On the constancy of nuclear DNA content during gametophyte development in Lepisorus thunbergianus.

Abstract

Morphological features and DNA content of nuclei at an early stage of development of the gametophyte of Lepisorus thunbergianus were observed.1. Nuclei of the cells of the young gametophyte were globe-shaped at early stage of cell age and became ellipsoidal-fusiform by age.2. The initiation of apical cell groups started just after the beginning of two dimensional division of the apical cell of the linear gametophyte. This is considered to be the signal for proliferation in these cells.3. Nuclear DNA content was constant at the 1C level in all of the cells of young gametophytes at both linear and flat stages, except for the apical cell of the former and the apical cell groups of the latter which varied from 1C to 2C. Both the development and differentiation of the cells of gametophyte were found to be carried out at 1C level.