Growth reaction of seedlings of common winter wheat varieties to solutions of different osmotic pressures

Radoslav Chipilski, Konstantina Kocheva, Georgi Georgiev

Abstract: Growth activity of 5-days-old seedlings of common winter wheat varieties grown on conditions of osmotic stress was evaluated on the basis of accumulated biomass, growth depression, injury index and water content. Seeds of Bulgarian varieties Katya, Gines, Geya-1 and Nikki from three vegetation years 2012-2014 were used. Seedlings were subjected to osmotic stress for 48 hours in thermostat by sucrose solutions with water potentials of -0.55 and -1.33 MPa. It was found that in the varieties Gines and Geya-1 the coleoptile fresh and dry mass were less negatively affected by the applied stress than in the variety Nikki, and in Gines and Geya-1 the coleoptile length was bigger than in Nikki. Katya and Gines showed higher water content of shoot under moderate stress (-0.55 MPa) which correlates with depression in organ growth. The severe water stress of -1.33 MPa induced similar depression in organ growth with no varietal differences. Based on these parameters, it was estimated that Nikki was most sensitive to mild and severe water stress compared with the studied varieties. Regression correlation curves of shoot dry mass and water content and dry mass and depression coefficient under moderate stress for Katya, Gines and Geya-1 proved that these varieties possessed adaptive mechanisms towards stress unlike Nikki.

Keywords: common winter wheat; injury index; osmotic stress; seedlings

Date published: 2017-07-03