The primary objectives of this research are to analyze the effects plant growth regulators and pinching practices have on the growth habit of Penstemon x mexicali Pikes Peak Purple and Red Rocks and to produce more marketable containerized Penstemon. A preliminary study analyzed the effects branching agent PGRs had on Pikes Peak Purple. We found that the PGRs benzyladenine and ethephon were successful at producing more branches than the untreated control when the plants were considered finished in the container. Another group of PGRs known as growth retardants were also evaluated on Pikes Peak Purple. Both high and low rates of foliar applications of paclobutrazol or uniconazole resulted in growth control of the crop. Liner drench or soak applications of paclobutrazol were the most effective at reducing growth but resulted in over-regulated and stunted plants. A separate study focused on the combination of branching agents and pinching practices on Pikes Peak Purple. Both pinching and the application of branching agents improved overall plant quality until the stage of flower initiation where further growth regulation was needed. Based on the results of the previous experiments, we conducted a study combining branching agents and growth retardants on Pikes Peak Purple and Red Rocks. We found that the most marketable Pikes Peak Purple plants were produced with one pinch during the liner stage, two applications of benzyladenine, and one drench application of paclobutrazol. The most marketable Red Rocks plants were produced with one pinch during the liner stage, and two applications of ethephon. / Master of Science

Made available in DSpace on 2015-03-26T13:36:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3423486 bytes, checksum: 6f5dcf6dbf9fc0e69461e7967c2babfd (MD5) Previous issue date: 2013-07-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study was carried out to analyze the physiological, metabolic and anatomic impacts promoted by both the endogenous and/or artificial variation of gibberellins (GAs) on tomato plants (Solanum lycopersicum L.). To this end, different experiments were performed using wild-type (WT) and mutant plants in the biosynthesis of gibberellins (gib3, moderately deficient; gib2, mildly deficient and gib1, extremely deficient). In the first experiment I used WT and the mutant plants gib3, gib2 and gib1 and evaluated the effects of endogenous reduction of GA levels. It was observed that the reduced levels of GAs negatively affected the growth and that this slower growth is not associated with lower photosynthetic rates. The higher net photosynthesis (A N ) found in the mutants were associated with both increased stomatal density and higher stomatal (g s ) and mesophyll (g m ) conductances. One clear imbalance between carbon metabolism and growth seems to occur in plants with reduced GAs levels, given that reductions in the levels of the majority of the metabolites occurred concomitantly to higher A N . Moreover, higher A N was accompanied by elevated respiratory rate and increments in protein concentration, suggesting a shift of energy in the form of ATPs to other routes, since more energy production was not associated with higher biomass accumulation. In the second experiment I used plants WT and gib3, the genotype most similar to WT in the first experiment, and subjected those plants to artificial variations in the content of GAs by applying GAs and/or paclobutrazol (PBZ), a GA biosynthesis inhibitor. The results obtained allowed the identification of both metabolic and physiological changes associated with both endogenous GAs variation, as well as the artificial variation caused by varying the GAs regime. In both genotypes growth was strongly reduced in presence of PBZ whereas it was incremented when applying GAs. Lower growth rates were accompanied by higher dark respiration (R d ) and higher A N , the former being influenced by larger stomatal density and stomatal opening, leaf thickness, as well as g s and absorptance. The levels of the majority of metabolites evaluated were positively associated with GAs content. Little or no variation in chlorophyll fluorescence a and antioxidative system parameters indicated no apparent stress. Taken as a whole, the information obtained within this study provide a better understanding of the physiological, molecular and metabolic disorders associated with GA deficiency in plants; however, future metabolic and molecular studies are still required to allow us a better understanding of the effects of reduced GA levels on the metabolism of these plants. / O presente trabalho foi conduzido com intuito de analisar os impactos causados pela variação endógena e/ou artificial (aplicação de GAs e paclobutrazol-PBZ) dos níveis de giberelinas sobre a fisiologia, metabolismo e anatomia de plantas de tomate (Solanum lycopersicum L.). Para tal, diferentes experimentos foram realizados utilizando-se plantas tipo selvagem (WT) e mutantes na biossíntese de giberelinas (gib3: moderadamente deficiente, gib2: medianamente deficiente e gib1: extremamente deficiente). No primeiro experimento foram utilizadas plantas WT e os mutantes gib3, gib2 e gib1 avaliando-se os efeitos da redução endógena dos níveis de GAs. Os resultados mostraram que a redução dos níveis de GAs afetou negativamente o crescimento dessas plantas e que este menor crescimento não estaria associado a menores taxas fotossintéticas. A elevada fotossíntese (A N ) nos mutantes apresentou-se associada com uma maior densidade e abertura estomática, assim como maiores condutâncias estomática (g s ) e mesofílica (g m ). Um desbalanço entre o metabolismo do carbono e crescimento parece ocorrer plantas com redução na concentração de GAs, visto que reduções nos teores da maioria dos metabólitos ocorreram concomitantemente com elevada A N . Ademais, maior A N foi acompanhada de uma elevada taxa respiratória e incrementos na concentração de proteínas, sugerindo um desvio de energia em forma de ATPs para outras rotas, já que uma maior produção de energia não se traduziu em acúmulo de biomassa. No segundo experimento foram utilizadas plantas WT e gib3, genótipo mais semelhante ao WT no primeiro experimento, submetidas à variações artificiais no conteúdo de GAs mediante a aplicação de GAs e/ou PBZ. Os resultados obtidos permitiram a identificação de mudanças metabólicas e fisiológicas associadas tanto à variação endógena de GAs, assim como as ocasionadas pela variação artificial de GAs. Para ambos os genótipos, o crescimento foi bastante reduzido em presença de PBZ e apresentou incrementos quando da aplicação de GAs. Menores taxas de crescimento foram acompanhadas de maiores respiração no escuro (R d ) e A N , a última influenciada por maiores densidade e abertura estomática, espessura foliar, assim como g s e absortância. A maioria dos metabólitos foi positivamente correlacionada com o conteúdo de GAs. Pouca ou nenhuma variação em parâmetros da fluorescência da clorofila a e sistema antioxidativo indicam ausência de estresses aparentes. Consideradas em conjunto, as informações obtidas com o presente estudo oferecem uma melhor compreensão dos mecanismos fisiológicos, moleculares e metabólicos associados à deficiência de GAs em plantas; contudo, estudos metabólicos e moleculares mais detalhados ainda serão necessários para uma melhor compreensão dos efeitos da redução dos níveis de GAs sobre o metabolismo dessas plantas.

Made available in DSpace on 2015-03-26T13:36:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 473132 bytes, checksum: cd8467b35d7e250c4c9f1ee1b8cc904c (MD5) Previous issue date: 2007-03-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Germination of non-dormant seeds of Townsville stylo (Stylosanthes humilis HBK), a tropical annual forrage legume was decreased by the growth retardant paclobutrazol (PBZ) [(2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4- triazol-1-yl)pentan-3-ol] suspensions. This effect was reverted by 2-chloroethylphosphonic acid, an ethylene-releasing substance, and 1-amino-1-cyclopropane-1-carboxylic acid (ACC), the immediate ethylene precursor in its biosynthetic pathway. A delay in ethylene emanation by non-dorment seeds and a significant decrease in the production of that gaseous regulador by dormant seeds were observed when they were treated with PBZ. The retardant also led non-dormant seeds to show significant lower free ACC content, a similar effect also exhibited by dormant seeds treated simultaneously with the retardant plus selenourea. In vitro activity of ACC oxidase of that enzyme was observed in the first 48 h exposure to the inhibitor. In vitro activity of ACC oxidase was decreased from 36 h onwards following incubation of non-dormant seeds with PBZ, but this phenomenn occurred after the germination decrease. / Sementes não-dormentes de estilosante (Stylosanthes humilis HBK), leguminosa tropical, forrageira anual, tiveram sua germinação decrescida por suspensões de pacobutrazol (PBZ) [(2RS, 3RS)-1-(4-clorofenil)-4,4-dimetil-2-(1,2,4-triazol-1-il)pentan-3-ol]. Esse efeito foi revertido com ácido 2-cloroetilfosfônico, composto liberador de etileno, e ácido 1-carboxílico-1-aminociclopropano (ACC), precursor imediato do etileno em sua rota biossintética. Observou-se um atraso na produção do etileno em sementes não-dormentes e uma redução significativa na produção desse hormônio em sementes dormentes tratadas com PBZ. Sementes não-dormentes tratadas com o inibidor apresentaram níveis significativamente menores de ACC livre, sendo o mesmo também observado em sementes dormentes tratadas com PBZ mais selenouréia. A atividade in vivo da oxidase do ACC foi diminuída em sementes dormentes e, em sementes não-dormentes, observou-se uma atividade decrescida nas primeiras 48 h de exposição ao inibidor. A atividade in vitro da oxidase do ACC mostrou-se diminuída a partir de 36 h de incubação em sementes não-dormentes tratadas com o PBZ, ocorrendo posteriormente à diminuição da germinação.

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Submitted by Amauri Alves (amauri.alves@ufv.br) on 2015-11-19T15:04:40Z No. of bitstreams: 1 texto completo.pdf: 4638007 bytes, checksum: af82a34557e6d91dd54c1505c5559089 (MD5) / Made available in DSpace on 2015-11-19T15:04:40Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4638007 bytes, checksum: af82a34557e6d91dd54c1505c5559089 (MD5) Previous issue date: 2015-06-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os frutos da mangueira ‘Ubá’ são preferidos pelas indústrias produtoras de suco devido à coloração atrativa da polpa (amarelo alaranjado), altos valores de sólidos solúveis e excelente sabor. Apesar de suas características desejáveis ao processamento industrial, poucas pesquisas relacionadas à indução de florescimento foram realizadas com essa cultivar. Como nem sempre as tecnologias desenvolvidas para outras cultivares se adaptam as peculiaridades da mangueira ‘Ubá’, alguns fatores limitam a expansão da cultura, dentre eles, a baixa produtividade média, desuniformidade no florescimento e consequentemente na colheita, alternância de produção e suscetibilidade a doenças, como oídio e antracnose. Desta forma, o objetivo desse trabalho foi avaliar a eficiência de diferentes doses de paclobutrazol aliado ao desponte dos ramos no florescimento de mangueiras ‘Ubá’, cultivadas na Universidade Federal de Viçosa, Pomar do Fundão, situado em Viçosa - MG. Os tratamentos foram distribuídos em esquema fatorial 5 x 2 + 1 e foram compostos por cinco doses de paclobutrazol (0; 0,50; 1,00; 1,50 e 2,0 g.m -1 linear de copa), com e sem desponte dos ramos. Foi acrescentado um tratamento adicional cujas plantas não foram submetidas à poda, aplicação de paclobutrazol e desponte dos ramos. O delineamento experimental foi em blocos casualizados com quatro repetições utilizando uma planta por parcela. Foi avaliado o comprimento e diâmetro do primeiro e segundo fluxo de brotação dos ramos, porcentagem de florescimento, número de panículas por ramo, total de flores por panícula, razão entre flores masculinas e hermafroditas e número de frutos por ramo, teores de carboidratos nas folhas em duas épocas (intumescimento das gemas florais (10/07/2014) e desenvolvimento dos frutos (15/11/2014)), e qualidade dos frutos, sendo esta representada por comprimento e diâmetro dos frutos, rendimento de suco, ângulo hue da casca e da polpa, sólidos solúveis totais, xiacidez titulável, ratio (relação sólidos solúveis totais/acidez titulável). O comprimento do ramo do primeiro fluxo de brotação foi menor nas plantas que não receberam poda (testemunhas). A porcentagem de florescimento foi maior em plantas tratadas com desponte e aumentou em resposta à dose de paclobutrazol, atingindo o máximo na dosagem de 1,62 g.m -1 linear da copa. O número de panículas por ramo foi superior nas plantas com desponte dos ramos. Houve aumento na razão entre flores masculina e hermafrodita com aumento na dose de paclobutrazol. O número de frutos por ramos aumentou com desponte dos ramos. Os teores de carboidratos reduziram em resposta o aumento na dosagem de paclobutrazol e nas diferentes épocas de avaliação. Não houve diferenças na qualidade dos frutos em resposta a aplicação do paclobutrazol. Conclui-se que a aplicação do paclobutrazol até a dose de 1,62g.m -1 linear da copa aliado ao desponte de ramos uniformizou e aumentou o florescimento de manga ‘Ubá’ na região de Viçosa-MG e não alterou a qualidade dos frutos. / The mango fruits ‘Ubá’ are preferred by industries producing juice due to attractive pulp color (yellow-orange), high values of the soluble solids and excellent flavor. Despite their desirable characteristics to the industrial transformation, little research related to flowering induction has been conducted with this cultivar. Since the technologies developed for other cultivars do not always fit the peculiarities of ‘Ubá’, some factors limit the expansion of culture such as the low average productivity, uneven flowering and consequently the harvest, production alternation and susceptibility to diseases such as powdery mildew and anthracnose. The aim of this study was to evaluate the efficacy of different doses of paclobutrazol combined with the tip pruning of branches on flowering of mango 'Uba' under cultivation in the Federal University of Viçosa, Orchard Fundão, located in Viçosa -MG. The treatments were distributed in factorial 5 x 2 + 1 and were composed of five doses of paclobutrazol (0; 0.50; 1.00; 1.50 and 2.0 g .m -1 linear canopy), with and without tip pruning. It was added an additional treatment whose plants were not subject to pruning, application in the paclobutrazol and tip pruning. The design was a randomized block of four replications, with one plant per parcel. Were evaluated the length and diameter of the first and second flow branches sprouting, flowering percentage, panicle number per branch, total of flowers per panicle, ratio of male flowers and hermaphrodites, number of fruits per branch, carbohydrate content in leaves in two periods (tumescence in the flower bud (10/07/2014) and fruit development (15/11/2014)), fruit quality (as the length and diameter of the fruits), juice yield, hue angle of the skin and pulp, total soluble solids, titratable acidity, ratio (total soluble solids / titratable acidity). The branch length of the first budding flow was lower in plants receiving no pruning (control treatment). The xiiipercentage of flowering was significantly higher in plants with tip pruning in the branches and increased in response to the dose of PBZ, peaking at a dose of 1.62 g.m -1 linear canopy. The number of panicles per branch was higher in plants with tip pruning branches. There was an increase in the ratio of male and hermaphrodite flowers with increased paclobutrazol dose. The number of fruits per branch increased with tip pruning. The carbohydrate levels decreased in response to increase in dosage in the paclobutrazol and at different times of evaluation. There were no differences in fruit quality in response to application of paclobutrazol. It is concluded that the application of paclobutrazol up to the dose of 1.62 g.m -1 linear canopy, combined with lopping of branches resulted in uniformity and increased the 'Uba' mango flowering in Viçosa-MG region but did not alter the fruit quality.

Made available in DSpace on 2015-03-26T13:40:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 756098 bytes, checksum: a9cbd1b83399512af451cd8184ee678a (MD5) Previous issue date: 2007-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Two experiments, one in the field and the other in a greenhouse, were carried out to evaluate the effect of paclobutrazol (PBZ) application on the growth of banana plants in Viçosa-MG. Both experiments were arranged in a 2 x 5 factorial scheme, with the cultivars Prata Anã and FHIA 01 combined with the following PBZ doses : 0 (control); 0.5; 1.0; 1.5 and 2.0 g of a.i. of PBZ plant-1. Soil application of PBZ was performed in the field experiment and compared to foliar application in the greenhouse experiment. No significant dose x cultivar interaction effect was observed for any of the variables evaluated. The cultivars studied showed a differentiated behavior according to the environment and mode of application for the characteristics pseudostem circumference, foliar area of the new leaves emitted after PBZ application, number of leaves, number of new leaves and pseudostem height. In both experiments, PBZ did not influence the number of days from planting to flowering and the total foliar area of both cultivars. Increased soil application doses increased the number of new leaves up to 1.5 g of a.i. plant-1, with a strong drop in new leaf production at 2.0 g of a.i. plant-1. However, in foliar application, the number of new leaves decreased continually with increasing PBZ doses. Foliar application of PBZ showed differences in the number of active leaves and pseudostem circumference between PBZ doses and the control. Regardless of mode of application, increased PBZ doses led to shorter pseudostem growth, on average, a height reduction of 25%. Considering sucker production, the recommended range is between 0.5 and 1.5 g of a.i. plant1 with lower values to be used under greenhouse conditions. The magnitude of PBZ effect under both modes of application was dependent on the height of the plants at the time of application, being more evident when the plants presented shorter height. / Com o objetivo de avaliar a ação do paclobutrazol (PBZ) sobre o crescimento de bananeiras, foram instalados dois experimentos em Viçosa MG, sendo um a campo e o outro em ambiente protegido. Ambos seguiram o arranjo fatorial 2 x 5, com os cultivares Prata Anã e FHIA 01 combinados com as doses de PBZ: 0 (controle); 0,5; 1,0; 1,5 e 2,0 g de i.a de PBZ planta-1. No experimento a campo aplicou-se o PBZ via solo, e no experimento instalado em ambiente protegido à aplicação ocorreu por via foliar. Não houve efeito significativo da interação dose x cultivares para nenhuma das variáveis avaliadas. Os cultivares estudados comportaram-se de forma diferenciada, de acordo com o ambiente e a modo de aplicação, para as características circunferência do pseudocaule, área foliar das folhas emitidas após a aplicação do PBZ, número de folhas, número de perfilhos e altura do pseudocaule. O PBZ, em ambos os experimentos, não influenciou o número de dias do plantio ao florescimento e a área foliar total das bananeiras FHIA 01 e Prata Anã . Acréscimos nas doses de paclobutrazol, aplicado via solo, proporcionaram aumento no número de perfilhos até a dose de 1,5 g de i.a planta-1, com forte queda na emissão de perfilhos na dose de 2,0 g de i.a planta-1. No entanto, na aplicação via foliar, o número de perfilhos decresceu continuamente com acréscimos nas dose do paclobutrazol. Quando a aplicação foi realizada via foliar, houve diferenças no número de folhas ativas e na circunferência do pseudocaule entre as doses de PBZ e o controle. Acréscimos nas doses de paclobutrazol, independente do modo de aplicação, proporcionaram menor crescimento do pseudocaule, em média uma redução da altura de 25%. Considerando a produção de perfilhos, a faixa recomendada situa-se entre 0,5 e 1,5 g de i.a planta-1 com menores valores a serem utilizados em ambiente protegido. A magnitude do efeito do paclobutrazol, em ambos os modos de aplicação, foi dependente da altura das plantas no momento da aplicação, sendo esta mais evidente quando as plantas apresentavam menor altura.

Embora o Brasil apresente grande potencial para a expansão da cultura do abacateiro, sobretudo devido as condições edafoclimáticas favoráveis, sua produção ainda é restrita no país, principalmente devido a fatores limitantes, como a não adoção do adensamento nos pomares comerciais e de manejos agronômicos que favoreçam a produção e qualidade de frutos; a presença de Phytophthora cinnamomi, principal patógeno que afeta a cultura em todo o mundo; o fato da grande maioria dos pomares comerciais serem cultivados sob condições de sequeiro; e devido a fatores inerentes a ecofisiologia da planta, como vigor excessivo, baixa fixação de frutos e a dificuldade em controlar a alternância de produção. A aplicação de fitorreguladores é um manejo importante e com bons resultados, nos pomares comerciais dos principais países produtores, sendo esta uma técnica que visa melhorar a produtividade, incrementar o tamanho dos frutos, diminuir a alternância produtiva e reduzir o vigor vegetativo. O objetivo desta pesquisa foi avaliar o efeito de distintos fitorreguladores no desenvolvimento vegetativo, produção, eficiência e alternância produtiva, tamanho e formato de frutos e na qualidade pós-colheita de abacateiros \'Hass\' não irrigados. Entre 2013 e 2016, foram avaliados sete tratamentos via pulverização foliar: T1: água (testemunha); T2: 250 mg.L-1 Viviful® (68,75 mg.L-1 prohexadione-cálcio); T3: 0,7% Cultar® 250 SC (0,175% paclobutrazol); T4: 0,7% Sunny® (0,035% uniconazole); T5: 1% Moddus® (0,25% etil-trinexapac); T6: 1250 mg.L-1 MaxCel® (25 mg.L-1 6- benziladenina) aplicados no florescimento; e T7: 125 mg.L-1 ProGibb® 400 (50 mg.L-1 ácido giberélico) aplicado no início do mês de dezembro antes da segunda queda natural de frutos. O delineamento experimental foi conduzido em blocos ao acaso, com 7 tratamentos, 4 repetições e 2 plantas por parcela. Nos distintos tratamentos foram avaliados: tamanho da planta; crescimento dos brotos de primavera; produção, tamanho e formato de frutos e a qualidade pós-colheita. Os fitorreguladores utilizados não afetaram significativamente o desenvolvimento vegetativo, a eficiência produtiva e a produção de frutos, bem como não influenciaram na qualidade pós-colheita dos mesmos. O inibidor de giberelina uniconazole (T4) foi o responsável por reduzir significativamente o crescimento dos brotos de primavera durante os três anos de avaliações. A citocinina 6-benziladenina (T6) reduziu de forma significativa a alternância produtiva de abacateiros \'Hass\' enquanto o uniconazole (T4), prohexadione-cálcio (T2) e 6-benziladenina (T6) aumentaram significativamente o tamanho dos frutos. A maioria dos fitorreguladores utilizados modificaram o formato dos frutos, tornando-os mais arredondados, com destaque para o efeito do etil-trinexapac (T5). A aplicação dos distintos fitorreguladores se apresentam inconstantes ao longo dos anos de pesquisa e não afetam número, produção de frutos (Kg.planta-1) e eficiência produtiva de abacateiros \'Hass\' não irrigados. / Although Brazil presents great potential for the expansion of the avocado crop, especially due to the favorable edaphoclimatic conditions, its production is still restricted in the country, mainly due to limiting factors, such as the non-adoption of high-density plantings in commercial orchards and agronomic managements to support high fruit yield and quality; the presence of Phytophthora cinnamomi, the main pathogen affecting avocados around the world; the fact that most of the commercial orchards are grown under rainfed conditions; and also due to factors that are inherent to the tree\'s ecophysiology, such as the excessive vigor, low fruit set and difficulty in controlling the alternate bearing. Plant growth regulators (PGRs) have become important management tools in the commercial orchards of the main producer countries for improving yields, increasing fruit size, reducing alternate bearing and reducing vegetative vigor. The aim of this research was to evaluate the effect of different PGRs on vegetative growth, fruit yield, yield efficiency and alternate bearing, fruit size and shape, and post-harvest quality of \'Hass\' avocados non-irrigated. Between 2013 and 2016, seven treatments were evaluated by foliar sprays : T1: water (control); T2: 250 mg.L-1 Viviful® (68,75 mg.L-1 prohexadione-calcium); T3: 0,7% Cultar® 250 SC (0,175% paclobutrazol); T4: 0,7% Sunny® (0,035% uniconazole); T5: 1% Moddus® (0,25% trinexapac-ethyl); T6: 1250 mg.L-1 MaxCel® (25 mg.L-1 6-benzyladenine) all applied in full bloom; and T7: 125 mg.L-1 ProGibb® 400 (50 mg.L-1 gibberelic acid) applied at the beginning of December, before the second natural fruit drop. The experiment was conducted in a randomized block design with seven treatments, four replications and two plants per plot. The following variables were evaluated: tree size, spring shoot growth, fruit yield, size and shape and post-harvest fruit quality. The applied PGRs did not significantly affect tree size, yield efficiency and fruit yield, nor did they influence the post-harvest fruit quality. Uniconazole (T4) was responsible of a significant shortening of spring shoots during the three years of evaluations. The cytokinin 6-benzyladenine (T6) significantly reduced alternate bearing of \'Hass\' avocado trees. Spring sprays of uniconazole (T4), prohexadione-calcium (T2) and 6-benzyladenine (T6) significantly increased fruit size. Most of the PGRs modified -fruit shape of \'Hass\' avocados to a more rounded format, with trinexapac-ethyl (T5) showing a stronger effect. The application of the different PGRs are inconsistent throughout the years of research and do not affect fruit number and yield (kg.tree-1) and yield efficiency of non-irrigated \'Hass\' avocados.

The Chrysanthemum (Dendranthema grandiflora Tzvelev) and Lisianthus (Eustoma grandiflorum Raf.) are species of ornamental plants of great prominence in the Brazilian and international floriculture. In the cultivation of ornamental plants in pots, is usually performed chemical control of plant growth seeking its standardization. This research aimed to evaluate the responses of these two species to plant growth retardant, sprayed on cutting cultivars conducted in pots in order to obtain a differentiated product, and also define the optimal dose for producing quality plant pots suited to commercial standards. The survey consists of tests in a randomized design. Lisianthus in the model is 3 x 5 factorial, with three cultivars ('Echo Pure White', 'Mariachi Misty Pink' and 'Echo Yellow') and five doses of Paclobutrazol (0, 16, 32, 48 and 64 mg.L-1) applied in spraying. The Chrysanthemum uses 2 x 4 factorial design, frequency of application being tested weekly and biweekly and plant growth retardant Daminozide (0, 2.000, 4.000 and 6.000 mg.L-1) on the cultivar 'Yellow Spithoven'. The results show that the cultivar of Lisianthus 'Echo Yellow' is the most suitable for growing in pots and the best fit is achieved with these commercial spraying of 64 mg.L-1 of Paclobutrazol. The cultivar of Chrysanthemum 'Yellow Spithoven' has driven its growth Daminozide and can be grown in pots, and 2.000 mg L-1 produces the weekly sprayed potted plants of better quality. / O Crisântemo (Dendranthema grandiflora Tzvelev) e o Lisianthus (Eustoma grandiflorum Raf.) são espécies de plantas ornamentais de grande destaque na floricultura brasileira e internacional. Nos cultivos de plantas ornamentais em vaso, normalmente é realizado o controle químico do crescimento da planta buscando a sua padronização. Esta pesquisa teve como objetivos avaliar as respostas dessas duas espécies a retardantes de crescimento de plantas, pulverizados sobre cultivares de corte conduzidas em vaso, visando obter-se um produto diferenciado, e ainda, definir a melhor dose para produção de vasos com plantas de qualidade adequados aos padrões de comercialização. A pesquisa foi constituída de ensaios, no delineamento inteiramente casualizado. No Lisianthus, o modelo foi bifatorial 3 x 5, com três cultivares ( Echo Pure White‟, Mariachi Misty Pink‟ e Echo Yellow‟) e cinco doses de Paclobutrazol (0, 16, 32, 48 e 64 mg.L-1) aplicadas em pulverização. Com o Crisântemo utilizou-se o modelo bifatorial 2 x 4, sendo testada a freqüência de aplicação semanal e bissemanal e o retardante de crescimento vegetal Daminozide (0, 2.000, 4.000 e 6.000 mg.L-1) sobre a cultivar Yellow Spithoven‟. Os resultados evidenciaram que, das cultivares de Lisianthus, a Echo Yellow‟ é a mais apropriada para o cultivo em vaso e a melhor adequação comercial destes é conseguida com a pulverização de 64 mg.L-1 de Paclobutrazol. A cultivar de Crisântemo Yellow Spithoven‟ tem seu crescimento controlado por Daminozide, podendo ser cultivada em vaso, e 2.000 mg.L-1 pulverizados semanalmente produziram os vasos com plantas de melhor qualidade.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 134-151).

This thesis examined aspects of the reproductive and molecular biology of Eucalyptus marginata (jarrah). The aims were to develop protocols for controlled pollination, that could be used in clonal orchard trees to breed jarrah seedlings that have a known genetic resistance to Phytophthora cinnamomi (dieback), for use in rehabilitation after mining and logging. An intimate knowledge of the breeding biology of jarrah was necessary to achieve this aim. The project also aimed to increase knowledge of the genetic diversity and structure of jarrah, in order to make informed decisions regarding the collection of material to be used for clonal propagation. Previous research has had little success in producing viable seed from any controlled pollinations, but clonal material resistant to P. cinnamomi has been produced using tissue culture. The question posed in this thesis was ‘Can we improve breeding and propagation techniques of jarrah?’ Techniques were developed for testing of in vitro pollen viability and pollen storage, pollination and fertilisation success after controlled pollinations, including determination of stigma receptivity and development of bud isolation techniques using alfoil. The variation in female fertility between genotypes was examined. The use of paclobutrazol was explored as a method of increasing the level of viable seed production in clonal orchard trees. The use of fertiliser as well as the growth retardant was also explored to see if it increased the level of seed production even more. Genetic diversity, genetic differentiation and phylogeny within Eucalyptus marginata were examined using nuclear and chloroplast DNA analysis with Restricted Fragment Length Polymorphisms. While it was first thought that the fertilisation rate was quite low, it was confirmed that the fertilisation rate is similar to other eucalypt species. The zygote abortion rate was quite high in one clone, but one wild tree had a similar seed production rate to other eucalypt species. The zygote and endosperm appeared to be different in the clone and the wild tree observed. The level of seed production was examined in clones and wild trees and it was found that the level was often quite low, particularly in the clones (0 – 13% in clones, 0 – 18% in wild trees) in comparison with other Eucalyptus species, and varied between genotypes. The use of a growth retardant such as paclobutrazol may increase the production of viable seed, if it is applied during autumn. The results were inconclusive for the fertiliser/paclobutrazol experiment, since the paclobutrazol was applied during spring which was the worst time of year for increasing seed production. There were differences between genotypes in reaction to both the paclobutrazol and the fertiliser/paclobutrazol. Genetic diversity was moderate in comparison with other Eucalyptus species, and there was a low level of genetic differentiation between populations in the nuclear genome. No differentiation was observed between the morphologically recognised subspecies in the nuclear genome, but differentiation between the populations on the Swan Coastal Plain and populations on the Darling Plateau was seen in the chloroplast genome, indicating that there was historical separation of these two areas. The conclusions arising from this work are that while controlled pollinations are possible in Eucalyptus marginata the clones that were used in these experiments have often behaved differently to the wild trees in the time of anthesis and levels of viable seed production, and in one clone (5J119) the zygote and endosperm nuclei appeared to be very different to the zygote and endosperm nuclei of a wild tree. Further investigation is necessary to see if these differences are related to the low level of seed production observed in the clonal populations. Paclobutrazol may be worth exploring further as a means of increasing seed production. Material to be used for rehabilitation and seed orchards can be collected from a wide area in the main distribution of the species, although trees on the Swan Coastal Plain are distinct from the trees in the main forest area in the chloroplast genome.