PLANT BELONGING TO GENUS ORYZA HAVING DOMINANT DWARF TRAIT, AND USE THEREOF

摘要

A seed or callus of a rice plant is subjected to a mutagenic treatment to regenerate the rice plant, and several dwarf individuals can be produced successively. Then, it is examined whether the dwarf gene is dominant or recessive in the dwarf individuals, and four mutants SLRD1-SLRD4, in which the dwarf trait is inherited dominantly, can be produced. When the four mutants are analyzed on their causative genes for the dwarf trait, it is found that the causative genes of the four mutants are allelic to one another and are induced by a point mutation in Slr1 gene carried on chromosome 4. Mating is performed between each of the four dwarf mutants and a wild-type Indian or Japanese species, and all of the first filial generations (F1) have an incompletely dominant phenotype with respect to plant height and show a semi-dwarf trait. It is demonstrated that a semi-dwarf hybrid rice plant and a dwarf fixed variety of a rice plant can be bred by utilizing the mutant gene.