scholarly journals Tropical Wetland Earthworm Vermifluid Promotes Mitotic Activities and Root Growth in Allium cepa at low concentrations

Author(s):  
Ebenezer Olasunkanmi Dada ◽  
Tirmizhi Abdulganiy ◽  
Stephen Olugbemiga Owa ◽  
Yusuf Olamilekan Balogun ◽  
Emmanuel Olorunleke Oludipe ◽  
...  

It is well established that earthworms and their products promote plant growth and improve crop yield, but more information about their mechanisms of action, especially at cellular level, is required. This study assessed the enzyme and bacterial activities of vermifluid secreted by a tropical wetland earthworm, Alma millsoni. The effects of the vermifluid on the mitotic activities and root growth of Allium cepa (onions) were evaluated. Vermifluid enzyme and bacterial activities were assessed using standard procedures. Mitotic activities were evaluated using the Allium assay squash technique. Root lengths in onions grown in graduated dilutions of vermifluid were measured using a metre rule. Phosphatase had the highest activity (39.00 ± 3.70 units/ml/min) in the vermifluid, followed by urease (4.90 ± 0.18 units/ml/min), protease (3.20 ± 0.28 units/ml/min), amylase (1.40 ± 0.09 units/ml/min) and lipase (0.001 ± 0.00 units/ml/min). The total microbial count (TBC) and total fungi count (TFC) in the vermifluid were 6.0 × 104 CFU/ml and 2.4 × 105 CFU/ml, respectively. Results also indicated that the lower the vermifluid concentrations, the higher the number of dividing cells and mitotic index in onion roots. Onion roots grown in 10% vermifluid had the highest significant (P < 0.05) root growth of 2.65 ± 0.30 cm, 4.01 ± 0.61 cm, and 4.54 ± 0.62 cm, at 12-hour, 24-hour, and 72-hour exposure period, respectively. The inverse relationships between onion mitotic activities, root growth and vermifluid concentrations imply that the growth-promoting enzymes and other products in vermifluid stimulate cellular root growth better in small concentrations. Keywords: Alma millsoni, earthworm fluid, enzymes, microbial activities, mitosis, phosphatase.

2020 ◽  
Vol 12 (1) ◽  
pp. 344-351
Author(s):  
U.A. Abdullahi ◽  
S. Ibrahim

Insufficiencies in dyeing and textile processing coupled with incomplete sewage treatment system lead to indiscriminate discharge of large amount of dyestuff into water bodies mostly used for irrigation and fishing. These wastes are potentially mutagenic and some are even carcinogenic. In this research, cytotoxicity of three industrial effluents viz; African Textile Manufacturer (ATM), Kofar Naisa and Kofar Mata dyeing centres were evaluated using Allium cepa bioassay. The concentrations of some heavy metals (Cr, Cd, Zn, Fe, Cu, Co, Pb, Mn and Ni) were also determined. Three sets of small onion bulbs were cultivated in 25%, 50% 75% and 100% effluent concentrations (v/v) and a control for each site. Root tips from each bulb were harvested and processed for cytological studies using squashing technique. After 48hrs of exposure, cytotoxic effects of the effluents on root tips (compared to control) showed root growth retardation which was more apparent at higher concentrations. This indicated that, the root growth inhibition was concentration dependent. Number of dividing cells observed and the Mitotic Index (MI) were also concentration dependent. There were decrease in number of dividing cells and MI with increase in concentration of the treatment. The effective concentrations that caused 50% effect (EC50) was 95% for ATM and K/Naisa dyeing points while it was 100% in K/mata dyeing point. Diverse structural aberrations and abnormalities were observed ranging from chromosomal bridge, which was apparent even at low concentrations of the treatment to cytokinesis failure, Micronucleus (MN) and nuclear buds or vacuolated nuclei. Analysis of Variance (ANOVA) showed no significant difference (P>0.05) in mean concentrations of Cr, Fe, Cu and Mn for K/Naisa and K/Mata dyeing centres, but there was statistical difference (P<0.05) for these parameters in ATM. Likewise, there was significant difference (P<0.05) in the root growth of A. cepa exposed to different concentrations of the effluent in ATM and K/Naisa sites but no statistical difference existed in root growth of A. cepa exposed to K/Mata effluents. Keywords: Allium cepa, Bioassay, Effluents, Cytotoxicity, Mitotic Index


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhua Shan ◽  
Min Lv ◽  
Wengang Zuo ◽  
Zehui Tang ◽  
Cheng Ding ◽  
...  

AbstractThe most important measures for salt-affected mudflat soil reclamation are to reduce salinity and to increase soil organic carbon (OC) content and thus soil fertility. Salinity reduction is often accomplished through costly freshwater irrigation by special engineering measures. Whether fertility enhancement only through one-off application of a great amount of OC can improve soil properties and promote plant growth in salt-affected mudflat soil remains unclear. Therefore, the objective of our indoor pot experiment was to study the effects of OC amendment at 0, 0.5%, 1.0%, 1.5%, and 2.5%, calculated from carbon content, by one-off application of sewage sludge on soil properties, rice yield, and root growth in salt-affected mudflat soil under waterlogged conditions. The results showed that the application of sewage sludge promoted soil fertility by reducing soil pH and increasing content of OC, nitrogen and phosphorus in salt-affected mudflat soil, while soil electric conductivity (EC) increased with increasing sewage sludge (SS) application rates under waterlogged conditions. In this study, the rice growth was not inhibited by the highest EC of 4.43 dS m−1 even at high doses of SS application. The SS application increased yield of rice, promoted root growth, enhanced root activity and root flux activity, and increased the soluble sugar and amino acid content in the bleeding sap of rice plants at the tillering, jointing, and maturity stages. In conclusion, fertility enhancement through organic carbon amendment can “offset” the adverse effects of increased salinity and promote plant growth in salt-affected mudflat soil under waterlogged conditions.


2014 ◽  
Vol 57 (3) ◽  
pp. 329-340
Author(s):  
Jadwiga A. Tarkowska

The effect of pure sodium cacodylate on dividing cells was studied. The root meristematic cells of <em>Allium cepa</em> L. (the roots were squashed in acetoorcein) and endosperm cells of <em>Haemanthus katherinae</em> Bak. (<em>in vitro</em> observations) were used. Serious disturbances in karyokinesis and cytokinesis were found that led most often to the formation of polyploid or multinucleate (<em>A. cepa</em>) cells. These results point to damage of the mitotic spindle and phragmoplast. Careful use of cacodylate buffer in ultrastructural studies of microtubules is advised.


Author(s):  
Doris Fovwe Ogeleka ◽  
Esther Obasi

Introduction: The constant impact on the environment occasioned by pollution, indiscriminate application of agricultural chemicals, security challenges and crisis in the Niger Delta ecological area of Nigeria has caused severe damage to plants, soil organisms and humans. Aim and Methodology: In this research, onions (Allium cepa L) was exposed to varying concentrations of an atrazine-based selective herbicide Arda-force® to estimate the phyto-toxic effects on the plant species using the Organization for Economic Co-operation and Development, (OECD) protocol #208. Results: The mean effective concentration (EC50) using root growth inhibition produced indications of phyto-toxicity to the exposed species at a concentration of 0.55 ± 0.06 mg/L. Similarly, the maximum root growth inhibition efficiency relative to the control was 65% as recorded in the highest test concentration of 1.25 mg/L. Discussion: The study indicated that constant application / indiscriminate use of the herbicide Arda-force® could cause deleterious influence on these plant and vegetable species, daily consumed by humans as a rich source of anti-oxidants. Conclusion: This study concluded that atrazine-based herbicide Arda-force® used in this assessment resulted in phyto-toxic effects to Allium cepa L. At the exposed concentrations of the herbicide to non-target specie – Allium cepa L. that are integral parts of the ecosystems, the ‘‘harmless’’ status of atrazine acclaimed by the United State Environmental Protection Agency (USEPA) is still very much in doubt.


1994 ◽  
Vol 86 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Wei Wang ◽  
Fengmei Zhao ◽  
Cheng Lu

2017 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Ana Paula Justiniano Régo ◽  
Ederio Dino Bidoia ◽  
Cassiana Maria Reganhan-Coneglian

The ametryne herbicide is largely used on sugar cane plantation in Brazil. It is persistent in the environment and can be found in bodies of water, impacting the aquatic and terrestrial ecosystems. Generally, in crops are applied mixtures of herbicides in order to obtain a higher success in combating weeds. This study evaluated the toxicity only of ametryne herbicide, without mixture with other herbicides, in order to quantify only the degree of dangerousness. This work evaluated the toxicity of ametryne to one aquatic test organism (Daphnia similis) and two land test organism (Eruca sativa and Lactuca sativa). Immobility of D. similis was evaluated in the presence of ametryne. Influences of ametryne on seed germination and root growth of E. sativa and L. sativa were evaluated. Even at low concentrations (5.00 mg/L), ametryne caused toxic effects on the mobility of D. similis, and 0.25 g/L caused toxic effects on the seeds. Root growth and the percentage of inhibition showed greater sensitivity to ametryne compared with seed germination. Thus, ametryne resulted in toxic effects to the analyzed organisms, which may bring damage to both aquatic and terrestrial ecosystems.


2020 ◽  
Vol 67 (4) ◽  
pp. 618-625
Author(s):  
N. V. Zhukovskaya ◽  
E. I. Bystrova ◽  
N. F. Lunkova ◽  
V. B. Ivanov

1994 ◽  
Vol 42 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Lin Guo ◽  
Yuqing Hao ◽  
Cheng Lu ◽  
...  

The effects of different concentrations of nickel sulfate on root growth and nucleoli in root tip cells of Allium cepa were studied. The concentrations of nickel sulfate (NiSO4 · 7H2O) used were in the range of 10−7-10−1M. The results showed that nickel sulfate has a stimulatory effect on root growth at lower concentrations, and an inhibitory effect at higher concentrations. Nickel has toxic effects on nucleoli at higher concentrations. Phenomena we observed were irregularly shaped nucleoli, weaker silver staining reaction at the periphery of the nucleolus, and extrusion of nucleolar material from nuclei into the cytoplasm after treatment with higher concentrations of Ni.


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