TOXICITY OF DIFLUBENZURON TO NYMPHS OF THE MIGRATORY GRASSHOPPER, MELANOPLUS SANGUINIPES (ORTHOPTERA: ACRIDIDAE)

1982 ◽  
Vol 114 (6) ◽  
pp. 479-484 ◽  
Author(s):  
R. H. Elliott ◽  
R. Iyer
Keyword(s):  
Potential Field ◽  
Laboratory Tests ◽  
Artificial Diet ◽  
Dry Weight ◽  
Toxic Effects ◽  
Continuous Exposure ◽  
Melanoplus Sanguinipes ◽  
Feeding Damage ◽  
Wheat Seedlings

AbstractLaboratory tests showed that nymphs of the migratory grasshopper are very sensitive to diflubenzuron (Dimilin) when reared continuously on treated wheat seedlings or artificial diet and fresh lettuce. At concentrations of 10 ppm or above, diflubenzuron completely inhibited moulting of 2nd-instar nymphs. With continuous exposure on treated wheat seedlings, the LC90 values after 8, 12 and 20 days were 10.0, 2.4 and 0.8 ppm, respectively. Comparable values were obtained with the artificial diet and lettuce. However, when 2nd instars were placed on diflubenzuron-treated wheat foliage for 1 day then transferred onto untreated plants, toxicity declined markedly.Although the toxic effects of diflubenzuron were delayed, dry weight determinations on wheat seedlings indicated that nymphal feeding damage was insignificant if the plants had been sprayed with 10 ppm diflubenzuron.The implications of these findings are discussed in terms of the potential field use of diflubenzuron against stationary and mobile grasshopper nymphs.

scholarly journals Seribiodiversity and their Role in Sustainable Development in India

2019 ◽  
Vol 5 (04) ◽  
pp. 243-246
Author(s):  
Debnirmalya Gangopadhyay ◽  
Ashmita Ghosh ◽  
Mrinal Ray
Keyword(s):  
Oxidative Stress ◽  
Sodium Nitroprusside ◽  
Dry Weight ◽  
Solution Culture ◽  
Tolerance Index ◽  
Promoting Effect ◽  
Wheat Seedlings ◽  
Biotic Stresses ◽  
Protein Thiols ◽  
Fe Toxicity

Nitric oxide (NO) is an important bioactive signaling molecule in plants which modulates a variety of physiological processes and responses to abiotic and biotic stresses. In this study, the effects of exogenous NO supplied as sodium nitroprusside (SNP) in wheat seedlings under ironinduced oxidative damage was investigated. An appropriate concentration of NO was determined by conducting a preliminary experiment. In solution culture, wheat seeds were grown in the control (100 μM Fe), and toxic Fe (400 μM Fe) levels and the toxic Fe supply was treated with various levels of (50, 100, 200 and 500 μM) sodium nitroprusside (SNP). The results indicated that 400 μM Fe significantly decreased percentage germination, tolerance index, root lengths as well as fresh and dry weight compared to control. Exogenous SNP attenuated the inhibition of wheat seed germination. The promoting effect was most pronounced at 100 μM SNP. The accumulated concentration of iron and active Fe was significantly decreased by SNP treated Fe toxic seedlings. Toxicity of Fe caused oxidative stress by elevating hydrogen peroxide (H2O2), malondialdehyde (MDA) and proline contents in roots of wheat seedlings. One hundred μM SNP counteracted Fe toxicity by reducing the H2O2, MDA and proline contents of toxic Fe exposed seedlings. Meanwhile, application of SNP markedly reduced the activities of superoxide dismutases (SOD), catalases (CAT), peroxidase (POD), ascorbate peroxidases (APX), non protein thiols (NPT) and of glutathione reductase (GR) and increased ascorbate (ASc) compared with Fe toxic treatment alone, thereby indicating the modulation of the antioxidative capacity in the root under Fe stress by NO. The results indicated that the exogenous application of SNP, improved the antioxidant enzymes activity of wheat seedlings against Fe induced oxidative stress.

The effect of two audible sound frequencies on the germination and growth of a spring and winter wheat

1968 ◽  
Vol 46 (9) ◽  
pp. 1151-1158 ◽  
Author(s):  
Pearl Weinberger ◽  
Mary Measures
Keyword(s):  
Growth Response ◽  
Germination Rate ◽  
Dry Weight ◽  
Continuous Exposure ◽  
Subsequent Growth ◽  
Sound Exposure ◽  
Audible Sound ◽  
Total Plant ◽  
Accelerated Growth ◽  
Germination And Growth

The effect of sound of 5 kc/s and 12 kc/s on the germination and growth of grains and seedlings of vernalized spring (Marquis) and winter (Rideau) wheats was investigated. Untreated controls were simultaneously followed, and all experimental series were replicated at least three times. Growth cabinets were systematically interchanged with the replications to eliminate other variables. Sound at both frequencies significantly stimulated the germination of Marquis grains maintained at 2° and 10 °C. At 25 °C the rate of germination was unchanged. An indication of a slightly elevated germination rate was observed in Rideau grains held at 2° and exposed to 5 kc/s. Neither frequency significantly affected germination at 10° or 25 °C.Growth of plants derived from fully vernalized grains was followed by measuring total plant height, wet and dry weight of "tops", number of roots, and their fresh and dry weights. Rideau wheat grew more vigorously at both sound frequencies. Continuous exposure to 5 kc/s both during vernalization and subsequent growth resulted in a 200% or greater increase in all parameters followed. The growth response of Marquis wheat was dependent upon treatment. Some conditions of sound exposure accelerated growth, whereas in others growth was depressed.

scholarly journals Ascorbic acid, thiamine or salicylic acid induced changes in some physiological parameters in wheat grown under copper stress

2011 ◽  
Vol 47 (No. 3) ◽  
pp. 92-108 ◽  
Author(s):  
A.-B.M. Al-Hakimi ◽  
A.M. Hamada
Keyword(s):  
Ascorbic Acid ◽  
Salicylic Acid ◽  
Dry Weight ◽  
Copper Stress ◽  
Soluble Carbohydrates ◽  
Slight Reduction ◽  
Wheat Seedlings ◽  
Associated Proteins ◽  
Induced Changes ◽  
Test Plants

The fresh and dry weight of roots and shoots of wheat seedlings showed a marked decrease as the concentration of copper (Cu) was increased. The contents of pectin, cellulose, soluble carbohydrates, and phospholipids in the roots and shoots of test plants were significantly lowered with the rise of Cu concentration. However, hemicellulose, lignin, total lipids, glycolipids, sterols and proline of roots and shoots were raised under Cu stress. Cu treatment also induced the stimulation of soluble, total and cell wall associated proteins, other free amino acids and total carbohydrates in shoots and a slight reduction in roots. The adverse effects of Cu toxicity treatments on root and shoot growth were partially alleviated by the treatment of test plants with ascorbic acid, thiamine (vitamin B<sub>1</sub>) and salicylic acid.

scholarly journals Engineering behaviour of stabilized laterite and kaolin using lignin

2018 ◽  
Vol 250 ◽  
pp. 01008
Author(s):  
Tuan Noor Hasanah Tuan Ismail ◽  
Siti Aimi Nadia Mohd Yusoff ◽  
Ismail Bakar ◽  
Devapriya Chitral Wijeyesekera ◽  
Adnan Zainorabidin ◽  
...  
Keyword(s):  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Laboratory Tests ◽  
Dry Weight ◽  
Optimum Moisture Content ◽  
Soil Samples ◽  
Dry Density ◽  
Laterite Soil ◽  
Maximum Dry Density ◽  
Steady Rate

Soils at many sites do not always have enough strength to bear the structures constructed over them and some of the soil may need to be stabilized in order to improve their geotechnical properties. In this paper, routine laboratory tests were critically carried out to investigate the efficacy of lignin in improving the strength behaviour of the soils. Two different soil samples (laterite and kaolin) were studied and mixed with different proportions of lignin (2% and 5% of dry weight of soil), respectively. Unconfined Compressive Strength (UCS) characteristics evaluated in this study were done on samples at their maximum dry density and optimum moisture content (obtained from compaction tests). The UCS tests on all the specimens were carried out after 0, 7, 15, 21 and 30 days of controlled curing. The research results showed that the addition of lignin into kaolin reduced its maximum dry density while giving progressively higher optimum moisture content. Contrarily, with the laterite soil, both maximum dry density and optimum moisture content simultaneously increased when lignin was added into the soils. The UCS results showed that the the stabilized laterite with 2% lignin continued to gain strength significantly at a fairly steady rate after 7 days. Unfortunately, lignin did not show a significant effect in kaolin.

Nitric Oxide Alleviates Iron Toxicity by Reducing Oxidative Damage and Growth Inhibition in Wheat (Triticum aestivum L.) Seedlings

2019 ◽  
Vol 5 (01) ◽  
pp. 16-22
Author(s):  
Nalini Pandey ◽  
Laxmi Verma
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Oxidative Damage ◽  
Sodium Nitroprusside ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Tolerance Index ◽  
Promoting Effect ◽  
Wheat Seedlings ◽  
Protein Thiols

Nitric oxide (NO) is an important bioactive signaling molecule in plants which modulates a variety of physiological processes and responses to abiotic and biotic stresses. In this study, the effects of exogenous NO supplied as sodium nitroprusside (SNP) in wheat seedlings under ironinduced oxidative damage was investigated. An appropriate concentration of NO was determined by conducting a preliminary experiment. In solution culture, wheat seeds were grown in the control (100 μM Fe), and toxic Fe (400 μM Fe) levels and the toxic Fe supply was treated with various levels of (50, 100, 200 and 500 μM) sodium nitroprusside (SNP). The results indicated that 400 μM Fe significantly decreased percentage germination, tolerance index, root lengths as well as fresh and dry weight compared to control. Exogenous SNP attenuated the inhibition of wheat seed germination. The promoting effect was most pronounced at 100 μM SNP. The accumulated concentration of iron and active Fe was significantly decreased by SNP treated Fe toxic seedlings. Toxicity of Fe caused oxidative stress by elevating hydrogen peroxide (H2O2), malondialdehyde (MDA) and proline contents in roots of wheat seedlings. One hundred μM SNP counteracted Fe toxicity by reducing the H2O2, MDA and proline contents of toxic Fe exposed seedlings. Meanwhile, application of SNP markedly reduced the activities of superoxide dismutases (SOD), catalases (CAT), peroxidase (POD), ascorbate peroxidases (APX), non protein thiols (NPT) and of glutathione reductase (GR) and increased ascorbate (ASc) compared with Fe toxic treatment alone, thereby indicating the modulation of the antioxidative capacity in the root under Fe stress by NO. The results indicated that the exogenous application of SNP, improved the antioxidant enzymes activity of wheat seedlings against Fe induced oxidative stress.

Toxic effects of 1-methyl-3-octylimidazolium bromide on the wheat seedlings

2010 ◽  
Vol 22 (12) ◽  
pp. 1974-1979 ◽  
Author(s):  
Ping Liu ◽  
Yifeng Ding ◽  
Haiying Liu ◽  
Liping Sun ◽  
Xiaoyu Li ◽  
...  
Keyword(s):  
Toxic Effects ◽  
Wheat Seedlings

scholarly journals DETECTION OF POTENTIALLY TOXIGENIC MICROCYSTIS STRAINS FROM DAU TIENG RESERVOIR

2018 ◽  
Vol 15 (4) ◽  
pp. 745-752
Author(s):  
Pham Thanh Luu ◽  
Ngo Xuan Quang
Keyword(s):  
Acute Toxicity ◽  
High Performance ◽  
Biological Effects ◽  
Dry Weight ◽  
Molecular Techniques ◽  
Toxic Effects ◽  
Public Water Supply ◽  
Aquatic Biota ◽  
Lethal Effects ◽  
Crude Extracts

Microcystis is a bloom-forming, common cyanobacterium in Dau Tieng reservoir used for public water supply. To assess the presence of potentially microcystin-producing Microcystis, molecular techniques were conducted and acute toxicity bioassays were performed with the microcrustacean Daphnia magna exposed to cyanobacterial crude extracts. Potentially toxigenic of isolated strains was characterized by amplifying mcyD genes and identification of Microcystis was confirmed by 16S rRNA amplification. Microcystins (MCs) concentration in bloom samples and cultured strains were quantified by High Performance Liquid Chromatography (HPLC). Results showed that there were 9/15 strains showed positive with the mcyD marker indicating that they are toxic strains. Three MCs variants including MC-RR, -LR and -YR were found in all extracts of toxic strains with the highest concentration of 1,218 μg/g dry weight (DW). The acute toxicity bioassays revealed that both toxic and non-toxic crude extracts elicited significant lethal effects on the tested animal with LC50 values ranged from 189-411 mg DW/L. The toxic effects of isolated strains were independent from the MCs concentration in some strains suggesting the presence of other metabolites contributed to the biological effects. In conclusion, microcystin-producing Microcystis from the Dau Tieng reservoir warn about possible toxic effects for aquatic biota and human health.

scholarly journals Calcium Can Prevent Toxic Effects of Na+ on Tomato Leaf Photosynthesis but Does Not Restore Growth

2007 ◽  
Vol 132 (3) ◽  
pp. 310-318 ◽  
Author(s):  
Francesco Montesano ◽  
Marc W. van Iersel
Keyword(s):  
Dry Weight ◽  
Leaf Length ◽  
Toxic Effects ◽  
Nutrient Concentrations ◽  
Dry Matter Accumulation ◽  
Basic Solution ◽  
Leaf Photosynthesis ◽  
Osmotic Effect ◽  
Leaf Physiology ◽  
Specific Effects

The availability of good-quality irrigation water is decreasing worldwide, and salinity is an increasingly important agricultural problem. To determine whether detrimental effects of NaCl on plant growth and leaf physiology can be minimized by additional Ca2+ supply, tomato (Solanum lycopersicum L.) ‘Supersweet 100’ was grown hydroponically. The basic nutrient solution contained 11.1 mm NO3 − and 2.8 mm Ca2+. Three levels of NaCl (14.1, 44.4, and 70.4 mm) were added to the basic solution to determine Na+ effects on leaf physiology and growth. To determine if Ca2+ could alleviate the toxic effects of Na+, treatments with 10 or 20 mm Ca2+ combined with 44.4 or 70 mm NaCl were included as well. To distinguish between osmotic and ion-specific effects, there were three treatments in which all nutrient concentrations were increased (without NaCl) to obtain electrical conductivity (EC) levels similar to those of the NaCl treatments. Nutrient solutions with 70.4 mm NaCl reduced leaf photosynthesis, chlorophyll content, gas-phase conductance, carboxylation efficiency, and dark-adapted quantum yield. Inclusion of 20 mm Ca2+ prevented these effects of NaCl. NaCl also decreased leaf length and elongation rate. This could not be prevented by adding extra Ca2+ to the solution; reductions in leaf elongation were due to osmotic effects rather than to Na+ specifically. Likewise, plant dry weight was negatively correlated with solution EC, suggesting an osmotic effect. Leaf area development apparently was more important for dry matter accumulation than leaf photosynthesis. Adding 20 mm Ca2+ to the 70 mm NaCl solution reduced the Na+ concentration in the leaf from 79 to 24 mg·g−1.

scholarly journals Microbiological Insights into the Stress-Alleviating Property of an Endophytic Bacillus altitudinis WR10 in Wheat under Low-Phosphorus and High-Salinity Stresses

2019 ◽  
Vol 7 (11) ◽  
pp. 508 ◽  
Author(s):  
Yue ◽  
Shen ◽  
Chen ◽  
Liang ◽  
Chu ◽  
...  
Keyword(s):  
Abiotic Stresses ◽  
Germination Rate ◽  
Acc Deaminase ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Culture Conditions ◽  
Wheat Seedlings ◽  
Bacillus Altitudinis ◽  
Phosphorus Stress ◽  
Low Phosphorus

An indole–3–acetic acid producing Bacillus altitudinis WR10 was previously isolated from the root of wheat (Triticum aestivum L.). In this study, the strain WR10 was used for relieving abiotic stresses in wheat under low phosphorus and high saline in hydroponic co-culture models. Significantly, strain WR10 improved wheat seed relative germination rate under salinity stress (200/400 mM NaCl) and the root dry weight in wheat seedlings under phosphorus stress (10 μM KH2PO3) when insoluble phosphates are available. To provide insights into its abiotic stress-alleviating properties, the strain was characterized further. WR10 grows well under different culture conditions. Particularly, WR10 resists salt (12% NaCl) and hydrolyzes both inorganic and organic insoluble phosphates. WR10 uses many plant-derived substrates as sole carbon and energy sources. It produces catalase, amylase, phosphatase, phytase, reductase, and 1–aminocyclopropane–1–carboxylate (ACC) deaminase. In addition, WR10 possesses long peritrichous flagella, and its biofilm formation, as well as phytase production, is induced by abiotic stresses. Overall, the salinity-alleviating property of WR10 in wheat can be attributed to its inherent tolerance to NaCl, formation of biofilm, and production of enzymes, like catalase, amylase, and ACC deaminase. Meanwhile, B. altitudinis WR10 reduces low-phosphorus stress in wheat by production of phosphatases and phytases in the presence of insoluble phosphates.

Effect of seedling damage by redlegged earth mite, Halotydeus destructor, on subsequent growth and development of yellow lupin, Lupinus luteus, in the glasshouse

2000 ◽  
Vol 51 (1) ◽  
pp. 113 ◽  
Author(s):  
A. Liu ◽  
T. J. Ridsdill-Smith ◽  
D. C. Nicholas
Keyword(s):  
Flowering Time ◽  
Seed Yield ◽  
Growth And Development ◽  
Dry Weight ◽  
Seedling Stage ◽  
Lupinus Luteus ◽  
Feeding Damage ◽  
Yellow Lupin ◽  
Halotydeus Destructor ◽  
Redlegged Earth Mite

Redlegged earth mite (Halotydeus destructor) causes feeding damage to some pulse species at the seedling stage. To quantify the effect of this damage on subsequent plant growth and development, an experiment was conducted in the glasshouse using yellow lupin, Lupinus luteus cv. Motiv, which is highly susceptible to the mites. After emergence, plants were infested with 0, 100, 150, and 250 mites/plant, collected from the field. Fourteen days after application, mites were removed. Damage to plants was estimated at seedling stage, flowering time, and maturity. At seedling stage (on Day 14), feeding damage scores to cotyledons and true leaves were greater at higher mite densities. Damaged plants produced fewer nodules, fewer lateral roots, and less dry weight than the control. On Day 35, severely damaged plants failed to recover and on the surviving plants, cotyledons and true leaves died earlier than on the plants without damage. On Day 78, when plants were flowering, the surviving plants produced fewer nodules and branches, and less dry weight per plant than the control. The flowering time of plants with the mite treatments was delayed by up to 6 days compared with the controls. The final shoot dry weight, pod number, seed number, and seed yield per pot were significantly reduced by the mite treatments. Feeding by H. destructor on seedlings of yellow lupin caused a reduction in seed yield of 58% at the highest mite density treatment. This significant economic loss needs to be confirmed under field conditions, but it signifies the need to develop appropriate control measures for this pest.

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