Breakthrough Technologies Ef fi cient Generation of Marker-Free Transgenic Rice Plants Using an Improved Transposon-Mediated Transgene Reintegration Strategy 1

State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control and Institute of Virology and Biotechnology (X.G., J.Zho., J.L., X.Z., J.Zha., Y.T., S.Q.), Institute of Crop Science and Nuclear Technology Utilization (D.W.), and Institute of Quality Standards for Agricultural Products (X.C.), Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310021, China; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China (Q.L., R.X., Q.X.); and Institute of Crop Science (R.Y., J.T.) and Institute of Insect Sciences (Z.Zu., Z.Zh.), Zhejiang University, Hangzhou, Zhejiang 310058, China