利用Mudgo/武育粳3号F2群体分析水稻抗灰飞虱QTL

灰飞虱是我国水稻生产上的重要害虫。Mudgo是一个高抗灰飞虱的籼稻品种，对灰飞虱具有强的排驱性和抗生性抗性。利用Mudgo/武育粳3号F₂群体，构建了含有177个单株的F₂群体的遗传连锁图谱。该连锁图包含104个SSR标记和3个Indel标记，覆盖整个水稻基因组1 409.9 cM，每两个标记之间的平均距离为13.2 cM。采用改进的苗期集团筛选法对177个F_2:3家系进行了抗性鉴定，通过Windows QTL Cartographer 2.5进行复合区间作图分析，在第2、3、12染色体上分别检测到抗灰飞虱QTL Qsbph2b、Qsbph3d和Qsbph12a，分别位于标记RM5791~RM29、RM3199~RM5442和I12-17~RM333 1之间，单个LOD值分别为3.25、3.11和6.82，贡献率分别为17.3%、15.6%和35.8%，各QTL增强抗性的等位基因效应均来自Mudgo。其中Qsbph12a与标记RM3331和I12-17紧密连锁。结合表型鉴定的结果，Qsbph12a应为抗灰飞虱主效QTL，与该位点紧密连锁的标记可用于抗灰飞虱快速选择辅助育种。

Analysis of QTLs for Resistance to Small Brown Planthopper(Laodelphax striatellus Fallen)in Rice(Oryza sativa L.) Using an F2 Population from a Cross between Mudgo and Wuyujing 3

The small brown planthopper (SBPH), Laodelphax striatellus Fallén (Homoptera: Delphacide), is an economically important pest in rice (Oryza sativa L.) anddistributes widely in China. It not only causes direct damage by sucking plant sap but also transmits several viral diseases such as Rice stripe virus(RSV) and Rice black-streaked dwarf virus(RBSDV). which often cause major yield losses.. Host resistance has been recoqnized as one of the most economic andeffective measures in controlling SBPH.Mudgo is one of indica rice cultivars with high resistance to SBPH,expressing strong antixenosis and antibiosis against SBPH. A genetic linkage map was constructed with an F₂ population, derived from a cross between Mudgo and a japonics cultivar Wuyujing 3 for mapping QTLs associated with resistance to SBPH. The linkage map comprised104 SSR and 3 Indel markers and covered 1 409.9 cM of rice genome with an average marker interval of 13.2 cM. One hundred and seventy-seven plants ofF_2:3 families were identified for resistance to SBPH by way of the modified seedbox screening test. QTL analysis of SBPHresistance was conducted using composite interval mapping implemented in Windows QTL Cartographer 2.5 software. A total of three QTLs,Qsbph2b, Qsbph3d, and Qsbph12a,conferring resistance to SBPH were detected on chromosomes 2, 3, and 12, locating in the regions of RM5791–RM29, RM3199–RM5442, and I12-17–RM3331, with LOD scores of 3.25, 3.11, and 6.82, respectively. The resistant alleles of Qsbph2b, Qsbph3d, and Qsbph12a, were all from Mudgo and could explain 17.3%, 15.6%, and 35.8% of total phenotypic variance, respectively. Qsbph12a linked tightly to the markers RM3331 and I12-17 has a potential value in breeding for SBPH resistance by rapid marker-assisted selection.