A novel gene controlling chasmogamy/cleistogamy of barley was successfully identified, and the mechanism of development of chasmogamy/cleistogamy of barley was successfully elucidated by positional cloning approach. In addition, it has been found that the use of the identified gene makes it possible to specifically and efficiently determine chasmogamy/cleistogamy of a plant and impart a cleistogamous trait to a plant.
