Aphid-Borne Virus Dynamics in the Potato-Weed Pathosystem

Alternate hosts that are reservoirs of the vector and/or virus in a pathosystem can significantly affect the epidemiology of the virus. The potato–viral pathosystem is characterized by the presence of numerous such hosts. These weeds are known to serve as reservoirs of persistently and non-persistently transmitted potato viruses such as potato leaf roll virus (PLRV) and potato virus Y (PVY). They are also reproductive hosts of several potato colonizing aphids, including the green peach aphid (Myzus persicae (Sulzer)) and the potato aphid (Macrosiphum euphorbiae (Thomas)). The role of these weeds as potential inoculum sources has largely been discounted in the temperate ecosystems due to severe winters. However, recent research has indicated that weed species can play a very important role in the epidemiology of potato viruses even there. Using various Solanum spp. as model hosts, numerous studies have been conducted to understand aphid–virus–host plant interactions. These studies have provided an enormous amount of information on the effect of weed hosts on aphid biology and behavior. The biology and behavior of aphids are influenced by numerous intricate interactions with their host plants with and without virus infection. In this chapter, we provide an overview of the weed–virus–vector–crop interactions in the potato viral pathosystem and discuss potential management options.