Effects of (±)-abscisin II on seed germination in four species of grasses.

Abscisin II (Ab II) inhibited germination of seeds of four species of grasses. The effects ranged from slight retardation of the onset of germination from the lowest concentration (0.1 mg/l) to complete inhibition throughout the 17-day test period from the highest concentration (10 mg/l). Intermediate concentrations induced some abnormalities of development.Seed viability was not destroyed even by the highest Ab II concentration applied, normal development and growth resuming when seeds were transferred from abscisin solutions to water.