DIFFERENTIATION OF YAM VIRUS ISOLATES USING SYMPTOMATOLOGY, WESTERN-BLOT ASSAY, AND MONOCLONAL-ANTIBODIES

Monoclonal antibodies (mAbs) were prepared against a yam mosaic virus (YMV) isolate from the Cote d'Ivoire. Symptomatology, Western immunobl otting, and ELISA were used to discriminate 69 isolates of YMV origina ting from different Dioscorea species and from various yam producing a reas. These isolates induced two types of symptoms, were of four diffe rent electrophoretic mobilities and formed two serogroups. These resul ts suggest that at least six different groups of isolates exist, three of which infect the main cultivated species in various geographical a reas while two others were from unusual samples in our collection. An isolate from 'Pilimpikou Yam' from Central Burkina Faso was serologica lly distinct. It is concluded that there is a significant variability among yam virus isolates which is unrelated to the origin of the isola te (geographic or host species). It is suggested that precautions shou ld be taken in order to avoid international exchange of infected mater ial.