Breeding for Genetic Resistance to Disease: Specific or General?

SummaryAll basic approaches to disease control: eradication, vaccination or medication and improvement of genetic resistance should be considered together in planning an effective programme of disease control. Existence of genetically determined specific disease resistance has been established in both animals and plants. General resistance to disease has been demonstrated in varying degrees in plants, and field observations suggest that it might also exist in animals. General disease resistance is defined as an ability to resist any alteration of the state of the body by external causes which interrupts or disturbs proper performance.Given the multiplicity of existing diseases, improving resistance against each disease separately is impractical. It is suggested that substitution of the concept of “general disease resistance” for “total mortality” could lead to improved effectiveness of selection, providing that adequate methods for measurement of general disease resistance and for its incorporation into breeding plans are developed. Approaches to breeding for general disease resistance and the need for related research are discussed.