Rate of Germination and Seedling Growth of Perennial Ryegrass Seed following Osmoconditioning

Abstract

This study evaluates the effects of seed osmoconditioning on germination and seedling growth of perennial ryegrass (Lolium perenne L.). Seeds were osmoconditioned in polyethylene glycol 8000 with water potentials ranging from 0 to -1.4 MPa for 48 hours. Osmoconditioning for this crop at -1.1 MPa resulted in a 35% germination increase after 48 hours under optimum (15/25C) germination conditions. This promotive effect was observed until 104 hours for percentage germination and root growth and 118 hours for shoot growth. Rate of seed germination and seedling root growth of osmoconditioned seeds also was enhanced when seeds were placed under suboptimum germination temperatures of 5, 10, and 15C. These results suggest that while osmoconditioning enhanced initial germination rate and seedling root growth under laboratory conditions, it did not do so under prolonged favorable conditions. However, the promotive effects of osmoconditioning were more beneficial when seeds were exposed to less favorable germination conditions.