A COMBINED INDEXING AND BUDWOOD PROPAGATION METHOD FOR CITRUS

Several budwood-transmitted citrus diseases, including citrus tristeza virus, citrus psorosis, citrus impietratura and a range of citrus vir oids, were tested both visually and biochemically on a combined indica tor (CInd) plant consisting of an Alemow (Citrus macrophylla) rootstoc k grafted with Etrog citron (C. medica) and Sour orange (C. aurantium) or Sweet orange (C. sinensis) buds. Indexing on CInd plants is econom ical for limited testing space; an additional advantage is that, by co llecting budwood directly from the CInd plants, the risk of diagnostic failure due to uneven pathogen distribution in the budwood source tre e is considerably reduced.