International networks to deal with tomato yellow leaf curl disease: The middle east regional cooperation program

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 the late 1980s (Laterrot, 1995). One goal was to test germplasm in different countries (Israel, Egypt, Jordan, Mali, and Sénégal) and then to combine the resistant plants into a population that could be used in breeding programs (e.g., Pimpertylc, Chiltylc). Subsequently, several international projects have been organized to focus on the management of whiteflies and begomoviruses. This chapter will not attempt to describe them all, but will discuss mainly two international projects that have as their main goal the development of breeding lines resistant to begomoviruses in the Mediterranean Basin and Central America (see http://www.plantpath.wisc. edu/GeminivirusResistantTomatoes/index.htm).