一个水稻雄性不育突变体的遗传分析和基因定位

Genetic Analysis and Molecular Mapping of a Male Sterile Mutant in Rice

ms-np是一个源于自然突变的水稻雄性不育突变体,明显较正常植株矮小,叶色浓绿。小花解剖观察发现,突变体小花花丝细长,花药干瘪,呈白色透明状,但雄性器官的数量和雌性器官正常。碘染证实,突变体的花药壁内没有花粉粒着色,是一个典型的无花粉型雄性不育材料。5个F2和2个BC1F1群体的遗传分析显示,该突变性状受1对隐性基因控制。对组合ms-np/M63衍生F2不育单株的连锁分析表明,ms-np(t)基因位于水稻第6染色体微卫星标记RM541和RM343之间,遗传距离分别为15.2cM和7.9cM。

Male sterility is an important inheritance phenomenon in plants and widely used in hybrid seed production. The male sterile plant can＇t produce normal male gametophyte for reproduction, while the female counterpart is normal. So far, more than 100 of male sterile mutants or genes have been reported in rice. Ms-np is a male-sterile mutant derived from a spontaneous mutation. The filaments of the mutant are long and thin, and the withered anthers are white and transparent. Ms-np was confirmed to be a none-pollen type mutant of male sterility, for no pollen grains were stained with I2-KI solution and the anther locules were always hollow. Genetic analysis of five F2 populations and two BC1F1 populations revealed that the mutation was controlled by a single recessive gene. To uncover the molecular basis of ms-np, the F2 population derived form the cross of ms-np/M63 was used for genetic mapping. Screening of 227 F2 mutant individuals with simple sequence repeat （SSR） markers indicated that ms-np（t） was located between the molecular markers RM541 and RM343, on chromosome 6, with the distances of 15.2 and 7.9 cM, respectively. The results provide a basis for further gene cloning and understanding of the molecular mechanism underlying rice male fertility.