Growth Correlates of Electromotive Forces in Maize Seeds

Each living maize seed being a physicochemical system has an inherent electrical potential which is measurable after the seed has been soaked for several hours in water.This potential is presumably the sum of the e.m.f.'s of each individual cell, and as such the degree of magnitude of this forte may be expected to show correlations with growth processes which are then being initiated.Burr (1943) has already shown a connection between the mean potential of an inbred line and its probable heterotic value in crosses.He further showed the large potential difference implicit in two inbred lines whose large size differences are conditioned by a single gene, the recessive a4lele in a homozygous condition, resulting in diminu- tion of plant and ear size.This seems to point rather clearly to a positive relationship between the electrical potential and the genetic constitution.Correlations between plant growth and the electrical potential are the easiest way to elucidate this relationship, and it was with this thought that this series of investigations was begun.The technique employed was as follows.The seeds were placed in tap water for 18-24 hours before measurement.A seed was picked at random after soaking and placed on a cone of plasticene located in the center of a revolving stage (Fig. 1).Silver-silver chloride electrodes in physiological salt solution, terminating in camel's hair brushes, were mounted in a Zeiss manipulator and brought into contact with the micropylar and germinal ends of the seed.The electrodes were connected by flexible unshielded copper wire to the input binding posts of a d.c. microvoltmeter (Burr, 1936).The magnitude of the potential difference was read from a standard galvanoineter calibrated to read in millivolts.By means of the revolving stage the seed was rotated 1800 and a second determination made.This was repeated until consistent readings were obtained; usually this re-