Studies on improvement of sterile line rice quality by new cytoplasm from Oryza rufipogon

中国人. 通过核置换回交，获得一种新的普通野生稻（O．rufipogon）雄性不育细胞质，称为FA细胞质，育成新质源不育系金农1A。研究表明，FA细胞质不育系与WA和HL不育系的恢保关系不同，野败型的保持系和恢复系、红莲型的保持系和恢复系都可以作为FA细胞质的保持系，而不能成为FA细胞质的恢复系。FA细胞质突破了WA和HL细胞质恢保关系的遗传局限，扩大了保持系育种范围，可以用品质优良的栽培品种培育成优质稻米不育系。新质源不育系金农1A不育度高，不育性稳定，农艺性状优良，抗稻瘟病和自叶枯病，开花时间早，稻米12项品质指标全部达到农业部颁发的优质米一级或二级标准。实质性地提高了不育系的稻米品质和综合水平。为培育优质米杂交稻奠定良好的遗传基础。

英语. The maintainer lines of wild abortive（WA）cytoplasmic male sterile line mainly come from early indica rice cultivars with the genetic background of Nan-Te-Hao and Ai-Zi-Zhan and so on in the valley of Changjiang River due to genetic restriction of the relationship between the WA cytoplasm and its restorer line. The high content of amylose and big chalkiness for these cultivars has long restricted the improvement of hybrid rice quality. The study was aimed at improving rice quality high efficiently and rapidly by using a new breeding approach. A male sterile cytoplasm of O. rufipogon, named FA cytoplasm, was obtained through nuclear substitution of the wild rice （ O. rufipogon ） with the nuclear of cultivated rice by backcrosses. The results showed that the male sterile line with FA cytoplasm was different from WA and HL sterile lines （table 5） in the relationship between restorer line and maintainer line. The restorer and maintainer lines of WA and HL both could be used as the maintainer line of FA cytoplasmic sterile line, but not as its restorer line. It was a newly found resource of rice male sterile cytoplasm. FA cytoplasm was free from the genetic confinement of the relationship between the restorer line and maintainer line of WA and HL, enlarging the circle of maintainer liners so that good cultivated cuhivars could be developed into fine male sterile lines. Jinnong 1A, a newly developed male sterile line with FA cytoplasm, had a high degree of stable sterility with superior agronomic traits and good resistance to diseases. It flowered earlier with good rice quality. All the twelve indexes of rice qualities reached the first or second class standards issued by the Ministry of Agriculture, China, which substantially improved the rice quality and comprehensive traits, and established a solid foundation for the development of fine quality hybrid rice. The development of FA cytoplasm and the male sterile line of Jinnong 1A made it possible to open up a new way of breeding high standard of fine quality male sterile lines. It was of great significance to the enriching of genetic diversities of hybrid rice cytoplasm and the increasing of hybrid rice quality and yield by leaps and bounds.