Effect of Negative Electrostatic Field Treatment on Germination of Seeds Soaked GA3

Tree seed germination improvement of tree species with shallow dormancy may represent an effective process to enhance restocking of forests and woodlands that have been depleted. Although sometimes conflicting results have been obtained, some studies showed the beneficial effects of applied static electric field (electrostatic field) on seed germination and seedling growth. We think that the different treatme nt effects reported maybe depended on the dosage, exposition time, process and vigor index of the seeds. We previously showed i mproved tree seed germination of pine seeds by positive electros tatic field treatment using our apparatus and procedure, and the purpose of the present study was to investigate the effects of the negative electrostatic field treatment on germination, using the same experimental procedure. The results indicated that the negative electrostatic field treatment on pine seeds soaked with 100 ppm of gibberellic acid (GA3) is not so effective as the po sitive one, with slightly improved germination percentage at the ele ctrical voltage of -500 kV/m 10 min, and increasing the intensity of the negative Seed soaking time had a significant effect on seed relative electroconductivity, seed germination under light, soluble protein and total soluble sugar content of seedling leaves. Electrostatic field intensity exerted a moderate e ffect on these indexes, and the exposition time only had no eviden t effect except for the total chlorophyll contents. Sidaway (1) observed inhibition of plant development by positive electrostatic field, and the nature of the plant response to the applied field depended on the sign and not merely by the presence of the field itself. Further more, light reduced the effect of positive polarity on plant de velopment, compared to dark condition. A source of electrons p rovided by an electrical conductor with negative charge, wa s able to extend the viability of seeds during artificial agi ng (9). Such anti-aging effect may be due to the reduction of th e free radical attack species to the subcellular structure s and biological macromolecules, counteracted by the elec tron donor negatively charged conductor. On the basis of this assumption, and considering t hat many investigators often reported contradictory results as showed by Lund (10), we have studied the application of el ectrostatic field in forestry science for many years in order t o improve germination of tree seeds, using different electric al methods, single and multiple factor treatments. Through the experience gained in this field of research by our group, we t hink that in many of the experiments conducted over the past years, the electrical field intensity was too weak and its dis tance from biological matter was too far; moreover the experim ental designs were not standardized, because many studies did not solve insulation, dosage, experimental condition, a nd so on. Based on the above problems, it is difficult to get ideal results and conclusions. Therefore, we decided to investiga te how the electrostatic treatment determines changes in seed vigor index through our apparatus and methods (11,12), also, an alyzing separately the effects generated by different elect rostatic charges.