Preliminary studies of seed dormancy in Datura stramonium

Seed germination studies of Datura stramonium suggest that the endosperm and to a lesser extent the testa impose dormancy on the embryos by restricting the growth of the radicle. Mechanical removal of the testa alone does not improve germination. However, removal of the endosperm in addition to the testa gives improved germination, as does the soaking of seeds with the testa removed in solutions of gibberellic acid or benzyladenine