MITIGATION OF SALT STRESS IN RICE BY EXOGENOUS APPLICATION OF SELENIUM

Abstract

A pot experiment with three boro rice varieties viz. BRRI dhan45; BRRI dhan47 and Nipponbare was conducted at the experimental shed of the Department of Agronomy, Sher-e Bangla Agricultural University, Dhaka during winter season (2013-2014) to investigate the role of exogenous Selenium (Se) in growth, yield and antioxidant defense systems of rice under different salt stress condition. The experiment was carried out in seven salt stress treatments viz. control (without salt), S50 (50 mM salt stress), S50+Se (50 mM salt stress with 0.5 μM Se), S100 (100 mM salt stress), S100+Se (100 mM salt stress with 0.5 μM Se), S150 (150 mM salt stress) and S150+Se (150 mM salt stress with 0.5 μM Se). Salt stresses significantly reduced the plant height and tillers hill-1 of three varieties at all growth duration. Leaf relative water content (RWC) and chlorophyll (chl) content also reduced due to salt stress. At harvest, salt stresses reduced the effective tillers hill-1, number of filled grains panicle-1, 1000 grain weight, grain yield and straw yield for three varieties. On the other hand, exogenous application of Selenium (Se) improved the plant height, effective tillers hill-1, panicle length, filled grains panicle-1, 1000-grain weight, straw yield and grain yield. The BRRI dhan47 can be recognized as naturally salinity tolerant rice variety. The BRRI dhan47 was observed better in response to exogenous application of Se under the stress condition. But Se application could not improve crop growth parameters, physiological parameters and yield at extreme level of salt stress (150 mM) significantly.