Inheritance of Resistance to Viral Diseases in Plants

Abstract

Publisher Summary This chapter focuses on plant resistance to viral diseases. Breeding for resistance has become an increasingly common practice in the development of methods for the control of viral diseases in economically important plants. Resistance to disease, as controlled by single or multiple genes in inheritance, may be of a number of kinds and of various degrees of efficiency. It may be absolute, constituting natural immunity. It may involve a tendency to escape infection despite inoculation. It may involve prompt death of invaded tissues (hypersensitivity), with or without the limitation of virus movement (localization of virus) and with or without the rapid inactivation of virus already formed. It also may be characterized by a tendency of not showing obvious disease (tolerance); usually this form of resistance is achieved by the partial suppression of viral multiplication, suppression of systemic spread, or both. The resistances to various diseases, such as cucumber mosaic, tobacco mosaic, and spotted wilt, in several hosts such as cucumber, tomato, and muskmelon are discussed in the chapter. It discusses the difficulties that arise during the breeding for disease resistance crops. The breeding difficulties may be posed by linkages between genes and nutritional defects in food plants. Future problems in the acquisition of resistances to disease are also discussed in the chapter.