基于抗稻瘟病基因Pi40特异性SCAR标记的MAS育种应用

Application of MAS Breeding Based on Specific SCAR Marker of Blast Resistance Gene Pi40

利用PCR从3份携带抗稻瘟病Pi40基因的粳稻材料中扩增、筛选获得特异性片段,通过测序分析比对和引物设计,开发出一个SCAR分子标记3F。该标记在15份抗稻瘟病单基因系和抗性品种中能够特异性的检出Pi40基因系。利用Pi40品系4163与丽江新团黑谷构建F2群体123株,发现3F在其中96个单株中检测到550 bp的目标条带,同时田间稻瘟病抗性鉴定结果表明该96个单株田间表现为R,另外27份未检出目标条带的单株表现S,卡方检测分离比符合3:1。进一步利用3F在183份云南水稻育成品种中检测,结果显示仅在其中9份材料中有目标带型出现,而在其它174份云南水稻品种中没有检测到目标带型,这为有目的地开展品种抗性改良提供直接而高效的筛选标记,结果表明3F是一个具有很高的特异性,在云南稻作系统中有实际应用价值的分子标记。以3份感病粳稻材料与4163杂交,构建稻瘟病抗性改良F2群体,利用3F筛选出来的单株经稻瘟病菌喷雾接种鉴定,表现为R,而未检出目标条带的单株则表现为S。

Specific fragments were obtained through PCR amplification and screening from 3 Japonica rice materials which carried Pi40 gene.A SCAR marker,named 3 F,was exploited by sequencing analysis and primer design.Primary research found that 3 F would select out the Pi40 lines distinctively among 15 monogenic lines and rice blast resistant materials.A F2 segregation population of 123 plants was constructed crossing by Pi40 line and LTH,and the aimed bands of 3 F were detected in 96 of them.The result field identification of resistance to rice blast showed that the 96 individual rice plants showed R in the field,and the other 27 plants with no aimed bands showed S.The Chi square test showed a separation ratio of 3:1.In addition,3 F was carried out among 183 bred Yunnan varieties,and in which only 9 varieties were detect the expansion band.The target band type was not detected in the other 174 Yunnan rice varieties which provided a direct and efficient screening marker for purposeful improvement of variety resistance.The results indicated that the 3 F was a molecular with high efficient and practical value in Yunnan MAS rice breeding.An improved F2 population with resistance to blast was constructed by crossing 3 japonica rice materials with 4163.The single plant screened by 3 F was identified as R by spraying inoculation with magnaporthe grisea,while the single plant with no target band was S.