Dry seeds of Hordeum vulgare cv. Zafer-160 were surface sterilized by rapid immersion, first treated with 95% eth-anol and then 20% sodium hypochlorite for 15 min and rinsed three times with sterile water. Ten seeds were ger-minated at dark, on plates between filter papers embedded in 0.1, 0.5 and 1.0 lM HBR-supplemented distilled water for 48 h with their control. Total two plates of HBR for each concentration with three separate experiments were used. All cultures were kept at dark in a controlled growth chamber (25?C). The number of germinated roots (primary and seminal roots) (Hochholdinger et al. 2007) was
recorded after 48 h. About 1 mg of HBR (H1267, Sigma)
was dissolved in ethanol to yield a 10 mM stock solution.