25%毒·唑磷乳油防治稻纵卷叶螟药效试验

为探索常规杀虫剂防治稻纵卷叶螟效果下降的替代农药,采用25%毒.唑磷乳油进行了田间药效试验。结果表明,25%毒.唑磷乳油防治稻纵卷叶螟虽然速效性不够理想,但具有持效期长、对2~3龄幼虫防治效果较好的特点,在稻纵卷叶螟偏重发生时,可达到理想的防治效果。未发现25%毒.唑磷乳油对水稻产生毒副作用,因此,是防治稻纵卷叶螟较理想的药剂。     

Effect of spray volume of two organophosphate pesticides on coverage and on mortality of California red scale Aonidiella aurantii (Maskell)

A trial under laboratory conditions was carried out to study the possibility of decreasing the delivered dose of organophosphate insecticides without affecting their efficacy against California red scale (CRS), Aonidiella aurantii (Maskell), by reducing the volume of water used whilst maintaining the concentration of pesticide. In order to establish an optimal application volume, the coverage and the efficacy against different stages of development of CRS of two commercial organophosphate pesticides (chlorpyrifos 750 g kg⁻¹ WG [Dursban^® 75 WG] and chlorpyrifos-methyl 224 g l⁻¹ EC [Reldan^® E]) at four volumes of water (1, 2, 3 and 4 ml) were compared. Results showed that in general Chlorpyrifos-methyl-based product (CMBP) provided greater coverage and impact size, but did not achieve the highest efficacy. The minimum-deposited volume (1.01 μl/cm²) produced 11% coverage with Chlorpyrifos-based product (CBP) and 22% with CMBP, reaching the highest efficacies (around 89-95%) against the youngest stages (N1 and N2 stages) with both products. To attain similar efficacy with males (prepupal and pupa stages), twice the volume (2.03 μl/cm²) of the CBP was required, producing 28% coverage. The CMBP required higher deposited volumes (3.41 μl/cm²) and higher coverage (51%). The maximum efficacy in the control of adult females (third instar and gravid female stages) was 70% with both pesticides. This level was attained with 3.41 μl/cm² of CBP (36% coverage) and 4.72 μl/cm² of CMBP (62% coverage). The research shows that greater coverage does not result in greater efficacy, so it would be possible to reduce the spray volume in field conditions. Further research will be carried out in order to check these results under real field conditions.     

重离子诱变鞘氨醇单胞菌选育毒死蜱高效降解菌株及应用

从青藏高原牦牛粪中分离出1株可降解毒死蜱的细菌,经形态和16SrDNA序列分析,鉴定其为鞘氨醇单胞菌属(Sphingomonas sp.)细菌。对其进行重离子诱变并筛选出菌株Sph-25-T1,该菌株对100mg.L-1毒死蜱的72h降解率达98.44%,比出发菌株提高27.37%。对Sph-25-T1进行传代培养,第5代时其对毒死蜱的降解率依然保持在90%以上。以喷洒毒死蜱1周后的不同土壤浸出液或蔬菜叶片做培养基时,Sph-25-T1对毒死蜱的降解率达到29.68%～78.40%。     

蔬菜中毒死蜱·三唑磷残留检测质量控制图的绘制及应用

为准确、可靠地检测蔬菜中毒死蜱、三唑磷残留,采用NY/T 761—2008《蔬菜和水果中有机磷、有机氯、拟除虫菊酯和氨基甲酸酯类农药多残留检测方法》,每7 d对同一质量浓度质控样品平行测定2~3次,统计20组有效数据,通过计算平均值、标准偏差得出上下控制限、警告限和辅助线,绘制出由实验室人员检测技术水平、试剂、设备、分析方法和环境因素条件下的质量控制图。该质量控制图不仅可用于实际检测过程中对检测结果进行监控,还可为实验室人员技术能力确认、实验室间比对和能力验证等分析质量控制行为提供判定依据。     

储藏和加工方式对稻谷中毒死蜱和三唑磷残留量的影响

[目的]了解稻谷加工方式和储藏方式对稻米中毒死蜱和三唑磷残留动态的影响机制。[方法]采用液相色谱-三重四极杆质谱法同时检测稻米中的毒死蜱及其代谢物3,5,6-三氯-2-吡啶酚(3,5,6-Trichloro-2-pyridinol,TCP)和三唑磷残留,分析碾磨、蒸煮、发芽加工以及储藏温度(37和4℃)对毒死蜱和三唑磷残留量的影响。[结果]毒死蜱及其代谢物TCP、三唑磷等农药残留多数分布在米糠层;短时间的蒸煮无法明显降低稻谷中毒死蜱的残留量;发芽稻谷中毒死蜱及其代谢物TCP、三唑磷的残留量显著低于未发芽稻谷;在37℃储藏条件下,毒死蜱的降解方程为C=0.899e~(-0.005t)(R~2=0.855 6),半衰期为138.6 d;三唑磷降解方程C=0.768e-0.009t(R~2=0.822 8),半衰期77.0 d,近似满足一级动力学模型方程;在4℃低温储藏条件下,稻谷中毒死蜱和三唑磷的残留量变化不大。[结论]碾磨和发芽加工有利于降低稻谷的农药残留量,低温储藏稻谷不利于残留农药的降解。研究可为稻米加工过程的风险评估以及开发稻米中农药残留的消解技术提供参考。     

两株蜡状芽孢杆菌对毒死蜱的降解动力学研究

利用微生物消除农药污染是一项安全、经济、有效的方法,降解动力学模型的构建有助于理解污染物的生物降解行为和估测系统中特征污染物的浓度变化,菌株对高浓度污染物的降解效果是降解菌在受污染水体中实际应用的关键。本研究采用基础培养基中定量添加毒死蜱和定时取样分析毒死蜱残留浓度的方法,探讨两株蜡状芽孢杆菌(HY-1和HY-2)的接种体培养时间、接种量和降解菌对毒死蜱的降解动力学,同时研究了降解菌对高浓度毒死蜱的降解率。结果表明:HY-1和HY-2最适接种体培养时间分别为10 h和19 h,接种体培养时间对菌株降解毒死蜱的影响较大。两菌株最适接菌量为8%(v/v),接种量从4%增至8%时,接种量对HY-1降解毒死蜱的影响大于HY-2。当毒死蜱的初始浓度为40 mg.L 1、80 mg.L 1、100 mg.L 1和120 mg.L 1时,一级动力学方程ln(C0/Ct)=kt可以用来拟合两菌株对毒死蜱的降解动力学及确定降解动力学参数,当毒死蜱初始浓度再次增加时,仅HY-2对毒死蜱的降解符合一级动力学方程。当毒死蜱初始浓度为40~120 mg.L 1时,菌株HY-1对毒死蜱的降解速率常数分布在0.013 5~0.015 7;当毒死蜱初始浓度为40~200 mg.L 1时,菌株HY-2的降解速率常数分布在0.008 0~0.015 3。菌株HY-2比HY-1可以在较高的毒死蜱浓度下发挥降解作用,且降解率较高。因此,两菌株在毒死蜱污染水体的净化去毒方面具有重要意义。     

毒死蜱不同施药方式对黄曲条跳甲的敏感性检测

本实验以黄曲条跳甲为试虫,以毒死蜱和啶虫脒为实验药剂,分别采用浸叶法和浸虫法测定了毒死蜱和啶虫脒单剂及相关混配对黄曲条跳甲的毒力。试验结果显示,毒死蜱和啶虫脒对黄曲条跳甲的浸叶LC50值分别为53．81、268．03mg／L。啶虫脒和毒死蜱按浓度比1：4混配、1：8混配浸叶LC50值分别为58．14、41．71mg／L,浸虫法结果显示啶虫脒和毒死蜱按浓度比1：4混配、1：8混配稀释4000倍液校正死亡率分别为23．3％、26．7％。     

气相色谱法测定毒死蜱在花生及土壤中的残留量

在山东济南和浙江杭州、河南焦作三地进行了毒死蜱在花生上最终残留试验,采用气相色谱法测定毒死蜱在花生及土壤中的残留量。结果表明,施药后到采收期时花生中的毒死蜱残留量均低于0.2 mg/kg。30%毒死蜱微囊悬浮剂用于防治花生蛴螬,施药剂量不超过2 250 g a.i./hm2(推荐高剂量)、施药1次是安全的。     

Genistein and daidzein reduced chlorpyrifos induced damage in PC12 cell

The present study preliminarily evaluated neurotoxicity injuries induced by chlorpyrifos in PC12 ​cell, which were used as a model for nervous cell system. In cultured PC12 ​cell, application of soy isoflavones (genistein, daidzein, monomer and mixture) significantly reduced chlorpyrifos induced toxicity, a widely used pesticide, and resulted in a better cell survival rate. Treatments with isoflavones reduced malondialdehyde content, reactive oxygengeneration and acetylcholine level in medium, and maintained mitochondrial membrane potential integrity. Daidzein enhanced endogenous antioxidant system in PC12 ​cell with an increasing in superoxide dismutase per-unit activity. Genistein reduced acetylcholine content in the medium. Daidzein and genistein showed different effects, and their combined effect were greater than individual. In conclusion, soy isoflavones as an antioxidant and neuroprotectant, enhanced choline metabolism, which effectively mitigated disadvantageous influence of PC12 ​cell caused by chlorpyrifos.     

快速检测法在蔬菜毒死蜱农药残留去除研究中的应用--以生菜不同清洗方式为例

为研究日常生活中盐水、果蔬洗涤剂水、碳酸氢钠水溶液和淘米水清洗对蔬菜农药残留去除的作用效果,模拟生菜毒死蜱农药残留超标(抑制率为90%左右),采用农残快速检测试剂盒配合农残快速检测仪检测不同方式清洗后毒死蜱的残留量,在单因素研究的基础上L_9(3~4)正交优化。结果表明,盐水清洗方式的优化结果为盐水浓度3‰、30℃水温浸泡15 min,毒死蜱去除率达78.0%±1.87%;洗涤剂水清洗方式的优化结果为某超能洗涤剂水浓度5%、35℃水温浸泡20 min,毒死蜱去除率达65.38%±2.12%;碳酸氢钠水溶液清洗方式的优化结果为碳酸氢钠水溶液浓度7 g/100 mL、40℃水温浸泡15 min,毒死蜱去除率达73.79%±2.63%;淘米水清洗方式的优化结果为淘米水浓度80%、浸泡10 min、浸泡1次,毒死蜱去除率72.35%±2.66%。4种清洗方式都能将抑制率90%左右的毒死蜱超标生菜通过清洗达到合格,建议采用盐水和淘米水清洗方式。