Effect of Light on Germination of Light-Sensitive Seeds

Abstract

1. The seeds of Rumex crispus, Datura Stramonium, and Phoradendron flavescens were found to be light sensitive. The germination of seeds of Rumex crispus and Phoradendron flavescens was promoted by light; the germination of seeds of Datura Stramonium was hindered by light. 2. Abrasion and removal of coats (ovary walls) of Rumex crispus seeds promoted their germination in darkness. 3. Treatment of seeds of Rumex crispus and Oenothera biennis with concentrated sulphuric acid caused an increase in the percentage of germination in darkness. 4. No reciprocal relation between the effects of light and temperature was found. 5. Light was not necessary for the absorption of sufficient water for germination. 6. Injection of water did not yield increased germination in darkness. 7. Almost all kinds of single electrolytes, regardless of the nature of the ions, seemed to promote germination of seeds of Oenothera biennis, Nicotiana Tabacum, and Verbascum Thapsus in darkness. 8. Embryos of seeds incubated in light became more acid than those incubated in darkness. 9. Light seemed to activate lipolytic enzymes which hydrolyzed fats to fatty acids. 10. The germination of seeds of Rumex crispus in darkness was promoted (increased) by hot water treatment, abrasion, treatment with concentrated sulphuric acid, increased oxygen pressure, fluctuating temperatures, and soaking in solutions of hydrochloric acid, sodium sulphocyanate, and hydrogen peroxide. 11. The germination of seeds of Nicotiana Tabacum in darkness was promoted by soaking in solutions of hydrochloric acid, sodium sulphocyanate, and hydrogen peroxide, as well as by the use of many single electrolytes as substrata. 12. The germination of seeds of Verbascum Thapsus in darkness was promoted by the action of light, fluctuation of temperature during incubation, alternating high and low temperatures, soil, and many single electrolytes as substrata. 13. The germination of seeds of Oenothera biennis in darkness was promoted during certain seasons by hot water treatment, sulphuric acid, preliminary incubation at low temperature, incubation in alternating high and low temperatures, and single electrolytes as substrata. 14. The germination of seeds of Daucus Carota in darkness was promoted by increased oxygen pressure and preliminary incubation at low temperature, while it was hindered by soaking in hydrochloric acid and by the use of single electrolytes as substrata.