Effects of high electric field seed treatment on the growth and biochemical aspect of the soybean plant

This paper presents a study on the effects of electric field on soybean. Pre-soaked soybean seeds were exposed for one hour to high electric field strength of 0, 10, 20, 40, 60, 80, 100 and 120kV/m. The treated seeds were sown and the subsequent growth and biochemical changes were examined. There were four replicates for each treatment with one plant representing one replicate. The second youngest leaf of each plant was used in the biochemical analysis. The protein content of 40kV/m treated soybean was increased, 148.3mg/g fresh weight was obtained as compared with control, 125.3mg/g fresh weight. The other treatments resulted in significantly lower protein content with lOOkV1m giving the lowest protein content of 65.1 mg/g fresh weight. However, all the electric field treatments resulted in significantly lower soluble nitrogen content when compared with the control. Specific peroxidase activity was found highest in treatment 120kV/m with 356.7 x 104 unit/g fresh weight indicating stress, when compared with the control having only 69.7 x 104 unit/g fresh weight. Treatments 60 and IOOkV1m also gave significantly higher peroxidase activity when compared with the control each measured 122.4 x 104 and 120.6 x 104 unit/g fresh weight, respectively. Protein banding pattern obtained from the SDS polyacrylamide gel reveals no major differences between the number of major protein bands. Quantitative plant growth parameters taken during twelve weeks of growth also gave some significant results when tested using Duncan Multiple Range Test (p = 0.05). The soybean plant height was found to be highest when the seeds were treated with 80kV/m, giving 138.3cm compared with the control with only 77.0cm. However, the root length of all the treated plants was insignificantly different except for lOOkV1m, which gave significantly shorter root with 13.3cm, compared with the control with 16.1 cm. The total fresh shoot weight was significantly higher in the 40, 60 and 80kV1m treatments with 8.6,9.1 and 9.0g respectively compared with the control with only 6.8g. The same trend was also observed for the fresh root weight with 40, 60 and 80kV1m giving 1.18, 1.35 and 1.28g respectively compared with the control with 0.68g. The mean number of leaves formed was found to be significantly higher in the plants treated with 80 and 60kV1m with 57 and 54 leaves respectively when compared with the control with only 37 leaves. The same trend was also observed for the mean number of pods formed, treatment 80kV1m gave the highest number of pods followed by 40 and 60kV/m with II, 9 and 9 pods respectively compared with the control with only a mean of 5 pods. Therefore, it can be concluded that electric field strength of 40,60 and 80kV/m is able to enhance the growth of the soybean plant.