In genetics, the term horizontal resistance was first used by J. E. VanderplankVanderplank, J.E. (1963) Plant Diseases: Epidemics and Control. Academic Press, New York and London, 349pp. to describe many-gene resistance, which is sometimes also called generalized resistance. This contrasts with the term vertical resistance which was used to describe single-gene resistance. Raoul A. RobinsonRobinson, Raoul A. (1976) Plant Pathosystems. Springer-Verlag, Berlin, Heidelberg, New York, 184pp.
Successive rounds of breeding for horizontal resistance proceed in a more traditional fashion, selecting plants for disease resistance as measured by yield. These plants are exposed to native regional pathogens, and given minimal assistance in fighting them.
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