Resumo: 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. / Abstract: 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. / Orientador: Euclides Braga Malheiros / Coorientador: David de Jong / Banca: Leomam Almeida Couto / Banca: Luis Carlos Marchini / Banca: Roque Takahashi / Banca: Jeffrey Frederico Lui / Doutor

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-23T13:54:28Z No. of bitstreams: 1 JOYCE EMANUELE DE MEDEIROS - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1718564 bytes, checksum: 08bf95bc06f72832fe2269039eb98219 (MD5) / Made available in DSpace on 2018-05-23T13:54:28Z (GMT). No. of bitstreams: 1 JOYCE EMANUELE DE MEDEIROS - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1718564 bytes, checksum: 08bf95bc06f72832fe2269039eb98219 (MD5) Previous issue date: 2013 / A partenocarpia em melancia agrega valor aos frutos, entretanto, para seu cultivo, o produtor poderá encontrar dificuldades, como: adaptação dos híbridos às condições regionais, alto preço das sementes, baixa germinação e baixo vigor das plântulas, além da necessidade de cultivar na mesma área uma variedade diploide como fonte de pólen para as triploides. Assim, objetivou-se avaliar o efeito da aplicação da citocinina CPPU, em diferentes concentrações, na indução da frutificação partenocárpica em melancieiras diploide e triploide. A pesquisa foi constituída por dois experimentos conduzidos em campo no Câmpus da UFCG, em PombalPB, no período de 15/12/2012 a 02/03/2013 utilizando-se o híbrido triploide ‘Extasy’ e a variedade diploide ‘Crimson Sweet’. Para ambos os experimentos, os tratamentos foram compostos por cinco concentrações do regulador de crescimento CPPU (0,75; 1,0; 1,5; 2,5 e 3,5 mg L-1 ) mais testemunha (polinização natural). O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições. A aplicação do CPPU ocorreu de forma exógena no ovário das flores na antese por dois dias consecutivos. As características avaliadas foram: taxa fotossintética (A), condutância estomática (gs), transpiração (E), concentração intercelular de CO2 (Ci), eficiência no uso da água (EUA), clorofilas, carotenoides, número de folhas, área foliar, massa seca das folhas, do caule e dos frutos e massa seca total, produção total e comercial, massa média dos frutos comercializáveis, número de frutos por planta, número de frutos comercializáveis por planta, índice de formato do fruto, espessura da casca e da polpa, sólidos solúveis, acidez titulável, pH, SS/AT e ácido ascórbico. O CPPU foi eficiente na indução da frutificação em melancieiras diploide ‘Crimson Sweet’ e triploide ‘Extasy’, independentemente da concentração utilizada. A concentração 2,5 mg L-1 de CPPU aplicada nas melancieiras diploides proporcionou o maior número de frutos comercializáveis por planta, maior produção total e produção comercial comparada à testemunha, já nas triploides possibilitou maior número de frutos por planta, número de frutos comercializáveis por planta, produção total e produção comercial em relação à testemunha. A indução da frutificação com CPPU na melancieira ‘Crimson Sweet’ não interferiu no acúmulo de massa seca, no crescimento e nas características fisiológicas da planta comparada à testemunha. Na ‘Extasy’, proporcionou maior acúmulo de massa seca no fruto, redução na massa seca das folhas, do caule e crescimento da planta, incremento na condutância estomática e na assimilação de CO2 quando comparada à testemunha. Nas melancieiras ‘Crimson Sweet’, a concentração de CPPU 2,5 mg L-1 proporcionou maior condutância estomática, taxa fotossintética e acúmulo de massa seca no fruto. Na melancieira ‘Extasy’, as concentrações de CPPU foram indiferente nas trocas gasosas e no crescimento da planta. / Parthenocarpy in watermelon adds value to fruits, however, for its cultivation, the producer may encounter difficulties such as: adaptation of hybrid to regional conditions, high seed prices, low germination and seedling vigor, beyond the need to cultivate, in the same area, a diploid variety as source of pollen for triploids. Thus, the objective was to evaluate the effect of application of cytokinin CPPU at different concentrations, in the induction of fruiting partenocarpic in diploid and triploid watermelon plants. The study comprised two field experiments conducted in the field in Campus of UFCG in Pombal -PB, from 12/15/2012 to 03/02/2013 using the triploid hybrid 'Extasy' and diploid variety 'Crimson Sweet'. For both experiments, treatments consisted of five concentrations of growth regulator CPPU (0.75, 1.0, 1.5, 2.5 and 3.5 mg L- 1 ) and the control (natural pollination). The experimental design was a complete randomized block designed with four replications. The application of CPPU occurred exogenously in the ovary of flowers for two consecutive days at anthesis. The variables evaluated were: photosynthetic rate (A), stomatal conductance (gs), transpiration (E), intercellular CO2 concentration (Ci), water use efficiency (EUA), chlorophylls, carotenoids, number of leaves, leaf area, dry mass of leaves, stem and fruit and total dry matter, total and marketable yield, average weight of marketable fruit , number of fruits per plant, number of marketable fruits per plant, fruit shape index, shell thickness and pulp, soluble solids, titratable acidity, pH, SS/TA and ascorbic acid. The CPPU was efficient in inducing fruiting of diploid watermelon 'Crimson Sweet' and triploid 'Extasy’, regardless of the concentration used. The concentration 2.5 mg L- 1 of CPPU applied in diploid watermelon provided the greatest number of marketable fruits per plant, higher total and marketable yield production compared to control, and in the triploid plants in increased the number of fruits per plant, number of fruits marketable per plant, total production and commercial production compared to control. Induction of fruiting with CPPU in watermelon ‘Crimson Sweet’ had no effect on dry matter accumulation, growth and physiological characteristics of the plant compared to the control. In 'Extasy', CPPU provided a greater accumulation of dry matter in the fruit decreased dry mass of leaves, stem and plant growth, increase in stomatal conductance and CO2 assimilation compared to the control. In watermelon 'Crimson Sweet' the concentration of 2.5 mg L- 1 yielded higher stomatal conductance, photosynthetic rate and dry matter accumulation in the fruit. In watermelon 'Extasy', concentrations of CPPU were indifferent gas exchange and plant growth.

La formation des fruits charnus est un processus de développement impliquant trois stades principaux : (i) la transition fleur/fruit ou nouaison, (ii) la croissance et enfin (iii) la maturation des fruits. Chacune de ces étapes correspond à une transition développementale associée à d’importants changements physiologiques et structurels. Parmi toutes les hormones, l’auxine est connue pour jouer un rôle important dans l‟initiation et la coordination du processus de nouaison et des phases précoces de développement du fruit. La mise en place de la réponse à l‟auxine nécessite l‟intervention de facteurs de transcription appartenant à la famille des ARF (Axin Response Factor) connus pour réguler l‟expression des gènes de réponse précoce à l‟hormone en se liant aux Cis-éléments de type AuxRE (Auxin Response Element) possédant le motif conservé de réponse à l‟auxine. Les ARF sont de ce fait des candidats forts pour faire partie du mécanisme moléculaire par lequel l’auxine intervient dans le processus de nouaison. Le projet de recherche réalisé au cours de la thèse a permis d‟isoler et de caractériser au total 22 gènes Sl-ARF chez la tomate (Solanum lycopersicum), la plante modèle pour l’étude du développement et de la maturation des fruits charnus. Les gènes Sl-ARF montrent des profils d‟expression distincts selon les tissus et organes considérés, suggérant des fonctions spécifiques pour les membres de cette famille multigénique. Il est de plus montré que certains gènes Sl-ARF sont régulés à la fois par l’auxine et par l’éthylène, suggérant qu‟ils participent potentiellement au dialogue entre les voies de signalisation des deux hormones. L’expression transitoire a révélé la capacité des Sl-ARF à agir comme activateur ou répresseur transcriptionnel des gènes de réponse à l’auxine. L‟étude des profils d’expression globale, réalisée par RNA-seq à l‟échelle du génome entier, a révélé pour la première fois l‟existence d‟un niveau important de régulation par épissage alternatif des ARFs pendant la transition fleur-fruit. La localisation nucléaire des protéines Sl-ARF8A / B a été déterminée par fusion avec le gène rapporteur GFP puis expression dans un système "signle cell". L‟étude d’expression a révélé des profils distinctifs entre ARF8A et ARF8B avec une augmentation notable des transcrits Sl-ARF8A suite à la pollinisation des fleurs. Le rôle physiologique du gène Sl-ARF8A a été par la suite abordé par une approche de génétique inverse fournissant un nouvel éclairage sur les événements moléculaires qui sous-tendent la mise à fruit. La surexpression de Sl- ARF8 dans la tomate engendre des phénotypes pléiotropiques touchant la croissance - 4 - végétative (réduction de la taille des plantes, altération du développement racinaire et des tiges latérales) et l‟appareil reproducteur avec la formation de fruits parthénocarpiques (absence de graines). L’analyse histologique a révélé une modification notable du placenta et des ovules chez les lignées de sur-expression de Sl-ARF8 et les études par RNA-Seq ont identifié plus de 2632 gènes différentiellement exprimés chez les surexpresseurs par comparaison avec les lignées non transformées. Au total, l‟étude réalisée au cours de la thèse fournit une description exhaustive de la famille des ARF chez la tomate et une caractérisation fonctionnelle du gène Sl-ARF8 qui souligne son rôle comme figure centrale du mécanisme de contrôle de la nouaison des fruits. / The making of a fleshy fruit is a developmental process involving three main stages known as (i) fruit set, (ii) fruit growth and (ii) fruit ripening each corresponding to a transition step associated with major physiological and structural changes. Among other hormones, auxin is known to play a dynamic role in triggering and coordinating the changes associated with the process of fruit set and early fruit development. Auxin responses are mediated at the transcriptional level by Auxin Response Factors (ARFs) which regulate early auxin-responsive genes by specific binding to TGTCTC Auxin Response Elements (AuxREs). ARFs are therefore good candidates for being among the components of the molecular mechanism by which auxin mediates the fruit set. In the present study, a total of 22 Sl-ARF genes have been isolated and characterized in tomato (Solanum lycopersicum), a model plant for the study of fleshy fruit development and ripening. Expression profiling revealed distinctive patterns for Sl-ARF genes in different tomato tissues. Hormone treatment indicated that Sl-ARFs can be regulated both by auxin and ethylene with Sl-ARF2B, 5 and 9 likely to be involved in the cross-talk between the two hormones. Transient expression using a single cell system uncovered the ability of Sl- ARFs to act either as transcriptional activator or repressor in regulating the expression of auxin-responsive genes. Genome-wide expression profiling performed by deep RNASequencing revealed for the first time the importance of the alternative splicing mode of regulation of ARF genes during tomato fruit set. The physiological significance of two closely related Sl-ARFs, Sl-ARF8A and Sl-ARF8B, was addressed in the present study via a reverse genetics approach providing new insight on the molecular events underlying tomato fruit set. Fusion to GFP reporter gene indicated that both Sl-ARF8A/B proteins are nuclear localized. Expression analysis by RT-qPCR revealed some distinctive features between Sl-ARF8A and Sl-ARF8B with a notable increase in Sl-ARF8A transcript upon flower pollination. Over-expression of Sl-ARF8A/B in tomato resulted in pleiotropic phenotypes, including dwarf plants, altered root and lateral shoot development and parthenocarpic fruits (seedless). Histological analysis revealed altered placenta and ovules development in SlARF8A-OX flowers and RNA-Seq profiling identified over 2632 differentially expressed (DE) genes in SlARF8A-OX flower buds compared to wild type control plants. Considering the dramatic change in gene expression of genes related to auxin, jasmonate and ethylene displayed in SlARF8A-OX lines, these phytohormones are likely to play an active role in coordinating the fruit set process. Altogether, the present - 6 - study provided a comphensive description of the tomato ARF gene family and a functional characterization of Sl-ARF8 defining this ARF member as a central figure of the control mechanism of the fruit set process.