Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
Diseases caused by insect-borne viruses cause serious losses in yield and quality in major food and fibre crops worldwide. Traditionally, one main method to control such losses has been the application of pesticides to kill the insect vectors involved. This approach has not been totally successful in the long term because of several factors. These include, the pesticide may not act quickly enough to prevent primary virus infection by insect feeding; the development by virus vectors of resistance to pesticides; the effect of pesticides on non-target organisms (especially natural enemies of the target insect) and the subsequent ecological imbalance that results. Furthermore, pesticides are too costly, especially for farmers in developing countries. Although other methods have given successful control in some circumstances, a much neglected approach is the development of plants with resistance to virus vectors. Nevertheless, there are several instances where this has been very successful and these will be highlighted in the presentation but, in most instances, these have been a bonus affect of breeding plants specifically for pest resistance. Breeding plants for resistance to virus infection by insects may require different criteria to those for selecting plants for resistance to pest damage. A diversity of mechanisms for resistance to virus transmission by insects exists widely in nature and some examples will be given. They include resistance by interfering with an insect's mechanism(s) for, (1) host finding, (2) initial settling and feeding, (3) sustained feeding, and even (4) specific transmission of virus. Breeding for such resistance may, in some circumstances, not be feasible or may present other difficulties and these will be discussed.
