12.4　 Gravitropic response on caulonemata

Tomomichi Fujita

(1) Materials

a. BCDAT agar plates supplemented with sucrose (2%) or glucose (0.5%).

b. Boxes to keep the plates in the dark

(2) Protocol

1.　 Inoculate protonemata on an agar plate and culture for 1-2 weeks under normal light conditions.

2.　 After culture in light, stick the plate on the bottom of a light-tight box. It is a good idea also to wrap the plate with aluminum foil to completely exclude light. Stand the box vertically and culture for 1-3 weeks.

(3) Results

You can easily observe the negative gravitropic response of protonemata, Similar gravitropic responses are also observed in Funaria hygrometrica and Ceratodon purpureus in the same conditions.　

Figure.

Protonemata were precultured at 25℃ for 10 days under standard light conditions, then placed vertically at 25℃ for 21 days in darkness.