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1.
J. Guan J. C. Kapteyn A. Kerkenaar M. A. De Waard 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(5):313-324
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 E300–3 accumulated 22% and 35%, respectively, less imazalil than the wild-type isolate W5. Imazalil accumulation at pH 5 and 6 was similar. Isolate E300–3 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 (E300–3), 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. 相似文献
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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。 相似文献
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Changyao Shan Baishu Li Li Li Xin Du Yonglin Ren Simon J. McKirdy Tao Liu 《Pest management science》2023,79(12):4942-4951
5.
《Communications in Soil Science and Plant Analysis》2012,43(12):1307-1318
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. 相似文献
6.
《Communications in Soil Science and Plant Analysis》2012,43(7):645-651
Abstract Two cultivars of cotton (Gossypium spp) were grown in Yolo loam soil in a glasshouse to determine phytotoxicity effects of Cr and Li and possible interactions with other metals. The Cr at 100 μg/g soil had no adverse effects on either cultivar studied. A Cr increase was not observed in either stems or leaves. Both cultivars tolerated 25 and 50 μg Li/g soil. The 50 μg Li/g soil resulted in leaves of Acala SJ‐2 with 432 μg Li/g leaves and 720 in Giza 45. The 100 μg Li/g soil resulted in 74% and 87% leaf yield reductions in Acala SJ‐2 and Giza 45 respectively. Leaf concentrations of Li respectively were 1950 and 1850 μg/g. Except at the highest level of Li, leaves had higher concentrations of Li than did roots. The Cr and Li resulted in some plant metal interactions. 相似文献
7.
《Communications in Soil Science and Plant Analysis》2012,43(4):299-310
Abstract Extractable li with ammonium acetate was determined by flamephotometry, in normal soils, alkaline soils and saline soils in the Province of La Pampa (Argentina). The soils were originated from differents parent material, with various rainfalls (arid to subhumid climate) and management. The higher contents were found in saline soils. In the other soils the extractable lithium content depends on the parent material, but not on rainfall. Different patterns of vertical and horizontal distribution of extractable lithium were found. The origin of extractable lithium is here discussed. 相似文献
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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. 相似文献
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