Effects of temperature, salt, and osmotic potential on early growth of wheat (Triticum aestivum). I. Germination

Kernels of spring wheat (cv. Katepwa) were germinated in Petri dishes at six osmotic potentials (−0.3 to −1.8 MPa) and eight temperatures (6–34 °C) in single-salt solutions of a variety of chloride and sulfate salts, and the time to onset of germination, germination rate index, and final percent germination were determined. Percent germination was maximal at 18–22 °C in the presence of osmotic stress, but was unaffected by temperature in its absence. At temperatures below 10 °C or above 30 °C and osmotic potentials below −0.3 MPa, germination was delayed, slowed down, and eventually inhibited. Temperature stress intensified the effects of osmotic stress on germination and vice versa. Main effects of temperature, osmotic potential, and salt type and all their interactions were highly significant (P < 0.01) for all variables.