谷子Si-SP1小穗突变基因的遗传分析和定位

通过EMS(Ethyl methylsulfonate,甲基磺酸乙酯)诱变豫谷1号获得一个遗传稳定的谷子小穗突变体si-sp1,该突变体突出表现为穗部变小,同时伴随有株高降低、单码小花数减少和根系变小等表现型变异。与野生型豫谷1号相比,突变体的穗长和株高分别降低了37.8%和9.0%,单穗粒重和单码小花数分别降低了40.3%和31.7%,但千粒重增加了20.2%。遗传分析表明,si-sp1突变性状由1对隐性基因控制。以si-sp1为母本、辽谷1号为父本构建的F2定位群体的隐性单株,将突变基因定位在8号染色体上CAAS8003与SSR1038间约11.02 M的距离内,为下一步精细定位并分离该基因奠定了基础。

Morphological effect and genomic mapping of Si-SP1 (small panicle1) in Foxtail millet

A small-panicle mutant si-sp1 induced by chemistry (EMS) mutagenesis was isolated. The mutant exhibits small-panicle trait, as well as low-plant-height, low-spike-number per panicle and less-roots. Compare with its wild-type Yugu1, panicle length, plant height, spike weight per plant and spike number per panicle of si-sp1 were decreased by 37.8%, 9.0%, 40.3%, 31.7%, respectively, while the 1000-grain weight was increased by 20.2%. Genetic analysis showed that the small-panicle trait of si-sp1 mutant was controlled by one recessive nuclear gene. Genetic mapping of the mutant gene was conducted using small-panicle individuals from the F2 segregating population of si-sp1/Liaogu1. Finally, the mutant gene was mapped into genomic region within SSR markers CAAS8003 and SSR1038 in chromosome 8, with physical distances of 11.02 M. This research has laid the foundation for fine-mapping of the small panicle mutant gene.