Memoir on the origin of wheat stocks used by Prof. Tetsu Sakamura, on the centennial of his discovery of the correct chromosome number and polyploidy in wheat.

Sakamura (1918) reported the discovery of a polyploid series among eight species of the genus Triticum; this series consisted of 2x, 4x and 6x species with 2n = 14, 28 and 42 chromosomes, respectively. He mentioned in this article that all the materials he used were gifted by T. Minami of the same department of Hokkaido University, Japan. In addition to carrying out an extensive collection of cereal germplasms in the period 1914 to 1916, Minami wrote on October 7, 1915 to K. A. Flaksberger, a wheat taxonomist at the Bureau of Applied Botany, Saint Petersburg, Russia, requesting seeds of Russian wheat and other cereals. He sent Flaksberger a letter of acknowledgement for seed stocks on May 19, 1916; thus, the requested seed package must have arrived from Flaksberger at some time between October 7, 1915 and May 19, 1916. Based on the available documents, there was a considerable period of time between these seed stocks reaching Minami and Sakamura's publication of the chromosome numbers with the discovery of polyploidy. In fact, the wheat species identified by Flaksberger (1915) and those studied by Sakamura (1918) were identical except for two wild species which appeared only in Flaksberger's list. The available information supports a proposal that the wheat species used by Sakamura (1918) in his discovery of polyploidy, and later by Kihara (1924, 1930) in his genome analysis, originated from Flaksberger's collection.