The production of ornamental plants plays an important role for Italian agriculture, accounting for about 6% of the whole agricultural production, with some local areas particularly devoted to these activities. Diseases caused by fungi, bacteria, viruses, viroids and phytoplasmas represent a major threat for the quality and yield along almost every step of the production chain. The phytopathological scenario of many ornamental species is rapidly changing due to several factors, among which are the import and cultivation of new species from exotic countries, cultivars lacking genetic disease resistance, the changes in the cultivation practices, the introduction of pathogens causing new diseases, and finally, the climatic changes. For many years, chemical control has represented the only solution for the management of the diseases, but the strategies for their application have been sometimes not efficient and rational. Environmental pollution, human health risks, high cost of agrochemicals and treatments are some of the drawbacks whose consequences are often underestimated. The correct and rapid diagnosis of a disease represent the first step for any successful control strategies. Diagnosis of plant diseases has witnessed huge progress in the last years due to the development of serological and molecular-based techniques. The development of new diagnostic techniques allowed to overcome many limiting factors of conventional ones, i.e. the need for well-trained personnel, the long time required for results, the difficulties in the detection of non-cultivable organisms. The complexity and high cost of some innovative diagnostics have often limited their application to specialized laboratories. However, new techniques and more user-friendly devices are being developed for diagnostic purposes, also for in situ application. In this paper, innovative techniques for the diagnosis of diseases of ornamental plants are reviewed with many examples of their practical application.
Keywords: plant diseases, serology, polymerase chain reaction, hybridization