PRODUCTION OF MONOCLONAL-ANTIBODIES AGAINST A MYCOPLASMALIKE ORGANISMASSOCIATED WITH SWEET-POTATO WITCHES-BROOM

Five stable hybridoma clones secreting specific monoclonal antibodies against the sweetpotato witches' broom (SPWB)-mycoplasmalike organism (MLO) were produced by employing an immunization scheme for the induct ion of the immunological tolerance of mice to plant antigens prior to the administration of MLO immunogens. Neonatal BALB/ c mice were injec ted first with nontarget plant antigens present in an immunogen prepar ation and were immunized with MLO-enriched antigens prepared by Percol l density-gradient fractionation or by enzyme treatments 6 wk later. W ith these monoclonal antibodies, SPWB-MLO in diseased sweetpotato and periwinkle was specifically identified by indirect enzyme-linked immun osorbent assay (ELISA) and by immunofluorescent staining. Antibody tit ers for hybridoma-culture supernatants (measured by indirect ELISA) ra nged from 320 to 5,120 for SPWB-MLO in diseased periwinkle. SPWB-MLO w as differentiated serologically from MLOs associated with loofah, paul ownia, and Ipomoea obscura witches' brooms, aster and elm yellows, and rice yellow dwarf in both ELISA and immunofluorescent staining. All m onoclonal antibodies cross-reacted with peanut and asparagus bean witc hes' broom MLOs and MLOs associated with the witches' broom weeds, Rhy nchosia minima and Alysicarpus vaginalis, found on the Penghu Islands, where there are serious occurences of SPWB.