Effects of Continuous and Intermittent Static Electric Fields of Positive and Negative on the Multiplication of Callus
1994 Volume 32 Issue 2 Pages 113-118
Details
1994 Volume 32 Issue 2 Pages 113-118
The calli of asparagus and carrot in a petri dish were exposed to positive and negative uniform electric field intensities of about ± 150 kV/m. The variance of the field intensity in a petri dish and the effect of the exposure for 20 days on the multiplication of callus were evaluated under the exposed conditions as follows : the continuous exposure (continuation plot), the repeat of pause of 4 hr after exposure of 8 hr (8-4 plot), the repeat of pause of 1 hr after exposure of 2 hr (2-1 plot) and the repeat of pause of 2 hr after exposure of 1 hr (1-2 plot) .
Generally, the petri dish is slightly charged to negative even under no electric field, and the field intensity in the plastic petri dish was smaller than that of the outside and grad-ually decreased, then was kept a constant value under the uniform field. The absolute value of the positive field intensity in a petri dish was smaller than that at negative, and the measured value of the positive field intensity was smaller than its theoretical value, the other way, the negative measured value was larger than the theoretical value. The accumulated exposed time was longer, the more the multiplication of callus was accelerated; and the periodic time of intermittent was longer, the more the multiplication was accelerated, but the short period suppressed the multiplication.
Both calli felt the different influence by the polarity, the intensity, the exposed time and the intermittent period of field. The multiplication rate of asparagus callus was most accelerated at the positive 8-4 plot and the negative continuation plot, and the dry weight and the dry matter rate were increased at the continuation plots of both polarities. In the case of carrot callus, the multiplication rate was most increased at the positive 2-1 plot and the negative continuation plot, and the dry weight and the dry matter rate were most increased at the negative continuation plot.
