Harold Henry Flor

Harold Henry Flor known as H. H. Flor[1][2] (1900–1991) was an American 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).

degree in June 1924 for his research work entitled ''Control of covered smuts of small grains''.

For a year between September 1925 to September 1926 he worked as a Research Fellow at the graduate school of the University of Minnesota, following which he completed a research work on root rot in sugarcane supervised by E.G. Edgerton at the State University of Louisiana.

His collective research at these three institutions earned him a PhD degree awarded by the University of Minnesota in June 1929.

Flor worked at the US Department of Agriculture at Washington State University, where he cultivated his interest in genetics.