<p><P>PROBLEM TO BE SOLVED: To provide a new rice mutant in which a rice starch synthase and a rice branching enzyme are mutated. <P>SOLUTION: There is provided a genetically immobilized rice mutant in which the gene loci of rice starch synthase IIIa type (SSIIIa) and rice branching enzyme IIb type (BEIIb) are recessive homozygous. The rice mutant has SSIIIa activity reduced compared with that of wild type rice. The rice mutant keeps≥80% in seed weight and maintains an agricultural character in comparison with wild type and parent line rice. The starch formed by the rice mutant is a high-amylose starch rarely found in rice and has an amylose ratio of≥40%. <P>COPYRIGHT: (C)2012,JPO&INPIT</p>
