica clara a importância de se considerar as dimensões temporal e espacial nas interações entre plantas e polinizadores, a fim de entender como essas evoluem e como impactam na evolução da morfologia floral e nos sistemas de polinização / Abstract: Patterns in ecology are the products of current factors interacting with a longstanding history of contingency. Nevertheless, few studies have attempted to disentangle the contribution of past and current factors on plant reproduction patterns. Here we studied pollination considering both, spatial and temporal dimensions. Time variation goes from hours to millennia as well as space, whose importance was considered from meters to the whole planet. The chapter¿s sequence within the thesis is planned to go from the small to the large scale. We show the importance of fine grained variations such as hours and meters in the flower differentiation and pollination of two Davilla species in the chapter 1. In the chapter 2 we studied pollen deposition and visitation frequency in Knautia arvensis considering a year scale and showed the most important pollinator changing every year. In the Chapters 3 we used Curatella americana with populations studied across Brazilian Cerrado and show spatial variation in flower and leaf morphology and pollen tube growth. Chapter 4 also using C. americana shows the variation on the reproductive system across space, with cross-pollination related to pollinator availability and the level of autogamy underpinned by past climate. To finish, Chapter 5 deal with 50 community-based assessments of wind and animal pollination over the world and show the importance of precipitation (current and past) and plant species richness as major drivers of these proportion. As a general conclusion, it is clear that temporal and spatial factors cannot be ignored in spite to understand floral evolution and the interactions between plant and pollinators / Doutorado / Ecologia / Doutor em Ecologia
33

Consequences of self-fertilisation for fecundity and progeny performance in invasive plants.

Rodger, James Gordon. 01 November 2013 (has links)
Plants that can self-fertilise should, on average, be more invasive than plants that can not self-fertilise because they can reproduce regardless of the availability of mates and pollinators. Self-fertilisation should have a strong effect on invasiveness because, to become invasive, introduced plants have to pass through bottlenecks of low plant abundance when mates and pollinators are likely to be scarce. Under these conditions, reproduction of plants that can not self-fertilise is often limited by pollen receipt. Selfing may thus contribute to invasiveness by alleviating pollen limitation Allee effects (pollen limitation caused by low abundance) especially as theoretical work indicates that ability to invade and rate of invasion are highly sensitive to fecundity of small and isolated populations and single individuals. Recently, a correlation between ability to self-fertilise and invasiveness has been observed in several invasive floras, consistent with the hypothesis that species that can self-fertilise should be more invasive. However, it has not yet been demonstrated that this relationship arises from reproductive assurance. To establish the causal basis of a correlation between a plant trait and invasiveness, a mechanism linking that trait to invasiveness must be demonstrated. For this it is necessary to show firstly that the trait actually affects performance in the introduced range and secondly that plant performance affects invasiveness. Self-fertilisation is hypothesised to increase invasiveness by enhancing reproductive performance. The first step in testing this hypothesis is therefore to show that being able to self-fertilise increases fecundity, i.e. that it provides reproductive assurance. However, progeny from self-fertilisation often suffer from inbreeding depression – they perform worse than those from cross-fertilisation – so it is also necessary to show that this cost does not outweigh the reproductive assurance benefit of selfing. So far, reproductive assurance has been assessed in only a few invasive plant species. These studies did not assess inbreeding depression and only one investigated reproductive assurance in relation to abundance, finding no relationship. In this thesis I have sought to understand the importance of self-fertilisation for reproduction of invasive plants in the introduced range through case studies. In particular, I assessed whether reproductive assurance from self-fertilization alleviates Allee effects via pollen limitation. To do this I tested whether pollen limitation and reproductive assurance were greater at low plant abundance. Further, I conducted progeny trials to assess inbreeding depression, as this cost of selfing potentially negates reproductive assurance benefits. I also conducted observations and experiments to identify the principle pollinators of my study species as reproductive assurance and its relationship to plant abundance depend on pollinator visitation, The Australian trees Acacia mearnsii and A. dealbata are highly invasive in the study region of KwaZulu-Natal, South Africa. Through controlled pollination experiments I established that A. dealbata was self-compatible and autonomously self-fertilising, while previous studies reported A. mearnsii as self-incompatible. I identified the native honeybee Apis mellifera scutellata as the principal pollinator of A. mearnsii, A. dealbata and a co-occuring related invasive species, Acacia decurrens, in the study region. I conducted pollen supplementation experiments in two of these species, aiming to indirectly assess reproductive assurance from selfing in the self-compatible A. dealbata by comparing pollen limitation between this species and the self-incompatible A. mearnsii. In both species, I conducted pollen supplementation in single isolated trees and trees in continuous populations, to test whether pollen limitation was more severe in isolation. These pollen supplementation experiments were inconclusive with respect to pollen limitation but indicated that if there was pollen limitation in A. mearnsii, it was not related to isolation. Progeny trials in A. dealbata revealed relatively strong inbreeding depression in progeny growth and survival. This suggests that selfed progeny may not reach reproduction, so even if self-fertilisation provides reproductive assurance, it may not contribute to invasion in this species. As floral morphology of Acacia species prohibits the use of emasculation experiments to directly measure reproductive assurance, I conducted further investigations on Lilium formosanum, a large-flowered, autonomously self-pollinating invasive geophyte native to Taiwan. I identified the long tongued hawkmoth Agrius convolvuli as its primary pollinator in its introduced range in KwaZulu-Natal, South Africa. Trials of progeny from self- and crosspollination in the field (to 31 months) and in a controlled shade-house environment (to 26 months) showed no evidence of inbreeding depression in germination, growth or survival. Flowering was assessed in the shade-house as most plants did not flower in the field. Only one of five populations showed inbreeding depression in probability of flowering in the second year of growth but none showed inbreeding depression in the third year. Inbreeding depression was thus generally undetectable in L. formosanum. I tested for reproductive assurance and pollen limitation in L. formosanum by conducting floral emasculations and pollen supplementations in multiple populations across a range of population size and isolation in three different years. These experiments demonstrated that reproductive assurance was substantial and that pollen limitation was low or absent. Contrary to expectations, reproductive assurance was not greater in smaller populations and was greater for more isolated populations in only one of three years. However, that study did not include many very small populations. To assess reproductive assurance at very low abundance, I created arrays of emasculated and intact plants within and around naturally occurring populations at two sites. Isolated plants had higher reproductive assurance than did plants placed inside the continuous population at one site, supporting the hypothesis that selfing provides reproductive assurance against pollen-limitation Allee effects. However, in these studies, generally inadequate pollinator visitation was the main reason that L. formosanum exhibited reproductive assurance through selfing. The substantial reproductive assurance and minimal inbreeding depression displayed by L. formosanum makes a compelling case for the hypothesis that self-pollination promotes invasion. Nevertheless, demographic modelling will be necessary to assess whether increased fecundity through reproductive assurance results in increased rates of population growth and spread, and hence invasion, in this species. To assess whether reproductive assurance accounts for the relationship between ability to self-fertilise and invasiveness in plants generally, the contribution of self-fertilisation to invasiveness will have to be evaluated for a larger sample of invasive and non-invasive introduced species, using the approaches taken in this thesis, followed up by demographic modelling. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
34

Importância relativa da dispersão primária e secundária de sementes / Relative importance of primary and secondary seed dispersion

Camargo, Paulo Henrique Santos Araújo 04 June 2014 (has links)
Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T14:41:35Z No. of bitstreams: 1 CAMARGO_Paulo Henrique Santos Araujo_2015.pdf: 71258066 bytes, checksum: 2ebd9b1abb70042f246bff7555c29baf (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T14:41:46Z (GMT) No. of bitstreams: 1 CAMARGO_Paulo Henrique Santos Araujo_2015.pdf: 71258066 bytes, checksum: 2ebd9b1abb70042f246bff7555c29baf (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T14:41:53Z (GMT) No. of bitstreams: 1 CAMARGO_Paulo Henrique Santos Araujo_2015.pdf: 71258066 bytes, checksum: 2ebd9b1abb70042f246bff7555c29baf (MD5) / Made available in DSpace on 2017-01-12T14:42:01Z (GMT). No. of bitstreams: 1 CAMARGO_Paulo Henrique Santos Araujo_2015.pdf: 71258066 bytes, checksum: 2ebd9b1abb70042f246bff7555c29baf (MD5) Previous issue date: 2014-06-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / *
35

A flora esfingófila de uma floresta ombrófila densa montana no sudeste brasileiro e relações mutualísticas com a fauna de Sphingidae / The sphingophilous flora of a highland atlantic rainforest in the southeastern Brazil and mutualistic relationships with the Sphingidae fauna

Amorim, Felipe Wanderley, 1982- 21 August 2018 (has links)
Orientador: Marlies Sazima / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T12:52:20Z (GMT). No. of bitstreams: 1 Amorim_FelipeWanderley_D.pdf: 21680900 bytes, checksum: d3888d6cbcafe24a20fcecee1b94e4fb (MD5) Previous issue date: 2012 / Resumo: Polinização por esfingídeos é provavelmente um dos sistemas menos estudados em comunidades tropicais, especialmente na Mata Atlântica, que constitui um dos biomas mais diversos e ameaçados do planeta. Foram estudadas a flora esfingófila e a fauna de Sphingidae em uma área de Floresta Ombrófila Densa Montana (FODM) e analisados os processos ecológicos subjacentes às interações entre esfingídeos e plantas. Ao todo 24 espécies compuseram a flora esfingófila da área estudada, dentre as quais, quatro espécies possuem adaptações estritas à polinização por esfingídeos. A fauna de esfingídeos foi composta por 50 espécies com grande predomínio de mariposas com probóscides curtas. Plantas e esfingídeos apresentaram ajustamento morfológico significativo na distribuição dos comprimentos de tubos florais e de probóscides, porém ao contrário do padrão geral de outras áreas na região Neotropical, não houve ajustamento fenológico estrito entre esfingídeos e plantas na Mata Atlântica. A presença sazonal de mariposas com longas probóscides na área está relacionada principalmente a emigração de espécies oriundas de ecossistemas adjacentes à FODM. Limitação de polinizadores foi comum nas espécies vegetais mais especializadas o que limitou a produção de frutos. Os processos de seleção mediada por polinizadores nestas espécies, também foram afetados. Porém, processos locais de seleção mediada por polinizadores, provavelmente devem agir na estruturação de ajustamentos morfológicos entre esfingídeos e plantas, mesmo sendo variáveis no tempo e no espaço, conforme sugerem os resultados. Apesar da ausência de ajustamento fenológico estrito entre esfingídeos e plantas na Mata Atlântica, o padrão geral registrado em outros biomas sugere ocorrência de esfingídeos de longas probóscides coincidente com a floração de espécies esfingófilas com longos tubos florais. Como este grupo de plantas oferece maior quantidade de néctar em um "nicho privado" aos esfingídeos de longas probóscides, esse ajustamento fenológico poderia ser visto como estratégia para minimizar a competição por recursos florais entre mariposas com probóscides longas e curtas nas comunidades de Sphingidae / Abstract: Hawkmoth pollination is probably one of the least studied pollination systems in tropical communities, particularly in the Atlantic Rainforest, one of the most diverse and threatened biomes in the world. In this work we studied the sphingophilous plants and the Sphingidae fauna in an area of Highland AtlanticRainforest (HARF) and analyzed the ecological processes underlying the interactions between plants and hawkmoths. Altogether, 24 species composed the sphingophilous flora recorded to the study site, among which four species had strict adaptations related to hawkmoth pollination. The hawkmoth fauna was composed of 50 species with great predominance of short-tongued moths. Hawkmoths and plants showed a significant morphological match in the distribution of floral tubes and proboscises lengths, but unlike the general pattern obtained for other areas in the Neotropical region, we did not record a strict phenological match between hawkmoths and plants in the Atlantic Rainforest. The seasonal occurrence of long-tongued moths in the study site is related mainly to the income of migrating species from adjacent ecosystems to the HARF. Pollinator-limitation was common in the most specialized sphingophilous plants limiting fruit-set. Pollinator-mediated selection processes in highly specialized species were also impaired. However, local processes of pollinator-mediated selection may operate structuring the morphological match between hawkmoths and plants in spite of being variable in time and space, as suggested by the results. Despite the absence of a strict phenological match between hawkmoths and plants in the Atlantic Rainforest, the general pattern recorded to other analyzed biomes suggests a concurrence of long-tongued hawkmoths and long-tubed flowers through the phenological time. Since this group of plants offers greater amounts of nectar in a "private niche" where only long-tongued hawkmoths can have access, such phenological match could be viewed as a strategy to reduce competition for floral resources between long- and short-tongued moths in the Sphingidae community / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

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