The Role of Gibberellic Acid, Sulfuric Acid and Cold Stratification on Seed Germination Parameters of Black Henbane (Hyoscyamus niger L.)

One of the main problems that prevent sustainable use of medicinal plants, native to the arid lands is that they readily germinate within the native environment, but fail to show good germination under laboratory conditions or when cultivation is attempted. Black henbane seeds have low germination rate even under normal laboratory conditions. In this study, seeds of black henbane were soaked in GA3 at four different concentrations (100, 150, 200 and 250 ppm) for 48 hours, and in H2So4 1% at 5 and 10 minute along with GA3 at 250 ppm, and two duration of cold stratification (30 days and 60 days stored in a refrigertor at 2 °C) for seed breaking dormancy of three locations (Karaj, Kermanshah, Kandovan) with different latitude. Results showed that GA3 stimulated the germination of all seeds. The highest germination percentage (95%) was recorded at 250 ppm GA3 for Kermanshah and Karaj sites. In all seeds increasing the concentration of GA3 up to 250 ppm and increasing the duration of soaking in H2SO4 from 5 min to 10 min, improved significantly both the germination percentage and rate. Seed treatment with cold stratification at 2 °C for 30 days was the best treatment only for germination percentage of Kandovan seeds, but this result was not observed in seeds those were collected from two other sites. The highest germination percentage (95%) and germination rate (0.17 seeds per day) and also the lowest mean germination time (5.68 day) was recorded in the concentration of 250 ppm GA3 for seeds