International Networks to Deal with Tomato Yellow Leaf Curl Disease: the Middle East Regional Cooperation Program

The Middle East is a major producer of both processing and fresh market tomatoes (Solanum lycopersicum); and tomatoes are a main component of the local cuisines. Since Tomato yellow leaf curl disease was first reported in Israel in the early 1950s, it has become one of the major, if not the most important, constraint to production (see historical perspective in Part I, Chapter 1). This disease has been reported in all countries of the Middle East, and the importance of this disease has been associated with the expanding range of vector Bemisia tabaci biotype B and of the pathogen, members of the Tomato yellow leaf curl virus complex. Management of this disease has mainly involved methods for reducing the vector population; and in many cases, this was primarily by the application of insecticides. Tomatoes with resistance to Tomato yellow leaf curl virus (TYLCV) would effectively reduce losses and reduce the quantity of insecticides needed to obtain satisfactory yields. Several breeding programs were initiated in the 1970s (see Part V, Chapter 3; Nakhla & Maxwell, 1998) and in general, progress was slow. In all cases, resistance to TYLCV was based on introgressions of resistance loci from wild tomato species (e.g., S. chilense, S. habrochaites, and S. peruvianum) (see Part V, Chapter 2). It was not until the 1990s that commercial hybrids with moderate levels of resistance were available. Because of the seriousness of this disease and the difficulty of managing it, international networks of scientists have been organized to provide solutions. Henri Laterrot from INRA, France, was the first to organize an international project, and it was funded by Commission des Communautés Européennes, in