A Simple Procedure to Observe Phototropic Responses in the Red Seaweed Pyropia yezoensis.

The marine red seaweed Pyropia yezoensis exhibits phototropic responses in gametophyte and conchosporangia phases, but not in sporophytes. These responses are easily monitored with a simple culturing box that has one side open to allow for unilateral light irradiation within an incubator. Confirmation of phototropic responses is achieved by changing the direction of unilateral light irradiation via rotation of the culture dishes clockwise 90°.