Great achievements have been madein breeding of semidwarf varieties(indica) since 1960e. Resultsshowed that the dwarf traits widelyused at present were controlled by thesame recessive major gene, sd-1,thus we faced the potential danger oflosing genetic diversity. The low yieldof semidwarf varieties newly-bred indomestic or abroad may be related tothe narrow use of dwarf resource. Soit was important to explore, appraise, Great achievements have been madein breeding of semidwarf varieties (indica) since 1960e. Resultsshowed that the dwarf traits widelyused at present were controlled by thesame recessive major gene, sd-1, thus we faced the potential danger oflosing genetic diversity. The low yieldof semidwarf varieties newly-bred indomestic or abroad may be related tothe narrow use of dwarf resource. Soit was important to explore, appraise,