Pretreatments With NaOCl Solution and the Application of Exogenous ABA on Seed Germination

For evaluating the effect of sodium hypochlorite solution, mature seeds at 120 DAP were collected and soaked in 0.5% NaOCl solution with two drops of a wetting agent Tween 20 (Sigma-Aldrich Co. St. Louis, MO, United States) for 10 or 20 min. For the control, seeds were soaked only in water. After treatments, seeds were rinsed three times with sterilized water and then placed on the culture medium or analyzed for ABA content. To examine the effect of exogenous ABA on seed germination, the mature seeds at 120 DAP which were pretreated with 0.5% NaOCl solution for 20 min were inoculated on the culture medium with the supplement of 0.0003, 0.0037, 0.0378, or 0.3787 μM (these concentrations were equal to 0.1, 1, 10, or 100 ng/mL) (±)-ABA (A1049, Sigma-Aldrich Co.). The culture medium without ABA supplement was used as control. ABA solution was filter-sterilized and added to the medium after autoclaved sterilization. The germination percentage was scored after 50 days of culture.