Evaluation of seed vigour enhancement techniques on physiological and biochemical basis in coarse rice (Oryza sativa L.)

Impact of pre-sowing seed treatments on the germination and seedling vigour of rice was evaluated through investigating the biochemical changes following seed invigoration by analyzing the sugars and α-amylase activity. The seeds were invigorated by traditional soaking, osmoconditioning (-1.1 MPa KNO₃) for 24 or 48 h and hardenening for 18 or 24 h. All the invigoration treatments significantly affected the germination rate and spread, fresh and dry weight of roots and shoots, shoot length, total, reducing and non- reducing sugars and α-amylase activity. Seed hardening for 24 h and traditional soaking performed the best as indicated by reduced germination time and increased germination rate, shoot dry weight and non-reducing sugars. In addition α-amylase activity and total and reducing sugars were also increased. Osmoconditioning failed to improve the seedling vigour.