Establishment of an Efficient Medium for Anther Culture of Rice Through Comparative Experiments on the Nitrogen Sources

The experiments have revealed that (NH4)2SO4 combined with KNO3 at low concentration is of advantage to the formation, growth and differentiation of pollen callus in rice, whereas the high concentration of (NH4)2SO4, whether used separately or in combination with KNO3, obviously inhibits the pollen callus formation. The optimum NH4+ concen- tration is about 7.0 mM (equal to 3.5 mM (NH4)2SO4). A basic medium containing 3.5 mM (NH4)2SO4 and 28 mM KNO3 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.