Identification and characterization of QTLs for brown planthopper resistance from wild rice, Oryza nivara (Sharma et Shastry)

Abstract

The brown planthopper (Nilaparvata lugens (Stål); BPH) is a serious insect pest of rice (Oryza sativa L.). Host plant resistance is an effective means of controlling this pest; up to date at least 46 BPH resistance genes have been identified. However, BPH can overcome resistance conferred by single resistance genes. Therefore, it is necessary to detect new and durable resistance genes. Here, we identified quantitative trait loci (QTLs) for BPH resistance from the wild rice Oryza nivara (Sharma et Shastry) IRGC 89073. Using backcrossed populations derived from IRGC 89073 × the susceptible ‘Taichung 65’, we detected two resistance QTLs, qBPH4 on chromosome 4 and qBPH11 on chromosome 11. qBPH11 was validated in the BC₃F₂ population. A near-isogenic line carrying qBPH11 showed significant resistance to BPH in antibiosis, antixenosis, MSST, and honeydew tests. These results suggest that IRGC 89073 harbors valuable genetic resources that could enhance BPH resistance in rice breeding programs, particularly through pyramiding strategies using marker-assisted selection.