Articles
THE APPLICATION OF MOLECULAR TECHNIQUES FOR THE DETECTION AND CONTROL OF VIRUSES OF ORNAMENTAL PLANTS
Advances in molecular techniques for the detection and control of plant viruses and viroids are discussed, with particular reference to ornamental plants.
Detection, identification and elimination of infected plants may be regarded as elements of active control of viruses and viroids.
Introduction of genes to confer resistance to infection may be regarded as passive control, but may be more effective than active control.
The genes may be derived from the viruses themselves, or from other plant species with genetic resistance to virus infection.
Molecular probes can be selected for broad spectrum reactivity or for strain specificity, and can have greater sensitivity than serological probes.
Even greater increases of sensitivity can be obtained with nucleic acid amplification techniques such as the polymerase chain reaction.
A combination of amplification and restriction enzyme digestion can be used to distinguish between viruses and/or isolates by revealing restriction fragment length polymorphisms (RFLPs). Cloned viral genes may be used as a source of pathogen-derived resistance for protection against virus infection.
As virus resistance genes are identified from plants, these too may be transferred to other plants, including ornamentals; lack of suitable transformation and regeneration protocols is a current barrier to introduction of resistance genes to many ornamentals.