蕨類植物根尖之頂端細胞分裂

A supplementary study on the cell division of root apical cells in some Pteridophytes

A study of the root apical meristems of three species of ferns, Ophioglossum petiolatum Hoole, Ceratopteris thalictroides (L.) Brongn. and Marsilea crenata Pr. has been made. These ferms were cultured in both the presence and absence of colchicine. The apical cells of some colchicine treated roots showed either a multinucleate condition or other abnormalities, whereas the apical cells of all nontreated roots were mononucleate. All the roots of these three species formed tumors after treatment. The typical c-metaphasic nucleus which has frequently been observed in angiosperms was not seen in this experiment. Apparently the dividing cells of pteridophytes show a different pattern from those in angiosperms in response to the act ion of colchicine. It is clear that the root apical cells in these three species always div ide more frequently than their adjacent cells. Among these, the root apical cells in Ceratopteris divides more frequently than the other two species. The presence of a quiescent center in the root apical meristem in these ferns has not been verified.