Study on creation and utilization of induced mutation rice materials

⁶⁰Co γ-ray, spaceflight, laser were respectively or combinedly used to treat rice lines or hybrid materials. Many special type of seed breed lines, including high yielding ones, top quality ones, stunt stem ones, disease/pest resistent ones, colourful rices, big size of grain ones etc. were selected from the mutation materials, some were directly used as new varieties and some were indirectly used to breed hybrid varieties. All the new varieties such as 'xiangzaonuo No.1', 'xiangzaoxian No.20', 'xiangzaoxian No.21', 'xiangfu 994', 'peiliangyou 721', 'zhuliangyou 124' were popularly planted and great social and economical benefit was obtained. (authors)