Diagnosis and control of cereal viruses in the Middle East.

Middle Eastern countries are major consumers of small grain cereals. Egypt is the biggest bread wheat producer with 7.4 million tons (MT) in 2007, but at the same time, it had to import 5.9 MT. Jordan and Israel import almost all the grains they consume. Viruses are the major pathogens that impair grain production in the Middle East, infecting in some years more than 80% of the crop. They are transmitted in nonpersistent, semipersistent, and persistent manners by insects (aphids, leafhoppers, and mites), and through soil and seeds. Hence, cereal viruses have to be controlled, not only in the field but also through the collaborative efforts of the plant quarantine services inland and at the borders, involving all the Middle Eastern countries. Diagnosis of cereal viruses may include symptom observation, immunological technologies such as ELISA using polyclonal and monoclonal antibodies raised against virus coat protein expressed in bacteria, and molecular techniques such as PCR, microarrays, and deep sequencing. In this chapter, we explore the different diagnoses, typing, and detection techniques of cereal viruses available to the Middle Eastern countries. We highlight the plant quarantine service and the prevention methods. Finally, we review the breeding efforts for virus resistance, based on conventional selection and genetic engineering.