Bibliography: leaves 247-268. A series of laboratory, greenhouse and field experiments were conducted to investigate aspects of seed quality in a range of bread wheat genotypes important in South Australia as well as a durum cultivar, Yallaroi. It was concluded that sound healthy seed does vary in quality and this affects seedling vigour, crop establishment and grain yield. Seed source can affect genotype performance in evaluation trials. There is genetic variability for embryo size, coleoptile length, nutrient efficiency and nutrient loading in to the seed which can be exploited by breeders. Agronomically, seed quality can be improved by managing seed crops to aid accumulation of mineral nutrients in the seed and then selecting, by grading, only large seed for sowing.

Made available in DSpace on 2014-06-11T19:32:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-03-28Bitstream added on 2014-06-13T18:44:37Z : No. of bitstreams: 1 denardi_jd_dr_botib.pdf: 4402382 bytes, checksum: bc0ab1570e2c005daa396bedb7a9263b (MD5) / Universidade Estadual Paulista (UNESP) / Considerando que Connaraceae e Oxalidaceae constituem um clado de Oxalidales bem representado na flora brasileira e pouco estudado relativamente à estrutura de órgãos reprodutivos, este trabalho aborda a morfoanatomia e a ontogênese de flores, frutos e sementes de Connarus suberosus (Connaraceae) e Oxalis cytisoides (Oxalidaceae), a fim de avaliar a existência de padrões estruturais comuns a essas espécies. O processamento das amostras para microscopia de luz e microscopia eletrônica de transmissão e de varredura seguiu as técnicas usuais. Verificou-se que, estruturalmente, C. suberosus possui heterostilia dimórfica, caracterizada pelas formas brevi- e longistila, as quais se mostraram funcionalmente masculina e feminina, respectivamente. Alguns caracteres morfológicos peculiares a cada forma floral, provavelmente estão associados à evolução da dioicia, como dimensões de sépalas e pétalas e distribuição de tricomas glandulares. Nesta análise, provouse que esses caracteres, aliados às diferenças de tamanho dos verticilos de estames das formas florais, foram utilizados equivocadamente na delimitação de C. suberosus var. fulvus e C. suberosus var. suberosus, que correspondem às formas brevistila e longistila, respectivamente. Independentemente da forma floral, houve variação no número de sépalas, pétalas e estames e tendência à restrição do tecido nectarífero aos setores antepétalos do tubo estaminal. A vascularização carpelar mostrou-se derivada em relação ao padrão descrito para Connaraceae, devido à formação de um complexo ovular mediante união parcial de traços ovulares àqueles derivados de feixes alas. O desenvolvimento do pericarpo e da semente, que pode ocorrer apomiticamente, não é concomitante, visto que a diferenciação seminal inicia-se após a expansão do pericarpo, quando este alcança... / Connaraceae and Oxalidaceae constitute a clade of Oxalidales that is well represented within the Brazilian flora although relatively poorly studied in terms of the structure of their reproductive organs. The present work examined the morphology, anatomy and ontogeny of the flowers, fruits, and seeds of Connarus suberosus (Connaraceae) and Oxalis cytisoides (Oxalidaceae) in order to evaluate the existence of structural patterns common to both species. Preparation of plant samples for viewing under light and electron microscopy followed established techniques. Connarus suberosus demonstrated dimorphic heterostyly, characterized by the brevi- and longistylous morphs, which were observed to be functionally masculine and feminine respectively. Some of the peculiar morphological characteristics of each floral form are probably associated with the evolution of dioecy, such as the dimensions of the sepals and petals and the distribution of the glandular trichomes. The present analysis indicated that these characters, allied to differences in the sizes of the verticils of the two floral forms, had been equivocally used in delimiting C. suberosus var. fulvus and C. suberosus var. suberosus, which correspond to thrum and pin morphs respectively. Independent of the floral form, variation in the numbers of sepals, petals, and stamens were observed, as well as a tendency for the nectary tissues to be restricted to the epipetalous sectors of the staminal tube. Carpel vasculature was observed to be derived in relation to the pattern described for Connaraceae due to the formation of an ovular complex resulting from the partial union of ovular traces derived from wing bundles. The development of the pericarps and seeds, which can occur in an apomixic manner, is not concomitant; the seed differentiation initiates after the expansion of the pericarp when this organ... (Complete abstract click electronic access below)

Plants regulate many physiological processes in response to adverse environmental stresses. This study focused on the seed germination and seedling establishment stage and investigated the molecular signaling events when abiotic stresses, such as osmotic, water and temperature, were applied. Seeds of Arabidopsis, mutants or wild type, were used to identify the signaling components. Cold-pretreatment (stratification) is widely used to break seed dormancy and improve germination rate. Stratification at 4. significantly broke the seed dormancy of Arabidopsis in wild-type, cyp707a2, sleepy1 and sleepy1/cyp707a2, but not in ga3ox1. Stratification and exogenous ABA treatment strongly enhanced the expression and the activity of a-amylase in the freshly harvested seeds among the wild-type and those mutants, which have relatively high ABA content. Similarly, the expression of RGL2 and ABI5 were also substantially suppressed by stratification. These results suggest that stratification firstly leads to GA biosynthesis and unlocks the inhibition of RGL2 on the expression of a-amylase. Stratification also relieves the inhibition of ABA on the germination process but the inhibition of ABA on seedling development is not affected. We have isolated an Arabidopsis mutant, dsptp1, which is hyposensitive to osmotic stress during seed germination and seedling establishment, indicated by exhibiting higher seed germination rate, lower inhibition in root elongation under osmotic stress, and more tolerance to drought compared with the wild type (Col0) plants. Osmotic stress and drought enhanced AtDsPTP1 expression in seed coats, the bases of rosette leaves and roots. Compared with the wild type, the dsptp1 mutant increased proline accumulation, reduced MDA content and ion leakage, and enhanced antioxidant enzyme activity under osmotic stress. AtDsPTP1 regulated the transcript levels of various dehydration responsive genes, ABA biosynthesis and metabolic enzyme gene under osmotic stress, resulting in reduced accumulation of ABA in dsptp1 mutant plants than wild type in response to osmotic stress. AtDsPTP1 also mediated the ABA signaling pathway under osmotic stress by suppressing the expression of ABI1 and enhancing the expression of the positive regulators ABI3 and ABI5 in ABA signaling. These data suggest that AtDsPTP1 positively regulates ABA accumulation and signaling during seed germination and seedling establishment in Arabidopsis under osmotic stress. To further investigate the regulation mechanism of DsPTP1 in osmotic stress and drought signaling, we analyzed the water holding capacity between wild type and dsptp1 mutant. The dsptp1 mutant exhibited enhanced water holding capacity compared to wild type under osmotic stress resulting from reduced water loss and increased relative water content, which shall contribute the osmotic and drought tolerance. To identify the signaling components, we investigated the activity of MAPKs under osmotic and drought stress and found that the DsPTP1 differentially regulates the activities of MAPK6 and a p38 MAPK, which is inferred as MAPK12 according to its molecular weight in Arabidopsis under osmotic and salt stress. However, there is no direct interaction between DsPTP1 and 20 MAPKs indicated by the results of the of specific interaction test. These results suggest that the differential regulation of MAPK6 and MAPK12 by DsPTP1 is indirect. In addition, we screened the interaction proteins of DsPTP1 under abiotic stress. Seventeen positive clones were acquired from the sequencing results. More work need to be done to confirmed the positive interactions and the signaling cascades. In summary, seed germination and seedling growth are closely regulated by environmental cues. This should be the result of evolutionary selection since successful new growth from the seed embryo depends on the sensitive perception of environmental conditions and effective regulation of many physiological processes that are involved. We have demonstrated that plant hormones, especially ABA, play central regulative roles during such regulations. Many other signaling components, such as protein kinases and phosphatases, are also involved. Identifying the detailed signaling pathways should be the focus of further research.

Orientadores: João Domingos Biagi, Leila Martins / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-15T17:49:41Z (GMT). No. of bitstreams: 1 CavalcanteFilho_FranciscoNahum_D.pdf: 1278202 bytes, checksum: 2ff48dadb1373517d2547b3e8757598f (MD5) Previous issue date: 2010 / Resumo: O revestimento constitui-se num grande avanço na produção tecnológica de sementes, inclusive de forrageiras. Apesar da crescente utilização dessa tecnologia pelas empresas produtoras de sementes nos últimos anos, poucas são as informações publicadas em relação ao comportamento de sementes revestidas durante o período de armazenamento. Os experimentos foram realizados na Faculdade de Engenharia Agrícola - FEAGRI/UNICAMP, com o objetivo de obter informações adicionais sobre a qualidade fisiológica de sementes de Brachiaria humidicola (Rendle) Schweick e Brachiaria brizantha (Hochst. ex A. Rich.) Stapf, submetidas a diferentes tratamentos. No início e após 45, 90, 135, 180, 270 e 360 dias de armazenamento nas temperaturas ambiente, 30°C e 40°C, as sementes foram submetidas às avaliações do grau de umidade (U), germinação (G), viabilidade-tetrazólio (TZ), envelhecimento acelerado (EA), primeira contagem de germinação (1ªCG), emergência das plântulas em areia (E), comprimento da parte aérea das plântulas (CPA), índice de velocidade de emergência (IVE), peso seco da plântula (PSP), peso de mil sementes (PMS) e atividade de água (Aw). Foi utilizado um delineamento inteiramente casualizado, com quatro repetições por tratamento e três temperaturas de armazenamento. A análise estatística foi realizada através do teste de Tukey para comparação das médias, em nível de 5% de probabilidade. Na avaliação do início do período de armazenamento as sementes tratadas tiveram resultados em valores absolutos superiores à testemunha, com superação da dormência para as duas espécies, sem diferenças estatísticas significativas. As sementes incrustadas tiveram redução acentuada do seu grau de umidade, com média de 2,80 para Brachiaria humidicola e de 2,90 para Brachiaria brizantha ao longo do armazenamento. Os maiores porcentuais de germinação ocorreram em períodos distintos para as espécies, aos 270 dias para Brachiaria humidicola e aos 135 dias para Brachiaria brizantha. A escarificação química das sementes com ácido sulfúrico é uma alternativa de tratamento se a intenção for realizar a semeadura até 45 dias após a colheita. Para armazenamento por períodos mais longos, a técnica de revestimento por incrustação é uma importante alternativa, pois não prejudica a germinação e permite a adição de diversos produtos químicos à semente, aumentando o seu valor agregado / Abstract: The coating is to be a major technological breakthrough in the production of seeds, including grasses. Despite the increasing use of technology by seed companies in recent years, there are few published information about the behavior of coated seeds during the storage period. The experiments were performed at the College of Agricultural Engineering, FEAGRI/ UNICAMP, in order of obtaining information about the physiology quality of Brachiaria humidicola (Rendle) Schweick and Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. seeds, submitted to different treatments. At the beginning and after 45, 90, 135, 180, 270 and 360 days of storage at ambient conditions and at temperatures of 30°C and 40°C. The seeds were evaluated by moisture content, germination, feasibility-tetrazolium, accelerated aging, first count germination, seedling emergence in sand, seedling length, speed of emergency index, seedlings dry weight, thousand seeds weight and water activity. A completely randomized design with four replications per treatment and three storage temperatures. Was used statistical analysis was performed using the Tukey test at 5% probability. The assessment at the beginning of storage the treated seeds were found to have absolute values greater than control, with dormancy for both species, no statistically significant differences. The incrusted seeds were embedded substantially reducing the moisture content, averaging 2.80 for Brachiaria humidicola and 2.90 for Brachiaria brizantha during storage. The highest percentage of germination occurred at different times for the species, to 270 days for Brachiaria humidicola and 135 days for Brachiaria brizantha. The chemical scarification of seeds with sulfuric acid is an alternative treatment if the intention is either to sow until 45 days after harvest. To store for longer periods, the technique of incrusting is an important alternative, since not affect the germination and allows the addition of various chemicals to the seed, increasing its aggregate value / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola

Orientadores: João Domingos Biagi, Claudio José Barbedo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-19T22:55:33Z (GMT). No. of bitstreams: 1 Parisi_JoaoJoseDias_D.pdf: 700508 bytes, checksum: 9956b2ce3f085d143589b761f27c7d01 (MD5) Previous issue date: 2012 / Resumo: O elevado metabolismo dificulta a manutenção da viabilidade de sementes de Inga vera. As principais estratégias para a conservação dessas sementes durante o armazenamento consistem na desidratação parcial, na adição de ácido abscísico, no uso de solução de polietileno glicol e de baixas temperaturas. Contudo, tais condições ainda podem conduzir à deterioração, tanto pela atividade do seu próprio metabolismo, como pelo desenvolvimento de micro-organismos favorecidos pela umidade. Desta forma, o presente trabalho teve como objetivo analisar o grau de interferência dos fungos no metabolismo respiratório dos embriões de Inga vera com diferentes níveis de hidratação e a eficiência do tratamento com fungicidas, visando à manutenção da viabilidade durante o armazenamento. Para tanto, os embriões foram obtidos em três anos, sendo em 2009 colhidos em duas fases distintas de maturação (imaturos e maduros), submetidos a dois níveis de secagem, tratados ou não com carboxin + thiram e armazenados sob 7 e 25 oC por até 65 dias. Em 2010, foram colhidos maduros, submetidos a quatro níveis de secagem, tratados ou não com carbendazin + thiram e armazenados a 7 ºC por 120 dias. Nos experimentos de avaliação da respiração, os embriões obtidos em 2010 foram tratados ou não com carbendazin + thiram, mortos ou não por congelamento e inoculados ou não com Aspergillus flavus. Os colhidos em 2011 foram mantidos sem secagem e tratados ou não com carbendazin + thiram e a respiração foi avaliada a 7 e a 25 ºC. Constatou-se que a incidência de fungos, principalmente Fusarium oxysporum, juntamente com o teor de água e a temperatura influenciam nas taxas respiratórias dos embriões de I. vera maduros e que o tratamento com carbendazin + thiram, na dose de 80 mL do produto comercial para 100 kg de embriões, é eficiente na manutenção da viabilidade de embriões maduros e sem secagem, a 7 ºC por 120 dias. Pestalotiopis sp., Phoma sp., Phomopsis diachenii e Colletotrichum gloeosporioides aparecem durante o armazenamento, simultaneamente à deterioração dos embriões de I. vera. O desenvolvimento de fungos em embriões de I. vera difere do padrão clássico definido com base em sementes ortodoxas / Abstract: The high metabolism hinders the maintenance of Inga vera seeds viability. The main strategies for the conservation of these seeds during storage consist of the partial dehydration, addition of abscisic acid, use of polietileno glicol solution and of low temperatures. However, such storage conditions can lead to further deterioration of the seed, either by the activity of its own metabolism, as the development of microorganisms favored by moisture. This study aimed to analyze the degree of interference of fungi on the respiratory metabolism of Inga vera embryos with different levels of hydration and the efficiency of fungicide treatment, as maintaining these embryos viability during storage. The embryos were obtained in three years. In 2009 they were collected in two distinct stages of maturation (immature and mature), subjected to two drying levels, treated or not treated with carboxin + thiram and stored at 7 and 25 º C for up to 65 days. In 2010 the embryos were collected mature, subjected to four drying levels, treated or not treated with carbendazin + thiram and stored at 7 º C for 120 days. In the experiments carried out to evaluate the respiration, the embryos obtained in 2010, were treated or not treated with carbendazin + thiram, killed or not by freezing and inoculated or not with Aspergillus flavus. The embryos collected in 2011 were kept without drying, treated or not treated with carbendazin + thiram and respiration was evaluated at 7 and 25 ° C. It was found that the incidence of fungi, primarily Fusarium oxysporum, together with the water content and temperature influence respiration rates of mature embryos of I. vera and that the treatment with carbendazin + thiram at the dose of 80 mL of the commercial product to 100 kg of embryos is effective for maintaining the viability of mature embryos without drying at 7 ° C for 120 days. Pestalotiopis sp., Phoma sp., Phomopsis diachenii and Colletotrichum gloeosporioides are detected during the storage time, along with the deterioration of the embryos of I. vera. The development of fungi on embryos of I. vera differs from the classic pattern verified for orthodox seeds / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola

No description available.

No description available.

No description available.

No description available.

No description available.