The term vertical resistance and horizontal resistance were coined by

Solution(By Examveda Team)

The terms vertical resistance and horizontal resistance were coined by Van der Plank (1963).
The term vertical resistance, used commonly in the context of plant selection, was first used by J. E. Vanderplank to describe single-gene resistance. This contrasted with the term horizontal resistance which was used to describe many-gene resistance.
Vertical resistance there are single genes for resistance in the host plant, and there are also single genes for parasitic ability in the parasite. This phenomenon is known as the gene-for-gene relationship, and it is the defining characteristic of vertical resistance.