Períodos de interferência das plantas daninhas na cultura de cebola (Allium cepa) transplantada

O trabalho foi realizado com o objetivo de estudar os efeitos de períodos de convivência (0, 14, 28, 42, 56, 70, 84 e 98 dias após o transplantio) de uma comunidade de plantas daninhas sobre a produtividade de quatro cultivares de cebola (Mercedes, Granex 33, Superex e Serrana), em sistema de transplantio de mudas. O experimento foi instalado em Jaboticabal-SP, de abril a outubro de 2000, utilizando delineamento experimental de blocos ao acaso, quatro repetições, em esquema fatorial 4 x 8. As principais populações de plantas daninhas no final dos períodos de convivência foram de Coronopus didymus, Amaranthus hybridus e Cyperus rotundus. Os cultivares Mercedes (2,90 kgm-2) e Granex 33 (2,64 kgm-2) foram os mais produtivos, independentemente da interferência das plantas daninhas. A convivência com as plantas daninhas durante os primeiros 98 dias reduziu a produtividade da cebola em 95% e o peso médio de bulbos em 91%. O período anterior à interferência (PAI) foi de 42 dias, não havendo diferença entre os cultivares de cebola.

Allium species poisoning in dogs and cats

Dogs and cats are the animals that owners most frequently seek assistance for potential poisonings, and these species are frequently involved with toxicoses due to ingestion of poisonous food. Feeding human foodstuff to pets may prove itself dangerous for their health, similarly to what is observed in Allium species toxicosis. Allium species toxicosis is reported worldwide in several animal species, and the toxic principles present in them causes the transformation of hemoglobin into methemoglobin, consequently resulting in hemolytic anemia with Heinz body formation. The aim of this review is to analyze the clinicopathologic aspects and therapeutic approach of this serious toxicosis of dogs and cats in order to give knowledge to veterinarians about Allium species toxicosis, and subsequently allow them to correctly diagnose this disease when facing it; and to educate pet owners to not feed their animals with Alliumcontaing food in order to better control this particular life-threatening toxicosis.

Hypoglycaemic and antioxidant effects of onion, Allium cepa: dietary onion addition, antioxidant activity and hypoglycaemic effects on diabetic rats

The purpose of the present study was to discover the relative potency of onion, Allium cepa, with respect to its hypoglycaemic and hypolipidaemic effects on the diabetic situation, and the association of these effects with the potential against oxidative stress. Male Wistar rats were divided into four groups. A normal control ( group A), and a non-diabetic group ( group B) were treated daily with 1 ml A. cepa solution (0.4 g A. cepa/rat). Groups C and D were made diabetic by an intraperitoneal injection of streptozotocin (STZ) ( 60 mg/kg body weight) in citrate buffer ( pH 6.3). These animals ( groups C and D) were the STZ diabetic control and STZ diabetic rats with onion intake, respectively. Onion increased the fasting serum high-density lipoprotein levels, and demonstrated alleviation of hyperglycaemia in STZ diabetic rats. The hypoglycaemic and hypolipidaemic actions of A. cepa were associated with antioxidant activity, since onion decreased superoxide dismutase activities while no increased lipid hydroperoxide and lipoperoxide concentrations were observed in diabetic rats treated with A. cepa.

N-Acetylcysteine an Allium Plant Compound Improves High-Sucrose Diet-Induced Obesity and Related Effects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Action mechanisms of petroleum hydrocarbons present in waters impacted by an oil spill on the genetic material of Allium cepa root cells

Chromosomal aberration (CA) assays have been widely used, not only to assess the genotoxic effects of chemical agents, but also to evaluate their action mechanisms on the genetic material of exposed organisms. This is of particular interest, since such analyses provide a better knowledge related to the action of these agents on DNA. Among test organisms, Allium cepa is an outstanding species due to its sensitivity and suitable chromosomal features, which are essential for studies on chromosomal damage or disturbances in cell cycle. The goal of the present study was to analyze the action mechanisms of chemical agents present in petroleum polluted waters. Therefore, CA assay was carried out in A. cepa meristematic cells exposed to the Guaeca river waters, located in the city of Sao Sebastiao, SP, Brazil, which had its waters impacted by an oil pipeline leak. Analyses of the aberration types showed clastogenic and aneugenic effects for the roots exposed to the polluted waters from Guaeca river, besides the induction of cell death. Probably all the observed effects were induced by the petroleum hydrocarbons derived from the oil leakage. (C) 2008 Elsevier B.V. All rights reserved.

Allium cepa test in environmental monitoring: A review on its application

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Micronucleus and chromosome aberrations induced in onion (Allium cepa) by a petroleum refinery effluent and by river water that receives this effluent

In this study, micronucleus (MN) and chromosome aberration (CA) tests in Allium cepa (onion) were carried out in order to make a preliminary characterization of the water quality of the Atibaia River in an area that is under the influence of petroleum refinery and also to evaluate the effectiveness of the treatments used by the refinery. For these evaluations, seeds of A. cepa were germinated in waters collected in five different sites related with the refinery in ultra-pure water (negative control) and in methyl methanesulfonate solution (positive control). According to our results, we can suggest that even after the treatments (physicochemical, biological and stabilization pond) the final refinery effluent could induce chromosome aberrations and micronucleus in meristematic cells of A. cepa and that the discharge of the petroleum refinery effluents in the Atibaia River can interfere in the quality of this river. (C) 2009 Elsevier B.V. All rights reserved.

Chromosome aberration and micronucleus frequencies in Allium cepa cells exposed to petroleum polluted water - A case study

In the present study, we applied Chromosome Aberration (CA) and Micronucleus (MN) tests to Allium cepa root cells, in order to evaluate the water quality of Guaeca river. This river, located in the city of Sao Sebastiao, SP, Brazil, had been affected by an oil pipeline leak. Chemical analyses of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs) were also carried out in water samples, collected in July 2005 (dry season) and February 2006 (rainy season) in 4 different river sites. The largest CA and MN incidence in the meristematic cells of A. cepa was observed after exposure to water sample collected during the dry season, at the spring of the river, where the oil leak has arisen. The F, cells from roots exposed to such sample (non-merismatic region) were also analyzed for the incidence of MN, showing a larger frequency of irregularities, indicating a possible development of CA into MN. Lastly, our study reveals a direct correlation between water chemical analyses (contamination by TPHs and PAHs) and both genotoxic and mutagenic effects observed in exposed A. cepa cells. (C) 2007 Elsevier B.V. All rights reserved.

The Allium cepa bioassay to evaluate landfarming soil, before and after the addition of rice hulls to accelerate organic pollutants biodegradation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Disponibilidade hídrica e germinação de sementes de cebola (Allium cepa L.)

Objetivando verificar a influência do teor de água do substrato na germinação de sementes de cebola (Allium cepa L.), conduziu-se um ensaio sob condições de ambiente de laboratório. Os efeitos de cinco níveis de água no substrato solo x areia (3:1), 20, 40, 60, 80 e 100% da capacidade de retenção foram avaliados através da porcentagem de emergência no 14° dia da semeadura e pesos da matéria verde e seca das plântulas normais. Para tanto, 200 sementes do cultivar Pira Ouro por tratamento, em quatro repetições de 50, foram semeadas a 1,5 cm de profundidade, mantendo-se constantes os níveis de água no substrato. Os resultados possibilitaram concluir que os níveis de umidade do solo indicados para germinação de sementes de cebola são de 40% e 60% da capacidade de retenção do substrato, por possibilitarem uma melhor emergência, peso da matéria verde e seca das plântulas.

Mechanism of micronuclei formation in polyploidizated cells of Allium cepa exposed to trifluralin herbicide

The trifluralin is an agent that promotes a cellular damage due to its direct action on the microtubules. This action leads to a decontrol in the cellular division, bringing about polyploid cells. In this work, we show the evidences that the exceeding genetical material of theses polyploidizated cells tends to be eliminated from the nucleus in the form of micronucleus. Our analyses prove this fact, both by the presence of a number of cells carrying micronucleus, and by the evidences of the elimination of the exceeding material itself, after exposition of the Allium cepa root tips tested with several concentration of trifluralin herbicide. It was noticed that the residual concentration induced a number of polyploid cells, micronuclei and mini cells. Inferences about the implications of the elimination of genetic material from micronuclei, such as cell viability and apoptosis, are also presented. (c) 2007 Elsevier B.V. All rights reserved.

Mutagenic potential evaluation of the water of a river that receives tannery effluent using the Allium cepa test system

Several studies are being conducted to assess the toxicity and cytotoxicity of water bodies receiving industrial and domestic effluents, using the Allium cepa test. To assess the toxicity and mutagenicity of water possibly contaminated with chromium, derived from tannery activities, seasonal water samplings were performed in 2001 and 2002 at five different sites along the Sapucaizinho river, Municipality of Patrocinio Paulista, State of São Paulo, Brazil. A. cepa seeds were used as the test material and were submitted to germination in waters from the different collection sites, in Milli-Q water (negative control) and in aqueous solution of chromium (positive control). For the determination of cell division rates and mitotic irregularities, slides were prepared with root tip cells according to the standard Feulgen methodology. The results showed that the collection sites most heavily compromised by chromium emission presented low mitotic indices and a higher frequency of mitotic changes such as irregular anaphases (disorganized, multipolar, laggard), cells with chromosomal adherences, cells with micronuclei, and binucleate and/or multinucleate cells. © 2004 The Japan Mendel Society.

Efeitos do extrato aquoso de cebola (Allium cepa L.) sobre a função renal e a pressão arterial em ratos Wistar

The vegetal species, Allium cepa, known as onion, is widely used in the folk medicine as diuretic, besides it has been used on the bronchitis, cough, cardiovascular diseases and hypertension treatment. In this study we evaluate the onion aqueous extract (AE) effect on water flow and electrolytes in anesthetized Wistar rats, besides we also evaluate arterial pressure alterations. Two groups were studied: Group 1 (control) - oral tratment with 1.0 mL of distilled water, and Group 2 (experimental) - oral treatment with 1.0 mL of AE 20%. The rats were anesthetized and we canulate the trachea, left carotide artery (for arterial pressure measurement and blood collecting), jugular vein (to execute inulin perfusion - to register glomerular filtration), and urinary bladder (to collect urine). The Group 1 results had shown that the animals had not presented significant alterations (p>0.05) in the analyzed parameters. The animals of Group 2 had a significant reduction (p<0.05) in the arterial pressure (22.0%). However, there were not significant alterations in renal parameters (p>0.05). These results show that the treatment with the AE lead a hypotensor effect in anesthetized Wistar rats, but not followed by renal parameters alterations.

Efeito do extrato aquoso de Allium sativum L. sobre parâmetros bioquímicos de ratas com diabete induzido por Streptozotocin

Many plants, even without scientific confirmation, are used in Brazil as hypoglycemic. The objective of the present work was to study the influence of the Allium sativum treatment, plant known popularly as garlic, on characteristic biochemical parameters in streptozotocin-induced diabetic rats. Female Wistar rats were injected with 40 mg kg-1 streptozotocin (STZ). Oral administration of an aqueous extract of A. sativum was given to the diabetic animals in 2 doses: 200 and 400 mg kg-1 (n=6 animals/group). Diabetic rats given distilled water constituted the control group. After 28 days of treatment, the female rats were anesthetized and died by decapitation for collection of the blood for biochemical determinations and retreat of liver samples for hepatic glycogen dosage. The treatment with Allium sativum in the doses of 200 and 400 mg kg-1 alter no concentrations of total proteins, hepatic glycogen, triglycerides and VLDL, but it promoted reduction in the total cholesterol rate (control=280.5 ± 30.9; 200 mg kg-1 A. sativum =169.9 ± 19.5 and 400 mg kg-1 A. sativum =148.4 ± 26.6 mg dL-1) and LDL (control=128.8± 25.3; 200 mg kg-1 A. sativum = 41.4 ± 16.2 and 400 mg kg-1 A. sativum=42.0 ± 26.0 mg dL-1). The extract presented beneficial effect because it decreased 13.0% of glycemia in the highest dose. Therefore, the of garlic extract reduced the HDL concentration in two tested doses (control= 81.4 ± 30.2; 200 mg kg-1 A. sativum=49.6 ± 14.3 and 400 mg kg-1 A. sativum=41.7 ± 16.1 mg dL -1), presenting impaired effect. Thus, the garlic extract showed efficiency in the analyzed experimental conditions, and it could be used as complementary therapy to diabetic patients.

Induction of chromosome aberrations in the Allium cepa test system caused by the exposure of seeds to industrial effluents contaminated with azo dyes

Numerous potentially mutagenic chemicals have been studied mainly because they can cause damaging and inheritable changes in the genetic material. Several tests are commonly used for biomonitoring pollution levels and to evaluate the effects of toxic and mutagenic agents present in the natural environment. This study aimed at assessing the potential of a textile effluent contaminated with azo dyes to induce chromosomal and nuclear aberrations in Allium cepa test systems. A continuous exposure of seeds in samples of the textile effluent in different concentrations was carried out (0.3%, 3%, 10%, and 100%). Cells in interphase and undergoing division were examined to assess the presence of chromosome aberrations, nuclear changes, and micronuclei. Our results revealed a mutagenic effect of the effluent at concentrations of 10% and 100%. At lower concentrations, the effluent (3% and 0.3%) did not induce mutagenic alterations in the test organism A. cepa. These findings are of concern, since cell damage may be transmitted to subsequent generations, possibly affecting the organism as a whole, as well as the local biota exposed to the effluent discharge. If the damage results in cell death, the development of the organism may be affected, which could also lead to its death. © 2008 Elsevier Ltd. All rights reserved.