Separation of Citrus Viroids by Shoot-Tip Grafting Invitro

Abstract

Arizona 861‐S1 citron (Citrus media L.) infected with a severe exocortis isolate containing four citrus viroids was used as source of tissue for shoot‐tip grafting in vitro. Out of 51 attempts, 25 successful grafts were obtained. Only 16 plants survived transplanting and of these 12 were viroid‐free. The viroid profile of the other four plants showed fewer viroids than the original field source. The significance of these results, as compared with previous reports on the recovery of viroid‐free plants, is discussed. The results show the usefulness of shoot‐tip grafting in vitro as a tool to recover single viroid isolates from complex field sources