Effective selection system is essential to high efficiency genetic transformation.In this study,the effects of different hygromycin concentrations,screening time and convalescence or not on differentiation and regeneration of immature embryo callus of Zhengmai 9023 were investigated,and callus of Zhengmai 9023,Han 6172,Longmai 30,Longmai 31 transformed by particle bombardment were selected using hygromycin.The results showed that 50mg·L-1 of hygromycin applied for 30d was suitable for screening after transf...