Seed dormancy mechanism and dormancy breaking methods of Datura stramonium L.

There is significant dormancy in Datura stramonium seeds.Present study investigated the seed dormancy mechanism by seed viability test,seed germination test,imbibition test and germination inhibitor assay.Physical and chemical treatments were carried out to find the best dormancy breaking method of D.stramonium.The results showed that:The reason of seed dormancy of new harvests includes seed coat barrier,deficient of germination hormone and germination inhibitors existing in both seed kernel and seed coat.It is comprehensive dormancy for D.stramonium seeds,but seed coat barrier is the primary limit factor.The seed kernel dormancy of D.stramonium can be relieved after storing at room temperature for 6 months,but seed coat barrier is always the main reason for its dormancy.Mechanical friction,NaOH and concentrated H2SO4 treatments were used to overcome seed coat barrier and improve the germination rate of D.stramonium seeds.All of them can reach the goal,but the best method was treating with 10% NaOH for 90 minutes,germination rate was increased by 83%.