Document Type : Original Article
Authors
1 Department of Agronomy and Plant Breeding, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran.
2 Agronomy and Plant Breeding Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
Abstract
Datura is an important medicinal plant for production of various alkaloids. Seed dormancy and the problem of germination is the most important barrier to produce this plant. In order to solve the germination problem in this important medicinal plant, the present study was carried out as a factorial experiment with three factors based on completely randomized design with three replications. The first factor consisted of two datura ecotypes (Hamadan and Esfahan), the second factor included three levels of physical treatments of breaking dormancy (no scratching; scratch with sandpaper and wet bathing of bain marie bath for 7 days at 60 °C; scratch with sandpaper and dry chilling for 7 days at 4 °C), and the third factor included five levels of chemical treatments of breaking dormancy (no application of chemical treatments [putting the seeds on distil water from the beginning of the experiment to the end of the experiment]; NaOH 20% for 90 minutes; NaOH 20% for 90 minutes + gibberellin 500 ppm for 48 hours; NaOH 20% for 90 minutes + potassium nitrate 300 ppm [putting the seeds in potassium nitrate solution from the beginning of the experiment to the end of the experiment]; NaOH 20% for 90 minutes + gibberellin 500 ppm for 48 hours + potassium nitrate 300 ppm). Interaction of ecotypes and seed dormancy breaking treatments was significant for most traits except; number of leaves per plant, root fresh weight, shoot length and stem fresh weight. The results showed that the chemical treatment of NaOH 20% + gibberellin 500 ppm, was the best dormancy braking treatment for the fresh harvested seeds of datura. Therefore, using this treatment is recommended to break seed dormancy more than 70 percent, without significant damage on the seeds. In general, it was found that the chemical treatments were more effective than physical treatment on breaking the dormancy of datura seed and the main cause of breaking seed dormancy and stimulation of vegetative growth of seedlings obtained was the combination of NaOH with gibberellin.
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