[Seed dormancy associated with embryo immaturity: Contribution for the study of Magnolia soulangeana Soul. Bod. and Magnolia grandiflora L. by means of in vitro culture].

At the time of seed dispersal, the embryos of Magnolia grandiflora L. and Magnolia soulangeana Soul. Bod. are still immature. When they are aseptically isolated and cultivated in a medium containing agar, mineral salts and sucrose, the pattern of development depends upon the morphological stage they have reached in the seed. With the older stages, precocious germination was obtained but in no case was true embryo dormancy observed. Furthermore, in Magnolia grandiflora L. the outer seed coat is responsible for preventing the seed germination.