Seed treatment with 24-epibrassinolide improves wheat germination under salinity stress

Abstract

Salt stress is a key ecological challenge to wheat establishment at the early stage of germination, especially in drylands. A germination experiment was conducted to determine whether an exogenous seed treatment with 24-epibrassinolide could mitigate salinity stress effects on wheat germination. Seeds of the Sudanese wheat cv. Imam were treated with 24-epibrassinolide (BR 1 ) or without (BR 0 ) at eleven concentrations of sodium chloride (NaCl) (0.00, 1.56, 3.13, 4.69, 6.25, 7.81, 9.38, 10.94, 12.50, 14.06 and 15.63 dSm -1 ), in a 2 x 11 factorial experiment arranged into a completely randomized design. Seed germination was progressively delayed with increasing salinity and the daily germination was reduced significantly. The germination average time and relative injury rate increased considerably (p≤0.05) at salt levels of 7.81 dSm -1 or more. The inhibitory effects of salinity on germination were significantly (p≤0.05) reversed by seed treatment with BR 1 . Wheat cv. Imam tolerated salt stress up to 6.25 dSm -1 at BR 0 with respect to velocity of germination, germination rate, final germination rate, germination percentage and germination index, relative to no salt (0.00 dSm -1 ). An early uniform establishment of wheat in saline media could be enhanced by seed treatment with BR.