Thesis (Ph. D.)--University of Chicago, 1920. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois, 1921." "Reprinted from the Botanical gazette, vol. LXXII, no. 1, July, 1921." "Literature cited": p. 29-30. Also available on the Internet.

Thesis (Ph. D.)--University of Chicago, 1916. / "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois." "Reprinted from the Botanical gazette, Vol. LXXI, No. 4, April 1921." "Literature cited": p. 286-288.

Seeds of a range of crop species were classified according to their ability to germinate after presowing soaking treatments of varying severity. The differences in soaking tolerance were then compared with changes in several metabolic parameters to determine the importance of metabolic adaptation in the avoidance of soaking injury in seeds. After seed soaking treatments those species most susceptible to injury exhibited the highest respiration rates under nitrogen. At the same time the species with the highest respiration rates under nitrogen showed more rapid utilization of their seed reserves. This was demonstrated as a positive correlation of respiration rate under nitrogen against the fall in sucrose content of seeds on soaking. A similar positive correlation of respiration under nitrogen with alcohol content and with fall in sucrose content on soaking seeds was found. However, when the malic acid content of, seeds was assayed the reverse trend was shown, where malic acid was negatively correlated both with respiration under nitrogen and with the fall in sucrose content on soaking seeds. Thus the changes in the alcohol and malic acid contents of seeds on soaking were negatively correlated with each other. Analysis of lactic acid content of soaked seeds was expressed as the percentage of the three anaerobic products measured (ie. alcohol plus malic acid plus lactic acid) and gave a significant negative correlation against respiration rate under nitrogen' on soaking seeds. Parallel studies of both alcohol and malic dehydrogenases were conducted after soaking seeds. The activity of alcohol dehydrogenase was highest in those species which were least tolerant of soaking injury, while the Michaelis constants for alcohol dehydrogenase with respect to acetaldehyde were low in species intolerant of soaking injury but higher in species tolerant of this treatment. Enhanced metabolic damage was observed as a result of both high (30°C) and of low temperature (0°C) soaking treatments, but only in species which were normally susceptible to soaking injury. In studies on a single species (Pisum sativum) metabolic injury followed a similar course to the above studies in high but not in low temperature soaking treatments. Studies on the enzyme invertase showed grossly enhanced activity with a rise in temperature. This increased activity was also related to germination counts.

The greater part of this work describes the biochemical and morphological changes accompanying grain development in cereals. Attention is focussed on those aspects most likely to be involved in the regulation of grain yield and composition. Thus, since starch is the major component of grain yield much of the work is concerned with the developmental enzymology of carbohydrate synthesis. The composition, properties and structure of the developing starch granules and amyloplasts have also been described. Grain development is associated with a range of catabolic processes and a number of enzymes active in carbohydrate degradation has been identified. Although oxygen levels in the developing endosperm are unknown, recent work suggests that the mitochondria present are fully func- tional. It is possible that oxygen required for grain respiration is derived from pericarp photosynthesis. At the same time this tissue may fix carbon dioxide derived from endosperm respiratory processes. Thus, the pericarp may be involved in the overall control of endosperm metabolic activity. Studies of endosperm cell division indicate that this continues for more than half the developmental period, later divisions producing mainly aleurone cells. Hence, stimulation of endosperm cell division early in development will increase the yield of carbohydrate whereas at later stages it will increase the yield of protein. Further studies describe the pattern of mineral ion accumulation, the growth and nutrition of the develop - ing embryo and the morphological changes in the crease region through which nutrients move from the vascular tissue of the pericarp to the endosperm. A second group of papers is concerned with the control of a- amylase and polyphenol oxidase activity during cereal grain germination. Finally, there is a small group of papers describing research on the properties of photosynthesising tissues including marine algae.

Orientador: Massanori Takaki / Banca: João Domingos Rodrigues / Banca: José Antonio Proença Vieira de Moraes / Banca: José Marcos Barbosa / Banca: Maria Auxiliadora Milaneze Gutierrez / Resumo: Informações sobre a ecofisiologia da germinação de sementes florestais amazônicas são escassas e fundamentais à compreensão do seu comportamento natural visando subsidiar programas de manejo, propagação ou estudos de regeneração natural. O objetivo deste trabalho foi estudar alguns aspectos da germinação de sementes de Calycophyllum spruceanum, espécie arbórea nativa da região amazônica. Foram avaliados o efeito da luz branca e de sombreamento, da temperatura constante e alternada, do fotoequilíbrio teórico do fitocromo, e ainda de diferentes substratos na germinação de sementes da espécie. Foi estudada também a permanência das sementes no solo sob dossel ou a pleno sol. O estudo da temperatura constante foi efetuado com intervalos de 2,5ºC a partir de 10ºC, e as melhores porcentagem, velocidade e sincronização da germinação foram obtidas sob temperatura de 20ºC, considerada ótima para a germinação da espécie. As alternâncias entre 20-25 e 15-25ºC foram as mais favoráveis para a germinação de sementes. A espécie apresentou fotoblastismo absoluto, não germinando em nenhuma das condições de escuro. As sementes germinaram em todos os fotoperíodos testados, com altas de porcentagens de germinação sob luz branca sem associação com a luz de sombreamento. A germinação foi inibida sob baixos fotoequilíbrios do fitocromo, e à medida que foi aumentado o fotoequilíbrio, houve um aumento também da porcentagem de germinação. As sementes de Calycophyllum spruceanum apresentaram resposta de fluência baixa e podem ser classificadas como sementes fotoblásticas positivas controladas pelo fitocromo B. A presença do nitrato de potássio afetou de forma negativa a germinação de suas sementes. Além disso, os resultados indicaram que podem ser utilizados para a germinação de sementes de Calycophyllum spruceanum, tanto terra vegetal, como vermiculita...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Information of ecophysiology of seed germination of Amazon forest species are of fundamental importance for the comprehension of their natural behavior for programs of propagation and forest regeneration. The aim of this paper was to study some aspects of seed germination of Calycophyllum spruceanum, arboreous species native from the Amazon region. The effect of white light and shade light, constant and alternating temperature, the theoretical photo-equilibrium of the phytochrome were evaluated, and also the effect of different substracts in the germination of seeds of this species. It was also studied the permanence of the seeds on soil under canopy or on full sun. The effect of the constant temperature was studied in the range of 10- 35,5ºC with intervals of 2,5ºC, and the best percentage, velocity and synchronization of the germination were obtained under temperature of 20ºC, considered optimal for the germination of the seeds. The alternations between 20-25 and 15-25ºC were the most favorable for the germination of seeds. The species presented absolute photoblast, with no germination in the dark. The seeds germinated in all the tested photoperiods, with high percentage germination under white light without association with the shade light. The germination was inhibited under low photoequilibrium of phytochrome, and when the photo-equilibrium was increased, increase in the germination percentage was observed. The germination of seeds of Calycophyllum spruceanum presented is controlled by low fluency response we suggest that this control is made through phytochrome B. The presence of potassium nitrate affected negatively the seed germination in Calycophyllum spruceanum. Moreover, the results indicated that soil, vermiculite or plantmax® can be used as substrate for the germination of Calycophyllum spruceanum seeds...(Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:23:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-19Bitstream added on 2014-06-13T19:28:53Z : No. of bitstreams: 1 barbosa_kc_me_rcla.pdf: 501282 bytes, checksum: 9c9b45d81798a7b40aa652323235e133 (MD5) / Universidade Estadual Paulista (UNESP) / O presente trabalho teve por objetivo investigar os fatores (de estrutura e composição da vegetação) que influenciam a chuva de sementes em uma área em processo de restauração florestal, bem como sua flutuação sazonal e os padrões de limitação de sementes, de fonte e de dispersão. O trabalho foi desenvolvido na Fazenda São Carlos (21º47'S e 46º47'W), município de Santa Cruz das Palmeiras (SP), com 12 ha correspondente a formação florestal heterogênea implantada há cerca de 10 anos como parte da recuperação ambiental da área. Foram utilizados 53 coletores de sementes medindo 1m x 1m x 0,15m de profundidade distribuídos sob as copas de quatro diferentes espécies implantadas na área: Schinus terebinthifolius e Trema micrantha (espécies zoocóricas), Schizolobium parahyba e Croton urucurana (espécies não zoocóricas). As sementes foram coletadas mensalmente no período de setembro de 2002 a agosto de 2003. As sementes coletadas foram classificadas segundo a síndrome de dispersão (zoocóricas, anemocóricas e autocóricas) e a origem na área (provenientes de espécies plantadas ou não, estas últimas chamadas de colonizadoras). A estrutura e composição da vegetação foi amostrada em parcelas circulares estabelecidas com raio de 5m ao redor de cada coletor. Os resultados indicaram uma intensa chuva de sementes na área em restauração, dominada por duas espécies plantadas (Trema micrantha, Schinus terebinthifolius) e duas colonizadoras (Tecoma stans e Maclura tinctoria) o que pode ser explicado pela grande produção de sementes destas espécies e/ou por ocorrerem em altas densidades na área de estudo. A densidade de sementes coletadas apresentou dois picos ao longo do período de amostragem, um em outubro de 2002 e outro menor em julho de 2003. A elevada quantidade de sementes em outubro de 2002 ocorreu devido à grande quantidade de sementes anemocóricas... / The purpose of this work is to investigate the factors (of structure and composition of the vegetation) that influence the seed rain in an area where there's an ongoing process of forest restoration. The seasonal flutuation in seed rain, and the patterns of seed, source, and dispersal limitation were investigate. The work was developed at Fazenda São Carlos Farm (21º47'S e 46º47'W), in the city of Santa Cruz das Palmeiras (SP), in 12 ha correspoding to a heterogenuous forest development started more than 10 years ago as part of the enviromental recovery of the area. It has been used 53 seed traps with 1m x 0,15m depth distributed below the canopies of four different species implanted in the area: Schinus terebinthifolius and Trema micrantha (zoochorous species) and Schizolobium parahyba e Croton urucurana (non-zoochorous species). Seeds were collected monthly between September/2002 and August/2003. The collected seeds were classified according to its dipersal syndrome (zoochorous, anemochorous and autochorous) and the origin in the area (deriving from planted species or not, these last ones called no-planted). The structure and composition of the vegetation were sampled in circular areas set up within a 5m radius around each seed trap. The results indicate an intense seed rain in the restoration area, dominated by two planted species (Trema micrantha and Schinus terebinthifolius) and two no-planted (Tecoma stans and Maclura tinctoria), what can be justified by the large production of seeds from those species and/or because of its ligh abundance in the study area. The density of the seeds collected showed two peaks along the sampling period, one in October/2002 and another one, smaller, in July/2003. The high amount of seeds in October/2002 occurred because of the high quantity of anemochorous seeds, while in July/2003, both zoochorous and anemochorous...(Complete abstract click electronic access below)

Orientador: Marco Aurélio Pizo Ferreira / Banca: Ricardo Ribeiro Rodrigues / Banca: Mauro Galetti Rodrigues / Resumo: O presente trabalho teve por objetivo investigar os fatores (de estrutura e composição da vegetação) que influenciam a chuva de sementes em uma área em processo de restauração florestal, bem como sua flutuação sazonal e os padrões de limitação de sementes, de fonte e de dispersão. O trabalho foi desenvolvido na Fazenda São Carlos (21º47'S e 46º47'W), município de Santa Cruz das Palmeiras (SP), com 12 ha correspondente a formação florestal heterogênea implantada há cerca de 10 anos como parte da recuperação ambiental da área. Foram utilizados 53 coletores de sementes medindo 1m x 1m x 0,15m de profundidade distribuídos sob as copas de quatro diferentes espécies implantadas na área: Schinus terebinthifolius e Trema micrantha (espécies zoocóricas), Schizolobium parahyba e Croton urucurana (espécies não zoocóricas). As sementes foram coletadas mensalmente no período de setembro de 2002 a agosto de 2003. As sementes coletadas foram classificadas segundo a síndrome de dispersão (zoocóricas, anemocóricas e autocóricas) e a origem na área (provenientes de espécies plantadas ou não, estas últimas chamadas de colonizadoras). A estrutura e composição da vegetação foi amostrada em parcelas circulares estabelecidas com raio de 5m ao redor de cada coletor. Os resultados indicaram uma intensa chuva de sementes na área em restauração, dominada por duas espécies plantadas (Trema micrantha, Schinus terebinthifolius) e duas colonizadoras (Tecoma stans e Maclura tinctoria) o que pode ser explicado pela grande produção de sementes destas espécies e/ou por ocorrerem em altas densidades na área de estudo. A densidade de sementes coletadas apresentou dois picos ao longo do período de amostragem, um em outubro de 2002 e outro menor em julho de 2003. A elevada quantidade de sementes em outubro de 2002 ocorreu devido à grande quantidade de sementes anemocóricas...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this work is to investigate the factors (of structure and composition of the vegetation) that influence the seed rain in an area where there's an ongoing process of forest restoration. The seasonal flutuation in seed rain, and the patterns of seed, source, and dispersal limitation were investigate. The work was developed at Fazenda São Carlos Farm (21º47'S e 46º47'W), in the city of Santa Cruz das Palmeiras (SP), in 12 ha correspoding to a heterogenuous forest development started more than 10 years ago as part of the enviromental recovery of the area. It has been used 53 seed traps with 1m x 0,15m depth distributed below the canopies of four different species implanted in the area: Schinus terebinthifolius and Trema micrantha (zoochorous species) and Schizolobium parahyba e Croton urucurana (non-zoochorous species). Seeds were collected monthly between September/2002 and August/2003. The collected seeds were classified according to its dipersal syndrome (zoochorous, anemochorous and autochorous) and the origin in the area (deriving from planted species or not, these last ones called "no-planted"). The structure and composition of the vegetation were sampled in circular areas set up within a 5m radius around each seed trap. The results indicate an intense seed rain in the restoration area, dominated by two planted species (Trema micrantha and Schinus terebinthifolius) and two no-planted (Tecoma stans and Maclura tinctoria), what can be justified by the large production of seeds from those species and/or because of its ligh abundance in the study area. The density of the seeds collected showed two peaks along the sampling period, one in October/2002 and another one, smaller, in July/2003. The high amount of seeds in October/2002 occurred because of the high quantity of anemochorous seeds, while in July/2003, both zoochorous and anemochorous...(Complete abstract click electronic access below) / Mestre

Orientador: Rogério Falleiros Carvalho / Banca: Lucas Aparecido Gaion / Banca: Priscila Lupino Gratão / Resumo: Atualmente, devido às mudanças no regime de chuvas, a escassez de água em diversas regiões agrícolas é cada vez mais frequente. Dessa forma, o déficit hídrico se torna uma questão preocupante, especialmente no cultivo da soja, uma das mais importantes espécies agronômicas. Concomitantemente, pesquisas indicam o importante papel do peróxido de hidrogênio (H2O2) como molécula sinalizadora, capaz de induzir respostas de tolerância ao déficit hídrico. Assim, buscamos neste estudo, avaliar as respostas de plantas de soja (Glycine max L.) submetidas ao déficit hídrico após pré-tratamento com concentrações de H2O2 em sementes. Para tal, sementes de soja foram embebidas em concentrações de H2O2 (0, 10, 50, 100 e 200 mM) seguido de secagem e, posteriormente foram submetidas ao estresse osmótico com polietileno glicol (PEG -0,2 MPa) e cloreto de sódio (NaCl -0,2 MPa). Avaliou-se germinação, crescimento, acúmulo de prolina, teor de H2O2 e malondialdeído (MDA) na fase de plântulas. Para as avaliações em planta, as sementes foram embebidas apenas com 10 mM de H2O2 ou água e, condicionadas ao déficit hídrico pela interrupção da irrigação 36 dias após a semeadura. Posteriormente, foi avaliado a umidade do solo, as relações hídricas (teor relativo de água e potencial hídrico foliar), crescimento, acúmulo de prolina, conteúdo de pigmentos, teor de H2O2 e MDA. As avaliações foram realizadas em 4 períodos de estresse (0, 4 e 8 dias de restrição hídrica e, 4 dias de reidratação após o estresse m... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently, due to changes in the rainfall regime, water scarcity in several agricultural regions is becoming more frequent. Thus, the water deficit becomes a matter of concern, especially in the cultivation of soybean, one of the most important agronomic species. Meanwhile, researches indicate the important role of hydrogen peroxide (H2O2.) as a signaling molecule, able to induce tolerance responses to water deficit. Thus, the purpose of this study was evaluating the responses of soybean plants (Glycine max L.) submitted to water stress after seed priming with H2O2. concentrations in seeds. Thus, soybean seeds were placed to soak in H2O2.solutions (0, 10, 50, 100 and 200 mM) followed by drying and subsequent exposition to osmotic stress with polyethylene glycol (PEG -0.2 MPa) and (NaCl -0.2 MPa). Germination, growth, proline accumulation and oxidative stress were evaluated in the seedling stage. For the plant evaluations, the seeds were only soaked with 10 mM H2O2. or water and, conditioned to the water deficit by the interruption of irrigation 36 days after sowing. Subsequently, soil moisture, water relations (relative water content and leaf water potential), growth, proline accumulation, pigment content and oxidative stress were evaluated. The evaluations were carried out in 4 stress periods (0, 4 and 8 days of water restriction and 4 days of rehydration after 8 days of maximum stress). Seed priming with 10 and 50 mM H2O2. improved germination of seeds, growth and dry mass ... (Complete abstract click electronic access below) / Mestre

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