Kölreuter, Josef Gottlieb

Born Apr 27, 1733, in Sulz-am-Neckar; died Nov. 12, 1806, in Karlsruhe. German botanist.

In 1755, Kölreuter graduated from the University of Tübingen. From 1756 to 1761 he worked at the St. Petersburg Academy of Sciences, becoming an honorary member there in 1766. He was the director of the botanical gardens in Karlsruhe from 1763 to 1769. Kölreuter proved experimentally the existence of sex in plants by crossing different varieties of one species of tobacco plant and obtaining the first interspecies hybrid (1760). He introduced the method of reciprocal crossing into selection practices and discovered the phenomena of heterosis and self-sterility. In his study of the biology of the flower, Kölreuter was the first to describe pollination by insects; he also explained the role of nectar and described dichogamy. His works greatly influenced the development of plant embryology and genetics.