Virus diseases of peas, beans, and faba bean in the Mediterranean region.

In the Mediterranean region, pea, bean, and faba bean production is affected by around 17 major viruses. These viruses do not have the same ecology and consequently require a variety of different preventive measures to control them. Some of these viruses have a narrow host range, such as Faba bean necrotic yellows virus (FBNYV), and others, such as Alfalfa mosaic virus (AMV) and Cucumber mosaic virus (CMV), a very wide host range. Such features are important when identifying sources of virus inoculum in a region, and the vectors can transmit viruses from natural reservoirs to the crop plants. Some of these viruses are seed borne and, consequently, can be disseminated long distances through infected seeds. Crop losses caused by these viruses are variable, depending on the sensitivity and susceptibility of the crop to infection. Host resistance genes have been identified for some of these viruses, but in others, such as FBNYV, no resistance genes in faba bean have been identified yet. Significant progress was made in developing precise methods for the identification of these viruses, and new virus problems are being identified every year. This chapter is not intended to be a review for pea, bean, and faba bean viruses, but rather focuses on the major viruses which affect these crops in the Mediterranean basin with focus on the progress made over the past two decades.