Heart-Shaped Prothallia of the FernAdiantum capillus-venerisL. Develop in the Polarization Plane of White Light

摘要

When red light-precultured filamentous protonemata ofAdiantum capillus-veneriswere cultured under linearly polarized white light, heart-shaped prothallia developed in the plane parallel to the vibration plane of electrical vector of polarized light, and were directed toward the light source. When the polarization plane was rotated during the culture, the prothallial wings twisted correspondingly to develop in the new plane. Continual observation of the early steps of prothallial development with a time-lapse video system revealed that the apical cell of protonema after the first transverse cell division became flattened in the vibration plane of electrical vector of polarized light, and that the first longitudinal cell division, that is, the first step in the transition from one-dimensional to two-dimensional growth, as well as the subsequent cell divisions, occurred perpendicularly to the electrical vector.