玉米基因雄性不育双杂合保持系的选育研究

A study on Breeding Corn Genetic Male Sterile Double Heterozygous Maintainer

本研究从1982年开始,选用玉米ms_1、ms_2和ms_(10)三个雄性核不育基因以及易位断点与相应ms基因紧密连锁的T_(4-6b)、T_(9-10a)、T_(4-10f)和T_(6-10(5519)四个易位系作为基础材料,采用细胞遗传技术育成若干个骨干自交系的基因雄性不育双杂合保持系。至今,已选育出黄早四和Mo17背景的ms_2基因双杂合保持系。保持系与ms_2基因不育系杂交,子代全部植株雄性不育;将其自交,后代分离出双杂合体和不育株。本研究结果表明:(1)不同杂易位的花粉败育率差异显著,不同自交系背景对花粉败育率无明显影响。(2)以杂易位作母本与杂合ms株杂交,子代中双杂合体出现的理论频率为7.4％。由于双杂合体生活力弱以及鉴定中存在的问题,实际选育双杂合体的频率更低。(3)黄早四ms_2基因双杂合体有三类花粉:饱满的占65％;小的和不饱满的占20％;败育的占15％。文章还讨论了双杂合保持系存在的问题和用途。

Four corn reclprocal transloctions T_(4-6b)、T_(9-10a)、T_(4-10f)、T_(6-10)(5519) andthree male sterile genes ms_1、ms_2、ms_(10) were used for breeding genic male steriledouble heterozygous maintainers in 1982 -- 1989. Each male sterile gene locus is closelinkage with the interchange point of a specific reciprocal transloction. Huang Zao Sidouble heterozygous maintainer of ms_2 was selected When they cross to male sterileplants, all male-sterile progenies will be produced. When they are self--pollinated, theprogenies will contain both double heterozygotes of parental constitution and malesterile plants. This paper outlines the breeding procedures of double heterozygousmaintainer. The experimental results indicated: (1) the four heterozygous transloctionsshowed significant differences in the degree of pollen abortion, but the various inbredline backgrounds had no significant effect on the abortive pollen percentages. (2)When the plants heterozygous for a specific translocation crossed as female with theplants heterozygous for the corresponding male sterile gene, the frequency of thedouble heterozygotes occured in progenies was 7.4% in theory. However, because oftheir poor viability, the frequency observed in this experiment was lower. (3) The pol-len grains of Huang Zao Si ms_2 double heterozygote exhibited three distinguishablephenotypes: normal (65%), small or partially filled (21%) and clearly abor-tive (15%). The demerits and uses of the double heterozygous maintainers arediscussed.