Current status of phytoplasma diseases of forest and landscape trees and shrubs

This paper summarizes the current knowledge of phytoplasma diseases of forest and landscape trees and shrubs, with special reference to molecular and taxonomic aspects of the associated phytoplasmas in the light of the plethora of data generated over the last years. Phytoplasma diseases of such kind of trees and shrubs are of considerable economic and ecological significance throughout the world, either because of the local impact or of their widespread distribution. However, information is still missing on many aspects of some of these diseases, including insect vectors, phytoplasma-vector relationships, phytoplasma-host plant interactions, strain virulence, strain interference, host tolerance, host range, and impact of the infections on the growth and yield of affected plants. In some instances, phytoplasma-infected forest and landscape trees and shrubs can serve as reservoirs of phytoplasmas affecting agricultural crops. Latent phytoplasma infections in some forest and landscape trees and shrubs are common.