O Passion flower little leaf mosaic virus (PLLMV) foi encontrado causando danos severos em plantios de maracujazeiro (Passilora edulis f. flavicarpa) em dois municípios do Estado da Bahia no ano de 2001. Nesses locais foi constatada que a incidência deste begomovirus estava relacionada à colonização das plantas por Bemisia tabaci, cujo biótipo não foi identificado. Até o momento este vírus não parece constituir grave ameaça a cultura do maracujazeiro, o que aparentemente esta relacionado ao fato de P. edulis f. flavicarpa não ser preferida para a alimentação desse aleyrodídeo. Assim, os objetivos deste trabalho foram: a) selecionar espécies silvestres de Passiflora resistentes a este begomovirus que possam ser úteis em futuro programa de melhoramento genético; b) identificar possíveis hospedeiros alternativos do patógeno entre algumas espécies da vegetação espontânea e cultivadas e c) avaliar se adultos de B. tabaci biótipo B presentes no Estado de São Paulo são capazes de transmitir esse vírus. A reação de espécies silvestres de Passiflora foi avaliada por enxertia em maracujazeiro amarelo infectado que serviu como de fonte de inóculo. As avaliações foram feitas por meio da expressão de sintomas, análise de PCR e teste de recuperação do vírus para maracujazeiro amarelo. As espécies P. alata, P. quadrangularis, P. morifolia, P. serrato-digitata, P. suberosa e P. foetida foram suscetíveis ao PLLMV, enquanto P. caerulea, P. cincinnata, P nitida, P. mucronata e P. giberti se mostraram resistentes a este vírus. No estudo de hospedeiros alternativos, primeiramente o PLLMV foi inoculado mecanicamente nas seguintes espécies vegetais: Capsicum annuum, Chenopodium quinoa, Solanum lycopersicon, S. tuberosum, P. edulis f. flavicarpa, Phaseolus vulgaris, Nicotiana benthamiana e Sida sp.. Somente N. benthamiana foi infectada sistemicamente. Posteriormente foram feitas tentativas de transmissão desse begomovirus por meio de enxertia, usando-se como fonte de inóculo (porta-enxerto), plantas infectadas de N. benthamiana. Foram avaliadas as seguintes espécies vegetais: S. pimpinellifolium, S. lycopersicon, S. tuberosum, N. benthamiana, D. stramonium, C. annuum, N. glutinosa e Sida rhombifolia. O vírus foi transmitido somente para plantas de S. pimpinellifolium. As sucessivas transmissões mecânicas do PLLMV em N. benthamiana permitiram a seleção de uma estirpe fraca e protetora deste begomovirus. B. tabaci biótipo B não foi capaz de transmitir o PLLMV. / The Passion flower little leaf mosaic virus (PLLMV) was found causing severe damage in passion flower (Passilora edulis f. flavicarpa ) orchards in two counties of Bahia state, in 2001. The high incidence of this begomovirus was related to the colonization of plants by Bemisia tabaci, whose biotype was not indentified. To date this virus doesnt seem to be a serious threat to the passion flower cultivation, which apparently is related to the fact that P. edulis f. flavicarpa is not a preferred specie for whitefly feeding. The aim of this work were: a) to select wild species of Passifloraceae resistant to PLLMV, that may be useful in future breeding program; b) to indentify some possible alternative hosts of the pathogen among some weed and cultivaded species and c) to evaluat whether adults of B. tabaci biotype B are capable of transmitting this virus. The reaction of wild species of Passifloracea was evaluated by grafting on infected yellow passion fruit that served as a source of inoculum. The evaluation of these plants were done by means of symptoms, PCR test and biological recovery of the virus to yellow passion fruit. The sepecies P. alata, P. quadrangularis, P. morifolia, P. serrato-digitata, P. suberosa and P. foetida were susceptible to PLLMV, while P. caerulea, P. cincinnata, P nitida, P. mucronata and P. giberti were resistant to this virus. In the study of alternative hosts, at first, PLLMV was mechanically inoculated in the following species: Capsicum annuum, Chenopodium quinoa, Solanum lycopersicon, S. tuberosum, Passiflora edulis f. flavicarpa, Phaseolus vulgaris, Nicotiana benthamiana and Sida sp. Only N. benthamiana was systematically infected. Subsequently, graft transmission of PLLMV was carried out using infected N. benthamiana as source of inoculum (root stock). The following species were evaluated: Solanum pimpinellifolium, S. lycopersicon, S. tuberosum, N. benthamiana, D. stramonium, C. annuum, N. glutinosa and Sida rhombifolia.The virus was transmited only to S. pimpinellifolium. Successive mechanical transmissions of PLLMV in N. benthamiana led to the selection of a mild and protective strain of this begomovirus. B. tabaci biotype B was not able to transmit the PLLMV.

Powering Kenya's agricultural economy, the Kenyan flower industry is prided as an example of successful African integration into global agricultural trade. Export markets are bifurcated due to a marked shift from the Dutch flower auctions and an increase in trade within 'direct markets' which includes supermarkets and florists. While flower production is dominated by a few vertically integrated, large scale flower farms (>100 ha), mid-scale (20-80 hectares) and small-scale (>0.25 hectares) flower farms which are the focus of the thesis, face a unique set of challenges in terms of navigating access to the more stable direct markets. The overall narrative is that even in a buyer-driven market, Kenyan cut flower producers at the mid and small scale have agency, and they exercise their bargaining power for favourable export access by diversification and differentiation in strategies and networks. Two meta-narratives framing the sector coalesce around the development angle which showcases contestations around labour and environmental abuses and the political economy angle focusing on governance structures and power relations of production. This thesis goes deeper than these meta narratives by introducing micro-level, relational perspectives using the GPN framework, and asks what strategies Kenyan mid and small scale cut flower producers employ to navigate the shifts in export markets as producers diversify from the Dutch auctions towards supermarkets. My findings identify diversification as the common factor in mid and small scale producers' strategies for securing a range of lucrative export markets. Producers' enhance their bargaining power to access diverse markets through adaptable production, relationally through collective action, and in the regulatory sphere by circumvention, compliance or contestation for more favourable 'rules of the game'. Going beyond labour and environmental analyses, the thesis uniquely analyses the knowledge economy originating from the cut flower sector as an undertheorized aspect of its development impact.

LEAFY (LFY) est un facteur de transcription central pour le développement des plantes, en particulier pour la floraison chez les angiospermes. LFY est très conservée, même chez les espèces ne portant pas de fleurs. On dispose de nombreuses données génétiques sur LFY et son réseau de régulation chez la plante modèle Arabidopsis thaliana, mais les mécanismes moléculaires impliqués dans son fonctionnement ne sont pas entièrement élucidés. LFY possède deux domaines conservés : un domaine de liaison à l'ADN et un domaine de fonction inconnue en position N-terminal. L'objectif a été de comprendre le rôle du domaine N-terminal et d'étudier l'évolution de la spécificité de liaison à l'ADN de LFY. Nous avons obtenu la structure cristallographique du domaine N-terminal de LFY et découvert qu'il s'agissait d'un domaine SAM (Sterile Alpha Motif) permettant l'oligomérisation de la protéine. Nous avons validé l'importance de cette propriété pour la fonction florale de LFY chez A. thaliana. Nous avons ensuite montré, par des analyses in vitro et in vivo en ChIP-seq que l'oligomérisation influençait la liaison à l'ADN en permettant une liaison coopérative sur plusieurs sites de liaison, en assurant la sélectivité de la protéine vis-à-vis de l'ADN et en permettant l'accès de la protéine à des régions génomiques où la conformation de la chromatine est normalement défavorable à la liaison. Cette étude intégrative a permis de mieux comprendre le fonctionnement de LFY. Des modifications dans les réseaux de régulation de l'expression des gènes sont source de nouveauté et d'évolution. LFY étant très conservée et ne faisant pas partie d'une famille multigénique, nous nous sommes demandé si sa spécificité de liaison à l'ADN avait évoluée. Nous avons montré que LFY était apparue chez les algues multicellulaires et que sa spécificité avait connue au moins deux changements majeurs au cours de l'évolution. Nous avons expliqué ces modifications au niveau moléculaire par des approches de biologie structurale et de biochimie. Nous avons identifié une espèce chez qui LFY a une spécificité relâchée et nous proposons qu'une telle forme ait pu permettre les transitions d'une spécificité à une autre. / LEAFY (LFY) is a key transcription factor for plant development, particularly for flowering in angiosperms. LFY is highly conserved in plants, including non-flowering species. Despite a wealth of genetic data about LFY and its regulatory network in the model plant Arabidopsis thaliana, how the protein works at the molecular level is not fully understood. It has two conserved domains: a DNA binding domain and a N-terminal domain of unknown function. My two main projects were to understand the role of the N-terminal domain and to study LFY DNA binding specificity evolution. We obtained LFY N-terminal domain crystal structure and discovered it was a Sterile-Alpha-Motif (SAM) mediating LFY oligomerisation. We validated the importance of that property for flower development in A. thaliana. Using both in vitro analyses and a ChIP-seq experiment, we pointed out that oligomerisation is required for proper DNA binding. It enables cooperative binding on several LFY binding sites, increases the protein selectivity towards DNA and allows LFY to access genomic regions where the chromatin conformation normally prevents binding. This integrative study provides a better understanding of how LFY works. The rewiring of transcriptional networks provides a rich source of evolutionary novelty. As LFY is highly conserved and single copy in most plant genomes, we asked whether its DNA binding specificity had evolved. We showed that LFY was present since multicellular algae and that it underwent at least two major shifts in DNA-binding specificity during plant evolution. We provided a structural explanation for the two newly identified DNA binding modes and we identified a LFY form with a relaxed specificity that could have served as an intermediate between evolutionary transitions.

Les palmiers constituent une famille emblématique de monocotylédones, comprenant 183 genres et environ 2500 espèces distribuées sur tous les continents dans les zones tropicales et subtropicales. Leurs feuilles et leurs stipes, très caractéristiques, les rendent facilement reconnaissables dans la nature. En revanche leurs fleurs passent souvent inaperçues. Elles sont généralement petites (quelques centimètres), trimères, unisexuées, peu colorées (blanches ou vertes) et regroupées sur de grandes inflorescences. Cependant les palmiers présentent une diversité importante au niveau du système sexuel et du nombre d’étamines. Les trois systèmes sexuels principaux des angiospermes : hermaphrodisme, monoécie et dioécie, sont présents chez les palmiers. Le nombre d’étamines varie entre quelques unités (oligandrie) et des dizaines, voire centaines, d’unités (polyandrie) chez certains genres. Nous avons étudié l’évolution du système sexuel et du nombre d’étamines à l’échelle de la famille. Nous avons pour cela utilisé une phylogénie comprenant tous les genres de palmiers, bien résolue, datée et qui a été publiée récemment. Notre étude a montré que l’ancêtre commun à tous les palmiers était probablement monoïque et possédait des fleurs oligandres à 6 étamines. A partir de ces états ancestraux, plusieurs transitions ont eu lieu : vers l’hermaphrodisme et la monoécie d’une part, et vers la polyandrie d’autre part. Dans l’objectif d’initier une recherche sur une éventuelle explication fonctionnelle de l’augmentation du nombre d’étamines, nous avons comparé celui-ci à la production de pollen, en étudiant la quantité totale de pollen produite par les fleurs de 82 espèces. Notre étude a montré que, chez deux sous-familles, les fleurs ont tendance à produire plus de pollen quand le nombre d’étamines est plus élevé. Nous avons également réalisé la phylogénie moléculaire d’une sous-tribu (les Ptychospermatinae) dans laquelle la variation du nombre d’étamines est exceptionnelle. De futures études sur la génétique, le développement, l’écologie et la biologie de la pollinisation sont nécessaires. / Palms (Arecaceae) are an emblematic family of monocots of 183 genera and around 2500 species distributed on all continents, throughout tropical and subtropical areas. Their characteristic leaves and stems make palms immediately recognizable in the field. The inconspicuous palm flowers are usually considered as rather dull. They are usually small (a few centimetres), trimerous, often unisexual, colourless (white or greenish) and grouped into huge inflorescences. However palms exhibit a large diversity in sexual system and in stamen number, diversity that is still poorly understood. The three main sexual systems of angiosperm, hermaphroditism, dioecy and monoecy are present in palms. Stamen number ranges between a few units (oligandry) to several dozens and even several hundreds of units (polyandry) in some genera. We studied the evolution of sexual system and stamen number at the family level. We used as historical framework a well-supported and dated phylogeny, published recently. Our study showed that the putative ancestor of palms was monoecious and bore oligandrous flowers with 6 stamens. From these ancestral states, several transitions occurred: towards hermaphroditism and dioecy and towards polyandry respectively. In order to initiate a research on a possible functional significance of increase in stamen number, we investigated the relationship between stamen number and pollen production, by extracting the total pollen content from flowers of 82 species. Our study showed a tendency towards higher pollen production when the number of stamen increases in two subfamilies. We also produced molecular phylogeny of a subtribe (Ptychospermatinae) in which the range of variation in stamen number is exceptional. Further investigations into genetic, developmental, ecology and pollination biology are needed.

Orientadores: Angelo Pires do Prado, Thomas Michael Lewinsohn / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-09-11T21:19:37Z (GMT). No. of bitstreams: 1 Braun_MarinaReiter_D.pdf: 4685052 bytes, checksum: 6fca81032502f6931c9f8333e10b544b (MD5) Previous issue date: 2011 / Resumo: Na presente tese foram descritas dez novas espécies de Agromyzidae endófagos de capítulos de Asteraceae. Essas espécies estão distribuídas nas duas subfamílias representadas nos gêneros Melanagromyza, Ophyomyia (Agromyzinae), Calycomyza e Liriomyza (Phytomyzinae). No gênero Melanagromyza, segundo maior da família, foram descritas sete novas espécies. Pela primeira vez foi encontrada nos gêneros Calycomyza, Liriomyza e Ophyomyia a herbivoria de capítulos de asteráceas. Além de aumentar o conhecimento sobre a diversidade do grupo, outra contribuição desta tese é a avaliação da especialização alimentar do grupo, que mantém o padrão da família com uma baixa proporção de generalistas. A partir dos dados de interação desses endófagos construímos uma rede de interações entre quinze espécies de Melanagromyza e suas plantas hospedeiras com o objetivo de avaliar sua estrutura de interações. Esta rede foi testada para investigar a existência de aninhamento e compartimentalização dessas interações. Outras questões investigadas foram a relação entre afinidade morfológica dos herbívoros e sua utilização de recursos, além do parentesco das plantas hospedeiras utilizadas pelas espécies de herbívoros. A estrutura de interações dessa rede possui um padrão bastante compartimentalizado, o que era esperado em interações de herbivoria entre insetos que apresentam alta especialização alimentar. Quanto aos efeitos do parentesco na estruturação da rede de interações, verificamos resultados diferentes para os insetos e as plantas. A classificação das espécies de Melanagromyza conforme sua morfologia genital não teve relação com o grupamento dos herbívoros análise de agrupamento bidirecional. Por outro lado, para as plantas, observamos grande concordância entre a classificação taxonômica das espécies e os grupos formados a partir da análise de agrupamento bidirecional / Abstract: This study describes ten new species of endophagous Agromyzidae of Asteraceae flower-heads. Those species belong to genera of the two subfamilies, respectively Melanagromyza, Ophyomyia (Agromyzinae), Calycomyza and Liriomyza (Phytomyzinae). In Melanagromyza, the second largest genus in the family, seven new species were described. Herbivory of Asteraceae flower-heads was recorded for the first time in Calycomyza, Liriomyza and Ophyomyia. Besides increasing the knowledge of agromyzid diversity, this study contributes to the evaluation of host range patterns in the family, which confirms that most agromyzids are specialized on a plant genus or tribe, with a small percentage of generalistic species. From the feeding records between endophages and their host plants we built an interaction matrix, in order to evaluate their interaction structure. The network shows both a nested and a compartmented pattern, suggesting a compound structure. The structure of the analyzed network has both a nested and a compartmented pattern. Compartmentation is expected for interactions between herbivore insects with such specialized feeding habits. In addition, other issues were investigated in this study: Do morphologically similar herbivore species use the same plants? Are plants used by the same herbivore species phylogenetically related? Regarding the family relationship based on the interactions structure, we found divergent results for insects and for plants. The categorization of Melanagromyza species based on their male genital morphology showed no relation with the herbivore groups based on their host use in a bidirectional cluster analysis. On the other hand, plants showed strong agreement between the taxonomic affinities of the species and the groups based on their shared herbivores in the bidirectional analysis / Doutorado / Ecologia / Doutor em Ecologia

Submitted by (ana.araujo@ufrpe.br) on 2017-02-10T11:58:18Z No. of bitstreams: 1 Fabio Rodrigo Araujo Pereira.pdf: 857390 bytes, checksum: f51e59231582ea88f2eb82c7049f64b7 (MD5) / Made available in DSpace on 2017-02-10T11:58:18Z (GMT). No. of bitstreams: 1 Fabio Rodrigo Araujo Pereira.pdf: 857390 bytes, checksum: f51e59231582ea88f2eb82c7049f64b7 (MD5) Previous issue date: 2012-02-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The heliconias stand out as one of the species most appreciated by consumers due to its exoticity flowers, postharvest durability and beauty of the flowers, and showy bracts present with intense colors and contrasting. The study aimed to characterize 15 half-sib families of Heliconia bihai (HB), H. chartacea (HC) and H. Wagneriana (HW), morphological and molecular markers by ISSR. Obtained higher means in HC3, HB9 and HW20 for number of leaves (NL) and number of tillers (NP). For the limb length (CPL) the highest averages were obtained in HC4, HB9 and HW20. HC8, HB9 HW20 and reached the highest averages for maximum width of the lamina (LML) and HC7, HB9 and HW20 for plant height (APL). Considering the standard error for the morphological characteristics used in the last evaluation, it was found that among the half-sib families, HB14 obtained a higher value of NF, HB9 and HC4 obtained higher values of CPL, all the families of H. bihai and H. chartacea had the best average to LML and APL There was no difference between families. The morphological characteristics enabled the detection of genetic variability among and within half-sib families of the species H. bihai, H. chartacea cv. Sexy Scarlet and H. Wagneriana. The oligonucleotides used 4023 fragments generated by amplifying 3-7 bands by primer. The product of genetic similarity analysis with ISSR markers showed that the genotypes were grouped by species, and HB11(5) and HC5(8) the most divergent, polymorphism generated with ISSR markers showed genetic variability between and within families sib species H. bihai and H. chartacea cv. Sexy Scarlet evaluated, and detected the absence of genetic variability within the family half-sib genotypes of H. Wagneriana, leading to the assumption of high rate of selfing in this species. / As helicônias destacam-se como uma das espécies mais apreciadas pelos consumidores de flores devido sua exoticidade, durabilidade pós-colheita e beleza das inflorescências, além de apresentarem brácteas vistosas com cores intensas e contrastantes. O trabalho objetivou caracterizar 15 famílias de meios irmãos de Heliconia bihai (HB), H. chartacea (HC) e H. wagneriana (HW), por marcadores morfoagronômicos e moleculares ISSR. Foram observadas as maiores médias em HC3, HB9 e HW20 para Número de folhas (NF) e Número de perfilhos (NP). Para Comprimento do limbo (CPL) as maiores médias foram obtidas em HC4, HB9 e HW20. HC8, HB9 e HW20 atingiram as maiores médias para Largura máxima do limbo (LML) e HC7, HB9 e HW20 para Altura da planta (APL). Considerando-se o erro padrão empregado para os caracteres morfoagronômicos na última avaliação, verificou-se que dentre as famílias de meios irmãos, HB14 obteve maior valor de NF, HB9 e HC4 obtiveram maiores valores de CPL, todas as famílias de H. bihai e H. chartacea tiveram as melhores médias de LML e para APL não foi registrada diferença entre as famílias. Os caracteres morfoagronômicos possibilitaram a detecção de variabilidade genética entre e dentro de famílias de meios irmãos das espécies de H. bihai, H. chartacea cv. Sexy Scarlet e H. wagneriana. Os oligonucleotideos utilizados geraram 4023 fragmentos, amplificando de 3 a 7 bandas por primer. O produto da análise de similaridade genética com marcadores ISSR mostrou que os genótipos foram agrupados por espécies, sendo HB11(5) e HC5(8) os mais divergentes, O polimorfismo gerado com os marcadores moleculares ISSR mostrou variabilidade genética entre e dentro de famílias de meios irmãos das espécies de H. bihai e H. chartacea cv. Sexy Scarlet estudadas, como também detectou a ausência de variabilidade genética dentro da família de meios irmãos dos genótipos de H. wagneriana, levando a suposição da elevada taxa de autofecundação na referida espécie.

Submitted by (ana.araujo@ufrpe.br) on 2017-02-22T13:55:03Z No. of bitstreams: 1 Taciana Leite de Andrade Lima.pdf: 1340293 bytes, checksum: 65b48cb5084fc7dd8f71ef97d3b4f55f (MD5) / Made available in DSpace on 2017-02-22T13:55:03Z (GMT). No. of bitstreams: 1 Taciana Leite de Andrade Lima.pdf: 1340293 bytes, checksum: 65b48cb5084fc7dd8f71ef97d3b4f55f (MD5) Previous issue date: 2012-02-22 / The cultivation and commercialization of tropical flowers in Pernambuco are increasing mainly of species of the Heliconia genus. Due to the great diversity of species and cultivars marketed, studies are necessary to provide information regarding the production and flower stem characteristics to use as an ornamental plant and cut flower. The objective of this study was to characterize and estimate the genetic parameters for cut flower in Heliconia bihai and Heliconia stricta of Federal Rural University of Pernambuco Heliconia Germoplasm Collection (CGH/UFRPE). The CGH/UFRPE is located in Camaragibe-PE, in full sun and distributed in a randomized block design with four replications. Were selected and evaluated four genotypes of Heliconia bihai (Hb1and; Hb2; Hb3 and HbNY) and Heliconia stricta (Hs1; HsFB, Hs3 and HsT) and the following agronomic characters: yield per plant, early flowering, number of days for emission of the first inflorescence, number of leaves on flowering stem, number of days to emission the inflorescence, number of days to harvest the inflorescence; productive cycle of the plant, inflorescence length and width, flower stem length and diameter, flower stem mass and post-harvest durability of the inflorescence. The genotypes of Heliconia HB1and Hb3 bihai were the most precocious and productive (260 and 311 days after planting; 45.08 and 42.31 flower stem/clump. year, respectively) and had shortest production cycle (204 and 211 days respectively) and floral stem mass (209 and 210 g, respectively). Regarding Heliconia stricta, HS1 genotype had the shortest production cycle (214.67 days) and floral stem mass (116 g). However the HST was most starting flowering 390 days after planting, and more productive (38.44 flower stem/clump. year). All the characters had heritability above 78% and demonstrate significant positive correlation between the number of days to harvest the inflorescence and post-harvest durability. For the graphical plot analysis, the characters days to inflorescence emission, the production cycle of plant, flower stem length and width of the inflorescence could be removed. The results indicate that there is variability between among genotypes Heliconia bihai and Heliconia stricta genotypes. Genotype Hb1could be indicated for the commercial cultivation of cut flower. / O cultivo e comércio de flores tropicais têm expressão econômica em Pernambuco, sendo espécies do gênero Heliconia algumas das mais comercializadas. Devido a grande diversidade de espécies e cultivares comercializadas, tornam-se necessários estudos que forneçam informações quanto à produção e às características da haste floral para utilização como planta ornamental e flor de corte. O objetivo deste trabalho foi caracterizar e estimar os parâmetros genéticos no uso para flor de corte em Heliconia bihai e Heliconia stricta da Coleção de Germoplasma de Helicônia da Universidade Federal Rural de Pernambuco (CGH/UFRPE). A CGH/UFRPE está localizada em Camaragibe-PE, a pleno sol e distribuída sob delineamento em blocos casualizados com quatro repetições. Foram selecionados e avaliados quatro genótipos de Heliconia bihai (Hb1; Hb2; Hb3 e HbNY) e de Heliconia stricta (Hs1; HsFB; Hs3 e HsT) quanto as seguintes características agromorfológicas: produtividade por touceira; início do florescimento, período em dias para a emissão da primeira inflorescência; número de folhas na haste floral; número de dias para emissão da inflorescência; número de dias para a colheita da inflorescência; ciclo produtivo da planta; comprimento da inflorescência; largura da inflorescência; comprimento da haste floral; diâmetro da haste floral; massa fresca da haste floral e a durabilidade pós-colheita das inflorescências. Os genótipos Hb1 e Hb3 de Heliconia bihai foram os mais precoces e produtivos (260 e 311 dias após o plantio; 45,08 e 42,31 hastes florais/touceira/ano, respectivamente) e apresentaram menor ciclo produtivo (204 e 211 dias, respectivamente) e massa fresca da haste floral (209 e 210 g, respectivamente). Em relação à Heliconia stricta, o genótipo Hs1 obteve o menor ciclo produtivo (214,67 dias) e massa fresca da haste floral (116 g), entretanto o HsT foi o mais precoce, iniciando o florescimento 390 dias após o plantio, e o mais produtivo (38,44 hastes florais/touceira/ano). Todos os caracteres obtiveram herdabilidade acima de 78% e houve correlação positiva e significativa entre o número de dias para colheita da inflorescência e a durabilidade pós-colheita. Pela análise de dispersão gráfica, foi indicado o descarte dos caracteres número de dias para emissão da inflorescência, ciclo produtivo da planta, comprimento da haste floral e largura da inflorescência. Os resultados obtidos indicam que há variabilidade entre os genótipos de Heliconia bihai e entre os genótipos de Heliconia stricta, sendo o genótipo Hb1 indicado para o cultivo comercial de flor de corte.

A degradação de pastagem é um dos maiores problemas da pecuária bovina do país. A implantação seguida de um sistema de manejo inadequado favorece a ocorrência de plantas daninhas em altas densidades, o que diminui a produtividade da gramínea forrageira. A espécie Tecoma stans, importante planta daninha em pastagens, é considerada de difícil controle, pois apresenta rebrota rápida e vigorosa após o corte do tronco, dificultando seu controle por métodos exclusivamente mecânicos. Visando encontrar alternativas de controle químico e conhecer a forma como fatores ambientais influenciam a germinação e emergência da espécie, analisou-se a influência da luz e temperatura sobre a germinação e o efeito da profundidade de semeadura na emergência de T. stans. Além disso, foram estudadas a absorção, a translocação e a eficácia do herbicida aminocyclopyrachlor. Para análise do efeito da luz, sementes foram distribuídas em caixas de plástico transparente e preto, e mantidas em germinador em temperatura constante e alternada. O efeito da temperatura foi avaliado em nove intervalos de temperatura, entre 15°C e 40°C. Para o estudo da influência da profundidade de semeadura na emergência de plântulas, as sementes foram depositadas a 0, 20, 40 e 80 mm de profundidade. A absorção e translocação de 14C-aminocyclopyrachlor foram estudadas ao longo do tempo em plantas jovens de T. stans e os experimentos no campo foram conduzidos com aplicações no toco de aminocyclopyrachlor e picloram e aplicações foliares da associação formulada dos herbicidas aminocyclopyrachlor + metsulfuron-methyl e glyphosate. Os estudos do efeito da luz e temperatura demonstraram que a espécie é fotoblástica neutra e que as temperaturas estudadas não são fatores limitantes para a germinação de espécie, apresentando porcentagem de germinação acima de 50%. A espécie apresentou maior porcentagem de emergência quando as sementes foram depositadas na superfície do solo e não ocorreu emergência das plântulas quando foram depositadas nas profundidades de 40 e 80 mm. Aproximadamente 20% do total de 14Caminocyclopyrachlor aplicado foram absorvidos pelas folhas de T. stans e a porcentagem de translocação não ultrapassou 5% do total aplicado em 72 horas após a aplicação. Aplicações no toco de aminocyclopyrachlor e picloram e foliares de aminocyclopyrachlor + metsulfuron-methyl e glyphosate foram eficazes no controle de T. stans. / Pasture lands degradation is one of the largest problems of cattle livestock in Brazil. The development of pasture lands and its consequent inadequate management are factors that favor weed proliferation, diminishing forage grass productivity. Tecoma stans, is a difficult to control widespread weed in pasture lands since resprouts vigorously and quickly after the stalk is cut hindering its control by mechanical means. In order to find chemical alternatives to control the species and to identify the environmental factors that contribute to its germination and emergence, this study analyzed light and temperature effects on germination and seeding depth effect on the emergence of T. stans. Moreover, was analyzed the absorption, translocation and efficacy of aminocyclopyrachlor. In order to analyze the light effect, the seeds were distributed in clear and dark plastic boxes that were kept in a germination chamber in constant and alternated temperatures. The temperature effect was assessed in nine temperature intervals ranging from 15 to 40°C. In order to analyze seeding depth effect in seedlings emergence, the seeds were sowed at 0, 20, 40 and 80 mm. Absorption and translocation of 14C-aminocyclopyrachlor were analyzed over time in young T. stans plants. Field experiments were conducted applying aminocyclopyrachlor and picloram in the cut-stump and foliar applications of aminocyclopyrachlor + metsulfuron-methyl and glyphosate. Light and temperature experiments allowed to conclude that the species is neutral photoblastic and that the temperatures used in the experiments did not limit the species germination, since there were germination in 50% of the cases. When the seeds were applied in the soil surface there was a higher index of emergence, however, when the seeds were at 40 and 80 mm depth, the plant did not emerge. Twenty percent of the 14Caminocyclopyrachlor dosage applied was absorbed by T. stans leaves. Translocation percentage did not surpass 5% of the dosage applied after 72 hours. Aminocyclopyrachlor and picloram cut-stump applications as well as aminocyclopyrachlor + metsulfuron-methyl and glyphosate foliar applications were efficacy to control T. stans.

No description available.

Le nombre de siliques par plante et le nombre de graines par silique sont les composantes du rendement du colza d'hiver qui présentent la plus grande variabilité. La production d'une graine résulte de la combinaison de plusieurs processus physiologiques, à savoir la formation des ovules et des grains de pollen, la fécondation des ovules et le développement de jeunes embryons. Un problème survenu à n'importe quelles des étapes peut entraîner l'avortement de graines ou de la silique. Le nombre potentiel d'ovules par silique et le nombre graines arrivant la maturité dépendraient de la position du dans l'architecture de plante et le temps de son apparition, mais le mode complexe de développement de colza rend difficile l'analyse des causes et effets. Dans cette étude, la variabilité des composantes du rendement suivantes est étudiée: (a) nombre d'ovules par silique, (b) nombre de graines par silique, et (c) nombre de siliques par axe en fonction d'une part, l'emplacement de la fleur dans l'inflorescence, et la position de cette dernière sur la tige, et l'autre part, le temps d'apparition de la silique, qui affectent la disponibilité d'assimilats. Basé sur les processus biologiques de la fertilité des fleurs, un modèle probabiliste est développé pour simuler le développement des graines. Le nombre de grains de pollen par fleur peut être déduit par le modèle et ainsi que les facteurs qui influent le rendement. Des expériences de terrain ont été menées en 2008 et 2009. Le nombre et la position des fleurs qui s'épanouissaient dans l'inflorescence ont été enregistrés sur la base des observations tous les deux à trois jours pendant la saison de floraison. Différents états trophiques ont été créés par tailler de la tige principale ou des ramifications à étudier l'effet de l'assimilation de la compétition. Les résultats montrent que la quantité d'assimilâtes disponibles a été le principal déterminant de la production de graines et de siliques. La répartition d'assimilâtes a été sensiblement affectée par l'emplacement de silique au sein d'une inflorescence et la location de l'inflorescence sur la tige colza. En outre, le paramètre de la distribution du nombre de pollen a indiqué que la production de graines pourrait être limitée par la pollinisation. La réduction de la viabilité des ovules pourrait entraîner la diminution du nombre de siliques et le nombre de graines par silique à l'extrémité de l'inflorescence. Le modèle proposé pourrait être un outil pour étudier la stratégie de l'amélioration du rendement des plantes à fleurs.