Water Relations of Some Steppe Plants Investigated by Means of the Reversibility of the Water Saturation Deficit

Abstract

In July 1962, during our studies of the water relations of some steppe plants in Hungary, I and my colleague were also interested in the sublethal value of the water saturation deficit. In our investigations we applied a method based on water inhibition measurements in plants dried up so that they reached various degrees of water deficit. The measurements were made on segments of grass blades. We were able to establish two types of saturation curves, with a characteristic difference between them:

• 1. Up to a certain limit the plants fully recovered from their water deficit by restoring their original water content.

• 2. An increase in the water deficit brought about a certain degree of increased water retention capacity of the leaf tissue. The water content in leaves saturated after the previous partial desiccation was found to be higher than that in the initial fully turgescent conditions, so that we may be justified in speaking about “oversaturation” with water.