The effects of seed size on sprout growth of potato seed pieces were investigated in controlled temperature conditions. The objectives were to quantify the effects of seed size, plant growth regulators (gibberellin and paclobutrasol) and calcium availability on sprout length, sprout and root dry mass, as well as the fraction of seed reserves utilised for sprout development. The interactive effect between seed size and temperature was also investigated Sprout length did not differ among seed pieces ranging from 1 to 8g in mass. For larger seed pieces sprout length, dry mass and dry mass per unit length, and the root dry mass increased with increasing seed size, reaching a maximum at a seed mass of 24g after 40 days. The smaller the initial seed piece the larger was the fraction of assimilates utilised for sprout growth. Sprout length and dry mass as well as assimilate mobilisation for growth, were promoted by dipping seed pieces in gibberellin solutions, with the greatest effect obtained with 30 ppm GA, the highest concentration used in the experiment. Paclobutrasol showed inhibiting effects on all growth parameters except for sprout thickness. The root dry mass did not differ among treatments. Sprout growth was enhanced by calcium availability, with the greatest effect obtained with exogenous supply of calcium at 10 mmol/I as CaS04. A similar effect was noticed when complete nutrient solution was supplied. CaC03 was less effective than CaS04. Calcium availability to sprout tips affected sprout growth only when the roots were deprived of nutrients. Sprout length of the two seed pieces (3 and 5g in mass) was similarly affected by temperature over time, with the sprouts at the low temperature initially shorter, but reaching the same lengths as those at the high temperature after 30 and 40 days. Sprout dry mass and thickness of 3 and 5g seed pieces were similarly affected by temperature, with higher dry mass and greater thickening at 16°C than at 26°C. Exposure to low temperature (16°C) was associated with the transfer of a large fraction of seed reserves to the sprouts. / Dissertation (MSc (Agric): Agronomy)--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted

Subtropical Thicket is the dominant vegetation biome in the Eastern Cape. Little regeneration through seedlings has been observed in Thicket. This is of serious concern, as Thicket has been degraded over large areas of its distribution. An understanding of the seed dynamics is necessary for any restoration project. A number of possible causes for the lack of seedlings were therefore investigated. Study sites were best classified according to the biogeographical regions of the Subtropical Thicket Ecosystem Planning (STEP) project. The seed bank of Thicket is dissimilar to the aboveground vegetation, as it lacks woody species and is dominated by herbs and grasses, making little contribution to the regeneration of Thicket species. An increase in canopy cover resulted in lower soil and air temperatures, as well as light, and an increase in litter depth. Seedling abundance and species richness increases with mean annual rainfall, with woody seedlings being dominant in the higher rainfall areas, and succulent species in the lower rainfall regions. Anemochorous species dominated the germinable seed bank, and zoochorous species were more prevalent underneath the canopy, compared to open areas, an indication of active seed dispersal. No germination was recorded in many Thicket species, and dormancy mechanisms were lacking in many of the species that did germinate. Immersion in hot water increased germination in the hard seeds of Acacia karroo, whereas shade enhanced germination in small seeded Burchellia bubalina. The response of seedlings of four Thicket species with varying distribution to shade and drought was studied. Ptaeroxylon obliquum and Aloe africana are drought tolerant species, whereas Burchellia bubalina and Rhus dentata were intolerant to low soil moisture. All four species were able to grow in deep shade, although Rhus dentata would be classified as a shade avoider, unlike the other three species that are shade tolerant. This results in the four species having different regeneration niches. It was concluded that dispersal and the lack of “safe sites” for seedlings were the main limitations to seedling establishment in Mainland Thicket.

No description available.

Peace education offers potential for transforming violent conflict into peace between groups in conflict. The research literature on conflict transformation theory and peace education has identified key assumptions for building long-term peace following violent conflict. The extent to which peace education programs have incorporated these theoretical notions, however, is not well known. This thesis explored the extent to which key theoretical insights from the literature on conflict transformation theory and peace education are incorporated in a prominent peace education program, Seeds of Peace. Data collection consisted of interviews with ten program staff members and written documentation produced by Seeds of Peace. Employing the analytical framework developed from a review of the literature, a comparison between theoretical notions and Seeds of Peace programming was done. Findings of this study highlight the extent to which there are gaps between theory and practice, and a case is made for the establishment of a more explicit connection between theory and practice. Furthermore, the thesis highlights the importance of further studies to address the research gap.

Orientadores: Fernando Roberto Martins, Lucia Garcez Lohmann / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T05:17:40Z (GMT). No. of bitstreams: 1 Rochelle_AndreLuisCasarin_D.pdf: 2530968 bytes, checksum: 4125ca228d54cbb9e8ca94ccbb3965ff (MD5) Previous issue date: 2013 / Resumo: Integramos biogeografia, ecologia, filogenia e evolução da tribo Bignonieae (Bignoniaceae) para testar as seguintes hipóteses: (1) a área de distribuição geográfica das espécies é positivamente relacionada com sua idade filogenética, conhecida como "hipótese da idade e área", formulada por J.C. Willis, em 1922 que prevê que espécies antigas ocupariam maiores áreas de distribuição enquanto espécies recentes ocupariam menores áreas (endêmicas); (2) área de distribuição geográfica das espécies é positivamente relacionada com o potencial de dispersão anemocórico das sementes; e (3) o potencial de dispersão anemocórico é negativamente relacionado com a idade filogenética das espécies. Realizamos experimentos em túnel de vento para mensurar o potencial de dispersão anemocórico das sementes medindo sua distância de voo (SFD) e investigamos sua relação com oito atributos morfológicos biomecânicos - tamanho total (STS), tamanho do núcleo seminal (SNS), tamanho das alas (SWS), massa (SM), área (SA), razão entre tamanho do núcleo seminal e tamanho da asa (SNS/SWS), razão entre massa e tamanho da asa (SM/SWS) e razão entre massa e área (SM/SA). Analisamos a relação entre as características biomecânicas das sementes responsáveis por um maior potencial de dispersão com a idade filogenética das espécies e sua distribuição geográfica para investigar a evolução dos caracteres relacionados à maior habilidade de dispersão. Realizamos experimentos para verificar diferenças na morfologia e no potencial de dispersão das sementes de herbário em comparação com sementes coletadas em campo, visando validar estudos com sementes herborizadas. Não encontramos relação entre idade filogenética e área de distribuição. Esta relação parece ser influenciada pela diferença na eficiência de dispersão das espécies, apontada como um importante fator na distribuição, especialmente em espécies anemocóricas. 83% das espécies apresentaram correlação entre variáveis morfológicas e SFD. A razão SM/SA apresentou a maior correlação com SFD (36 espécies). SWS e SA apresentaram correlação positiva com SFD. SNS/SWS e SM/SA apresentaram correlações negativas com SFD, demonstrando que características morfológicas das sementes influenciam seu potencial de dispersão, principalmente massa e área. SFD apresentou correlação positiva com área de distribuição e negativa com idade. SNS apresentou correlação positiva com idade. SM/SA apresentou correlação positiva com idade e negativa com área de distribuição. Os resultados mostraram que espécies com sementes de maiores capacidades de voo possuem maiores áreas de distribuição e são mais recentes, evidenciando uma possível seleção no sentido da redução do núcleo seminal que diminuiu a massa das sementes e consequentemente reduziu a razão massa/área, aumentando a capacidade de voo e o potencial de dispersão da espécie. Inferimos que características morfológicas biomecânicas podem ter sido selecionadas no sentido de aprimorar o potencial de dispersão das sementes, principalmente na combinação entre sua massa e área, favorecendo as espécies mais jovens, possibilitando uma dispersão mais eficiente e a expansão da sua distribuição. Complementarmente, demonstramos que o processo de herborização não afeta significativamente os caracteres morfológicos e a distância de voo das sementes, validando os dados gerados pelo nosso experimento. Conhecimentos sobre distribuição de espécies são importantes para a conservação na região tropical onde a megadiversidade é composta majoritariamente por espécies endêmicas / Abstract: We integrated biogeography, ecology, phylogeny and evolution of the tribe Bignonieae (Bignoniaceae) to test the hypothesis that: (1) geographic range size is positively related with species phylogenetic age - the "Age and Area Hypothesis" - formulated by J.C. Willis (1922) and which states that older species would have larger geographic range sizes because they had more time to disperse while younger species would have smaller geographic range sizes; (2) range size is positively related with seed wind dispersal potential; and (3) wind dispersal potential is negatively correlated with species age. We used a wind tunnel to experimentally measure the seed wind dispersal potential measuring the seed flight distance (SFD). We analyzed the correlations of SFD with: seed total size (STS), seminal nucleus size (SNS), seed wing size (SWS), seed mass (SM), seed area (SA), ratio SNS/SWS, ratio SM/SWS, and ratio SM/SA. We analyzed the correlations between seed morphological traits related to wind dispersal potential with species phylogenetic age and their extant geographic range size to investigate a possible evolution of the traits related to an improved dispersal. We conducted an experiment to check if there are significant changes in morphology and flight potential in anemochoric seeds before and after herborization, aiming to validate experiments realized with herbarium seeds. We found no correlation between species phylogenetic age and their geographic distribution area. This relationship found for other taxonomic groups could have been affected here by species dispersal ability, which is an important driver of geographic distribution, especially in wind-dispersed species. 83% of the species had at least one variable correlating with SFD. Ratio SM/SA showed correlation with SFD in 36 species. Considering all the species together, SWS and SA showed positive correlation with SFD. Ratios SNS/SWS and SM/SA showed negative correlations with SFD. Results showed that seed morphological traits are correlated with wind dispersal potential, especially seed mass and area. Seed dispersal distance was positively correlated with the extant geographic range size, and negatively correlated with species phylogenetic age. SNS showed positive correlation with age, and ratio SM/SA showed positive correlation with age and negative correlation with geographic range size. Results indicate that species that have seeds with higher flight capacities are more recent phylogenetically and have larger geographic range sizes. It suggests a selection towards the reduction of the SNS, which reduced the seed mass and therefore their ratio SM/SA, increasing their flight ability and colonizing potential. We infer that some seed morphological traits may have been selected in order to improve seed dispersal potential, especially in the trade-off between seed mass and seed area. Therefore, it benefited younger species enabling them to disperse over larger areas in less time. Complementarily, we showed that herborization does not significantly affect seed morphological traits neither their flight distance, validating the data generated with experiments realized with Bignonieae herbarium seeds. Knowledge about the factors that shape species distribution is important for conservation, especially for the tropical region where the megadiversity is composed in most part by species with small distribution areas (endemics) / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

The Acacia hybrid (Acacia mangium x A. auriculiformis, Leguminosae: Mimosoideae) has created considerable interest for plantations because of its adaptability and growth performance when compared to the parental species. This study concentrated on sexual reproduction, and seed and seedling quality using light and electron microscopy, histochemistry, and seed and seedling tests. Two peak flowering periods in the hybrid appear to coincide with high rainfall and temperature, whereas two fruit-maturation periods occur during a windy dry season. The hybrid is andromonoecious. A floral spike consists of about 150 loosely arranged flowers. Flowers are cream colored and fragrant and have no floral nectaries. The pistil has a solid style with a smooth, wet stigma and amphitropous ovules with immature integuments at pollination. The flowers are weakly protogynous. Anthesis is complete at 0500-0600 h but peak female receptivity begins at 0200-0300 h and is completed that day. The stigmatic exudate is of the lipophilic type and is secreted from the stigmatic cells by a holocrine mechanism. Pollen is the main floral reward for the insect pollinators. There are several floral characteristics which facilitate pollen transfer from anthers to the stigmas. Apis mellifera and Ceratina sp. are the most effective pollinators. They are the most common insect visitors and carry a heavy load of hybrid polyads. However, their behavior in foraging for pollen in the same tree may promote self-pollination. The 16-pollen polyads have the highest viability at anthesis (over 80%) but lose viability within 3 days. In vivo pollen germination occurs within a few hours and pollen tubes grow up to 16 μm/min, reaching the ovarian chamber 7 to 8 hr after pollination. In vivo pollen tube growth is supported by the stylar secretion that may be stimulated by pollination and an ovarian secretion which is independent of pollination. Abnormalities of pollen tube growth were observed and probably result from self-pollination. There is no evidence of pollen-tube competition and pollen tube penetration of the ovules appears to occur randomly. Fertilization in the hybrid occurs within 3 days after pollination. One of the two synergids is the site of pollen tube penetration and its degeneration is triggered by the pollen tube penetration of the nucellus. Endoplasmic reticulum is likely involved in the polar nuclear fusion but not in the fusion of sperm nuclei with the egg and polar nuclei. Because no sperm-cytoplasmic fusion occurs during karyogamy, the hybrid, therefore, possesses maternal cytoplasmic inheritance. The hybrid zygote is metabolically inactive and has a two-month dormant period due to delays in embryo nutrition. Proembryo cell divisions are of the Trifolium variation of the Onagrad type without formation of a suspensor. Endosperm formation is of the nuclear type. The breakdown of stored products, abundant in the central cell and nucellus, provides nourishment to the developing endosperm through many nutrient pathways. The endosperm then becomes the main nutrient source for the embryo. Carbohydrates, lipids and proteins are the main seed storage products. The hybrid has very low reproductive success (0.0054). Low fruit set in the hybrid (2%) was attributed primarily to insufficient pollination (65% of total) and early fruit abortion (33% of total). Low seed set (24%) is mainly caused by failure of pollen tube penetration of the ovules (over 70%). The seed treatment of soaking seeds in boiling water for 1 min gives high germination percentages (over 80%) and is practical. The F2 hybrid seedlings possess features intermediate between the parental species. At 3 months, the F2 seedlings have a high survival rate (90%) and their height and diameter growths vary significantly among parental trees but are superior to those of the parental species. / Graduate

Orientador: Rinaldo César de Paula / Banca: Cibele Chalita Martins / Banca: Sérgio Roberto Garcia dos Santos / Resumo: O presente trabalho objetivou avaliar a qualidade fisiológica e caracterizar as sementes de Cedrela fissilis de diferentes procedências do Estado de São Paulo. Sementes de seis procedências (Assis, Bauru, Mogi Guaçu, Pindorama, Piracicaba e Promissão) foram submetidas a caracterização biométrica (comprimento, largura, espessura e massa de 1.000 sementes); ao teste de germinação a 25 °C, sob luz continua, entre papel, por 14 dias e aos seguintes testes de vigor: teste de envelhecimento acelerado a 45 °C por 48 h; condutividade elétrica a 25 °C e 75 mL de água por 2, 4, 6, 12, 24, 48, 72, 96 e 120 h; comprimento de plântulas; massa de matéria seca de plântulas e germinação sob estresse hídrico simulado com o uso de polietileno glicol (PEG 6000), nos seguintes potenciais osmóticos: 0,0; -0,1; -0,2; -0,3; -0,4; -0,5; -0,6; -0,8; -1,0 e -1,2 MPa. Os dados foram submetidos à analise de variância, teste de Tukey para comparação das médias e regressão. Verificou-se diferenças em tamanho e massa de sementes, bem como na capacidade germinativa e vigor das sementes de cedro de diferentes procedências. O teste de envelhecimento acelerado foi eficiente para a avaliação da qualidade fisiológica das sementes de cedro. Não houve influência do tamanho e massa das sementes sobre a germinação. A tolerância de sementes de cedro ao estresse hídrico é variável entre as procedências / Abstract: This study aimed to evaluate and characterize the physiological quality of seeds of different provenances Cedrela fissilis the State of São Paulo. Seeds of six provenances (Assis, Bauru, Mogi Guaçu, Pindorama, Piracicaba and Promissão) were evaluated to biometric characteristics (length, width, thickness and weight of 1000 seeds) to the germination test at 25 °C under light continues among paper for 14 days and the following tests vigor: accelerated aging test at 45 °C for 48 h; the electrical conductivity at 25 °C, and 75 mL of water for 2, 4, 6, 12, 24, 48, 72 , 96 and 120 h; seedling length, dry weight of seedlings and also to the germination test under water stress, simulated with polyethylene glycol (PEG 6000) in the following osmotic potentials: 0.0, -0.1, -0.2, -0.3, -0.4, -0.5, -0.6, -0.8, -1.0 and -1.2. The data were subjected to analysis of variance, Tukey test and regression. There were differences in biometric traits and germination and vigor of cedar seeds from different provenances. The accelerated aging test is efficient to evaluate the physiological quality of seeds of cedar. There were not influence the size and weight of seeds on germination. The tolerance of seeds to water stress varies among provenances / Mestre

Orientador: Rinaldo César de Paula / Banca: Cibele Chalita Martins / Banca: Miguel Luiz Menezes Freitas / Resumo: A Ceiba speciosa St. Hil. (paineira-rosa) é uma espécie arbórea tropical pertencente à família Malvaceae, cuja árvore na idade adulta, pode superar os 20 metros de altura e 120 centímetros de diâmetro a altura do peito (DAP). Possui reprodução mista, com predominância de alogamia. Seus principais agentes polinizadores são aves, insetos e morcegos. Sua madeira pode ser empregada na indústria para confecção de canoas, cochos, móveis, aeromodelos, caixotaria e produção de pasta celulósica; a sua paina é bastante utilizada para o enchimento de almofadas, cobertores e travesseiros. A espécie apresenta grande importância na recuperação de ecossistemas degradados. O presente estudo objetivou avaliar a divergência genética entre árvores matrizes de Ceiba speciosa, a partir de caracteres de frutos e sementes. Para tanto foram coletados frutos e sementes de 36 árvores matrizes, determinando-se em cinco frutos por matriz o diâmetro, comprimento, massa de matéria fresca e seca e número de sementes/fruto e em 100 sementes (5 repetições de 20 unidades), o comprimento, diâmetro e peso de 100 sementes. Quatro repetições de 25 sementes por árvore matriz foram submetidas ao teste de germinação, conduzido a 27 ºC por 21 dias em substrato mata-borrão, avaliando-se a porcentagem de sementes com protrusão de radícula e o índice de velocidade de germinação. A qualidade fisiológica das sementes foi avaliada pelo teste de envelhecimento acelerado (EA), conduzido a 45 ºC por 72 horas, de condutividade elétrica conduzido com quatro repetições de 40 sementes embebidas em 75 mL de água desionisada a 25º C por 24 h e pelo teste de submersão, em que as mesmas sementes do teste de condutividade elétrica foram mantidas na mesma solução por 120 h. Após o teste de EA e de submersão, as sementes foram submetidas ao teste de germinação a 27 ºC durante 10 dias. Os dados foram submetidos à análise de variância e ... / Abstract: Ceiba speciosa St. Hil. is a tropical tree species of the Malvaceae family, which in adulthood, the tree may exceed 20 meters in height and 120 cm in diameter at breast height. Reproduction has mixed, predominantly outcrossing. Its main pollinators are birds, insects and bats. Its wood can be used in industry for making canoes, troughs, furniture, model airplanes, crates and production of pulp; their seed cotton is widely used for filling pillows, blankets and pillows. The species has great importance in the recovery of degraded ecosystems. The present study aimed to evaluate the genetic divergence among mother trees of Ceiba speciosa, from characters of fruits and seeds. Fruits and seeds of 36 mother trees of C. speciosa were collected, determining in five fruits per array diameter, length, fresh weight and dry weight and number of seeds per fruit and 100 seed (5 replicates of 20 units), the length, diameter and weight of 100 seeds. Also, four replicates of 25 seeds per mother tree were subjected to germination test, conducted at 27 º C for 21 days in substrate blotter, by assessing the percentage of seeds with radical protrusion and the germination speed index. The seed quality was evaluated by accelerated aging test conducted at 45 ° C for 72 hours, electrical conductivity conducted with four replications of 40 seeds soaked in 75 mL of deionized water at 25 ° C for 24 h by the submersion test in which the seeds of the same electrical conductivity test were kept in this solution for 120 h. After the EA and submersion test, seeds were subjected to germination test at 27 º C for 10 days. Data were subjected to analysis of variance and comparison of means by the Scott-Knott test, estimating also the genotypic determination coefficient, repeatability and correlation among traits. The genetic divergence among mother trees was obtained by the method of Ward and optimization Tocher, from the average Euclidean distance between pairs ... / Mestre

Orientador: Rinaldo Cesar de Paula / Banca: Sérgio Roberto Garcia dos Santos / Banca: Marina Crestana Guardia / Banca: Sergio Valiengo Valeri / Banca: Eduardo Custodio Gasparino / Resumo: Senna multijuga (Rich.) H. S. Irwin e Barneby vem sendo muito utilizada em reflorestamentos por apresentar grande potencial de adaptação em diferentes ambientes. O presente estudo teve como objetivo determinar a qualidade fisiológica de sementes de Senna multijuga provenientes de diferentes localidades do Estado de São Paulo por meio de testes de germinação e vigor. Nove lotes foram formados com sementes provenientes dos municípios de Promissão, Ribeirão Grande, Capão Bonito, Pradópolis, Altinópolis, Luiz Antônio, Batatais e Guatapará. O teste de germinação foi realizado a 25, 30, 35 e 25-35 ºC com sementes de cada lote escarificadas com ácido sulfúrico por 10, 15 e 20 minutos. O teste de envelhecimento acelerado foi conduzido com sementes de cada lote pelo método tradicional e com solução salina saturada de NaCl, por 96 horas a 45 ºC. Para o teste de condutividade elétrica, 30 e 60 sementes por lote foram embebidas em 75 mL de água a 25 ºC por 2, 4, 6, 12, 18 e 24 horas. O teste de lixiviação de K+ e Na+ foi realizado com 30 e 60 sementes por lote embebidas por 24 horas a 25 ºC. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Há pequenas diferenças de germinabilidade entre os lotes de sementes provenientes de diferentes localidades do Estado de São Paulo. O teste de germinação pode ser conduzido a 25 ºC com sementes escarificadas com ácido sulfúrico por 15 minutos. O teste de envelhecimento acelerado tradicional conduzido a 45 ºC por 96 horas é eficiente para promover alterações na capacidade germinativa das sementes. Os testes de envelhecimento acelerado com solução salina saturada de NaCl, conduzido a 45 ºC por 96 horas, de condutividade elétrica conduzido a 25 ºC com 30 e 60 sementes embebidas em 75 mL de água por períodos de 2, 4, 6, 12, 18 e 24 horas e de lixiviação de K+ e Na+ realizado com 30 e 60 sementes embebidas ... / Abstract: Senna multijuga (Rich.) H. S. Irwin and Barneby have been widely used for reforestation with great potential for adaptation in different environments. The present research aimed to evaluate the physiological quality of Senna multijuga seeds from different locations in São Paulo State through seed germination and vigor tests. Nine lots were formed with seeds from the cities of Promissão, Ribeirão Grande, Capão Bonito, Pradópolis, Altinópolis, Luiz Antônio, Batatais and Guatapará. The germination test was conducted at 25, 30, 35 and 25- 35 °C with seeds of each lot scarified with sulfuric acid for 10, 15 and 20 minutes. The accelerated aging test was conducted with seeds of each lot by the traditional method and saturated NaCl solution for 96 hours at 45 ºC. In the electrical conductivity test, 30 and 60 seeds of each lot were soaked in 75 mL of water at 25 °C for 2, 4, 6, 12, 18 and 24 hours. The leaching test of K+ and Na+ was conducted with 30 and 60 seeds of each lot soaked for 24 hours at 25° C. Data were subjected to variance analysis and means were compared by Tukey test at 5% probability. There are small differences between the germination of seeds from lots of different places of São Paulo State. The germination test can be carried out at 25 °C with scarified seeds with sulfuric acid for 15 minutes. The traditional accelerated aging test at 45 °C for 96 hours is effective in promoting changes in seeds germination. The accelerated aging test with saturated NaCl solution conducted at 45 °C for 96 hours, the electrical conductivity test carried out at 25 °C with 30 and 60 seeds soaked in 75 mL of water for periods of 2, 4, 6, 12, 18 and 24 hours and leaching test of K+ and Na+ performed with 30 and 60 seeds soaked in 75 mL of water for 24 hours at 25 °C are not effective to discriminate seed lots of the physiological quality / Doutor

No description available.