Distribution and Research Advances of Citrus tristeza virus

Citrus tristeza virus (CTV) is one of the most important causal agents of citrus diseases and exists as numerous strains. CTV is replicated in phloem cells of plants within the family Rutaceae and is transmitted by a few of aphid species. CTV epidemics have caused death of millions of citrus trees in many regions all over the world, where the sour orange (Citrus aurantium) was used as rootstock. Also the production of grapefruit (C paradisi) and sweet orange (C sinensis) has been affected by CTV strains. CTV gives uplift to three prominent syndromes, namely quick-decline (tristeza), stem-pitting and seedling-yellows. The disease is graft-transmissible in nature but not seed-transmitted. However, the tristeza disease in most citrus groves was a man-made problem created by the desire of horticulturists to introduce cultivars from other citrus growing areas. The utmost importance of the disease called for review articles in numbers of plant protection, epidemiology books, citriculture and proceedings. This review collects the information with respects to disease history, distribution host range, virus isolates association, identification and detection, transmission and management; especially on the current status of CTV prevailing and controlling in Pakistan. It provides valuable information for CTV disease and its controlling approaches.