Important landmarks in the history of plant virology : Temperate fruits-I Tree fruits (apple, pear, quince, loquat)

Myriad of plant viruses are detrimental hampering the production of fruit crops. To control these viruses and assuring high yield, knowledge about the intricate relationships between the virus, host plants, and the vector, or carrier, is seminal in developing effective management systems. The era of next-generation sequencing and high-throughput sequencing has revealed that there are more viruses than virus species. These techniques have accelerated virus identification, thus tripling the number of known viruses in less than a decade with new viruses being constantly discovered of which many waits further molecular and biological characterization as well as classification. This chapter provides detailed information about the latest achievements of science on five viruses, which are widespread on pome fruits and cause considerable damage. In this article, the taxonomy of viruses, host range, symptoms, transmission manner geographical distribution, especially the economic effects of the virus, as well as diagnostic methods for viruses and their isolates, also detailed control measures to prevent viruses damaging are presented.