Harold Henry Flor

Harold Henry Flor (1900–1991) was a plant pathologist famous for proposing the gene for gene hypothesis of plant-pathogen genetic interaction whilst working on rust (Melampsora lini) of flax (Linum usitatissimum). He received his PhD from the University of Minnesota in 1929. He worked for three years at Washington State University and the rest of his career at North Dakota State University where he came up with his hypothesis.