ESTABLISHMENT OF AN EFFICIENT MEDIUM FOR ANTHER CULTURE OF RICE THROUGH COMPARATIVE EXPERIMENTS ON THE NITROGEN SOURCES

The experiments have revealed that (NH 4 ) 2 SO 4 combined with KNO 3 at low concentration is of advantage to the formation, growth and differentiation of pollen callus in rice, whereas the high concentration of (NH 4 ) 2 SO 4 , whether used separately or in combination with KNO 3 , obviously inhibits the pollen callus formation. The optimum NH 4 + concen- tration is about 7.0 mM (equal to 3.5 mM (NH 4 ) 2 SO 4 ). A basic medium containing 3.5 mM (NH 4 ) 2 SO 4 and 28 mM KNO 3 as nitrogen sources has been established. On such medium the frequency of the pollen callus formation is higher than that on Millers me- dium, and the differentiation of shoot from pollen callus is satisfactory.