Effect of plant host resistance on the virus populations of barley yellow dwarf virus (BYDV) and their transmissibility by aphids

Barley yellow dwarf disease (BYDV) is one of the most important and re-emerging diseases of cereals in Europe and is responsible for major losses on the production of cereal crops globally. The disease causes reduction in yield and quality of cereals and can have serious economic consequences. In wheat, yield losses of 13-45 kg/ha for each 1% increase in yellowing virus incidence have been reported.

Over 10 different viruses commonly referred to as barley/cereal yellow dwarf viruses (YDVs) have been demonstrated to be responsible for the disease, they belong to two different genera: Luteovirus (CYDV-RPV, CYDV-RPS and MYDV-RMV) and Polerovirus (BYDV-PAV, BYDV-PAS, BYDV-MAV, BYDV-kerII and BYDV-kerIII).The disease is the result of infection by at least one virus and plants are commonly found to be infected by several species of viruses.

The losses depend on different factors including the host cultivar, the virus species infecting the crops, the transmission efficiency by the aphid vectors, the number of viruliferous aphids, and environmental conditions. At least 25 aphid species, including Rhopalosiphum padi and Sitobion avenae have been reported to be responsible for the persistent transmission YDVs of cereals. The transmission efficiency of each virus species varies with the vector species and is an important parameter of the epidemiology of the disease. Traditionally the control of the disease has largely relied on the control of insect vectors using chemical insecticides. However, the recent ban on the outdoor use of neonicotinoid insecticides, which provided efficient control against aphid vectors, together with emerging insecticide resistance in some vectors and climate change makes the control of yellowing viruses increasingly difficult.

The use of genetic resources with resistant phenotypes (i.e., plants that reduce infection rate and/or viral accumulation) or tolerant phenotypes (i.e., plants that multiply the virus without expressing symptoms) is an...