栽培稻种间育性S1基因桥梁亲本培育及分子验证研究

Study on Development of S1 Near Isogenic Line and Molecular Confirmation in Rice (Oryza sativa L.)

栽培稻种间杂种的高度不育是从非洲栽培稻向亚洲栽培稻转移有利基因的最主要障碍.用携带非洲栽培稻的不育基因S1,以亚洲栽培稻为背景的桥梁亲本与非洲栽培稻杂交,可望大大缓解种间杂种的不育.以亚洲栽培稻合系39和非洲栽培稻IRGC104049为材料,培育出一批BC2F10中间材料,其表现型与轮回亲本表现型一致,供体遗传背景占14.18%.用其与合系39回交培育出的BC3F1花粉和小穗均为半不育,BC3F2群体的花粉育性和小穗育性呈双峰分布,分成半不育和可育两类.第六染色体的RM589、RM588、RM190、RM7639、RM586标记与目标性状相关极显著,并把控制育性的位点定位在RM190和RM7639间,距离分别为3.2cM、4.8cM,说明非洲栽培稻的不育基因S1已导入合系39,紧密连锁的SSR标记RM190和RM7639可用于分子标记辅助选择,S1在合系39背景下的配子消除作用达到79.61%,遗传基本符合单位点孢子体-配子体互作模式.

High sterility of interspecific hybrid between Oryza sativa and O.glaberrima is the most serious obstacle to introgressing useful genes from O.glaberrima into O.sativa.Using a bridge parent with the genetic background of O.sativa,which carries S1 introgressed from O.glaberrima,to hybridize O.glaberrima may greatly reduce the interspecific sterility of the hybrid.In this study,O.sativa cultivar Hexi 39 was crossed as the recurrent parent with O.glaberrima cultivar IRGC104049 as the donor,and a number of BC2F10 lines were obtained.The phenotype of the NILs was nearly the same as that of their recurrent parents and 14.18% fragments was introgressed from O.glaberrima,among which one line was semi-sterile when hybridized to Hexi 39 again.Pollen fertility and spikelet fertility of the BC3F2 population showed a bimodal distribution and consisted of fertile and semi-sterile plants.The markers RM589,RM588,RM190,RM7639 and RM586 on Chromosome 6 were significantly correlated with the target traits.The sterility-controlling locus was mapped between RM190 and RM7639 with 3.2 cM and 4.8 cM,respectively,which showed that S1 of O.glaberrima had been introgressed into O.sativa.The SSR markers RM190 and RM7639 could be used for marker-assisted selection of S1.The female gamete eliminated by S1 was 79.61% in an O.sativa background.The one-locus sporophyte-gamete interaction mode could be used to explain the inheritance of S1.