Seed germination as a biological test for the study of fluctuating phenomena

Abstract

The original method to perform the P test of Piccardi (1962) was used in a study on correlation between variations in the time of precipitation of bismuth oxichloride and seed germination carried out at daily and three hour intervals from 26 March until 23 April, 1971. The chemical tests were repeated each day at 12.00 hr and at 18.00 hr, while the biological test was starting with seed imbibition at 12.00 hr and giving a short light stimulation at 18.00 hr. In both cases the experiments were repeated contemporaneously in open air and under screen, using a Faraday cage made of copper mesh. Fluctuations in seed germination and in the P test were observed in this study. The analysis of the data by considering absolute and relative values for both the tests at different times, has revealed positive correlation between absolute values, and negative correlation between the differences of these. This fact suggests that fluctuations of the biological test follow a trend which is dependent also on an endogenous mechanism. This determines the threshold within which germination response to external fluctuation phenomena can occur. For the chemical test these thresholds do not exist. On the other hand the common pattern of variation in time observed in both cases can be explained by a common receptor to environmental stimulations. This could be the water which is essential for both chemical and biological processes. The study on the different behaviour of the P test at different temperatures, in which it appears that at 38.5°C the chemical reaction does not respond to environmental changes (condition of equilibrium), demonstrates that variations in water structure is one of the main factors involved in the case of fluctuating phenomena.

Abstracting keywords:

• Fluctuating phenomena of seed germination
• Piccardi test

Notes

Orto Botanico Università, 35100 Padova, Italy.

Formerly: Centro Universitario Fenomeni Fluttuanti, 26 Via Gino Capponi, I 50121 Florence, Italy. Professor Piccardi died 22 December 1972.