Source of PDV and PPV infected tissues

INTRODUCTION Prune dwarf ilarvirus (PDV) and its various strains cause many types of stone fruit diseases of considerable economic importance (Nemeth, 1986). The virus induces considerable damage in many hosts either by itself or in a mixed infection with other stone fruit viruses. PDV is transmitted naturally by infected pollen. PDV has worldwide distribution, especially where sweet and sour cherry are cultivated. Plum pox disease, Sharka, is caused by Plum pox potyvirus (PPV) (Dunez and Sutic, 1988; Hadidi and Candresse, 2001). Sharka, is the most important viral disease of stone fruit diseases in Europe and the Mediterranean region because of reduced fruit quality, premature fruit drop, rapid natural spread by aphid vectors, and rapid decline and death of trees when co-infected with other viruses. During the last decade, PPV has been reported also from South and North America (Hadidi and Candresse, 2001). Introduction of PDV and PPV through the international and national movement of stone fruit cultivars and germplasm to local stone fruit industry is of concern to federal and local governments. For this reason, effective control measures of PDV and PPV must be established to safely introduce stone fruit cultivars and/or germplasm that are free of PDV and/or PPV to prevent serious losses to the local stone fruit industry and significantly reduce PDV and/or PPV infection to stone fruits in countries where either virus is present.