Ecologia da germinação de sementes e desenvolvimento de plantas de Platymiscium floribundum Vog. (Sacambu) - Fabaceae em viveiro e sob dossel de floresta ombrófila densa, São Paulo, SP
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Data
2005-12-02
Autores
Figliolia, Marcia Balistiero [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O objetivo geral da pesquisa foi estudar aspectos da germinação de sementes de Platymiscium floribundum Vog. em laboratório e viveiro e desenvolvimento das mudas em condições de viveiro e natural sob o dossel, com vistas a estabelecer indicadores biológicos quanto à fisiologia e ecologia da germinação e desenvolvimento das plantas para subsidiar projetos de conservação, de manejo e de revegetação de áreas alteradas ou desprotegidas. Tendo como enfoque o estudo das temperaturas cardeais de germinação das sementes e o estabelecimento de padrões tecnológicos de análise foram testadas, em condições controladas de laboratório, temperaturas no intervalo de 10 a 40ºC, com presença contínua e ausência total de luz branca. Verificou-se que a faixa limite de germinação está entre 10 e 12,5 e 37,5 e 40ºC; a 10ºC iniciou-se somente a protrusão radicular, sem emissão da raiz primária e, a 40ºC, houve morte total das sementes. A faixa ótima de temperatura para a germinação, na presença contínua de luz, está entre 15 a 25ºC, com maiores índices de velocidades de germinação a 20 e 25ºC. Para o estudo ecofisiológico foram testadas as interações entre diferentes regimes de temperatura, quantidades de água e luz. As temperaturas onde a germinação das sementes se mostrou superior foram 25, 20 e 15ºC. Os resultados de germinação com as quantidades de água do ii substrato de 30 e 60mL foram superiores à de 90mL. Os percentuais de germinação foram inferiores à medida que se associaram elevadas quantidades de água e temperatura. As sementes da espécie apresentaram insensibilidade à luz, germinando tanto na presença quanto na ausência de luz, não apresentando variação significativa entre os espectros de luz testados. Os resultados indicam que P. floribundum apresenta plasticidade...
The purpose of the present work was the study of germination under laboratory and nursery conditions and seedling development under nursery and field conditions for getting biological indicators of ecophysiology of germination and establishment of Platymiscium floribundum Vog for conservation, management and reforestation projects. Determination of cardinal, and optimum temperatures was done by isothermic incubations in the range of 10 to 40°C, under continuous white light and darkness. The minimum temperature was 12.5°C and the maximum 37.5°C. At 10°C, only radicle protrusion was observed and at 40°C the seeds have died. The optimum temperature range from 15 to 25°C with highest germination rate at 20 to 25°C. For ecophysiological study, different temperatures were tested under different conditions of substrate humidity and light. The germination under low humidity (30mL) and moderate humidity (60mL) of the substrate was higher than high humidity (90mL). Seeds of P. floribundum were light insensitive. The seedling emergence capacity under nursery conditions were high under both natural light (NL) and far red light (FR) in all tested shading percentage (10, 18, 30, 50 and 80 shading), with high seedling survival under 30 and 80% shading NL and 18, 30 and 50% shading FR. Seedling development was high under FR at 18, 30 and 50% and in stem diameter at all WL treatments. Plants accumulated more root and aerial dry matter under NL. By aerial to root dry matter ratio, highest aerial development was observed under 0, 30, 18 and 80% shading WL and 18 and 80% shading FR. Analysis of seedling development was carried out under natural conditions under two shading intensities under canopy at Serra da Cantareira, São Paulo... (Complete abstract, click electronic address below)
The purpose of the present work was the study of germination under laboratory and nursery conditions and seedling development under nursery and field conditions for getting biological indicators of ecophysiology of germination and establishment of Platymiscium floribundum Vog for conservation, management and reforestation projects. Determination of cardinal, and optimum temperatures was done by isothermic incubations in the range of 10 to 40°C, under continuous white light and darkness. The minimum temperature was 12.5°C and the maximum 37.5°C. At 10°C, only radicle protrusion was observed and at 40°C the seeds have died. The optimum temperature range from 15 to 25°C with highest germination rate at 20 to 25°C. For ecophysiological study, different temperatures were tested under different conditions of substrate humidity and light. The germination under low humidity (30mL) and moderate humidity (60mL) of the substrate was higher than high humidity (90mL). Seeds of P. floribundum were light insensitive. The seedling emergence capacity under nursery conditions were high under both natural light (NL) and far red light (FR) in all tested shading percentage (10, 18, 30, 50 and 80 shading), with high seedling survival under 30 and 80% shading NL and 18, 30 and 50% shading FR. Seedling development was high under FR at 18, 30 and 50% and in stem diameter at all WL treatments. Plants accumulated more root and aerial dry matter under NL. By aerial to root dry matter ratio, highest aerial development was observed under 0, 30, 18 and 80% shading WL and 18 and 80% shading FR. Analysis of seedling development was carried out under natural conditions under two shading intensities under canopy at Serra da Cantareira, São Paulo... (Complete abstract, click electronic address below)
Descrição
Palavras-chave
Sementes, Produção de mudas, Germination, Plant growth, Canopies development, Atlantic forest
Como citar
FIGLIOLIA, Marcia Balistiero. Ecologia da germinação de sementes e desenvolvimento de plantas de Platymiscium floribundum Vog. (Sacambu) - Fabaceae em viveiro e sob dossel de floresta ombrófila densa, São Paulo, SP. 2005. xix, 126 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2005.