Erwin Baur (1875, Ichenheim, Grand Duchy of Baden – 1933) was a German geneticist and botanist. Baur worked primarily on plant genetics. He was director of the Kaiser Wilhelm Institute for Breeding Research (since 1938 Erwin Baur-Institute). Baur is considered to be the
father of plant virology. He discovered the inheritance of plastids. In 1908 Baur demonstrated a lethal gene in the Antirrhinum plant.
In 1909 working on the chloroplast genes in Pelarganium (geraniums) he showed that they violated four of Mendel's five laws. Baur stated that : plastids are carriers of hereditary factors which
are able to mutate. in variegated plants, random sorting out of plastids is taking place. the genetic results indicate a biparental inheritance of plastids by egg cells and sperm cells in
pelargonium.
Since the 1930s and the work of Otto Renner, plastid inheritance became a widely accepted genetic theory. In 1921 and 1932 Baur co-authored with Fritz Lenz and Eugen Fischer two volumes
that became the book Human Heredity, which was a major influence on the racial theories of Adolf Hitler. The work
served a chief inspiration for biological support in Hitler's "Mein Kampf".