Citrus Phantom Disorders of Presumed Virus and Virus-like Origin: What Have We Learned in the Past Twenty Years?

Abstract

In the process of recording and studying citrus diseases in the 20th century, citrus pathologists reported several suspected grafttransmissible disorders that were thought to be of virus or virus-like origin. While later work clarified and characterized most of these disorders, others were left unaddressed beyond their initial reports, and their status has remained unresolved for decades. For this reason, and for lack of a better term, such disorders are considered "phantoms". In this work, our group performed an extensive literature review and communicated with renowned citrus pathologists and members of the International Organization of Citrus Virologists from around the world. Here we summarize and present in an organized manner the most up to date information for multiple phantom disorders, including disorders that have been subsequently characterized as a result of research efforts of the past 20 years. This review article could act as a reference point for citrus pathologists, regulatory agencies, and industry to clear up any confusion regarding citrus phantom disorders.