Seed Germination Of Lactuca Sativa Research Articles

Enhancing bricks with titanium dioxide ore waste: Mechanical and environmental assessments

Using residues, generated in various production chains of goods and services through developing new materials for civil construction, has proven to be a promising approach to addressing environmental issues. The residue generated during titanium dioxide (TiO2) production, commonly called Unreacted Ore Waste (UOW), presents potential utilization routes in the ceramic materials production chain, thereby avoiding disposal in industrial landfills. This study aimed to investigate the effects of combining UOW with ceramic blocks for any beneficial results. The properties of ceramic blocks obtained from the mixture of clay and UOW were evaluated after adding 5 %, 10 %, 15 %, and 20 % of UOW relative to the clay’s total mass. The ceramic blocks produced were assessed for their mechanical, photocatalytic, morphological, granulometric, mineralogical, and chemical properties. The results indicated that UOW did not negatively affect the structural properties studied. The addition of UOW led to a significant 9 % increase in the self-cleaning efficacy of the ceramic block produced. The textural parameter values of the ceramic blocks decreased with UOW incorporation due to more efficient particle packing. The surface area reduced from 16.6 to 9.1 m2/g, and the pore volume decreased from 0.045 to 0.025 cm3/g for samples from 0 % to 20 % UOW, respectively. Decreased porosity values contributed to increased compressive strength, resulting in a 6.5 MPa increment. The results suggested that the addition of UOW causes an increase in Al concentrations in leachate samples, from 647.64 to 5128.92 ppb for samples from 0 % to 20 % UOW, respectively. The presence of leachate and solubilized components from UOW impaired the germination of Lactuca sativa seeds. Based on the results, although the addition of UOW resulted in toxicity from the leachate/solubilized components, it did not adversely affect any fundamental properties of the ceramic materials. It can be incorporated up to 20 % into the process, replacing traditional raw materials. This suggests promising future trends in sustainable construction, with broader applications in the development of eco-friendly building materials.

Anaerobic biodegradation of dipyrone: Determination of transformation products by LC-HRMS and ecotoxicity assessment using target organisms and QSAR model

The degradation of dipyrone (metamizole) was studied for the first time under mesophilic anaerobic conditions using a synthetic wastewater similar to that found in anaerobic digestion (AD) treatment plants. Dipyrone concentration effect (250–25,000 µg L−1) was evaluated in short term batch and long-term semi-continuous operation. After 48 days, biogas production and biodegradability were reduced in the batch AD by 17.7% and 18.8%, respectively, regardless of the dipyrone concentration. However, additions of 1000 µg L−1 to the long-term AD system stimulated biogas production and increased organic matter removal by 68% and 30%, respectively. Although removals of the main metabolite 4-MAA (N-methyl-4-aminoantipyrine) and other transformation products were observed in the batch tests after 48 days, a continuous accumulation of dipyrone by-products in the long-term AD reflected its recalcitrant nature. The occurrence of these metabolites coincided with an increased toxicity of the AD effluent to Aliivibrio fischeri of 79% bioluminescent bacteria-inhibition observed immediately after the addition of the dipyrone, while the germination of Lactuca sativa seeds and growth of Raphidocelis subcaptata were stimulated by the same conditions. The toxicity of by-products was mainly attributed to hydrazinic group according to predictions elaborated by ECOSAR software. The results showed that long term exposure to dipyrone main by-product 4-MAA, as a consequence of build up into environment over continuous discharges of effluents, can significantly affect freshwater organisms.

Uso de planejamento fatorial no estudo do potencial fitotóxico de Amburana cearensis (Fabaceae), Delonix regia (Fabaceae), Tabebuia avellanedae (Bignoniaceae) sobre sementes de alface

RESUMO: As plantas daninhas são um dos principais problemas no cultivo de produtos agrícolas e o principal método de controle ainda é o uso de herbicidas químicos, que embora eficientes, trazem consequências diretas e indiretas superando os benefícios em muitos casos, abrindo assim caminho para a pesquisa e desenvolvimento de bioherbicidas. Diante disso, o objetivo deste estudo foi avaliar, por meio de um planejamento fatorial 23, qual o melhor caminho experimental para inibição de germinação de sementes de Lactuca sativa, estudando as variáveis concentração, parte da planta e solvente de extração além de suas interações. Com isso, foram obtidos os extratos etanólicos, bem como, extratos aquosos da casca do caule e das folhas de três espécies de ocorrência no estado de Alagoas. Seguindo a realização dos bioensaios de germinação e crescimento inicial de sementes de L. sativa frente aos extratos nas concentrações 50% e 100% em laboratório. Ficou evidenciado que o extrato etanólico da Delonix regia numa concentração mais diluída é mais eficiente na inibição da germinação. Em relação as espécies Amburana cearensis e Tabebuia avellanedae melhores efeitos de inibição foram apresentados quando os extratos eram do caule e folha respectivamente.
 PALAVRAS-CHAVE: Aleloquímicos, Controle de Pragas, Análise Estatística.

Role of Smoke Stimulatory and Inhibitory Biomolecules in Phytochrome-Regulated Seed Germination of Lactuca sativa.

The biologically active molecules karrikinolide (KAR1) and trimethylbutenolide (TMB) present in wildfire smoke play a key role in regulating seed germination of many plant species. To elucidate the physiological mechanism by which smoke-water (SW), KAR1, and TMB regulate seed germination in photosensitive 'Grand Rapids' lettuce (Lactuca sativa), we investigated levels of the dormancy-inducing hormone abscisic acid (ABA), three auxin catabolites, and cytokinins (26 isoprenoid and four aromatic) in response to these compounds. Activity of the hydrolytic enzymes α-amylase and lipase along with stored food reserves (lipids, carbohydrate, starch, and protein) were also assessed. The smoke compounds precisely regulated ABA and hydrolytic enzymes under all light conditions. ABA levels under red (R) light were not significantly different in seeds treated with TMB or water. However, TMB-treated seeds showed significantly inhibited germination (33%) compared with water controls (100%). KAR1 significantly enhanced total isoprenoid cytokinins under dark conditions in comparison with other treatments; however, there was no significant effect under R light. Enhanced levels of indole-3-aspartic acid (an indicator of high indole-3-acetic acid accumulation, which inhibits lettuce seed germination) and absence of trans-zeatin and trans-zeatin riboside (the most active cytokinins) in TMB-treated seeds might be responsible for reduced germination under R light. Our results demonstrate that SW and KAR1 significantly promote lettuce seed germination by reducing levels of ABA and enhancing the activity of hydrolytic enzymes, which aids in mobilizing stored reserves. However, TMB inhibits germination by enhancing ABA levels and reducing the activity of hydrolytic enzymes.

Phytotoxic potential of selected medicinal plants on germination of Lactuca sativa seeds

Medicinal plants are best sources to treat various illnesses with them. So they might prove be a good source of developing novel herbicides. The aim of the present study was to investigate the potential inhibition effects of Cucumis sativus, Portulaca oleracea, Malus baccata, Saxifraga flagillaris, Geranium wallichianum and Monotheca buxifolia powdered material on germination of Lactuca sativa seeds. Sandwich method was used for determining phytotoxicity of these plants in terms of radicle and plumule length of Lactuca sativa seeds with different amounts of 10, 20, and 40mg of powdered plant material. Cucumis sativus and Monotheca buxifolia were found the most phytotoxic among the selected medicinal plants at all concentration. The results can be sum off as Monotheca buxifolia > Cucumis sativus > Malus baccata > Saxifraga flagillaris > Geranium wallichianum > Portulaca oleraceae. From the results it can be assumed that the phyto-toxic effects of the aforementioned plants could be helpful in searching and development of new pharmaceuticals that can be used as positive sources for the development of new weedicides. Keywords: Allelopathy; Lactuca sativa; Medicinal Plants; Phyto-toxic Potential http://dx.doi.org/10.19045/bspab.2019.80103

4',4‴,7,7″-tetra-O-methylcupressuflavone inhibits seed germination of Lactuca sativa.

Biflavonoids have been isolated from a wide variety of plant species, but little is known about their native biological functions. Here we report a possible ecological role for biflavonoids by describing the isolation of the biflavonoid 4',4‴,7,7″-tetra-O-methylcupressuflavone (1) from Araucaria columnaris and its inhibitory effect on seed germination. Compound 1 was isolated from needles of a single A. columnaris specimen and inhibited germination of Lactuca sativa seeds in a culture-dish assay; it was also detected in soil samples under the canopy where reduced germination was observed, but not in a location away from the canopy where germination was uninhibited.

Alkaloid profile, antibacterial and allelopathic activities of Lupinus jaimehintoniana B.L. Turner (Fabaceae)

Herein we describe some aspects of the ethnobotanical use and the first alkaloid profile of Lupinus jaimehintoniana, the 5 to 8 m high arboreous lupine. Five quinolizidine alkaloids identified as sparteine, 5,6-dehydrolupanine, lupanine, nuttalline, and d-thermopsine, were characterized by the respective elution order according to their electronic impact spectra, lupanine being the most abundant in the four different tissues analyzed. Simultaneously, an antibacterial assessment of the four corresponding crude methanolic extracts, as well as the four semi-purified alkaloids was performed on specific Escherichia coli and Agrobacterium tumefaciens strains. These experiments resulted in MIC ranges of 37-61 ?g mL-1 and 130-146 ?g mL-1, respectively. for both bacterial species. Finally, the allelopathic activity of these extracts on the germination of Lactuca sativa seeds was demonstrated to be in the range of 50-300 ?g mL-1 for both semi-purified alkaloid and methanolic extracts.

Invasion of the noxious weed Nicotiana glauca R. Graham after an episodic flooding event in the arid zone of Australia

During November 1997, an extreme rainfall event caused flooding in the Olary Creek and created a terminal lake within mallee vegetation on Nagaela Station, far western New South Wales. To assess the effect of this rare event on native flora, six 25×25 m 2 grazing exclusion plots were established on flooded (4), and un-flooded control (2) areas. We investigated (i) the distribution of Nicotiana glauca in relation to the 1997 flooding event (ii) the variation in density of N. glauca soil-stored seed between soil in control and exclosure plots (iii) the allelopathic effects of N. glauca on germination of Lactuca sativa seeds. Analysis of N. glauca stem sections revealed a maximum of five growth rings, confirming an origin following the 1997 flood event. At a September 1998 assessment, no N. glauca were found across flooded and control plots. In October 2000 N. glauca occurred at densities of 24 and 12 N. glauca seedlings ha −1 in the flooded unfenced and fenced plots respectively. No N. glauca individuals were recorded either from control fenced or unfenced plots. The soil-stored seed study revealed that larger numbers of N. glauca seeds were recovered from the flooded open plot (1936±968) than in flooded fenced plots (856±428.12) but none was found in the control plots. Leachates obtained from dry leaves and twigs had a significantly greater negative impact ( p>0.001) on germination of L. sativa seeds than leachates obtained from fresh leaves and bark. This study showed that the density of N. glauca is high in areas where grazing had eliminated competition from native shrubs and grasses. N. glauca is potentially a serious weed along the Olary Creek and ephemeral lake boundaries. Management strategies such as reducing grazing pressure from native and introduced animals and/or effective eradication programs should be adopted, to minimize further infestation.

Investigation of the sublethal effects of some petroleum refinery effluents

In Canada, environmental regulations for protection of the biota from the adverse effects of effluents from petroleum refineries have tended to focus on acute toxicity. There is concern those effluents may have other subtle, but still deleterious, long-term effects on aquatic ecosystems. We have used a battery of toxicity tests to assess the acute toxicity, genotoxicity, and chronic toxicity of effluent samples from two Ontario refineries. The test organisms included representatives of the bacterial, algal, plant, cladoceran, and fish communities. The results of our preliminary study indicate that the effluent samples had little acute toxicity to the test organisms. There were indications of some sublethal toxicity to Ceriodaphnia dubia, Panagrellus redivivus, and Pimephales promelas. One of the effluents inhibited the growth of Selanastrum capricornutum (IC50 of 59.9%) and Lemna gibba (IC25 of 73.3%) and also caused a 15 percent reduction in the germination of Lactuca sativa seeds. The SOS-Chromotest, a commercially available test that measures the activity of a bacterial DNA repair system, detected genotoxic effects in a single effluent that had been concentrated ten fold. There was no apparent relationship between several chemical parameters and the observed sublethal effects. Further research is needed to establish whether or not the observed toxic effects are typical of effluents from Ontario refineries.