8 - Ecology of Plant Viruses, with Special Reference to Whitefly-Transmitted Geminiviruses (WTGs)

Abstract

This chapter discusses the ecology of plant viruses with emphasis on geminiviruses transmitted by the whitefly Bemisia tabaci. The ability of the virus to spread and reach epidemic proportions depends on several ecological factors that directly or indirectly influence the population dynamics of the aerial vectors, its feeding behavior, or its movement over long distances, and certainly the availability of susceptible cultivated or wild hosts. Plant viruses are classified into different genera using a set of established criteria based on their morphological, physical, and biochemical properties. Plant virus diseases result from a complex interplay of host, virus, and vector over time under favorable environmental conditions that allow efficient spread and survival of both the virus and its vector. This chapter discusses the management strategies to prevent virus infections. It also highlights the role of man by manipulating the agro-climatic environment and indiscriminate movement of plant material, which, in some instances, has led to the emergence of new recombinant viruses.