Characterisation of energy-dependent efflux of imazalil and fenarimol in isolates of Penicillium italicum with a low,medium and high degree of resistance to DMI-fungicides

Differential accumulation of [¹⁴C]imazalil and [¹⁴C]fenarimol by germlings of wild-type and DMI-resistant isolates ofPenicillium italicum was studied at various pH values. At pH 7 and 8 the low-resistant isolate E_300–3 accumulated 22% and 35%, respectively, less imazalil than the wild-type isolate W₅. Imazalil accumulation at pH 5 and 6 was similar. Isolate E_300–3 also accumulated less fenarimol as compared with the wild-type isolate. This difference was much more obvious than for imazalil and was observed at all pH values tested. Differences in accumulation of both imazalil and fenarimol between low (E_300–3), medium (H₁₇) and high resistant (I₃₃) isolates were not observed. These results suggest that decreased accumulation of DMIs is responsible for a low level of resistance only and that additional mechanisms of resistance might operate in isolates with a medium and high degree of resistance. With all isolates fenarimol accumulation was energy-dependent. This was not obvious for imazalil.The wild-type and DMI-resistant isolates had a similar plasma membrane potential as determined with the probe [¹⁴C]tetraphenylphosphonium bromide ([¹⁴C]TPP⁺). Various test compounds, among which ATPase inhibitors, ionophoric antibiotics and calmodulin antagonists, affected the accumulation of [¹⁴C]TPP⁺, [¹⁴C]imazalil and [¹⁴C]fenarimol. No obvious correlation between the effects of the test compounds on accumulation levels of the fungicides and [¹⁴C]TPP⁺ could be observed. These results indicate that the plasma membrane potential does not mediate the efflux of DMI fungicides byP. italicum.     

内装纸箱集装箱中溴甲烷气体分布及残留检测研究

采用 4 0英尺集装箱熏蒸处理纸箱 ,实验对箱中溴甲烷气体分布及散气后溴甲烷残留进行了检测研究。结果表明 ,温度高低、集装箱中纸箱堆放和电扇鼓风等情况对溴甲烷分布与扩散影响明显。集装箱装满纸箱情况下 ,当温度≥ 2 1℃ ,投药 2h后上、下检测点平均溴甲烷浓度达到最低浓度要求 ;当温度 <2 1℃时 ,投药 2 4h后上检测点平均溴甲烷浓度仍达不到最低浓度要求。当集装箱中间留有通道或使用电扇鼓风情况下 ,投药 2h后各检测点溴甲烷浓度分布达到最低浓度要求。集装箱装满纸箱情况下 ,溴甲烷向大气扩散较慢 ,即使电扇鼓风散气2h ,2 4h后溴甲烷残留量仍达不到安全指标要求。集装箱中间留有通道情况下 ,箱中溴甲烷残留量下降很快 ,并可达到安全指标要求。     

应用真空熏蒸技术杀灭蔗扁蛾

利用真空熏蒸技术对受蔗扁蛾Opogona sacchari Bojer危害的发财树进行了真空熏蒸处理.结果表明,在真空条件下,仅需要较低的熏蒸剂量在较短的时间内即可全部杀死发财树里的蔗扁蛾,杀虫效果达100%,达到快速、高效、安全、环保的要求.为花卉害虫的处理提供了一种新的方法.     

Nitrate and bromide contents of glasshouse radish as affected by soil content and global radiation

Abstract

Samples (208) of radish (Raphanus sativus L.) foliage and root were collected from commercial glasshouses. Simultaneously corresponding soil samples were taken. Both plant and soil samples were analysed for nitrate and bromide.

The nitrate contents of foliage and root are affected by global radiation and by nitrate content of the soil. An interaction between the two factors was found; It indicated that soil nitrate content had a considerable effect in summer, but much less so in winter under poor light conditions, when the level of nitrate in the crop is high regardless of the nitrogen status of the soil. To study the effect of radiation on nitrate content of radish in summer it was found best to consider the cumulative amount of radiation during 10 days before harvest; in winter, a period of 20–30 days was more suitable.

The bromide content of foliage and root (highest values being resp. 390 and 73 mg Br per kg fresh product) was correlated with the concentration of bromide in the 1:2 volume soil extract. An increase of 1 mmol NO₃ per 1 soil extract lowered the Br content of fresh radish roots by 5.8 mg Br per kg.     

玫瑰对溴甲烷耐药性机理及其预防措施研究

本文研究了澳甲烷对玫瑰熏蒸药害的机理和预防措施，结果表明高剂量溴甲烷能破坏玫瑰的抗氧化系统，导致品质受损。玫瑰熏蒸前用甘油喷雾或内吸Vc或硫酸铝，可降低药害。     

Analysis of chromosome aberration due to ethidium bromide using AFM

AIM: To study chromosome aberration due to ethidium bromide (EB),a heterocyclic organic compound and an organic fluorescence dye commonly used in biochemical experiment,and to help further understanding the molecular mechanism of tumor or cancer induced by EB and other heterocyclic organic compounds.METHODS: The toxicity action of EB was evaluated from three aspects including DNA,chromosome and embryo stem cells (ESCs) using atomic force microscopy (AFM),and thereinto,the morphology structural difference of ESCs treated with two EB doses was also valuated.RESULTS: The morphological structures of DNA,chromosome and ESCs were dramatically damaged.The average height of DNA decreased 0.5 nm;chromosomal arms were ruptured from centromere location;molecules of cellular membrane congregated and loop-like structure formed,and ES cell masses were collapsed and became dead after large EB doses treatment and mesh-like morphological structure was discernable.CONCLUSION: The toxicity action of EB is strong and destroys the surface structure of DNA and chromosome.EB induces structural aberration of ES cellular membrane and cell death.The results indicate that the action of EB is externalized at gene level and cell level,which is important to study the carcinogenicity of EB.     

溴甲烷土壤消毒替代技术研究进展

概述了溴甲烷替代品的新进展。在土壤消毒方面,新的进展有化学替代品:氯化苦胶囊、氯化苦乳剂、氯化苦+噻唑磷混用、C₂N₂、氰铵化钙、异硫氰酸烯丙酯、异硫氰酸甲酯、1,3—二氯丙烯和氯化苦混剂、碘甲烷、环氧丙烷、叠氮化合物、硫酰氟等。在使用技术上,采用化学灌溉和注射施药技术进一步提高药剂分布的均匀性。在非化学替代技术上,生物熏蒸和有机质补充正受到重视。减少溴甲烷的技术正在快速地发展。     

苯扎溴铵对几种淡水水生动物的急性毒性

采用静水生物毒性试验方法测试了苯扎溴铵对大型溞（Daphnia magna）,团头鲂（Megalobrama amblycephala）幼鱼、草鱼（Ctenopharyngodon idellus）幼鱼、田螺（Cipangopaludina cathayensis）、中华绒螯蟹（Eriocheir sinensis）芋期仔蟹和幼蟹的半致死浓度（LC50）及安全浓度（SC）。结果显示：大型溞的24、48、72、96h的LC50分别为0.56、0.34、0.19、0.13mg/L,团头鲂幼鱼的为1.53、1.44、1.38、1.31 mg/L,草鱼幼鱼的为4.59、4.42、4.36、4.23 mg/L,田螺的为15.21、10.52、7.76、5.01 mg/L,芋期仔蟹的为10.33、6.73、5.41、5.02 mg/L,幼蟹的为17.95、2.42、8.67、6.22 mg/L;SC分别为0.04、0.38、1.23、1.51、0.86、1.78 mg/L。根据SC高低,耐苯扎溴铵毒性能力依次为幼蟹＞田螺＞草鱼幼鱼＞Ⅲ期仔蟹＞团头鲂幼鱼＞大型溞。苯扎溴铵在防治固着类纤毛虫病泼洒浓度为0.35mg/L下时,不会对团头鲂幼鱼、草鱼幼鱼、田螺、Ⅲ期仔蟹和幼蟹产生毒性作用,而对大型溞会产生毒性杀死作用,池塘中可通过适量增加投饵量或投放其他饵料以补充减少的大型溞饵料生物数量。     

干腌火腿加工过程中虫害防治研究进展

虫害问题一直以来都是影响干腌火腿品质的重要因素,火腿发酵阶段是虫害发生高峰期,其中腐食酪螨和酪蝇对其危害程度最为严重。为了为今后实际生产中干腌火腿的综合防治提供一些参考依据,通过分析、总结国内外干腌火腿虫害防治方法的相关研究进展,概述了化学防治法、物理防治法、生物防治法的杀虫效果及优缺点,以及各方法在实际生产应用中需要注意的问题。分析表明溴甲烷替代品熏蒸法、在火腿表面使用丙二醇涂膜剂以及植物源性杀虫剂是较为理想的防治方法,并对其进行了展望。