Abstract
A study was conducted to determine the effect of osmotically-induced moisture stress at different temperatures on the rate and total germination for different spring wheat genotypes. In the first experiment, five spring wheat varieties (Alexandra, Axona, Canon, Tonic, and Wembley) were subjected to three osmotic potentials (0, -0.8, and -1.2 MPa), while in the second, three wheat genotypes (Axona, Canon, and Wembley) were subjected to the same osmotic potentials at three temperatures (10, 20, and 30°C). For all genotypes, speed of germination and total germination during stress and after recovery decreased with decreasing osmotic potentials at all temperatures. Differences between genotypes generally increased with decreasing osmotic potential, while differences between osmotic potentials increased with increasing temperature. There were clear genotypic differences in seed germination at low osmotic potential and water stress tolerance (indicated by ability to germinate at low osmotic potential). Ability to recover following stress relief of the genotypes were in the order of Wembley, Tonic, Canon, Alexandra, and Axona. The results also indicated that water stress tolerance and recovery ability may not necessarily be correlated thereby suggesting that these parameters should be measured separately where necessary.
