Abstract
“Chosen-shu”, Japanese semi native oil rape varieties of Brassica napus, derived from socalled “Seiyo-karashi”, a western oil rape plant, which was firstly planted by Mr. GORO ChO in Fukuoka Pref. in 1878. The ancestor of the Seiyo-karashi was estimated to be a special Swedish turnip rape introduced from U. S. A. in early of the Meiji era. The latter changed to the Chosen-shu probably by an interspecies cross with some native oil rapes of B. campestris.
