Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-17Bitstream added on 2014-06-13T20:09:14Z : No. of bitstreams: 1 tomaz_ca_me_botfca.pdf: 487855 bytes, checksum: be47693a22aa1ab44526ee86dda601aa (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O tempo de 28 dias recomendado pelas Regras para Análise de Sementes (RAS) para o teste de germinação de sementes de Panicum maximum é considerado excessivo para produtores, comerciantes e laboratórios de análise de sementes forrageiras, que dependem dos resultados do teste para a tomada de decisões de controle de qualidade e comercialização. Desta forma, o presente trabalho teve o objetivo de determinar o tempo necessário para a condução do teste de germinação de Panicum maximun cv. Tanzânia. Na pesquisa, 30 lotes de sementes fiscalizadas foram submetidas ou não (testemunha) aos seguintes tratamentos para a superação dormência: germinação em substrato umedecido com KNO3 (0,2%), escarificação com ácido sulfúrico (98% 36N) por 5 minutos e testemunha. Os lotes foram avaliados pelo teste de germinação sob duas condições de temperaturas alternadas (20-30ºC e 15-35ºC), com luz (78 μmol s-1 m-2/ 8h). Para a identificação da data de término do teste foram realizadas contagens diárias do número de plântulas normais e para cada lote, tratamento de superação de dormência e temperatura, foi ajustada uma curva de crescimento para a avaliação da germinação. As sementes remanescentes do teste de germinação foram seccionadas longitudinalmente e medianamente através do embrião para a realização do teste de tetrazólio. As duas metades da semente foram imersas em uma solução de tetrazólio a 0,1% e mantidas em câmara escura, à 37ºC, por um período de 3 horas e após esse período as sementes foram lavadas e a leitura feita imediatamente, classificando-se as sementes em viáveis e não viáveis (mortas). No delineamento experimental os 30 lotes foram considerados... / The time of 28 days recommended by the Rules for Seed Analysis (RAS) to test the germination of Panicum maximum is considered excessive for producers, traders and laboratory analysis of forage seeds, which depend on the results of the test for making decisions of quality control and marketing. The present study aimed to determine the time required for the conduct of the germination test of Panicum maximum cv. Tanzania. In the survey, 30 seed lots were audited or not (control) to the following treatments to overcome dormancy: germination in soak with KNO3 (0.2%), scarification with sulfuric acid (98% 36N) for 5 minutes and witness. The lots were assessed by the germination test under two conditions of alternating temperatures (20-30ºC and 15-35°C) with light (78 μmol s-1 m-2/ 8h). To identify the date of termination of the test were made daily counts of the number of normal seedlings for each lot, treatment of overcoming dormancy and temperature, was fitted a curve of growth for the assessment of germination. The remaining seeds in the germination test were sectioned longitudinally through the embryo and medium for the completion of the tetrazolium test. The two halves of the seeds were immersed in a solution of tetrazolium to 0.1% and kept in dark room, at 37º C for a period of 3 hours and after that period the seeds were washed and reading made immediately, sorting out the seeds into viable and non viable (dead). In the experimental design the 30 lots were considered the repetitions, resulting in estimates of the parameters of the segmented regression model for each treatment, was performed an analysis of variance where the treatments were compared to overcome dormancy and temperature. Through regression model was targeted to estimate the time required to conduct the germination test, determining whether the value at which the difference between the estimated asymptote... (Complete abstract click electronic access below)

Orientador: Cibele Chalita Martins / Banca: João Nakagawa / Banca: Ciniro Costa / Resumo: O tempo de 28 dias recomendado pelas Regras para Análise de Sementes (RAS) para o teste de germinação de sementes de Panicum maximum é considerado excessivo para produtores, comerciantes e laboratórios de análise de sementes forrageiras, que dependem dos resultados do teste para a tomada de decisões de controle de qualidade e comercialização. Desta forma, o presente trabalho teve o objetivo de determinar o tempo necessário para a condução do teste de germinação de Panicum maximun cv. Tanzânia. Na pesquisa, 30 lotes de sementes fiscalizadas foram submetidas ou não (testemunha) aos seguintes tratamentos para a superação dormência: germinação em substrato umedecido com KNO3 (0,2%), escarificação com ácido sulfúrico (98% 36N) por 5 minutos e testemunha. Os lotes foram avaliados pelo teste de germinação sob duas condições de temperaturas alternadas (20-30ºC e 15-35ºC), com luz (78 μmol s-1 m-2/ 8h). Para a identificação da data de término do teste foram realizadas contagens diárias do número de plântulas normais e para cada lote, tratamento de superação de dormência e temperatura, foi ajustada uma curva de crescimento para a avaliação da germinação. As sementes remanescentes do teste de germinação foram seccionadas longitudinalmente e medianamente através do embrião para a realização do teste de tetrazólio. As duas metades da semente foram imersas em uma solução de tetrazólio a 0,1% e mantidas em câmara escura, à 37ºC, por um período de 3 horas e após esse período as sementes foram lavadas e a leitura feita imediatamente, classificando-se as sementes em viáveis e não viáveis (mortas). No delineamento experimental os 30 lotes foram considerados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The time of 28 days recommended by the Rules for Seed Analysis (RAS) to test the germination of Panicum maximum is considered excessive for producers, traders and laboratory analysis of forage seeds, which depend on the results of the test for making decisions of quality control and marketing. The present study aimed to determine the time required for the conduct of the germination test of Panicum maximum cv. Tanzania. In the survey, 30 seed lots were audited or not (control) to the following treatments to overcome dormancy: germination in soak with KNO3 (0.2%), scarification with sulfuric acid (98% 36N) for 5 minutes and witness. The lots were assessed by the germination test under two conditions of alternating temperatures (20-30ºC and 15-35°C) with light (78 μmol s-1 m-2/ 8h). To identify the date of termination of the test were made daily counts of the number of normal seedlings for each lot, treatment of overcoming dormancy and temperature, was fitted a curve of growth for the assessment of germination. The remaining seeds in the germination test were sectioned longitudinally through the embryo and medium for the completion of the tetrazolium test. The two halves of the seeds were immersed in a solution of tetrazolium to 0.1% and kept in dark room, at 37º C for a period of 3 hours and after that period the seeds were washed and reading made immediately, sorting out the seeds into viable and non viable (dead). In the experimental design the 30 lots were considered the repetitions, resulting in estimates of the parameters of the segmented regression model for each treatment, was performed an analysis of variance where the treatments were compared to overcome dormancy and temperature. Through regression model was targeted to estimate the time required to conduct the germination test, determining whether the value at which the difference between the estimated asymptote... (Complete abstract click electronic access below) / Mestre

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a warm-season, perennial grass which is native to large areas across North America. Cultivars, selections and ecotypes suitable for erosion control, wildlife planting, ornamental, forage and biofuel applications are commercially available. Plantings are commonly established from seed; however, seed quality and dormancy are barriers to establishment. The objective here was to investigate parameters that contribute to inconsistent performance of this seed kind to subsequently improve seed lot quality. Forty-two seed lots were used, with seed fill and germination potential ranging from 78- 100% and 11-91%, respectively. Actual germination and dormant seed ranged from 0-40% and 1-85%, respectively. Seed count per pound ranged from 3195 to 8344 and was influenced by genotype. Alternating laboratory temperature regimes were generally more effective in promoting germination than constant temperatures. Optimal germination occurred at 15/25, 20/30 or 20/35 ºC (16/8 hours), but was not consistent across cultivars or seed lots. These data suggest that germination temperature contributes to inconsistent laboratory germination and poor stands observed for untreated and pretreated seeds sown under field conditions. Eleven primary dormancy breaking treatments were tested and most improved germination. Although not commercially feasible, cupule removal plus caryopsis scarification hastened germination and completely eliminated seed dormancy. Soaking in H2O2 (18 hr) improved germination, but the effect was not consistent. Moist chilling (5 or 10 °C) was generally superior to other treatments and remains the most simple, effective and consistent dormancy-breaking treatment, although duration varies by seed lot. Benefits of moist chilling and H2O2 treatment were retained for short periods in seeds dried from approximately 55% to 13% moisture content. Removal of empty and light-weight cupules improved seed lot purity and germination, although removal of as much as 40% of the volume was necessary. The priming treatments tested were less than satisfactory in improving germination or the range of germination temperatures compared to moist chilling treatment alone. Eastern gamagrass seed lot quality is highly variable, but can be improved. Multiple physical and physiological targets of opportunity have been identified to improve seed lot quality in eastern gamagrass.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

The biology of seed dormancy and germination of 46 species representing 11 of the 12 tribes in Convolvulaceae were compared in laboratory (mostly), field and greenhouse experiments. Seeds were tested for kind of dormancy and storage behavior; artificial or simulated natural treatments were applied to break physical dormancy (PY); the initial route of water entry (“water gap”) into seeds was identified; the morphoanatomy of the water gap was compared in seeds of 17 species; ontogenetical differences between water gap and seed coat away from the hilum were described in Ipomoea lacunosa seeds; cycling of sensitivity to dormancy break was elucidated in seeds of I. lacunosa, I. hederacea, Cuscuta australis and Jaquemontia ovalifolia; and mechanism of opening of the water gap was determined for seeds of I. lacunosa and of I hederacea. Seeds of only three of the 46 species were nondormant. Two of these were recalcitrant (Maripa panamensis and Erycibe henryi), and the other one was orthodox (Bonamia menziesii). Seeds of the other 43 species were orthodox and had PY except those of Cuscuta europea, which also had physiological dormancy (PD) i.e. combinational dormancy (PY + PD). Two bulges adjacent to the micropyle were identified as the water gap in all seeds with PY except those of Cuscuta, in which the hilar fissure is the water gap. Anatomy of the bulges (water gap) adjacent to the micropyle differs from that of seed coat away from the bulges. A different sequence and phase of anticlinal and periclinal cell divisions during development created weak transitional zones between bulge - hilum and bulge - seed coat away from hilum. Water vapor pressure changes below the bulges caused formation of the opening(s) in water gap. Seeds of I. lacunosa I. hederacea, C. australis and J. ovalifolia cycle between sensitive and insensitive states to dormancy break, but not between PY and nondormancy. Seed dormancy and storage characteristics and anatomy and morphology of dormancy of seeds of Convolvulaceae closely follow the molecular phylogeny of the family. I suggest that PY in seeds of subfamily Convolvuloideae evolved from nondormant recalcitrant seeds of an ancestor closely related to Erycibeae.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-27T14:19:14Z No. of bitstreams: 1 PGPV16MA206.pdf: 1048498 bytes, checksum: 04e05c3e20369493786d1dd1aa3287d8 (MD5) / Made available in DSpace on 2018-02-27T14:19:14Z (GMT). No. of bitstreams: 1 PGPV16MA206.pdf: 1048498 bytes, checksum: 04e05c3e20369493786d1dd1aa3287d8 (MD5) Previous issue date: 2016-07-15 / Capes / The Brazilian strawberry breeding programs have stagnated in recent decades. This shows that the evolution of culture in the country is dependent on imported material. The breeding programs of strawberry plants have found it difficult to produce productive and high-quality commercial genotypes. In addition, information about the available germplasm diversity in breeding programs are scarce. Another critical issue is to overcome dormancy of achenes obtained by mating because the achenes have cutaneous numbness and a natural germination around 10 to 20%. In this sense, it is essential to test effective methods to overcome dormancy in order to improve the performance of germination and allow to obtain seedlings in a short period of time and with the same physiological age. In this sense, the work was divided into two chapters, where the objectives were i) to characterize the genetic variability in eleven genotypes of strawberry for seven morphological characters of fruits and select promising parents; ii) test the effects of scarification with concentrated sulfuric acid to overcome dormancy of strawberry achenes, in order to increase the germination and germination speed index (GSI). The first experiment was conducted in the field of Embrapa Temperate Climate headquarters, using design of randomized blocks with three replications. The characters evaluated were number of fruits, fruit weight, firmness, color fruit, color pulp, brightness and total soluble solids over four harvest seasons. The second experiment was conducted in the Official Laboratory of Embrapa Seed Analysis Temperate using completely randomized design in a factorial 3x3x2 with three genotypes (Aromas, Camarosa and Festival), three periods of stratification (0, 30 and 60 days) and acid scarification of achenes (presence or absence), with four replications. We evaluated the germination and germination speed index. It is recommended, based on morphological characteristics crossing the Campinas genotype with Daewang and 2010.57.3 genotypes to obtain segregating populations of strawberry. The Daewang and Campinas genotypes can be used to increase the genetic basis of breeding programs of strawberry. The scarification with concentrated sulfuric acid (36N) for 20 and 40 min increased the germination and achenes germination speed index of strawberry plants and can be used as a technique to overcome dormancy / Os programas brasileiros de melhoramento do morangueiro se estagnaram nas últimas décadas. Esta situação revela que a evolução da cultura no país é dependente do material importado. Os programas de melhoramento genético do morangueiro têm encontrado dificuldades em produzir genótipos produtivos e de alta qualidade comercial. Além disso, as informações sobre a diversidade do germoplasma disponível em programas de melhoramento são escassas. Outra questão crítica é a superação da dormência dos aquênios obtidos por meio de cruzamentos, pois os aquênios apresentam dormência tegumentar e uma germinação natural em torno de 10 a 20%. Nesse sentido, é fundamental testar metodologias eficazes na superação da dormência a fim de melhorar o desempenho da germinação e possibilitar a obtenção de mudas em curto período de tempo e com a mesma idade fisiológica. Nesse sentido, o trabalho foi dividido em dois capítulos, onde os objetivos foram i) caracterizar a variabilidade genética em onze genótipos de morangueiro para sete caracteres morfológicos de frutos e selecionar genitores promissores; ii) testar os efeitos da escarificação com ácido sulfúrico concentrado para superar a dormência de aquênios de morango, a fim de aumentar a germinação e o índice de velocidade de germinação (IVG). O primeiro experimento foi conduzido a campo na sede da Embrapa Clima Temperado, utilizando delineamento de blocos ao acaso, com três repetições. Os caracteres avaliados foram número de frutos, peso de frutos, firmeza, cor de fruto, cor de polpa, brilho e sólidos solúveis totais ao longo de quatro épocas de colheita. O segundo experimento foi realizado no Laboratório Oficial de Análise de Sementes da Embrapa Clima Temperado, utilizando delineamento inteiramente casualizado, em esquema fatorial 3x3x2, com três genótipos (Aromas, Camarosa e Festival), três períodos de estratificação (0, 30 e 60 dias) e escarificação ácida dos aquênios (presença ou ausência), com quatro repetições. Avaliou-se a germinação e o índice de velocidade de germinação. Recomenda-se, com base nos caracteres morfoagronomicos o cruzamento do genótipo Campinas com os genótipos Daewang e 2010.57.3, para a obtenção de populações segregantes de morangueiro. Os genótipos Daewang e Campinas podem ser utilizados para aumentar a base genética em programas de melhoramento genético de morangueiro. A escarificação com ácido sulfúrico concentrado (36N) durante 20 e 40 min aumentou a germinação e o índice de velocidade de germinação de aquênios do morangueiro e pode ser utilizada como técnica para superação da dormência