基于抗病功能基因标记的中国三系杂交水稻骨干亲本遗传多样性研究

摘要

为探究实现水稻广谱持久抗性育种,以及水稻病害的有效防治,本研究利用文献中报道的与抗稻瘟病及白叶枯病相关的43个功能基因相关标记,研究了76个中国籼型(Oryza sativa ssp.indica)三系杂交水稻骨干亲本的遗传多样性.结果显示,36个标记具有多态性,多态性位点百分率(P)81.81％,共检测到87个等位基因位点；其中有效等位基因(Ne)61.96个,占71.22％,Nei's遗传多样性指数(He)变幅为0.358～0.974,平均值0.629.76份材料间的遗传相似系数(Gs)变幅为0.341～0.925,平均值0.550.采用UPGMA法进行聚类分析,在遗传相似系数0.624处分为保持系和恢复系两类.保持系和恢复系间的遗传分化系数(Fst)为0.158,呈高度遗传分化,Nei遗传距离(D)0.201.结果显示,功能基因相关标记具有较高的DNA多态性检测效率,用于类群划分和种质资源的多样性分析等方面更具准确性和可靠性；中国三系杂交稻骨干亲本在43个功能基因位点的亲缘关系较近,遗传基础狭窄,同源性较高.但保持系群和恢复群系间在这些功能基因位点的遗传差异较大,遗传分化程度较高.研究结果提示,所研究材料在DNA水平存在丰富的杂种优势利用空间,特别随着更多更细的功能基因位点的发掘,为水稻分子辅助抗性选育以及病害防治提供了有效的实现途径.%To explore broad-spectrum and durable rice resistance in breeding, as well as effective prevention and treatment of rice diseases, 43 SSR primers of functional genes related to blast and bacterial leaf blight (BLB) resistance were used to detect genetic diversity among 76 Chinese three-line hybrid rice (Oryza saliva ssp. Indica) parents. The result indicated that 36 primers showed polymorphism and 87 alleles loci were detected; While the number of effective alleles (Ne) were 61.96, account for 71.22%, and Nei's genetic diversity index (He) ranged from 0.358 to 0.974, on an average of 0.629. The genetic similarity(G5) of 76 varieties ranged from 0.341 to 0.925, on an average of 0.550. UPGMA cluster analysis showed that the 76 accessions could be classified into two distinct classes, maintainer lines and restoring lines, at similarities coefficient 0.624. The coefficient of genetic differentiation (Fst) was 0.158, showed high variation level, and the Nei's genetic distance (D) was 0.201. The study suggested that the functional gene markers had high DNA polymorphisms detection efficiency, and could be used as useful tool for measuring genetic diversity accurately and reliably; overall, the backbone parents studied in research showed nearer genetic relationship and higher homology sort of genetic basis. However, there still showed higher genetic differentiation between maintainer lines and restoring lines, which suggesting that, with more and more functional locus going to be expiscated, there can be more value in use to rice resistance by heterosis breeding.