When the callus tissues, derived from rice embryos, had been aseptically subcultured for several passages, a thirty-fold increase in fresh weight was obtained after four weeks of culture. Each callus of Te-Tep and Konansen indicated a marked growth, and that of Tan-ginbozu was very slight, especially at low levels of 2, 4-D. Also many roots occurred from the blackening region which was induced as the callus had been inoculated in lower levels of 2, 4-D. Rooting was vigorous in Te-Tep callus, but slightly in Konansen callus, and very rare in Tan-ginbozu. Further this communication reported successful induction of shoot from callus in the second passage.
