Baseline Sensitivity of Botrytis cinerea from Liaoning Province to Boscalid

[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value （1.973μg/ml） of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid.

IMPROVED CALIBRATION METHOD FOR AIRBORNE ATI-SAR BASELINE

Airborne Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) baseline error is a main error resource affecting the precision of velocity measurement of moving objects and therefore should be calibrated externally. The Jet Propulsion Laboratory (JPL) has proposed a calibration scheme for tasks of PacRim98 and PacRim2000 based on several static objects on the ground. In this paper, the influence of phase center uncertainty on baseline determination by using PacRim method proposed by JPL is analyzed. According to the analysis, the phase center uncertainty can cause a constant part of error to the result of baseline calibration. In order to deal with this problem, an improved calibration method on the basis of sensitivity equations and some ground moving targets, whose velocities are already known, is proposed in this paper. The simulation results show that our proposed calibration method has improved the accuracy of baseline calibration and has obviously prohibited the effect of antennas' phase center uncertainty.

A SUPER SENSITIVITY MINICYCLOTRON MASS SPECTROMETER SPECIALIZED FOR CARBON-14 DATING

The structure consideration of a minicyclotron as super- sensitivity mass spectrometer for carbon -14 dating being constructed at this Institute is described. Some new design ideas and techniques are presented.

Relation between Baseline Lipid Levels and Effectiveness of HMG-CoA Reductase Inhibitors in Patients with Hyperlipidemia

Objective To evaluate whether the effects of HMG - CoA reductase inhibitors on patients with hyperlipidemia are closely related to baseline lipid levels. Methods The data analyzed originated from 3 separate multicenter clinical trials with similar designs during 1994 to 1999. 166 patients with mean age 58. 9±9. 2 years were involved in Simvastatin Clinical Trial with simvastatin 10 mg once daily for 8 weeks. 146 patients with mean age 57. 9±8. 7years were involved in Lovastatin Clinical Trial with lovastatin 20 mg once daily for 8 weeks. 105 patients with mean age 57. 8±9. 3 years were involved in Atorvastatin Clinical Trial with atorvastatin 10 mg once daily for 6 weeks. Baseline total cholesterol (TC) was more than 5. 98 mmol. L - 1, and baseline triglyceride (TG) was less than 4. 52 mmo. L - 1. The patients were grouped by baseline lipid levels. Results The higher the baseline TC, low density lipoprotein cholesterol (LDL - C) and TG levels were, the more effective the simvastatin, lovastatin, or atorvastatin was in reducing serum TC, LDL - C, and TG, respectively. A positive linear correlation was found between baseline values and effects of simvastatin, lovastatin, or atorvastatin in reducing serum TC, LDL - C, and TG, respectively. Conclusion The changes of reduction on serum lipid with HMG - CoA reductase inhibitors in patients with hyperlipidemia were influenced by baseline lipid levels.

The Changes of Baroreflex Sensitivity During Head-up Tilt Test and Its Clinical Significance in the Patients with Vasovagal Syncope

Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.

Pore-scale study of the pressure-sensitive effect of sandstone and its influence on multiphase flows

The pressure-sensitive effect on the pore structure of sandstone was investigated using X-ray computed micro-tomography and QEMSCAN quantitative mineral analysis. In a physical simulation study, we extracted the pore network model from digital cores at different confining pressures and evaluated the effect of pressure sensitivity on the multiphase displacement process. In both the pore network model and QEMSCAN scanning, the pore structure was observed to be damaged under a high confining pressure. Due to their different scales, the pores and throats exhibited inhomogeneous changes; further, the throats exhibited a significant variation compared to that exhibited by the pores. Meanwhile, the heterogeneity of the pore structure under the two aforementioned activities was aggravated by the elastic-plastic deformation of the pore structure.The pressure-sensitive effect increased the proportion of mineral particles, such as quartz(the main component of the core skeleton), and reduced the proportion of clay minerals. The clay minerals were originally attached to the pore walls or interspersed in the pores; however, as the pressure increased, the clay minerals accumulated in the pores resulting in blockage of the pores. While simulating the multiphase displacement process, increasing the confining pressure was observed to severely restrict the flowability of oil and water. This study promises to improve the efficiency of reservoir development in terms of oil and gas exploitation.

Optimization Design for Fixed Table of Gantry Machining Center Based on Sensitivity and Topology Analyses

In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.

A SENSITIZED PHOTOINITIATION SYSTEM ——BIS (7-DIETHYLAMINO COUMARIN ) KETONE-3 AND DIPHENYLIODONIUM SALT COMBINATION

Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.

多主棒孢菌对乙霉威和腐霉利敏感基线的建立及抗药性监测

为明确我国山东和辽宁地区多主棒孢菌对乙霉威和腐霉利的抗药性现状,采用菌丝生长速率法,测定了多主棒孢菌对乙霉威和腐霉利的敏感性,建立了敏感基线;采用区分剂量法,测定了多主棒孢菌对乙霉威和腐霉利的抗药性。结果表明,乙霉威和腐霉利对多主棒孢敏感菌株的平均EC50值分别为(0.22±0.06)μg·mL^(-1)和(2.75±0.91)μg·mL^(-1),两者的敏感性频率均呈连续性单峰曲线,总体呈正态分布,可作为多主棒孢菌对乙霉威和腐霉利的敏感基线。对采集自山东和辽宁地区的828株多主棒孢菌进行抗性水平监测,发现多主棒孢菌对乙霉威和腐霉利的抗性水平不断升高,山东地区多主棒孢菌对乙霉威和腐霉利抗性频率从2017年的58.06%和43.55%上升到2021年的91.30%和78.99%,辽宁地区多主棒孢菌对乙霉威和腐霉利抗性频率从2017年的67.44%和53.49%上升到2021年的82.14%和83.33%。表明多主棒孢菌对乙霉威和腐霉利具有高度的抗性风险,建议在黄瓜生产中乙霉威和腐霉利与其他类型杀菌剂交替或者混合应用,延缓抗药性的发展。

氟唑菌酰羟胺对烟草赤星病的防效及对烟叶和土壤的安全性

为明确烟草赤星病菌对新型杀菌剂氟唑菌酰羟胺的敏感性水平以及该药在烟叶和土壤中的安全性,采用菌丝生长速率法和孢子萌发法测定了烟草赤星病菌对氟唑菌酰羟胺的敏感性,并在云南、四川、贵州、福建、重庆等省市开展了田间防效试验,分析了其在烟叶上的残留降解,同时采用高通量测序分析了其对土壤细菌和真菌群落结构和共发生网络的影响。结果表明,烟草赤星病菌在不同发育阶段对氟唑菌酰羟胺敏感性差异较大,其中菌丝生长阶段最为敏感,对169株病株的EC50值为0.0064~0.1832 mg/L。氟唑菌酰羟胺2次施药对烟草赤星病的田间防效达到69.42%~88.09%,并增加了烟叶产量。另外,氟唑菌酰羟胺在鲜烟叶和干烟叶的降解半衰期范围为3.2~8.8 d。氟唑菌酰羟胺使用后土壤中链霉菌属、假单胞菌属、木霉菌属、拟青霉属等有益菌显著富集,且细菌和真菌共发生网络的复杂度增加。因此,氟唑菌酰羟胺可用于烟草赤星病的防治。

小麦白粉病菌对氟唑菌酰羟胺的敏感基线建立

氟唑菌酰羟胺是一种新型琥珀酸脱氢酶抑制剂(succinate dehydrogenase inhibitor,SDHI)类杀菌剂,2019年在我国登记在小麦上防治赤霉病,为明确其对小麦白粉病的潜在防治效果,以及为监测小麦白粉病菌群体对其是否产生抗药性,本文采用离体叶段法测定了2000年前和2019年采自我国河南、山东等9省市的110株小麦白粉病菌菌株对氟唑菌酰羟胺的敏感性。结果表明,采自2019年的88株菌株,其EC_(50)范围为0.0102~0.7668μg/mL,平均EC_(50)为(0.2243±0.1796)μg/mL;采自2000年前的22株菌株,其EC_(50)范围为0.0521~0.8824μg/mL,平均EC_(50)为(0.3563±0.2796)μg/mL;两组菌株群体间的敏感性无显著差异。氟唑菌酰羟胺对110株菌株的EC_(50)范围为0.0102~0.8824μg/mL,平均EC_(50)为(0.2507±0.2103)μg/mL,敏感性频率分布呈单峰曲线,可作为小麦白粉病菌对氟唑菌酰羟胺的敏感基线。本研究结果可为氟唑菌酰羟胺防治小麦白粉病以及未来监测该病原菌对药剂的抗性提供参考依据。

引起山西省玉米纹枯病的主要丝核菌融合群对3种杀菌剂的敏感性

为明确引起山西省玉米纹枯病的主要丝核菌融合群对氟酰胺、噻呋酰胺和戊菌隆3种杀菌剂的敏感性,采用菌丝生长速率法测定了氟酰胺、噻呋酰胺和戊菌隆对268株丝核菌菌丝生长的EC_(50)值,建立敏感基线并分析了噻呋酰胺和其他杀菌剂对病菌活性的相关性。结果表明:立枯丝核菌Rizoctonia solani融合群AG-5和玉蜀黍丝核菌R.zeae融合群WAG-Z对噻呋酰胺最为敏感,对氟酰胺敏感性次之,对戊菌隆敏感性最差;立枯丝核菌融合亚群AG-1-IA则对戊菌隆最为敏感,对噻呋酰胺次之,对氟酰胺最差。通过箱形图分析剔除异常的EC50值后,融合群AG-5和WAG-Z对氟酰胺、噻呋酰胺和戊菌隆的敏感性频率均呈连续的单峰曲线分布,符合正态分布。因此,将EC50均值0.165、0.048和2.500μg/mL分别作为融合群AG-5对氟酰胺、噻呋酰胺和戊菌隆的敏感基线;将0.518、0.106和1.616μg/mL分别作为融合群WAG-Z对氟酰胺、噻呋酰胺和戊菌隆的敏感基线。噻呋酰胺与氟酰胺、戊菌隆、己唑醇或咯菌腈对融合群AG-5和WAG-Z的抑制活性不存在相关性。研究结果可为山西省玉米纹枯病杀菌剂施用策略的制定、病原菌抗性的监测及风险评估提供一定的参考依据。

梨火疫病菌对四霉素敏感基线的建立及抗药性评价

【目的】建立新疆库尔勒地区和阿克苏地区梨火疫病菌(Erwinia amylovora)对四霉素的敏感基线,监测梨火疫病菌对四霉素的抗药性水平,为四霉素防治梨火疫病田间用药、抗药性监测与抗药性治理提供理论依据。【方法】采用抑菌圈法测定100株梨火疫病菌株对四霉素的敏感性;采用平板划线法和含药培养基法药剂驯化抗药突变体,进行抗药性评价。【结果】共监测到敏感菌株74个,低抗菌株26个。100株菌株对四霉素的敏感性频率接近正态分布,因此可将该曲线(平均EC50=1.59±1.029μg·mL^(-1))作为新疆库尔勒地区和阿克苏地区梨火疫病菌对四霉素的敏感基线;共获得4株抗药突变体,均不具有稳定遗传性;四霉素与84%噻霉酮、中生菌素均会产生交互抗药性。【结论】建立了新疆梨火疫病菌分离菌株对四霉素药剂的敏感基线,仅监测到少数低抗菌株,梨火疫病菌对四霉素的抗性风险低。

Comparative study of CEA and CA19-9 in esophageal,gastric and colon cancers individually and in combination(ROC curve analysis)

Objective： To determine the clinical serum levels of carcinoembryonic antigen （CEA） and carbohydrate antigen 19-9 （CA19-9）, individually and in combination, for the diagnosis of 50 healthy subjects and 150 cases of esophageal, gastric, and colon cancers. Methods： The sensitivities of the two markers were compared individually and in combination, with specificity set at 100%. Receiver operating characteristic （ROC） curves were plotted. Results： Serum CEA levels were significantly higher in cancer patients than in the control group. The sensitivity of CEA was determined： in esophageal cancer, sensitivity=28%, negative predictive value （NPV）=61.72%, and AUC=0.742 （SE=0.05）, with a significance level of P〈0.0001; in gastric cancer, sensitivity=30%, NPV=58.82%, and AUC=0.734 （SE=0.0S）, with a significance level of P〈0.0001; in colon cancer, sensitivity=74%, NPV=79.36%, and AUC=0.856 （SE=0.04）, with a significance level of P〈0.0001. The sensitivity of CA19-9 was also evaluated： in esophageal cancer, sensitivity=18%, NPV=54.94%, and AUC=0.573 （SE=0.05）, with a significance level of P=0.2054. In gastric cancer, sensitivity=42%, NPV=63.29%, and AUC=0.679 （SE=0.05）, with a significance level of P〈0.0011. In colon cancer, sensitivity=26%, NPV=57.47%, and AUC=0.S80 （SE=0.05）, with a significance level ofP=0.1670. The following were the sensitivities of CEA/CA19-9 combined： in esophageal cancer, sensitivity=42%, NPV=63.29%, SE=0.078 （95% CI： 0.0159-0.322）; gastric cancer, sensitivity=S8%, NPV=70.42%, SE=0.072 （9$% CI： -0.0866-0.198）; and colon cancer, sensitivity=72%, NPV=78.12%, SE=0.070 （9S% CI： 0.137-0.415）. Conclusion： CEA exhibited the highest sensitivity for colon cancer, and CA19-9 exhibited the highest sensitivity for gastric cancer. Combined analysis indicated an increase in diagnostic sensitivity in esophageal and gastric cancer compared with that in colon cancer.

A system-wide approach to minimize the operational cost of bench production in open-cast mining operations

The production cycle of open-cast coal mines generally in eludes drilling, blasting, loading, hauling and coal preparation activities. Individual optimization of these activities does not mean that the whole system is optimized. This paper proposes a cost model considering all activities in mining cycle and system-wide approach to minimize the total mining cost of bench production. Since the fragmentation size and blast-hole diameter are linked to all activities of mining system, they are considered as decision variables in the problem form ul at io n. The operatio n costs are then minimized by using the evolutionary algorithm. Moreover, the impact of the change in the explosive price, and the hourly unit cost of equipment on total mining cost is quantified by sensitivity analysis. A case study is implemented to demonstrate the developed model.

CO_2-triggered gelation for mobility control and channeling blocking during CO_2 flooding processes

CO2 flooding is regarded as an important method for enhanced oil recovery （EOR） and greenhouse gas control. However, the heterogeneity prevalently dis- tributed in reservoirs inhibits the performance of this technology. The sweep efficiency can be significantly reduced especially in the presence of ＂thief zones＂. Hence, gas channeling blocking and mobility control are important technical issues for the success of CO2 injection. Normally, crosslinked gels have the potential to block gas channels, but the gelation time control poses challenges to this method. In this study, a new method for selectively blocking CO2 channeling is proposed, which is based on a type of CO2-sensitive gel system （modified polyacry- lamide-methenamine-resorcinol gel system） to form gel in situ. A CO2-sensitive gel system is when gelation or solidification will be triggered by CO2 in the reservoir to block gas channels. The CO2-sensitivity of the gel system was demonstrated in parallel bottle tests of gel in N2 and CO2 atmospheres. Sand pack flow experiments were con- ducted to investigate the shutoff capacity of the gel system under different conditions. The injectivity of the gel system was studied via viscosity measurements. The results indi- cate that this gel system was sensitive to CO2 and had good performance of channeling blocking in porous media. Advantageous viscosity-temperature characteristics were achieved in this work. The effectiveness for EOR in heterogeneous formations based on this gel system was demonstrated using displacement tests conducted in double sand packs. The experimental results can provide guideli- nes for the deployment of theCO2-sensitive gel system for field applications.

Factors associated with early virological response to peginterferon-α-2a/ribavirin in chronic hepatitis C

AIM: To evaluate the impact of sociodemographic/clinical factors on early virological response (EVR) to pegin-terferon/ribavirin for chronic hepatitis C (CHC) in clinical practice. METHODS: We conducted a multicenter, cross-sectional, observational study in Hepatology Units of 91 Spanish hospitals. CHC patients treated with peginterferon α-2a plus ribavirin were included. EVR was defined as undetectable hepatitis C virus (HCV)-ribonucleic acid (RNA) or ≥ 2 log HCV-RNA decrease after 12 wk of treatment. A bivariate analysis of sociodemographic and clinical variables associated with EVR was carried out. Independent factors associated with an EVR were analyzed using a multiple regression analysis that included the following baseline demographic and clinical variables: age (≤ 40 years vs > 40 years), gender, race, educational level, marital status and family status, weight, alcohol and tobacco consumption, source of HCV infection, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and gamma glutamyl transpeptidase (GGT) (≤ 85 IU/mL vs > 85 IU/mL), serum ferritin, serum HCV-RNA concentration (< 400 000 vs ≥ 400 000), genotype (1/4 vs 3/4), cirrhotic status and ribavirin dose (800/1000/1200 mg/d).RESULTS: A total of 1014 patients were included in the study. Mean age of the patients was 44.3 ± 9.8 years, 70% were male, and 97% were Caucasian. The main sources of HCV infection were intravenous drug abuse (25%) and blood transfusion (23%). Seventyeight percent were infected with HCV genotype 1/4 (68% had genotype 1) and 22% with genotypes 2/3. The HCV-RNA level was > 400 000 IU/mL in 74% of patients. The mean ALT and AST levels were 88.4 ± 69.7 IU/mL and 73.9 ± 64.4 IU/mL, respectively, and mean GGT level was 82 ± 91.6 IU/mL. The mean ferritin level was 266 ± 284.8 μg/L. Only 6.2% of patients presented with cirrhosis. All patients received 180 mg of peginterferon α-2a. The most frequently used ribavirin doses were 1000 mg/d (41%) and 1200 mg/d (41%). The planned treatment duration was 48 wk for 92% of patients with genotype 2/3 and 24 wk for 97% of those with genotype 1/4 (P < 0.001). Seven percent of patients experienced at least one reduction in ribavirin or peginterferon α-2a dose, respectively. Only 2% of patients required a dose reduction of both drugs. Treatment was continued until week 12 in 99% of patients. Treatment compliance was ≥ 80% in 98% of patients. EVR was achieved in 87% of cases (96% vs 83% of patients with genotype 2/3 and 1/4, respectively; P < 0.001). The bivariate analysis showed that patients who failed to achieve EVR were older (P < 0.005), had higher ALT (P < 0.05), AST (P < 0.05), GGT (P < 0.001) and ferritin levels (P < 0.001), a diagnosis of cirrhosis (P < 0.001), and a higher baseline viral load (P < 0.05) than patients reaching an EVR. Age < 40 years [odds ratios (OR): 0.543, 95%CI: 0.373-0.790, P < 0.01], GGT < 85 IU/mL (OR: 3.301, 95%CI: 0.192-0.471, P < 0.001), low ferritin levels (OR: 0.999, 95%CI: 0.998-0.999, P < 0.01) and genotype other than 1/4 (OR: 4.716, 95%CI: 2.010-11.063, P < 0.001) were identified as independent predictors for EVR in the multivariate analysis. CONCLUSION: CHC patients treated with peginterferon-α-2a/ribavirin in clinical practice show high EVR. Older age, genotype 1/4, and high GGT were associated with lack of EVR.

抵制敏感属性相似性攻击的(p,k,d)-匿名模型

针对当前p-Sensitive k-匿名模型未考虑敏感属性语义相似性,不能抵制相似性攻击的问题,提出一种可抵制相似性攻击的(p,k,d)-匿名模型。根据语义层次树对敏感属性值进行语义分析,计算敏感属性值之间的语义相异值,使每个等价类在满足k匿名的基础上至少存在p个满足d-相异的敏感属性值来阻止相似性攻击。同时考虑到数据的可用性,模型采用基于距离的度量方法划分等价类以减少信息损失。实验结果表明,提出的(p,k,d)-匿名模型相对于p-Sensitive k-匿名模型不仅可以降低敏感属性泄露的概率,更能有效地保护个体隐私,还可以提高数据可用性。

Enhanced piezoresistivity in Ni-silicone rubber composites

This paper reports that the nickel-silicone rubber composites with enhanced piezoresistivity were synthesized with much reduced nickel concentration. A large piezosensitivity of 0.716/kPa and a gauge factor of 600 have been obtained for a composite sample with filler-polymer ratio of 2.7：1 by weight. Measurements of resistance as a function of uniaxial force reveal that the piezoresistance arises predominantly from the internal heterogeneity of the material and the effect of geometrical changes of samples under pressure is negleetably small. The nonlinear current-voltage characteristic of the composite depends strongly on the filler content, the initial compression and the electrical current flowing in the sample. Ohmic behaviour has been observed only in the highly compressed samples. The breakdown strength decreases with increasing filler content of the composite. Both I - V and R - f characteristics indicates that the resistivity of the composites decreases with electrical field, suggesting that the composite may also be used to make voltage sensitive resistors for protecting circuits. All the experimental results favour a quantum tunnelling mechanism of conductivity. It finds that the concept ＇negative resistance＇, often used to describe the phenomena that current decreases with increasing voltage, is not appropriate and should be avoided.

瓜实蝇成虫对不同杀虫剂相对敏感基线的建立

为了监测瓜实蝇田间抗药性和筛选用于防治该害虫的化学药剂,采用点滴法和饲毒法,研究测定了17类30种杀虫剂对瓜实蝇成虫的毒力并建立了相对敏感基线,同时采用建立的相对敏感基线比较分析了点滴法和饲毒法对抗阿维菌素品系抗性水平测定结果的差异。结果表明,采用点滴法测得9类18种药剂LD50值在3.422~576.842 ng·头^(-1);采用饲毒法测得10类21种药剂LC50值在0.035~60.542 mg·L^(^(-1))。2种方法测得的不同药剂对瓜实蝇毒力高低排序较一致,3种微生物源农药甲维盐、多杀霉素、阿维菌素和有机磷类乐果对瓜实蝇均表现出较高的毒力,菊酯类、有机磷类和烟碱类等药剂次之,鱼藤酮毒力最低。点滴法和饲毒法测得的瓜实蝇抗阿维菌素品系的抗性倍数分别为18.22倍和17.37倍,较为接近。综上所述,采用点滴法和饲毒法分别建立了瓜实蝇成虫对18种和21种杀虫剂的相对敏感基线,为瓜实蝇的抗药性监测和化学防治提供了科学依据。