Potential valorization as fertilizers of Humic Substances extracted from landfill leachate

In this study, four leachates samples from 3 different landfills localized in the north of Portugal were characterized and fractionated, to understand the decomposition degree and to evaluate their potential as an agent for fertilization. Humic substances (HS) were extracted, quantified, chemical characterized and further fractionated in humic acid (HA) and fulvic acid (FA). Keeping in mind the purpose to use these fractions as fertilizers, the phytotoxicity of HS, HA and FA solutions was evaluated on cress seed germination. The HS concentration was similar for all the leachates evaluated and was higher than 780 mg/L of total organic carbon. All the leachates analysed registered higher FA concentration than HA. The chemical characterization indicated that HA had a relatively higher aromatic character than the FA obtained from same sources. These results suggest that the HS from landfill leachates were in an early stage of humification, once the degree of humification increase as the landfilling age increase. Overall, the HS extracts showed absence of phytotoxicity, with germination index greater than 80% for samples treated to achieve low electric conductivity values. This suggests that the HS from the leachate may be used to produce liquid organic fertilizers.

Desempenho fisiológico de sementes de soja submetidas ao teste de envelhecimento acelerado e postas a germinar após vários períodos de espera.

2016

Estimativas de parâmetros genéticos para a germinação de sementes de guaraná (Paullinia cupana var. sorbilis (Mart.) Ducke).

As sementes de guaraná (Paullinia cupana var.sorbilis (Mart.)Ducke) perdem a viabilidade de germinação rapidamente após a colheita, e apresentam um processo de germinação lento e desuniforme, contribuindo para uma baixa eficácia para produção de mudas. Por isto, há interesse na obtenção de cultivares com germinação mais rápida e uniforme. Neste trabalho estimaram-se parâmetros genéticos para a capacidade e velocidade de emergência em progênies do banco de germoplasma da Embrapa Amazônia Oriental. Tomaram-se 100 sementes de cada 28 progênies de polinização livre e instalou-se um experimento em blocos ao acaso com duas repetições em condições naturais de canteiro. Com os dados de germinação, estimaram-se a percentagem e o índice médio de velocidade de mergência (IVE). As estimativas de variâncias genéticas e ambientais, herdabilidade e índice b mostraram que a maior parte da variabilidade presente entre as progênies foi devido aos efeitos genéticos. Pelas estimativas de ganho genético esperado entre progênies, é possível obter-se ganho de seleção para capacidade e velocidade de emergência, sendo que o ganho foi mais expressivo quando se considerou o Índice de Velocidade de Emergência.

Design, development and characterization of DHA-based emulsion for Nutrilipidomics strategies

The industrial PhD project presented here is part of the R&D strategies of the Lipinutragen company. The innovation brought by the company concerns nutrilipidomics, i.e. the correlation between the lipid composition (in fatty acids) of the cell membrane and lipid-based nutraceuticals, especially starting from the well-known dependence of the lipid composition on the intake of essential fats, omega- 6 and omega-3 polyunsaturated fatty acids. Among the results obtained from the membrane lipidomic profiles, the case of autistic subjects is here highlighted, showing the significant deficiency of docosahexaenoic acid (DHA). The activity during the PhD was devoted to the nutrilipidomic approach. Part of the activities were devoted to scientific research in lipidomics: a) the study of lipidomic profiles in the frame of two collaboration projects: one with the group of Dr. I. Tueros at AZTI, Bilbao, regading obese population, and the other one regarding seed germination with the changes of the fatty acid profiles with the group of prof. A. Balestrazzi of the University of Parma; b) the liposome preparation for protection and lifetime prolongation of the peptide somatostatin, which was an important premise to the formulation of the DHA-containing microemulsion. The activities was also focused on the development of DHA-containing nutraceutical formulations in the form of emulsion, overcoming the difficulty of the capsule ingestion, to be administered orally. The work pointed to study the combination of active ingredients, based on the previous know-how regarding the bioavailability for the cell membrane incorporation. The ingredients of the formulation were studied and tested in vitro for the bioavailability of DHA to be incorporated in the cell membranes of different types of cultured cells. Part of this study is covered by non-disclosure agreement since it belongs to the know-how of Lipinutragen.

Physiological and biochemical adaptation to salinity in wild halophytes suitable for Mediterranean agriculture

Due to the accelerating processes of soil salinization and shortage of fresh water, the practice of saline agriculture is gaining momentum in many areas of the world. However, there are some concerns that using saline water for irrigation may be non-environmentally sustainable, with potential to cause irreversible soil degradation. In addition, there is a lack of information on the morphological, physiological, and biochemical changes that can occur in plants when irrigated with saline water. In light of the above, the major aim of this work was to investigate the effects of a range of water salinity levels and irrigation regimes on the performances of salt tolerant species promising as future crop plants for saline agriculture. The following objectives were addressed: To determine the effects of different water regimes (leaching irrigation vs. no leaching irrigation) with water at increasing salinity concentrations on the growth, ion accumulation and water relations of Sorghum bicolor plants grown under saline soil conditions. To describe the germination response of Salicornia europaea seeds across a wide range of water salinity levels through six reliable indices for screening salinity tolerance at the seed germination stage. To explore the different physiological responses of six wild halophytes commonly found in the Mediterranean area (Artemisia absinthium, Artemisia vulgaris, Atriplex halimus, Chenopodium album, Salsola komarovii, and Sanguisorba minor), and rank their tolerance after exposure to growing levels of water salinity. To identify the main adaptation mechanisms that distinguish C3 from C4 halophytes when exposed to increasing salinity in the growth media, through a comparative study between the C3 species Atriplex hortensis and the C4 species Atriplex halimus. To identify the main adaptation mechanisms that distinguish annual from perennial halophytes when exposed to severe conditions of salinity and drought, through a comparative analysis between two annual Salicornia spp. and the perennial Sarcocornia fruticosa.

Seed production characters and germination performance of reed canary grass in Finland

Selostus: Ruokohelven siementuotanto-ominaisuudet ja itävyys Suomessa

Germination and development of pecan cultivar seedlings by seed stratification

Abstract: The objective of this work was to evaluate the effect of seed stratification on germination rate, germination speed, and initial development of seedlings of six pecan (Carya illinoinensis) cultivars under subtropical climatic conditions in southern Brazil. For stratification, the seeds were placed in boxes with moist sand, in a cold chamber at 4°C, for 90 days. In the fourteenth week after sowing, the emergence speed index, total emergence, plant height, stem diameter, and number of leaves were evaluated. Seed stratification significantly improves the germination potential and morphological traits of the evaluated cultivars.

Germination of cotton seed in relation to temperature

The effect of constant temperature on the germination rate and percentage of two cotton seed lots was determined using a thermogradient plate. A gradient of 10 ºC to 40 ºC was established across the plate so that temperatures changed 2 ºC for each 5 cm increment in length, resulting in sixteen different temperature treatments. The optimal temperature zone for germination was 28 ºC to 30 ºC. As temperature decreased from the optimal zone, the rate of germination also decreased but germination percentages during the 10-day period were significantly lower only below 20 ºC. As temperature increased above the optimal zone, the rate of germination decreased and the percentage of germination sharply decreased above 32 ºC - 34 ºC. As expected, high quality cotton seed performed better than medium quality seed for a low temperature range (16 ºC to 22 ºC), but the most intriguing results were observed for the high temperatures range (36 ºC to38 ºC). The germination of medium quality cotton seed was consistently higher than for high quality seed, especially at 38 ºC after the second day of evaluation. This response has not been reported in the literature and further research is needed to better understand the germination physiology of cotton seed at high temperatures.

Seed dormancy and germination of Ficus lundellii and tropical forest restoration

We investigated seed dormancy and germination in Ficus lundellii Standl. (Moraceae), a native species of Mexico's Los Tuxtlas tropical rain forest. In an 8-h photoperiod at an alternating diurnal (16/8 h) temperature of 20/30 degrees C, germination was essentially complete (96%) within 28 days, whereas in darkness, all seeds remained dormant. Neither potassium nitrate (0.05-0.2%) applied continuously nor gibberellic acid applied either continuously (10-200 ppm) or as a 24 hour pretreatment (2000 ppm) induced germination in the dark. Germination in the light was not reduced by a 24-h hydrochloric acid (0.1-1%) pretreatment, but it was reduced both by a 24-h pretreatment with either H2O2 (0. 1-5 M) or 5% HCl, or by more than 5 days of storage at 40 degrees C (4.5% seed water content). In a study with a 2-dimensional temperature gradient plate, seeds germinated fully and rapidly in the light at a constant temperature of 30 degrees C, and fully but less rapidly in the light at alternating temperatures with low amplitudes (< 12 degrees C) about the optimal constant temperature. The base, optimal and ceiling temperatures for rate of germination were estimated as 13.8, 30.1 and 41.1 degrees C, respectively. In all temperature regimes, light was essential for the germination of F lundellii seeds.

Ecophysiology of seed dormancy and the control of germination in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus (Amaryllidaceae)

Seed dormancy induction and alleviation in the winter-flowering moist temperate woodland species Galanthus nivalis and Narcissus pseudonarcissus are complex and poorly understood. Temperature, light and desiccation were investigated to elucidate their role in the germination ecophysiology of these species. Outdoor and laboratory experiments simulating different seasonal temperatures, seasonal durations, and temperature fluctuations; the presence of light during different seasons; and intermittent drying (during the summer period) over several ‘years’ investigated the importance of these factors in germination. Warm summer-like temperatures (20°C) were necessary for germination at subsequent cooler autumn-like temperatures (greatest at 15°C in G. nivalis and 10°C in N. pseudonarcissus). As the warm temperature duration increased so did germination at subsequent cooler temperatures; further germination occurred in subsequent ‘years’ at cooler temperatures following a second, and also third, warm period. Germination was significantly greater in darkness, particularly in G. nivalis. Dormancy increased with seed maturation period in G. nivalis, because seeds extracted from green capsules germinated more readily than those from yellow. Desiccation increased dormancy in an increasing proportion of N. pseudonarcissus seeds the later they were dried in ‘summer’. Seed viability was only slightly reduced by desiccation in N. pseudonarcissus but was poor and variable in G. nivalis. Shoot formation occurred both at the temperature at which germination was greatest and also if 5°C cooler. In summary, continuous hydration of seeds of both species during warm summer-like temperatures results in the gradual release of seed dormancy; thereafter, darkness and cooler temperatures promote germination. Cold temperatures, increased seed maturity (G. nivalis), and desiccation (N. pseudonarcissus) increase dormancy while light inhibits germination.

Mobilization of seed reserves during germination of four tropical species of the Amazon Rainforest

Seed reserve mobilization during germination of the Amazonian species Myciaria dubia (camu-camu), Eugenia stipitata(araca-boi), Dipteryx odorata (cumaru) and Hymenaea courbaril (jatoba) was evaluated. Seeds were placed in germination chambers at 30 degrees C with it 12 h photoperiod. Analysis of primary metabolites (carbohydrates, lipids and proteins) and fatty acid composition were carried out in quiescent seeds and at four germination stages after radicle protrusion. Germination was high in all species but there were statistically significant differences between species. Differences were also observed with regard to the duration of the germination period. The seeds showed variation in the content and composition of the analyzed compounds. indicating that the mobilization rates of these compounds may affect germination velocity.