| Abstract: | Abstract Antigrowth substances of plant origin. 1) A method for quantitative evaluation of antigrowth activity. The antigrowth activity of various kinds of plant extracts has been quantitatively evaluated, by determining the reduction of lenghtening of the lateral radicles of wheat grains induced by them. Grains are allowed to develop on water moistened filter paper until the lateral radicles have reached a lenght of about 5 mm.; then grains, carefully selected for approximately equal redicles lenght, are uniformly distributed in Petri dishes lined with filter paper, and moistened with 10 ml of distilled water, for the controls, or of the extracts under examination. All the operations are performed as much as possible under steril conditions. After 36 hrs incubation at 28° C, in the dark, the lenght of the lateral radicles is measured and the percent inhibition determined. This, when plotted against the log of the extract concentration, gives a straight line. The method is very sensitive and its reproducibility makes it possible to follow quantitatively the purification of antigrowth principles. |
