Abstract

Soil salinization is a major limiting factor to seed germination and seedling establishment, especially in arid and semi-arid regions. In this study, we determined whether seed treatment with 24-epibrassinolide (BR) may promote germination in saline media. A growth chamber experiment was conducted to monitor soybean seed germination with BR1 (0.5 ml) or without BR0 (0.0 ml) at eleven concentrations of NaCl salinity (0.00-15.63 dSm-1). Sixty-six 10 cm diameter petri dishes were filled with 80 g of sterilized soil and moistened with 10 ml of the respective saline water, while deionized water without salt served as control. Germination indices were recorded for 10 days. The salt concentration range of 10.94-15.63 dSm-1 significantly (P ≤ 0.05) reduced the final germination rate, germination average time, velocity of germination, germination rate, germination percentage and daily germination. These reductions were reasonably (P ≤ 0.05) reversed with BR application. The seeds tolerated salt stress up to 9.38 dSm−1 at BR0, but the germination potential was clearly enhanced by seed treatment with BR, especially in moderately saline culture.

Key words: Arid region; brassinolide; germination indices; glycine max (L); saline stress; tachiyukata-8428h