PROBLEM TO BE SOLVED: To identify new genes controlling the degree of seed dormancy in a plant, and to provide a method for efficiently determining the degree of the seed dormancy of the plant and a method for efficiently creating a plant in which the seed dormancy is modified by utilizing the identified genes.SOLUTION: Identification of SD2 gene controlling the seed dormancy of barley and Phs1 gene which is a wheat gene corresponding thereto is successfully achieved by a technique of positional cloning. In these genes, single nucleotide polymorphism (SNP) correlating with the seed dormancy is successfully specified and a fact that a weak seed dormancy type gene is dominant in the genes is successfully elucidated. It is found that effective determination of the degree of the seed dormancy of the plant and creation of the plant in which the seed dormancy is modified can be carried out by utilizing the identified genes.
