| As a nature material, electric field has a different affect on organism growth in the environment. Physical agricultural technique that plant seeds are treated by high voltage electric field ?HVEF? can enhance its germination vigor and increase agricultural benefit. Now, it has become the important content in the research of biophysics. In this study, Seed germination Experiment was done in the tissue culture laboratory of Yuncheng Agricultural Vocational Technical College and test of physiological and biochemical indexes of seed germination was finished in the physiological laboratory of Cotton Research Institute, Shanxi Academy of Agricultural Sciences, testing of field experiment in the LanHua farm of Cotton Research Institute, Shanxi Academy of Agricultural Sciences. Nongda 8 ?Millet seeds? was used the testing material by using the integrated method combining quadratic general rotary unitized design and principal component analysis to build model for optimal conditions to filtrate the optimization condition in this paper. On the basis of regression model, the optimum condition obtained was that electric field strength was 340 kV/m and treatment time was 14 min while the Y value attained its maximum. In order to reveal the control effects of dynamic content changes of endogenous hormone on germination activity of Millet seeds treated by HVEF, under the optimized condition for HVEF, the dynamic content changes of endogenous hormone and a-amylase activity in the process of millet seeds germination were investigated in this paper; On the meanwhile, the study analyzed the causes of this change of physiological and biochemical indexes of seeds germination in the optimized areas ?electric field strength was 300 kV/m,350 kV/m,400 kV/m, and treatment time was 5min, 10min? by completely random Experimental design; By using randomized block design, the effect of HVEF on photosynthesis characteristic during seedling period and drought-resistant physiological characteristics in booting stage were studied in field trial.Firstly, testing results of seeds germination in the range electric field strength was 100-800 kV/m, and treatment time was 5-60 min by quadratic general rotary unitized design indicted that the eermination indexes had significant difference ?P<0.05?, compared to the control. Germination rate, germination potential, bud length, root length, germination index, fresh weight, vigor index of all the treatment were higher than the control group except germination potential and germination rate of T4, germination rate and root length of T5, in especial, bud length and vigor index were 52.47%,31.53% respectively compared to the control. seven germination indexes was simplified into comprehensive index Yto obtain the mathematical model:Y= 0.357Z1+0.375Z2+0.372Z3+0.385Z4+0.372Z5+0.384Z6 +0.400Z7. Principal component analysis indicated that comprehensive index value were all higher than the control by HVEF, the effects in sequence is T10, T11, T9, T13, T12, T8, T2, T3, T1, T7, T6, T4, T5, CK. Y value of T10, T11, T9, T13, T12 were changed obviously, followed by Ts, the improvement was not as obvious for T5, compared to the control.Secondly, the mathematical model was obtained. through regression analysis of comprehensive index Y, The result showed that the influence of different HVEF treatment on comprehensive index was significant ?P<0.05?, the matching effect is preferable which reflected the relation between comprehensive index and two factor?electric field strength and treatment time?; analysis of main effect indicated that the effects of electric field strength were more than that of treatment time on the germination comprehensive index, and suggesting a positive effect; single effect analysis indicated that the influence of electric field strength and treatment time on the germination comprehensive index had thresholds; the interactive influence of electric field strength and treatment time on the germination comprehensive index presented a negative effect which was significant ?P<0.05?, and the interactive influence of electric field strength and treatment time on the germination comprehensive index had thresholds. After optimizing the model, the optimization scheme which should be met simultaneously that germination comprehensive index were greater than or equal 0.35 was that electric field strength was 295-432 kV/m and treatment time was 10-17 min.Thirdly, on the basis of regression model, electric field strength was 340 kV/m, and treatment time was 14min while the Y value attained its maximum, the content of endogenous hormone and a-amylase activity dynamic changes in the process of millet seeds germination ?seeds, seed budding, radical length equals to seeds length, twofold, threefold, fourfold of seeds length and end of germination? were investigated in this paper to discuss the effect of millet seeds germination. Dynamic changes of endogenous hormone content in millet germination indicated that the optimal condition of treating millet by HVEF could induce the increase of IAA, ZR and GA content increased but inhibit the increase of ABA. When seed germinating IAA and GA increase quickly while ABA decreases quickly, and ZR was up to the maximum, which is beneficial for radicle to break through the seed coat, and to improve seed germinating. The dynamic content changes of Endogenous hormones showed that GA/ABA, IAA/ABA ratio of Millet seeds treated by HVEF were higher than control groups, which indicated that the ratio change of Millet endogenous hormones seeds treated by HVEF was incentives to improve germination activity of Millet seeds. When radical length equals to seeds length, the radio of GA/ABA, IAA/ABA continued to increase, which indicated seedling grow has a close relation with its regulation and control.Fourthly, the study analyzed the causes of this change of physiological and biochemical indexes of seeds germination in the optimized areas that electric field strength was 300 kV/m,350kV/m,400kV/m, and treatment time was 5min, 10min by completely random experimental design. The result showed that SP content, SOD activity, POD activity of all the treatment were all higher than the control, it indicated that it could accelerate nutrients'transition and metabolic activity in the seed, meanwhile it can promote the seeds'germination, abatement the lipid peroxidation of cell membrane, enhance the repair capability of membrane system through millet seeds processed by HVEF. MDA content of all treatment were lower than the control that it can alleviate the damage of membrane lipid peroxidation.Fifthly, the change of chlorophyll content and N content of leaf in the optimized areas ?electric field strength was 300 kV/m,350 kV/m,400 kV/m, and treatment time was 5min, 10min? was analyzed by completely random experimental design in the paper. The result showed Pn, Tr, Gs, of different time frame were higher than the control, Ci are just the opposite. Between Pn and Tr, Gs are positively correlated relationship, and Pn and Ci was the negative relationship.Sixthly, the result of drought resistant physiology in booting stage indicated that the content value of SS and SP of processed millets' leaf were all higher than that of control group, the effect of T4, T2 was so obvious that the differences were significant?P<0.05?, the difference of other treatment were not remarkable; SOD, POD activity of all the treatment were higher than that of control group, and the differences are significant ?P<0.05? ?but Ti?, the effect of T2, T4 were most obvious; All the treatments' content of MDA were lower than that of control, and the differences were significant?P<0.05?. |
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