Mapping of QTL s conferring resistance in rice to brown planthopper, N ilaparvata lugens

Brown planthopper ( BPH ), N ilaparvata lugens S tål ( H emiptera: D elphacide), is a destructive insect pest of rice, O ryza sativa L. ( P oaceae), in rice‐producing areas worldwide. Host plant resistance is a major aspect of managing this pest. In this study, a mapping population consisting of 150 F 3 lines, derived from a cross of MR 276 and Rathu Heenati, was used to detect and analyse quantitative trait loci ( QTL s) for the resistance to BPH . Composite Interval Mapping ( CIM ) was used for QTL detection. In total 10 QTL s controlling BPH resistance were mapped on chromosomes 1, 3, 6, 7, 9, 10, and 12. Four QTL s – qB ph‐1‐1, qB ph‐3‐1, qB ph‐6‐1, and qB ph‐7‐1 – were mapped on chromosomes 1, 3, 6, and 7 in the standard seedbox screening test, explaining 41% of the phenotypic variance. Two QTL s, qB ph‐6‐1 and qB ph‐9‐1, were detected on chromosomes 6 and 9 in the honeydew test, accounting for 32% of the total phenotypic variance. Moreover, four QTL s – qB ph‐3‐1, qB ph‐6‐1, qB ph‐10‐1, and qB ph‐12‐1 – were identified on chromosomes 3, 6, 10, and 12 expressing antixenosis to BPH and explaining 41% of the phenotypic variance. QTL qB ph‐3‐1 was located in the chromosomal region between markers RM 231 and RM 3872 on chromosome 3, and QTL qB ph‐6‐1 was located in the region between RM 588 and RM 204 on chromosome 6, indicating that these regions have a major effect in controlling the resistance to BPH in the population studied. The molecular markers linked to QTL s that are identified will be useful in the development of varieties resistant to BPH . Our study contributes to the development of genetic material for breeding programmes and marker‐assisted selection ( MAS ) in rice to improve BPH resistance.