| In this research,concentration of negative air ion(NAI)released by 17 species(varieties)of Agavaceae under natural conditions and different pulsed electric field stimulation was studied.Plants of Agavaceae had strong adaptability,wide application,high ornamental value,and easy survival.The changes of the ultrastructure of mesophyll cell under pulsed electric field stimulation were also observed.The main results were as follows:1.The study on NAI released by 17 species(varieties)of Agavaceae plants under natural state.NAI generated by 17 species(varieties)of Agavaceae plants within 1800 seconds in sealed glass chamber with the dimensions 80×80×80cm under natural conditions was detected with DLY-4G-232 air ion detector.(1)Agavaceae plants can generate NAI under natural conditions,but the concentration was very low.Among these plants,the average NAI concentration produced by Dracaena fragrans'Massangeana'was 939ion/com3 which was the highest levels.The paired t-test between the mean concentration of NAI released by the plants under natural conditions and that of no treatment control group showed that the NAI had significant difference between them(t=3.423,P=0.003<0.05).The correlation test of paried-sample showed:that concentration of NAI released by plants under natural conditions and no treatment control group had significant correlation(R=0.981,P=0.00).(2)Concentration of NAI released by 17 species of different Agaveaceae plants had difference.Cluster analysis was performed on the concentration of NAI pruduced by 17 species(varieties)of plants,which were divided into four categories(I>II>III>IV).The classification result showed that the plants with rich leaf tips,such as Agave sisalana,Agave americana 'marginata alba',Agave americana 'marginata' might not released more NAI than the plant without rich leaf tips,such as Dracaena fragrans'Massangeana'and Dracaena reflexa 'Anita'.The NAI generated by the plants might influenced by integrative factors such as leaf tips,temperature and light.2.The study on concentration of NAI released by 17 species(varieties)of Agavaceae plants under constant pulsed voltage stimulation.NAI generated by 17 species(varieties)in sealed glass chamber with the dimensions 80 X 80×80cm upon 1800 seconds under 5kV and 10kV(T?1 s,? ?100ms)pulsed electrical stimulation was detected with DLY-4G-232 air ion detector.(1)The concentration of NAI of 17 species of Agaveaceae plants measured under pulsed electrical stimulation increased different times as compared with that of the control group(the concentration of NAI in sealed 80×80×80cm glass chamber with pot Agaveaceae plants under natural conditions).There was significant difference in NAI between control group and 5kV(P=0.028<0.05).There had extremely significant difference between control group and 10kV,5kV and 10kV(P<0.01).(2)There had significant correlation in NAI concentration between 5kV pulsed electrical stimulation and natural conditions(R=0.580,P=0.015<0.05).However,There had not significant correlation in NAI concentration between lOkV pulsed electrical stimulation and natural conditions(R=-0.075,P=0.775>0.05).(3)14 species(varieties)out of 17species(varieties)plants produced higher concentration of NAI upon 10kV pulsed electrical stimulation than 5kV pulsed electrica stimulation.The correlation test results showed that the NAI concentration measured under lOkV pulse voltage stimulation was no significant correlation with that under 5kV stimulated(R=0.286,P=0.266>0.05).(4)Cluster analysis was performed on the concentration of NAI pruduced by 17 species(varieties)of plants upon 5kV and lOkV pulsed electrical stimulation.The cluster analysis results showed that the larger of pulse voltage,the more obvious difference of the ability to released NAI between plants.3.The study on concentration of NAI of 8 species(varieties)of Agaveaceae plants measured stimulated by gradient intensity of pulsed voltage.NAI concentration of 8 species(varieties)of Agaveaceae plants measured in sealed glass chamber upon 1800 seconds of six gradient intensity of pulsed voltage(6kV,8 kV,10 kV,12 kV,14 kV,16 kV)and constant pulse interval(T)and pulse width(?)(T=1s,??100ms)different intensity pulsed electrical stimulation was detected and analysed.(1)one-way-Anova test showed that 7 species of plants except Dracaena sanderiana(P=0.166>0.05)had extremely significant difference(P<0.01)in concentration of NAl.(2)Regression analysis with 11 kinds aquation about concentration of NAI(Y)and gradient intensity of pulsed voltage(X)showed that regression equation for Dracaena sanderiana was Y=exp(15.207-1.811/X)(R2=0.833,P=0.011),for Agave potatorum 'Verchaffeltii,was Y=exp(16.375-23.751/X)(R2=0.874,P=0.006);for Sansevieria trifasciata 'laurentii' was Y=4403.619-1302.339*X+158.558*X*X-5.498*X*X*X(R2=0.977,P= 0.034);for Agave americana 'marginata' was Y=-10565986.651+ 3382571.200*X-270232.694*X*X+ 6662.402*X*X*X(R2=0.850,P=0.00).However,there was no the right curve to indicate the relationship of NAI released by the other 4 species(varieties)plants between different intensity pulsed voltage.4.The study on the change of the ultrastructure of mesophyll cell under pulsed electrical stimulation.The leaf blade of Agave americana 'marginata',Sansevieria trifasciata 'laurentii'and Dracaena sanderiana 'Lotus' under natural conditions and stimulated by lOkV and 16kV intensity of pulsed voltage for 1800s was prepared according to standard technic for transmission electron microscopy.(1)Pulsed electrical stimulation had different degree of damage to mesophyll cell of the different plants.The degree of damage upon 16kV pulsed electrical stimulation was more serious than upon 10kV pulsed electrical stimulation.(2)Seeing from the damage of Chloroplast,Sansevieria trifasciata 'laurentii' was the most serious,followed by Agave americana 'marginata',Dracaena sanderiana 'Lotus' was the most slight. |
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