Problems and Prospects in Plant Virus Identification1

Abstract

AbstractReliable identification is a prerequisite to the study and control of plant viruses and virus diseases. Viruses are now increasingly studied for their intrinsic properties, in addition to their variable biological properties. This has caused some degree of order to emerge from the intricacy of plant viruses. Ten « commandments » are listed which permit reasonably reliable diagnosis of plant virus diseases in the scientific laboratory. New viruses are still often discovered.Routine tests for virus infection, carried out by plant protection, quarantine and especially certification services, never guarantee absolute freedom from viruses. A simple, but the least reliable of indexing methods, is that of visual observation. Infectivity tests are meant to trace the infectious agents with indicator plants. Using serology, one can detect certain viruses more directly and specifically. Electron microscopy allows the observation of the virus particles themselves.The choice of test is always a compromise between efficiency and reliability. Through scientific research both are constantly being improved. With the increasing amount of information on plant viruses, diagnosis is tending to shift from mere visual observation to the more reliable study of aetiology.