In vitro studies on the induction of sporogenous tissue on leaves of cinnamon fern. III. The role of reduced nitrogen

Abstract

Excised set III leaf primordia of cinnamon fern cultured on either Knop's or Knudson's medium containing ammonium sulfate produced fertile leaves provided that the media included the appropriate concentration of sugar and the cultures were exposed to the optimal environmental factors. The highest percentage of fertility (about 80%) was obtained on leaves cultured on media containing 6% sucrose and the usual concentration (250 mg/liter) of ammonium sulfate, and placed in continuous darkness at 26 °C. However, leaf primordia cultured under the same conditions without ammonium sulfate or this substance included at concentrations 3 × or higher than the usual amount produced sterile leaves only.From other experimental evidence, a possible mechanism by which sugar supply and ammonium ions influence development is postulated and discussed for the induction of sporangia on cultured cinnamon fern leaves. However, further research is necessary to uncover the biochemical role of reduced nitrogen and carbohydrate in leaf fertility.