Effects Of High Voltage Electrostatic Fields On Population And Physiological And Biochemical Characteristics Of The Sitobion Avenae

With the development of industrialization,a large scale of using electrical facilitates has been significantly increasing the electromagnetic pollution,and result in destroying the ecological balance of the electromagnetic environment,in which posed a tremendous selection pressure to organisms.To date,most of the studies were focused the effects of High Voltage Electrostatic Fields on the field of medical and botany science,few studies reported the impact of HVEF on herbivore insects.Cereal aphids are regarded as major pests of wheat crops,and usually cause huge economic losses in wheat production.They can also transmit the plant virus.The Sitobion avenae(F.)(Hemiptera: Aphididae)has the typical feature of R-strategist,which can be served as a typical experimental material to study the effect of environmental stress on the evolution of biological genetics.In the previous studies,only the one-way effects of HVEF on S.avenae,including the development,reproduction,physiology,biochemistry and genetic differentiation were studied.However,research has not been focused on the compound effects of treat intensity and time of HVEF on this aphid.In the present study,the life-table was employed to determine the compound effects of intensity and time of HVEF on performance of S.avenae.The amount of CO2 released per unit and enzyme activity of S.avenae under HVEF stress was studied to reflect its physiological and biochemical levels.The purpose of this study is to provide experimental and theoretical basis for control of S.avenae under HVEF stress.The main results were as follows:1.The intrinsic rate of increase(r)and net reproductive rate(R0)of the same generation electrical field exposure in different dose were significantly reduced than that of the control,the time threshold was 20 min for intensity of 3 k V/cm and 4 k V/cm,whereas 40 min for 5 k V/cm.These results showed that exposing S.avenae to the HVEF at 3k V/cm,4 k V/cm for 20 min or 5 k V/cm for 40 min had seriously decreased the population increase of S.avenae in all generations.Compared with other generations,the survival area of S.avenae in the seventh generation was the smallest,which indicated that the HVEF had the seriously adverse effect on it.2.The respiration rates of all treatments were lower than that of the control,and there were significant difference with the control.And the most obvious inhibition to the respiration of S.avenae was observed in the treatments of 3 k V/cm for 20 min,4 k V/cm for 20 min,and 5 k V/cm for 40 min.3.The activities of peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT)were significantly lower than that of the control after HVEF irradiation.Also the most obvious inhibition to the activities of three enzymes of S.avenae was at 3k V/cm for 20 min,4 k V/cm for 20 min,and 5 k V/cm for 40 min,indicating that the three key enzymes were significantly inhibited under the electrostatic stress.Based upon the main results described above,we conclude that the combination of specific treatment time and intensity(4k V/cm-20 min,3k V/cm-20 min and 5k V/cm-40 min)can significantly affect S.avenae population parameters,enzyme activity and respiration rate;Moreover,the cumulative effect of HVEF stress on the survival and reproduction peaked at the seventh generation rather than the first,fourth or the tenth generation.