Effects of sodium fluoride on hepatic toxicity in adult mice and their suckling pups

In this investigation, we have evaluated the effect of sodium fluoride (NaF) on hepatic function in pregnant and lactating mice and their suckling pups. Experiments were carried out on female Wistar mice given 500 ppm sodium fluoride (226 ppm fluoride ion) in their drinking water from the 15th day of pregnancy until day 14 after delivery. All mice were sacrificed on day 14 after parturition. Our results showed a significant decrease in serum levels of total protein and albumin, a marked hypoglycaemia and a significant decline in serum cholesterol and triglyceride levels in fluoride-treated mice and their pups. Whereas globulin and biluribin levels in serum were not significantly changed by NaF treatment. On the other hand, serum transaminase activities (aspartate transaminase; alanine transaminase), which well known as markers of liver function, were elevated indicating hepatic cells’ damage after treatment with fluoride. Lipid peroxidation increased in NaF-treated mice and pups, as revealed by high liver malondialdehyde levels, while serum total antioxidant status showed a significant decline. These biochemical modifications in NaF-treated mice also correspond histologically with extensive ballooning, hepatocellular necrosis and infiltration of mononuclear cells. These effects were not observed in controls.     

Nephrotoxicity induced by dimethoate in adult rats and their suckling pups

The purpose of this study was to investigate the effect of dimethoate (DM), an organophosphorus insecticide, on oxidative stress in kidneys of adult rats and their suckling pups. Female Wistar rats were given daily DM in drinking water 0.2 g/L equivalent to 40 mg/kg bw from day zero until day 10 after delivery. A significant increase was found in relative kidney weights of treated adult rats and their offspring. DM administration affected strongly specific markers of kidney function such as the 24-h urine volume which was higher than in the controls. In test group we have found higher plasma levels and lower urinary levels of creatinine, a specific indicator of glomerular function, and urea than in the controls. Significant increase in creatinine clearance was also found in treated mothers and their suckling pups. These results indicated that DM exposure provoked low glomerular filtration rate in treated group. Interestingly, these biochemical modifications were accompanied by a marked enhancement of lipid peroxidation in kidney indicating significant induction of oxidative damage and alterations of enzymatic antioxidant defences in test group. Impairment of renal function corresponds histologically. In fact, histological changes, seen in the kidney of mothers and their pups treated with DM are characterized by a narrowed Bowman’s space, degenerative of tubular epithelial cells and widened tubular lumen. Moreover in mothers, extensive vascular congestion was observed.We concluded that the effect of DM treatment in lactation period of mothers was fairly reflected in the offspring in all parameters analysed.     

Evaluation of propolis effects on some biochemical parameters in rats treated with sodium fluoride

The present study in which 42 female rats, each weighing 200−250 g, were used covered a period of 21 days. The animals were divided into six groups. The first group served as the control group, whereas Group 2 was administered propolis at a dose of 200 mg/kg/bw in drinking water for 21 days. Group 3 was first provided with normal drinking water for a period of 14 days, and was subsequently administered propolis at a dose of 200 mg/kg/bw in drinking water for 7 days. Group 4 was first given normal drinking water for 14 days, and was secondly administered 100 ppm fluoride as a sodium fluoride in drinking water for 7 days. Group 5 was first administered propolis alone at a dose of 200 mg/kg/bw in drinking water for 14 days, and was secondly administered 100 ppm fluoride in association with 200 mg/kg/bw propolis for 7 days. Finally, Group 6 was first provided with normal drinking water for 14 days, and was secondly administered 100 ppm fluoride in association 200 mg/kg/bw propolis for a period of 7 days. At the end of the 21st day, blood samples were collected from the heart of each animal into both heparinised tubes and tubes without anticoagulants. Glucose, triglyceride, cholesterol, total protein, and uric acid levels, and aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities in the serum, as well as malondialdehyde (MDA) levels, glutathione peroxidase (GSH-Px) in the plasma, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities were measured. When compared to the control group, statistical differences were determined to exist with respect to oxidative stress parameters which involved increase in MDA levels in Groups 4−6, decrease in SOD activity in Groups 4 and 6, increase in CAT activity in Groups 5 and 6, and decrease in GSH-Px activity in Groups 4 and 6. Furthermore, in comparison to the control group, significant differences were observed with respect to certain serum biochemical parameters, including decrease in glucose levels in Groups 5 and 6, decrease in triglyceride levels in Groups 2 and 4, decrease in cholesterol levels in Groups 2 and 5, decrease in the total protein level of Groups 4−6, decrease in the ALT activity of Groups 5 and 6, increase in the AST activity of Group 4, decrease in the ALP activity of Groups 2−6 and increase in the uric acid level of Group 2. In the groups that were administered propolis in association with fluoride, improvement was observed in some oxidative stress parameters and certain other biochemical parameters. Changes determined in the oxidative stress parameters (especially MDA and SOD) were indicative of the anti-radical activity of propolis on the free radicals generated by sodium fluoride. However, the values not drawing completely close to those of the control group can be explained with propolis not being able to completely eliminate the free radicals and the other adverse effects generated by fluoride.     

Effects of dichlorvos on lipid peroxidation in mice on subacute and subchronic periods

In this study, the effects of dichlorvos to lipid peroxidation were investigated at subacute and subchronic periods. Dichlorvos was given with drinking water to Swiss Albino male mice in three dosage levels as 10, 20, and 40 mg/kg b.w. Lipid peroxidation was evaluated by determining the malondialdehyde (MDA) levels in plasma, determining the superoxide dismutase and catalase activities in erythrocytes. The analysis of these enzymes was done in blood samples collected from mice on the days 15 and 45. The results showed that MDA levels increased in dichlorvos treated groups. Actually MDA levels in control and dichlorvos treated groups were determined (as nmol/ml) 10.49, 13.83, 14.30, and 14.50, respectively, at subacute period; 7.77, 8.15, 10.88, and 12.33, respectively, at subchronic period. Catalase activity in erythrocytes decreased at subacute and subchronic periods in dichlorvos treated groups. At subacute period CAT activities were determined (as k/mg Hb) in control and dichlorvos treated groups, 563.45, 532.11, 524.76, and 497.08, respectively; 660.53, 588.84, 525.85, and 512.01, respectively, at subchronic period. When subacute and subchronic periods were compared with each other; it was shown that SOD and CAT activities increased at subchronic period.     

Dose-dependent sub-chronic toxicity of diethyl phthalate in female Swiss mice

The experiment was conducted to study the after effects of administering DEP at different doses to female Swiss mice for a period of 90 days. Group I mice were fed on normal diet and water ad libitum. Group II mice were maintained on normal diet mixed with corn oil at 8.25 mg/kg of the diet/day as oil control. Group III, IV and V mice were given diethyl phthalate dissolved in corn oil mixed with the diet at 10, 25 and 50 mg/kg of the diet/day, which is approximately equal to 1.25, 3.125 and 6.25 mg/kg body weight/day. A significant dose dependent increase was observed in serum acid phosphatase (ACP) whereas, serum and liver triglycerides levels showed a significant increase only in the high-dose treated group. Significant dose-dependent increase in serum aspartate and alanine aminotransferase (AST and ALT) and liver glycogen was observed. Serum lactate dehydrogenase (LDH) was significantly increased only in 25 and 50 ppm DEP-treated mice. Liver cholesterol was significantly increased in all the treated groups. Liver histology by light microscopy showed intracellular vacuolations in all the treated groups which was much more evident in the 25 and 50 ppm DEP-treated mice while hepatocellular degeneration and hypertrophy of the hepatocytes was evident in 50 ppm DEP-treated mice. Proliferation of mitochondria and peroxisomes was evident in the electron micrographs of the 10 ppm DEP-treated mice while 25 and 50 ppm DEP-treated mice showed increase in lipid droplets and severe mitochondrial proliferation.     

Effects of pyrethroids on neuronal excitability of adult honeybees Apis mellifera

Pyrethroids act on the nervous system as a primary target organ and exert their neurotoxic effects primarily by altering the conductance of sodium channel, leading to hyperexcitation. However, few studies investigated the effects of pyrethroids on neuronal excitability of honeybee brain neurons. In this study, a whole-cell patch-clamp technique was used to record current threshold, the minimum current to induce an action potential, and peak sodium current in the dissociated honeybee brain neurons treated with bifenthrin, deltamethrin and fluvalinate in vitro & in vivo. The study showed that these pyrethroids greatly suppressed the neuronal excitability as revealed by increasing current injected and inhibited the peak sodium current in honeybees. The three pyrethroids also inhibited steady-state inactivation in addition to reduction of sodium peak current.     

溴甲烷和硫酰氟对进境美国苜蓿草的穿透效果研究初探

为明确溴甲烷和硫酰氟对捆包苜蓿草的熏蒸穿透效果,本文分别使用溴甲烷和硫酰氟对捆包苜蓿草进行了帐幕熏蒸,并研究了2种熏蒸剂在苜蓿草不同深度内的穿透。结果表明,随熏蒸进行,2种熏蒸剂均可逐渐穿透到捆包苜蓿草内部(60 cm深度),其中溴甲烷完全穿透至60 cm深度的时间为24 h,高浓度熏蒸48 h后,苜蓿草内部20 cm、40 cm和60 cm处的溴甲烷浓度仍仅有外部空间的77.3%、57.8%、56.2%;硫酰氟完全穿透60 cm深度的时间为8~12 h,高浓度熏蒸48 h后,20 cm、40 cm、60 cm深度内的硫酰氟浓度分别是空间硫酰氟浓度的102.2%、101.8%、97.2%,苜蓿草内部硫酰氟浓度与外部空间浓度基本达到平衡。这些结果表明,硫酰氟熏蒸对进境捆包苜蓿草的穿透力强于溴甲烷。     

The effects of deltamethrin on some serum biochemical parameters in mice

Sixty white male mice were used in this study. Three groups, each comprising 20 mice were established. The control group (Group 1) was provided ad libitum pellet feed. On the other hand, the experimental groups, namely, Groups 2 and 3 were given pellet feed containing deltamethrin throughout the day, so that the animals were administered doses of 7.5 and 30 mg/kg/body weight/day, respectively. Blood samples were collected from all groups on the 15th, 30th, 45th, and 60th days of the experiment for measurement of serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alcaline phosphatase (ALP), amylase and cholinesterase activities, and levels of glucose, urea, creatinine, triglyceride, cholesterol, calcium, phosphor, sodium, potassium, and chloride. According to data obtained, on the 15th day of the study, compared to the control group, statistically significant increase in urea, cholesterol, ALP, cholinesterase, calcium, and potassium levels/activities, and significant decrease in SGOT activity and chloride levels in Group 2, and significant increase in cholesterol, ALP, cholinesterase, calcium, potassium and chloride levels/activities in Group 3, and significant decrease in SGOT activity in Group 3 were determined. On the 30th day of the study, in comparison to the control group, triglyceride and cholesterol levels and ALP activity were determined to be significantly increased in the Group 2, whereas SGOT activity were significantly reduced in Group 2, and triglyceride and cholesterol levels were demonstrated to be significantly increased and SGOT activity was significantly reduced in Group 3. On the 45th day of the study, compared to the controls, significant increase in cholesterol and sodium levels, and significant decrease in triglyceride levels and ALP activity in Group 2, significant increase in creatinine, cholesterol and sodium levels and cholinesterase activity, and significant decrease in glucose, SGPT, ALP and phosphor levels/activities were detected in Group 3. On the 60th day, in other words, in the last period of the study, ALP activity, and triglyceride, calcium, and phosphor levels were determined to be significantly increased and significant decrease in amylase activity in Group 2. Furthermore, significant increase in triglyceride, ALP, amylase, calcium, phosphor, and potassium levels/activities, and significant decrease in glucose and creatinine levels were observed in Group 3. However no correlation was determined to exist between the changes were found to be statistically significant, and the administration dose and duration of deltamethrin in all periods and groups.     

北京南部地区地下水氟化物分布特征及成因分析

以大兴区为研究对象,基于全区99眼机井的地下水水质调查结果,应用数学统计分析方法和水文化学分析软件,研究了北京南部地区地下水中氟化物的分布特征及成因。结果表明:该区域地下水化学类型相对比较简单,以HCO3-Ca.Mg型为主。氟化物在研究区地下水中广泛分布,影响着地下水水质状况。浅层地下水中氟化物浓度变化范围在0.13～1.76mg/L之间,浓度高值区主要分布在研究区南部和东南部。与浅层地下水相比,深层地下水中氟化物浓度较低,未出现超标现象。地下水中氟化物浓度与pH值及Ca2+浓度分别呈正、负相关关系,与取水深度也存在一定相关关系。地下水中氟化物主要由自然因素造成,但近年来人类频繁活动也影响着水体中氟化物浓度变化。     

黄斑星天牛硫酰氟检疫熏蒸技术研究

黄斑星天牛 (Anoplophoranobilis)硫酰氟熏蒸的毒力试验结果说明 ,当熏蒸时间为2 4h ,4.4℃、1 0 .0℃、1 5.5℃和 2 1 .1℃条件下推算出死亡机率值 9要求的CT值分别为70 0 4.2 0、3 2 96.97、974.63和 52 7.0 4g .h/m3;当熏蒸时间为 48h ,4.4℃和 2 1 .1℃分别为 2 82 8.2 2和 50 5.45g .h/m3。室内验证试验中 ,1 5.5℃和 2 1 .1℃投药剂量为 1 0 4g/m3,能够全部杀灭杨树携带的黄斑星天牛幼虫、蛹 ,以及芳香木蠹蛾东方亚种 (Cossuscossusorientalis)和杨干透翅蛾 (Spheciasiningensis)幼虫 ;而在 1 0℃以下 ,黄斑星天牛或芳香木蠹蛾东方亚种和杨干透翅蛾幼虫没有完全死亡。     

Effects of trichlorfon and sodium dodecyl sulphate on antioxidant defense system and acetylcholinesterase of Tilapia nilotica in vitro

The effects of organophosphorus insecticide trichlorfon, surfactant sodium dodecyl sulphate (SDS), and the mixture of trichlorfon and SDS on the antioxidant defense system and acetylcholinesterase (AChE) in Tilapia nilotica were assessed in vitro. Various concentrations of trichlorfon (0, 0.0001, 0.001, 0.01, 0.1 and 1 g/L) and SDS (0, 0.0625, 0.125, 0.25, 0.5, 1 g/L) were incubated with homogenate of liver and muscle, respectively, at 25 °C for 0, 30, 60 and 90 min. Two concentrations of mixture of trichlorfon and SDS (0.0001 g/L trichlorfon + 0.5 g/L SDS, 0.1 g/L trichlorfon + 0.5 g/L SDS) and 0.0001 g/L trichlorfon, 0.1 g/L trichlorfon, 0.5 g/L SDS and control, were incubated simultaneously with homogenate of liver and muscle, respectively, at 25 °C for 60 min. After incubation, the content of reduced-glutathione (GSH) and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) in homogenate of liver were determined, and the activities of AChE in homogenate of muscle were also measured.Treatment with trichlorfon caused a significant concentration-dependent and time-related inhibition of AChE activity at all treatment concentrations and times since trichlorfon is a cholinesterase inhibitor. For the same trichlorfon treatment, an apparent decrease in GSH content was found in concentration of 0.01, 0.1, 1 g/L, whereas no significant alteration in antioxidant enzyme activity were found at all experiment concentrations and times, which might indicate that antioxidant enzymes have not involved in the metabolism of trichlorfon. The depletion of GSH might indicate that ROS could be involved in the toxic effects of trichlorfon. Exposure of SDS can inhibit activities of AChE, GST and CAT at concentrations of 0.5 and/or 1 g/L, which could be due to the denaturing process of SDS to the enzymes. For the mixture exposure of trichlorfon and SDS, the effect of the mixture of 0.0001 g/L trichlorfon and 0.5 g/L SDS on inhibition of AChE shows synergistic other than simple additive of trichlorfon and SDS. The combined effects of chemicals and detergents deserve to be particularly noted. It should be noted that the toxicity experiments were made in tissue homogenates instead of whole organisms. The responses against the toxic compounds will not be the same in both systems.     

Acute toxicity and histopathological effects of sublethal fenitrothion on Nile tilapia, Oreochromis niloticus

Organophosphothionate insecticide fenitrothion is known as potential toxic pollutant contaminating aquatic ecosystems. The effects of fenitrothion were studied to determine the 96 h LC₅₀ value on Nile tilapia (Oreochromis niloticus) and investigate histopathological responses of fish exposed to sublethal fenitrothion concentrations. Data obtained from the fenitrothion acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The 96 h LC₅₀ value and 95% confidence limit for Nile tilapia (58.70 ± 6.97 g) was estimated as 0.84 (0.68-1.15) mg/L. Behavioral changes were observed closely during the acute toxicity test. The bioassay experiments were repeated three times and static test method was used. Some fish exposed to 96 h 0.1, 0.5 mg/L fenitrothion concentrations showed histopathological alterations in the gills, liver, kidney, brain and testes. Severely deformations were observed at 0.5 mg/L fenitrothion on the gills lamella such as hyperemia, epithelial hyperplasia, fusion and telangiectasis, in the liver tissue such as cloudy swelling, hydropic degenerations and lipid infiltration. In addition hyperemia and hemorrhage observed in kidney tissue and hyperemia was determined in brain tissue.     

甘肃省农田害鼠主要种类及区域分布的研究

近10年来甘肃省在全省48个县、区对农田害鼠进行了较系统的调查研究,明确了本省农田的主要害鼠有27种,隶属2目6科14属。根据动物地理区划原则,可将本省农田害鼠分布划分为4个生态区域。①陇东旱塬区,农田害鼠有15种,优势鼠种为中华鼢鼠和大仓鼠;②陇南阴湿山区,有12种,优势鼠种为中华鼢鼠、黑线仓鼠和黑线姬鼠;③中部干旱区,有10种,优势鼠种为达乌尔黄鼠、中华鼢鼠和褐家鼠;④河西走廊区,有10种,优势鼠种为黑线仓鼠、长爪沙鼠和五趾跳鼠。     

Cloning of a sodium channel gene and identification of mutations putatively associated with fenpropathrin resistance in Tetranychus urticae

Tetranychus urticae Koch is the most serious mite pest to various orchard trees and garden plants. Biochemical and molecular analyses were conducted to elucidate resistance mechanisms in a fenpropathrin-resistant mite strain (FenR). No significant differences were found in the activities of carboxylesterase and glutathione-S-transferase between the susceptible (UD and PyriF) and FenR strains. Cytochrome P450 activity was highest in PyriF, followed by FenR and UD. Analysis of detoxification enzyme assays, therefore, suggested that metabolic detoxification plays little role, if any, in fenpropathrin resistance. However, the FenR strain showed approximately 104- and 33.3-fold slower knockdown responses than UD and PyriF strains, respectively, suggestive of sodium channel insensitivity as a major resistance mechanism. We cloned cDNA fragments of the para-homologous sodium channel α-subunit gene (Tuvssc) and determined its full-length nucleotide sequences. The complete open reading frame of Tuvssc was 6627 nucleotides, encoding 2209 amino acids. The amino acid sequences of Tuvssc were 47.5% and 51.2% identical to the fruit fly and varroa mite, respectively. Amino acid sequence comparison between the three strains revealed two mutations (L1022V and A1376D) and one deletion (HisDel^1278-1280) found only in FenR mites, among which the L1022V mutation was proposed to play a major role in knockdown resistance to fenpropathrin.     

乙烯利对小鼠的免疫毒性研究

为了探讨乙烯利对人体健康的影响,选用溶血空斑试验、血清溶血素检测试验、迟发型变态反应试验和碳粒廓清试验,分别从体液免疫、细胞免疫和非特异性免疫功能等不同角度研究了乙烯利对小鼠的免疫毒性。结果表明,乙烯利67~268 mg/kg bw各剂量组的小鼠足跖肿胀程度、溶血空斑对数值以及半数溶血值均显著低于对照组(PPP<0.05)。结果提示,乙烯利对小鼠的免疫功能具有一定的抑制作用。     

Effects of sodium on nitrate uptake and osmotic adjustment of Suaeda physophora

Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings were exposed to 1 mmol/L NaCl (control),300 mmol/L NaCl,150 mmol/L NaCl plus 150 mmol/L KCl or 300 mmol/L KCl treatments for 24 d. Dry weight was not affected greatly by different salt treatments,but water content and succulence in leaves of S. physophora were significantly increased at 300 mmol/L NaCl and 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The concentrations of Na+ and NO3’ in leaves of S. physophora were the highest at 150 mmol/L NaCl plus 150 mmol/L KCl,but lowest at 300 mmol/L KCl treatment. Moreover,the increase of NO3’ concentration did not result in the decrease of Cl-concentration at 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The estimated contribution of NO3’ to osmotic potential (CNO3) in leaves of S. physophora was 9.8% at 150 mmol/L NaCl plus 150 mmol/L KCl,and CNa and CCl were 31.0% and 23.3%,respectively. However,CNO3,CNa and CCl were respectively 1.6%,7.9% and 11.9% at 300 mmol/L KCl treatment. It is concluded that Na+ stimulates NO3’ absorption and the stimulation is independent on the internal or the external Cl-concentration in the euhalophyte S. physo-phora. These characteristics may explain the high levels of N in leaves of saline desert plants in arid ecosystem.     

Effects of vitamin E and selenium on tissue bio-element status in organophosphate toxicity of rats

The present study was designed to investigate the effects of vitamin E (vit E), selenium (Se) and vit E + Se against organophosphate (OP) toxicity in tissues’ trace and major element levels and erythrocyte antioxidant enzyme activities of rats. Trace and major element concentrations in the tissues were measured by inductively coupled plasma-optical emission spectroscopy. Erythrocyte antioxidant enzyme activities were studied by using spectrophotometer. Antioxidant enzyme activities such as superoxide dismutase, glutathione peroxidase and catalase increased in the fenthion-treated groups (control) more than that of sham group subjects. Heart and pectoral muscle tissue Se and Zn concentrations in the control group were higher than sham group. However, jejunum, kidney, liver and pancreas Se and Zn concentrations in the control group were found to be lower than those in the sham group. The Mn concentrations in the all of the tissues were lower in the control group when compared with the sham group. Brain, heart, jejunum, kidney and pancreas Fe concentrations and heart, jejunum, liver, pectoral muscle and pancreas Cu concentrations were found to be lower in the control group. The treatment of vit E, Se and vit E + Se were increased bio-element levels in the many tissue. In conclusion, the results of the present study demonstrate that the tissue trace and major element concentrations and enzymatic antioxidant system were significantly affected OP toxicity. Furthermore, we have shown an association between bio-elements and antioxidant enzymes in OP toxicity. In addition, administration of vit E, Se and vit E + Se might regulate some trace and major element levels in the many tissues.     

Effects of diazinon at different doses on rat liver and pancreas tissues

Diazinon is one of the most widely used organophosphates in agriculture. Toxic effects of diazinon are due to the inhibition of acetylcholinesterase, an enzyme needed for proper nervous system function. This study was designed to investigate the effects of diazinon at different doses on pancreas and liver tissues and in which dose level diazinon shows its effects. Sixty male Wistar albino rats were included in this study. Animals were initially divided into control and diazinon given groups. There were 10 animals in the control group and 50 animals in diazinon administered group. The latter was divided into five equal subgroups: 25, 50, 100, 200 and 300 mg/kg of diazinon administered groups. Control group was given only saline. All animals in 300 mg/kg diazinon group died. After 24 h, rats were sacrificed under ether anesthesia. Tissue and blood samples were taken for biochemical and histopathological analysis. Sample tissues were examined under light microscope. In biochemical analysis, AST, ALT, LDH, amylase and lipase enzyme activities were measured. One-way ANOVA test was used to compare the groups. In 200 mg/kg diazinon given group, it has been observed some histopathological changes in pancreas and liver tissues. Cholinesterase activities were significantly decreased and alkaline phosphatase levels were increased in all diazinon given groups, when compared with the controls. There was statistically significant difference between the control and diazinon given groups by means of serum amylase, lipase, ALT and AST activities (p < 0.05). LDH activities were significantly increased in 100 and 200 mg diazinon given groups, when compared with the controls (p < 0.05). Histopathological changes were observed only in 200 mg diazinon given group. This evidence suggest that diazinon effect is dose dependent and this is possibly 10-15% of the LD₅₀ dose (200 mg/kg), which cause acute pancreatitis and histopathological changes in liver.     

四硫代碳酸钠对蔬菜根病的防治效果及对土壤生物学性状的影响

为明确四硫代碳酸钠(sodium tetrathiocarbonate,STTC)在蔬菜根病防治上的应用价值及制定应用技术,本研究通过室内瓶土熏蒸法,进行了STTC对病菌的室内毒力测定;用温室盆栽法,进行植前熏蒸处理,测定土壤中病菌数量的变化和对病害的防效,同时进行植后熏蒸处理,测定药剂处理点和根际处病菌数量的变化;通过土壤施药后随即移栽幼苗的方法,评价药剂对蔬菜幼苗的安全性;通过室内模拟田间熏蒸条件,测定药剂不同浓度和熏蒸时间对土壤中主要微生物类群数量和主要土壤酶活性的影响。结果显示STTC对辣椒疫霉病菌Phytophthora capsici、黄瓜枯萎病菌Fusarium oxysporumf.sp.cucumerinum、茄子黄萎病菌Verticillium dahliae、番茄立枯病菌Rhizoctonia solani和蔬菜菌核病菌Sclerotinia sclerotiorum均有较好的杀灭活性,LD50分别为3.956、4.241、5.222、5.457和6.197mg/kg;80g/m2 STTC移植前处理对辣椒疫霉病和黄瓜枯萎病的防效可分别达到91.01%和82.51%;浓度低于900μg/mL的STTC对当日熏蒸后移栽的3叶期辣椒、黄瓜、番茄、白菜和油菜幼苗均表现安全;在辣椒和黄瓜生长期穴施1 200μg/mL STTC能有效减少土壤中辣椒疫霉病菌和黄瓜枯萎病菌的数量;土壤中微生物类群数量监测结果表明,在0.1~50.0μg/g浓度范围内,STTC对土壤真菌有强烈抑制作用,对土壤细菌和放线菌为先抑制后促进。对土壤酶活性测定结果表明,当STTC用量为0.1、1.0、5.0、10.0和50.0μg/g时,对土壤脲酶和蔗糖酶的活性表现为先抑制后促进,对蛋白酶的活性表现为在STTC低浓度时活性增加,高浓度时为先抑制后增加。综合结果表明,STTC用于经济作物生产中的土壤熏蒸具有安全、有效和施用简便的特点,或可广泛使用。     

成虫日龄与交配状态对棉褐环野螟繁殖力的影响

[目的]研究影响棉褐环野螟(棉大卷叶螟)[ Haritalodes derogata (Fabricius)]产卵量、孵化率及成虫寿命的因素,为性信息素的研究开发提供理论依据.[方法]在温度(25±2)℃,光周期L∥D=14 h//10 h的条件下,研究棉褐环野螟的繁殖适度.[结果]交配时间短于40min时成虫的产卵前期明显延长,而交配时间长于40 min时成虫产卵期延长,产卵量与孵化率显著提高.0次交配产卵量极小且不能正常孵化,交配1次或多次能使产卵量与卵孵化率明显提高.雌虫延迟交配对其产卵期、产卵量、孵化率和雌虫寿命会产生明显的影响,与正常交配之间存在显著差异,其中3日龄的雌性成虫与7日龄的雄性成虫交配后产卵期(4.2±0.76)d、寿命(15.40±0.62)d最长,产卵量(189±17.17)粒/头、孵化率(54.39±0.07)％最大.[结论]明确了雌虫交配持续时长、交配次数以及雌雄不同年龄组配对繁殖的影响.