This edited book elucidates the evolution of plant virus, genomic structure, diversity, plant-virus interaction, subcellular movement etc. The book reviews the biological machineries which allow the emergence of virus populations adapted by plant. The main objective of this book is the demonstration of a clear synergistic effect of plant viruses, an effect that was unexpectedly as important as applied alone.Ornamental plants are very popular and economically important worldwide. The international market of ornamentals is constantly expanding. Viruses and viroids can significantly reduce both...