Tagging of Brown Planthopper Resistance Genes in F2s of IR50 × Ptb33 of Rice by Using Bulked Segregant Analysis

Abstract: Brown planthopper (Nilaparvata lugens Stål) is one of the most damaging pests causing hopper burn in rice, and thereby reducing the productivity and also the quality of the product. The effective management strategy to control this pest is the identification and transfer of desirable genes to local rice cultivars. The most important approach for developing resistant cultivars is the identification of markers, which can help in marker-assisted selection of more durable resistant genotype. The susceptible parent IR50 and the resistant parent Ptb33, and their F2 populations were used in bulked segregant analysis for identification of resistant genes with random amplified polymorphic DNA marker (RAPD) primers. The primers OPC7 and OPAG14 showed both dominant and susceptible specific banding pattern so called co-dominant markers. Moreover, OPC7697 and OPAG14680 showed resistant specific bands and thus being in coupling phase, whereas OPC7846 and OPAG14650 showed susceptible specific genotypic bands in bulked segregant analysis. Therefore, the coupling phase markers, OPC7697 and OPAG14680, are considered to be more useful in marker-assisted selection of rice genotypes in crop improvement. Key words: random amplified polymorphic DNA marker; brown planthopper; bulked segregant analysis; marker-assisted selection; Oryza sativa Rice (Oryza sativa L.) is the staple food over half of the population in Asian countries., but the diseases and insect pests affected its production and productivity. Among the pests