Effects of simulated microgravity on the germination and elongation of protonemata of Adiantum capillus‐veneris

Germination of spores and elongation of protonemata of Adiantum capillus‐veneris L., which can be controlled by light irradiation, were examined under various gravitational conditions including microgravity simulated by a three‐dimensional clinostat. The elongation of protonemata that had been irradiated from below and grew downwards was greater than that of protonemata growing horizontally or upwards. Under microgravity, protonemata were shorter than the controls. Germination of spores, direction of growth, and cell division were not affected by gravitational conditions.