Fig. 1.

Effect of KNO₃ and closterium medium on start of conjugation on agar plate. About 100 filaments were incubated on agar plates prepared using APW, APW supplemented with 1 mM KNO₃ or closterium medium at 23°C under a 12:12 h L–D cycle for 4 days. When papilla was observed, we judged that the cell started conjugation. Results were presented as a ratio of filaments started formation of conjugation tube to the total number of filaments. Experiments were repeated 3 times and the data are represented as the mean and standard error of the mean (SEM)