Soil seed banks are a reservoir of viable seeds present in the soil in plant communities. They have been studied and characterized in various ways in different habitats. However, these studies are limited to modern seed banks. This study extends seed bank studies to the Paleozoic Era. It was hypothesized that size distribution and seed density in Paleozoic seed banks exhibit similar patterns as in modern seed banks. Seed sizes and seed density of fossil seed from Wise Virginia were estimated. Modern seed bank information was obtained from published data. Data were analyzed using one-way ANOVA and Kruskal-Wallis test. The Paleozoic size distribution was predominated by larger seeds and the estimated seed density of 19 200 seeds m-3 falls within the range of modern seed banks but at a higher end of modern seed bank densities. During the Paleozoic they were sufficient to insure regeneration of these economically important forests.

The aim of this dissertation is to study the systematics and evolution of Euphorbiaceae vines (tribe Plukenetieae), a diverse pantropical lineage (~365 species and 18 genera) composed of three morphologically distinct subtribes, Dalechampiinae, Plukenetiinae, and Tragiinae. Through the course of my research I largely resolved the evolutionary history of Plukenetieae and made broader contributions to the study of pollen and seed evolution, pantropical biogeography, and plant diversification. In chapter two I developed the first well-sampled molecular phylogeny for Plukenetieae (154 terminals, ~93 species, 2,207 character dataset composed of ITS and psbA-trnH with indel gap-scored data), and determined baseline species group relationships of the tribe. Molecular phylogeny largely agreed with pollen morphology hypotheses and confirmed that the large genus Tragia was para- and/or polyphyletic and should be split into smaller genera. Analysis of pollen morphology revealed a trend towards aperture reduction and loss in Tragiinae, with four origins of weakly defined apertures and up to three origins of inaperturate pollen. In chapter three, I studied the seed size evolution of Plukenetia, a pantropical genus with large edible oil-rich seeds, by developing a near-exhaustive phylogeny (83 terminals, 20 of ~24 species, 5,069 bp dataset of ETS, ITS, KEA1 introns 11 and 17, TEB exon 17, matK, ndhF) and conducting ancestral state estimation and phylogenetic regression. Seed size evolution in Plukenetia was dynamic and associated with competing selective pressures of plant size, fruit type (and inferred dispersal syndrome), and seedling ecology. In chapter four I presented a revised sectional classification of Plukenetia based on phylogeny and morphological evidence, including three new taxa from South America. Chapters three and five included biogeographical investigations on Plukenetia and Plukenetieae. Analyses revealed that pantropical disjunct distributions arose one to three times in each subtribe via periodic long-distance dispersals from the Oligocene to the Pliocene, most often from South America to Africa and then Southeast Asia. Lastly, in chapter five, I developed an improved phylogeny for Plukenetieae (289 terminals, ~109 species, 5,160 bp dataset of ETS, ITS, KEA1 intron 11, TEB exon 17, matK, ndhF) to study the influence of innovative traits (twining growth form, stinging hair defences, and pseudanthial inflorescences) on diversification in the tribe. However, increased diversification was not associated with innovative traits. Instead, diversification was associated with clades that shifted into drier open habitats, aided by habitat expansion following the Late Miocene cooling period.

This thesis is a comparative study of the life history strategies, and in particular seed germination requirements, in Australian species of the halophyte plant genus Frankenia L. (Frankeniaceae). Frankenia is a cosmopolitan genus that occurs in Mediterranean, semi-arid, and arid regions on distinctive soil types – commonly on saline, sodic or gypseous soils – in habitats such as coastal cliffs, and on the margins of salt lakes, salt-pans and saltmarshes (Summerhayes 1930; Barnsley 1982). The plants are small shrubs or cushion-bushes with pink, white or pale purple flowers, and salt-encrusted recurved leaves. This project investigates germination requirements for Frankenia in relation to seed age, light requirements, temperature preferences, salinity tolerance, and soil characteristics. It also explores two divergent reproductive strategies – notably seed packaging strategies – in relation to environmental variables. Within the 46 currently recognized endemic Australia species, some species have a few ovules per flower and produce only a few larger seeds per fruit, while other species have many ovules per flower and produce many small seeds per fruit. Large-seededness is thought to increase the probability of successful seedling establishment in drought and salt-stressed environments. As both larger- and smaller-seeded species of Frankenia co-occur in close geographical proximity, hypotheses regarding the advantages of large-seededness in stress environments can be tested. By restricting the analysis of seed mass variation to similar habitats and within a single plant genus, it is possible to test ecological correlates that would otherwise be masked by the strong effects of habitat differences and phylogenetic constraints. Overall, larger-seeded Frankenia species were demonstrated to be advantageous for rapid germination after transitory water availability, and for providing resources to seedlings if resources became limiting before their successful establishment. Smaller-seeded species delayed germination until both soil-water availability and cooler temperatures persisted over a longer time period, improving chances of successful establishment for the more slowly growing seedlings that are more reliant on their surroundings for resources. This study produces information on the seed and seedling biology of many Australian species of Frankenia including several that are of conservation significance, e.g. F. crispa with its isolated populations, and the rare and endangered F. plicata. This information is important for the development of conservation management plans for these and other arid zone, halophyte species. In addition, the results of this study are of practical significance in determining the suitability of Frankenia for inclusion in salinity remediation and mine-site rehabilitation projects, and for promoting Frankenia as a drought and salt tolerant garden plant.

A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. Small seeds, however, are numerous and small-seeded species are therefore more fecund. Moreover, a pattern with small-seeded species being associated with open habitats and large-seeded species being associated with closed habitats has been reported in the literature. In this thesis I assess effects of seed size on recruitment, and how relationships between seed size and recruitment may relate to habitat conditions. Seed sowing experiments were performed in the field to assess inter- and intra-specific relationships between seed size and recruitment in open and closed habitats (Paper I and II). Seed removal experiments were performed in the field to assess what effects seed predation may have on a relationship between seed size and recruitment (Paper III). A garden experiment was performed based on contests between larger-seeded and smaller-seeded species, in order to examine different models on co-existence of multiple seed size strategies. The results showed that there was a weak positive relationship between seed size and recruitment in the field, and that this relationship was only weakly and inconclusively related to habitat (Paper I and II). Seed removal was negatively related to seed size in closed habitats and unrelated to seed size in open habitats (Paper III). This indicates that any positive relationship between seed size and recruitment may be an effect of higher seed removal in small-seeded species. However, when grown under controlled conditions in a garden experiment, there was a clear advantage of larger-seeded species over smaller-seeded species (Paper IV). This advantage was unaffected by seed density, indicating that there was no competitive advantage of the larger-seeded species. Instead, indirect evidence suggests that larger-seeded species exhibit higher tolerance to stress. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Accepted.</p><p> </p>

Micronutrient malnutrition is a leading worldwide health problem that affects billions of people particularly in the developing countries resulting in serious health conditions. The domestication of crops produced high yield and larger seed size but with a reduction in nutritious quality. The locus NAM or Gpc-1 affects both the seed size and nutrient content in wheat and barley. A non-functional allele of the gene increases the seed size but at the expense of protein and micronutrient content. However, this gene was found to be lost in wheat during the early domestication resulting in lower nutrient content. Therefore, the selection for high yield has lead to lower grain nutrients. Our aim of the present study is to investigate when the selection for yield occured in barley and to check the existence of the wild type allele in the 19th century of landrace barley crops. In addition, to analyse the barley grain concentration of protein, iron and zinc among the landrace and cultivars from various time periods of northern Europe. The grain nutrient concentration of Nitrogen, Iron and Zinc did not show significant difference among the investigated 80 Scandinavian barley accessions. The grain nutrient concentration did not correlate with the seed size and chlorophyll content. The polymorphism was not observed among the allelic diversity of HvNAM-1 gene indicating that the NAM-B1 gene still prevails in the 19th century barley cultivars.

Seed size is regarded as a functional trait with very important consequences for the fitness of plant species. Seedlings emerging from larger seeds are more competitive but are more costly to produce than seedlings from smaller seeds. Seed size is also a trait with transgenerational effects, affecting both the fitness of the parent as well as that of the offspring. Theory on the evolution of offspring size predicts an optimum balance between size and number, seen from the parent's perspective; while empirical studies often show selection for larger seeds, seen from the offspring's perspective. Seed size selection arising from post germination traits is, however, often not unidirectional, nor operating with the same strength in all life history stages of the plant. Seed size selection is also environmentally dependent. Even environmental influence might not operate with the same consistency and strength uniformly through the plant's life cycle. This dissertation is intended to study these questions concerning the dynamics of seed size selection in the wild. This work is to my knowledge, the first to document how seed size selection operates through the whole life cycle, with naturally germinated annual plants from the Sonoran Desert. In my first chapter I explored the offspring fitness consequences of seed size in a multiyear observational study using plant demography and relating vital rates (germination, survival, and fecundity) to the size of the seeds that originate individual plants and the environmental variables of precipitation and competition. I detected positive directional selection operating both through survival and fecundity. Water availability increased both survival and fecundity but also strengthened survival selection and had no effect on fecundity selection. Competition detrimental effects were only observed in fecundity but not in plant survival. In my second chapter I ask whether seed size-specific germination could influence seed size selection later in the life cycle. We found that because germination is differential in relation to seed size, the time of optimal conditions for germination in the field would determine the variance of seed size in the germinated fraction and thus influencing the strength of seed size selection operating through survival. In my third chapter I explored the dispersal consequences of phenotypic plasticity in seed provisioning. We found that mother plants that experienced more competition made smaller seeds and affected the seed dispersal process. Smaller seeds were better able to disperse farther away from their mothers and therefore increased their probability of escaping competition in the next growing season. These studies demonstrated that seed size selection varies through the life cycle and in intensity depending on interactions with the environment.

A expansão da floresta sobre o campo, a partir do estabelecimento de araucárias isoladas (nucleação), forma uma paisagem única no planalto sul-brasileiro, sendo que o uso de uma abordagem de metacomunidades pode auxiliar a compreender melhor esse processo. Existem quatro modelos de metacomunidades que explicam a relação entre comunidades locais: dinâmica de manchas, seleção de espécies, efeitos de massa e neutro. Esses modelos possuem diferentes premissas quanto aos processos de nicho e de dispersão que atuam na dinâmica da metacomunidade. No entanto, há uma lacuna entre a teoria e o teste desses modelos em estudos empíricos. Uma forma de testar mais claramente esses modelos é através de uma abordagem funcional. Nesse contexto, o objetivo do trabalho foi avaliar a importância (i) de atributos relacionados às estratégias de dispersão e de crescimento das espécies, (ii) da abundância das espécies no pool regional e (iii) do tamanho da mancha, na organização de comunidades de indivíduos lenhosos juvenis em áreas de nucleação florestal sobre o campo, a fim de compreender quais modelos de metacomunidades melhor explicam esse processo. Para tanto, calculamos o CWM (Community Weighted Mean) e índices de diversidade funcional, considerando a ocorrência (sesFD) e a abundância (sesFDis) das espécies, para tamanho da semente e área foliar específica (SLA), em manchas florestais de distintos tamanhos e na floresta contínua adjacente ao campo, e testamos se as áreas diferem entre si de acordo com o tipo de ambiente. Avaliamos ainda se a abundância relativa das espécies nas áreas de nucleação é determinada pela abundância das mesmas na floresta contínua, através do uso dos modelos de Community Assembly by Trait Selection (CATS). Os resultados foram então comparados com o esperado para cada modelo de metacomunidade. A maior parte dos sítios apresentou índices de diversidade funcional para SLA e tamanho da semente de acordo com o esperado ao acaso. As áreas não diferiram quanto ao CWM para SLA. No entanto, foram observadas diferenças quanto ao CWM para o tamanho da semente, com o favorecimento de espécies com sementes menores em áreas mais abertas, e espécies com sementes maiores em áreas mais sombreadas. De acordo com os modelos CATS, a abundância das espécies no pool regional foi mais importante do que os atributos para a determinação da abundância das mesmas nas comunidades locais. Concluiu-se que o modelo de metacomunidades que melhor explica o processo de nucleação florestal sobre o campo no planalto das araucárias é o modelo de efeitos de massa, o que ressalta a importância da dispersão para a estruturação das comunidades locais. Como a maior parte das espécies lenhosas existentes na área possui dispersão zoocórica, esse resultado indica que a preservação da fauna dispersora é fundamental para a dinâmica desse ecossistema. Com o uso de uma abordagem funcional, em conjunto com os modelos CATS, foi possível testar os quatro modelos de metacomunidades. Assim, o método proposto pode ser aplicado a outros sistemas naturais, auxiliando na compreensão do funcionamento de diferentes metacomunidades. / The forest expansion over the grassland, from the establishment of isolated Araucaria (nucleation) forms a unique landscape in south brazilian plateau, and the use of a metacommunity approach can help to better understand this process. There are four metacommunity models that explain the relationship between local communities: patch-dynamics, species-sorting, mass-effects and neutral. These models have different assumptions about niche processes and dispersion that act in metacommunities dynamics. However, there is a gap between theory and the test of these models in empirical studies. One way to test these models more clearly is through a functional approach. In this context, the objective of this study was to evaluate the importance of (i) attributes related to dispersion and growth species strategies, (ii) species abundance in the regional pool and (iii) patch size, on structuring communities of juvenile woody individuals in forest nucleation areas on the grassland in order to understand which metacommunity model explain this process. Therefore, we calculate the CWM (Community Weighted Mean) and functional diversity indices, considering species occurrence (sesFD) and abundance (sesFDis) for seed size and specific leaf area (SLA), in forest patches of different sizes and in adjacent continuous forest and tested if sites differ according to ambient. Further, we evaluated if species relative abundance in nucleation areas is determined by the abundance in the continuous forest, by the use of Community Assembly by Trait Selection (CATS) models. Then, we compared results with expected for each metacommunity model. Most of sites presented functional diversity values for SLA and seed size as expected by chance. Areas did not differ in CWM to SLA. However, we observed differences for CWM to seed size, favoring species with smaller seeds in more open areas, and species with larger seeds in more shaded areas. According to CATS models, species abundance in regional pool was more important than attributes to determine species abundance in local communities. We concluded that the metacommunity model that best explains forest nucleation on the grassland in Araucaria plateau is the mass-effects model, which emphasizes the importance of dispersion for structuring local communities. As most of existing woody species has zoochorous dispersion, this result indicates that preservation of disperser fauna is essential for ecosystem dynamic. By using a functional approach in combination with CATS models, it was possible to test the four metacommunity models. Thus, the method proposed in this work can be applied to other natural systems, helping understanding different metacommunities operation.

Made available in DSpace on 2014-06-11T19:28:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-26Bitstream added on 2014-06-13T18:57:39Z : No. of bitstreams: 1 rodrigues_ab_me_jabo.pdf: 262758 bytes, checksum: eeb6f68931fbab4337440ae0330c2d84 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente trabalho teve por objetivo avaliar se sementes de milho classificadas em diversos tamanhos e comercializadas pelas empresas, podem apresentar desempenho germinativo diferente, comparando-se as sementes misturadas com cada uma das classes de tamanho que constituem a mistura. As sementes foram coletadas junto a produtores rurais do Município de Careaçu-MG, e em pontos de revenda. Foram utilizadas sete cultivares de milho de diferentes empresas, sendo elas Soma, Exceler, AL-Bandeirante, BR 206, AG 1051, BR 201 e AG 7575. As amostras coletadas de cada material foram homogeneizadas e após a homogeneização, tomouse, de cada material uma amostra de sementes de 500 gramas, que foi denominada original no presente trabalho e que continha, misturadas, diferentes classes de tamanho. O restante do material foi classificado em peneiras de crivo circular. Das diferentes classificações de peneira encontradas para cada classe de tamanho com quantidade suficiente de sementes e para as sementes denominadas original foram realizados os seguintes testes: peso de 1000 sementes, teor de água, germinação, envelhecimento acelerado, sanidade, emergência em solo: primeira contagem, contagem final e índice de velocidade de emergência. O delineamento estatístico utilizado foi o delineamento inteiramente casualizado (DIC), com 4 repetições de 50 sementes, para cada classe de tamanho, em cada teste realizado. As médias foram comparadas pelo teste de Tukey, a 5% de probabilidade Os resultados permitiram concluir que a mistura de sementes de tamanhos próximos não deve resultar em alterações significativas no desempenho germinativo dessas sementes, quando em comparação com cada classe isoladamente, confirmando assim que a mistura de classes de tamanho é prática que pode ser adotada para semeadura fluidizada. / The objective of this research was to investigate whether the mixing of different size classes of corn seeds would represent any chance of germinative performance variation in comparison to that shown by the seeds when isolated in each one of the size classes. This evaluation was deemed necessary due to the growing tendency of the corn seed industry to mix seeds of different sizes viewing the possibility of fluidized sowing in replacement of the traditional sowing technique. Part of the seeds used in this experiment were collected at farms located in the municipality of Careaçu, state of Minas Gerais, Brazil, just before the sowing moment; the other part was collected from seed selling stores at the same city. Seeds from 7 corn cultivars were used : ‘Soma’, ‘Exceler’, ‘AL-Bandeirantes’, ‘BR 206’, ‘AG 1051’, ‘BR 201’, and ‘AG 7575’. The samples from each cultivar were homogenized and then a sample of 500 grams from each cultivar was taken this sample representing the cultivar in which seeds of different sizes were mixed in different proportions. This mixed sample was designated the original sample. The remaining part of each cultivar was then passed through specific round hole sieves and the amount of each size class in the whole sample was weighed. Each one of those size classes as well as the seeds of the original sample were submitted to the following evaluations : 1000 seeds weight, seed water content, germination, accelerated aging, seed sanitary test, performance in the soil ( first count, final count and speed of emergence ). The results indicated that the mixing of seeds of different size classes for the fluidized sowing does not lead to any significant deviation in seed germinative performance.

Resumo: O presente trabalho teve por objetivo avaliar se sementes de milho classificadas em diversos tamanhos e comercializadas pelas empresas, podem apresentar desempenho germinativo diferente, comparando-se as sementes misturadas com cada uma das classes de tamanho que constituem a mistura. As sementes foram coletadas junto a produtores rurais do Município de Careaçu-MG, e em pontos de revenda. Foram utilizadas sete cultivares de milho de diferentes empresas, sendo elas Soma, Exceler, AL-Bandeirante, BR 206, AG 1051, BR 201 e AG 7575. As amostras coletadas de cada material foram homogeneizadas e após a homogeneização, tomouse, de cada material uma amostra de sementes de 500 gramas, que foi denominada original no presente trabalho e que continha, misturadas, diferentes classes de tamanho. O restante do material foi classificado em peneiras de crivo circular. Das diferentes classificações de peneira encontradas para cada classe de tamanho com quantidade suficiente de sementes e para as sementes denominadas original foram realizados os seguintes testes: peso de 1000 sementes, teor de água, germinação, envelhecimento acelerado, sanidade, emergência em solo: primeira contagem, contagem final e índice de velocidade de emergência. O delineamento estatístico utilizado foi o delineamento inteiramente casualizado (DIC), com 4 repetições de 50 sementes, para cada classe de tamanho, em cada teste realizado. As médias foram comparadas pelo teste de Tukey, a 5% de probabilidade Os resultados permitiram concluir que a mistura de sementes de tamanhos próximos não deve resultar em alterações significativas no desempenho germinativo dessas sementes, quando em comparação com cada classe isoladamente, confirmando assim que a mistura de classes de tamanho é prática que pode ser adotada para semeadura fluidizada. / Abstract: The objective of this research was to investigate whether the mixing of different size classes of corn seeds would represent any chance of germinative performance variation in comparison to that shown by the seeds when isolated in each one of the size classes. This evaluation was deemed necessary due to the growing tendency of the corn seed industry to mix seeds of different sizes viewing the possibility of fluidized sowing in replacement of the traditional sowing technique. Part of the seeds used in this experiment were collected at farms located in the municipality of Careaçu, state of Minas Gerais, Brazil, just before the sowing moment; the other part was collected from seed selling stores at the same city. Seeds from 7 corn cultivars were used : 'Soma', 'Exceler', 'AL-Bandeirantes', 'BR 206', 'AG 1051', 'BR 201', and 'AG 7575'. The samples from each cultivar were homogenized and then a sample of 500 grams from each cultivar was taken this sample representing the cultivar in which seeds of different sizes were mixed in different proportions. This mixed sample was designated the original sample. The remaining part of each cultivar was then passed through specific round hole sieves and the amount of each size class in the whole sample was weighed. Each one of those size classes as well as the seeds of the original sample were submitted to the following evaluations : 1000 seeds weight, seed water content, germination, accelerated aging, seed sanitary test, performance in the soil ( first count, final count and speed of emergence ). The results indicated that the mixing of seeds of different size classes for the fluidized sowing does not lead to any significant deviation in seed germinative performance. / Orientador: Nelson Moreira de Carvalho / Coorientador: Édila Vilela de Resende Von Pinho / Banca: Ana Dionisia da Luz Coelho Novembre / Banca: Gisele Herbst Vazquez / Mestre

This study expanded the knowledge on tamarind (Tamarindus indica L.) seedling production by analyzing the effects of different container sizes and vermiculite doses in a commercial substrate and seed size and different sowing depths in a nursery seedling production. The experiments were done at the experimental farm Água Limpa in the sector of Fruit Crops, in a nursery with anti-aphid screens, with 0.38 mm2 opening. The farm is located at 19º05 23 S and 48º21 28 W, at 792 m altitude, in the county of Uberlândia, Minas Gerais, Brazil. The experimental design of the trials were randomized blocks, in a 3 x 3 or 2 x 3 factorial. In the first trial, were utilizadas three vermiculite doses (0%, 10% or 20% v v-¹) in three container sizes (18 x 30 cm, 20 x 25 cm or 25 x 35 cm), and in the second trial, utilizou-se two seed sizes (small and large) and three sowing depths (1cm; 2cm or 3cm), both of them with 5 repetitions and 5 plants per plot. The experiments were done from December 26 2006 to June 4 2007. In the first trial, results indicated that tamarind seedlings were not affected by container size, nor by the use of vermiculite. However, the largest container (25 x 35 cm) yielded longer root length, although reducing stem diameter and above ground fresh and dry matter. Mixing vermiculite to the substrate yielded better results for stem diameter, number of leaves, fresh and dry matter of roots and above ground mass. In the second trial, the results indicated that bigger seeds yielded greater quality tamarind seedlings for plant height, stem diameter, fresh and dry matter for above ground mass and roots. There were no significant differences in the parameters evaluated as a function of sowing depth. CHAPTER I: This study evaluated the effects of different vermiculite doses and container sizes in the development and quality of tamarind seedlings. The experiment was done in a nursery with anti-aphid screens, with 0.38 mm2 opening, in the sector of fruit Experimental Farm Água Limpa, county of Uberlândia (MG), from December 26 2006 to June 4 2007. The experimental design was randomized blocks , in a 3 x 3 factorial, with 5 repetitions and 5 plants per plot. The factors were three vermiculite doses (0%, 10% or 20% v v-¹) and three container sizes (18 x 30 cm, 20 x 25 cm or 25 x 35 cm). The development of tamarind seedlings was evaluated by the determination of the number of leaves, stem diameter, plant height, root length, fresh and dry weight of roots and above ground matter. The results showed that tamarind seedling height was not affected by container sized nor by the use of vermiculite. The largest container (25 x 35 cm) yielded better root length; however, stem diameter and above ground fresh and dry matter were reduced. Mixing vermiculite to the substrate yielded better results for stem diameter, number of leaves, fresh and dry matter of roots and above ground mass. CHAPTER II: The effect of seed size and different sowing depths on tamarind (Tamarindus indica L.) seedling vigor and vegetative growth was evaluated in a trial done in a screened nursery, with 0.38 mm2 opening, at the experimental farm Água Limpa, in a nursery with anti-aphid screens, in the county of Uberlândia,. The farm is located at 18º55 33 S and 48º17 19 W, at 872 m altitude, Minas Gerais, from December 26 2006 to June 4 2007. The experimental design was randomized blocks, in a 2 x 3 factorial, with 5 repetitions and 5 plants per plot. The factors were two seed sizes, small and large (65.60 g and 94.54 g respectively), defined according to the weight of 100 seeds and three sowing depths (1cm; 2cm or 3cm). The number of leaves, stem diameter, plant height, root length, fresh and dry weight of roots and above ground matter were evaluated. The results indicate that tamarind seed size affected seedling initial development. There were no significant differences in the parameters evaluated as a function of sowing depth. / O trabalho teve como objetivo ampliar os conhecimentos na produção de mudas de tamarindeiro (Tamarindus indica L.) estudando os efeitos de diferentes tamanhos de recipientes e doses de vermiculita em substrato comercial e tamanho de semente em diferentes profundidades de semeadura na produção de mudas durante a fase de viveiro. Os experimentos foram conduzidos na Fazenda Experimental Água Limpa no setor de Fruticultura, em um viveiro com telado anti-afídios, malha de 0,38 mm2. A Fazenda está situada a 19º05 23 de latitude sul e 48º21 28 de longitude oeste, e altitude de aproximadamente 792 m, no município de Uberlândia-MG. Os delineamentos experimentais foram inteiramente casualizados, com os tratamentos distribuídos em esquemas fatoriais 3 x 3 e 2 x 3. No primeiro experimento, foram utilizadas três doses de vermiculita (0%, 10% e 20% vv ¹) em três tamanhos de recipiente (18 x 30 cm, 20 x 25 cm e 25 x 35 cm), e no segundo experimento, utilizou-se dois tamanhos de semente (pequenas e grandes) e três profundidades de semeio (1; 2 e 3cm), ambos com 5 repetições e 5 mudas por parcela. Os experimentos foram realizados no período de 26 de dezembro de 2006 a 4 de junho de 2007. No primeiro experimento, os resultados mostraram que a altura das mudas de tamarindeiro não foi influenciada pelos diferentes tamanhos de recipiente e uso de vermiculita. No entanto, o maior recipiente (25 x 35 cm) propiciou melhor comprimento de raiz. Todavia, diminuiu o diâmetro de caule e a massa seca da parte aérea das mudas de tamarindeiro. Já a mistura de vermiculita ao substrato promoveu melhores resultados quanto ao diâmetro de caule, número de folhas, massa seca da parte aérea e de raízes. No segundo experimento, os resultados mostraram que as sementes grandes propiciaram mudas de tamarindeiro de qualidade superior, em relação à altura de muda, diâmetro de caule, massa seca, tanto do sistema radicular, como da parte aérea. Quanto à profundidade de semeio, não houve diferença significativa para todas as características avaliadas. CAPITULO I: O objetivo do presente experimento foi avaliar o efeito de diferentes doses de vermiculita e o tamanho dos recipientes no desenvolvimento e na qualidade de mudas de tamarindeiro. O experimento foi conduzido em um viveiro com tela anti-afídios, malha de 0,38 mm2, no setor de Fruticultura da Fazenda Experimental Água Limpa, município de Uberlândia (MG), no período de 26 de dezembro de 2006 a 4 de junho de 2007. O delineamento experimental foi inteiramente casualizado, com os tratamentos distribuídos em esquema fatorial 3 x 3, com 5 repetições e 5 mudas por parcela, sendo os fatores três doses de vermiculita ( 0%, 10% e 20% vv ¹) e três tamanhos de recipiente (18 x 30 cm, 20 x 25 cm e 25 x 35 cm). Para a avaliação do desenvolvimento das mudas de tamarindeiro, foi determinado o número de folhas, diâmetro do caule, altura da muda, comprimento da raiz, peso da matéria seca da parte aérea e das raízes. Os resultados mostraram que a altura das mudas de tamarindeiro não foi influenciada pelos diferentes tamanhos de recipiente e uso de vermiculita. O maior recipiente (25 x 35 cm) propiciou melhor comprimento de raiz, todavia, diminuiu o diâmetro de caule e a massa seca da parte aérea das mudas de tamarindeiro. Já a mistura de vermiculita ao substrato promoveu melhores resultados quanto ao diâmetro de caule, número de folhas, massa seca da parte aérea e de raízes. CAPITULO II: Com o objetivo de avaliar a influência dos tamanhos de semente e a profundidade de semeadura sobre o vigor e o desenvolvimento vegetativo das mudas de tamarindeiro (Tamarindus indica L.), conduziu-se um experimento em um viveiro telado, de malha 0,38 mm2, na Fazenda Experimental Água Limpa, no setor de Fruticultura, município de Uberlândia (MG), no período de 26 de dezembro de 2006 a 4 de junho de 2007. O delineamento experimental foi inteiramente casualizado, com os tratamentos distribuídos em esquema fatorial 2 x 3, com 5 repetições e 5 mudas por parcela, sendo os fatores: dois tamanhos de semente, pequenas e grandes (65,60 g/100 sementes; 94,54 g/100 sementes) respectivamente, e três profundidades de semeio (1; 2 e 3cm). Avaliou-se o número de folhas, diâmetro do caule, altura da muda, comprimento da raiz, massas secas da parte aérea e das raízes. Os resultados obtidos mostraram que as sementes de tamarindo influenciaram o desenvolvimento inicial das mudas. Quanto à profundidade de semeio, não houve diferença significativa entre todas as características avaliadas nas mudas. / Mestre em Agronomia