Osmotic Adjustment in the Spikelets and Leaves of Wheat

Abstract

The response of osmotic potential to changes in water potential in the spikelets and leaves of wheat genotypes was studied in a controlled environment. While there was evidence of osmotic adjustment in the leaves of only some genotypes, it seemed to be present in the spikelets of all genotypes. Spikelets also differed from leaves in that osmotic potentials at full turgor were usually higher. During grain growth, levels of osmotic potential were observed in the spikelets of some genotypes which were up to 1·1 MPa greater than the corresponding water potential. Osmotic responses in both spikelets and leaves are discussed in terms of responses expected from concentration effects only.