Genotyping and Identification of Candidate Genes for Resistance to Brown Planthopper Nilaparvata lugens (Stal) in Traditional Rice Varieties

Rice (Oryza sativa L.) feeds more than half of the global population, but its production is severely threatened by the rice specific pest brown planthopper (Nilaparvata lugens Stål). Developing resistant rice varieties is the most cost effective control strategy, making the identification of resistance genes and mechanisms a key focus in breeding programs. In this study, analysis of 25 SSR markers associated with BPH resistance genes and QTLs identified PTB 60 (Vaisakh) as having the highest number of resistance genes/QTLs (bph4, BPH7, Bph27, Bph31, Bph32 and qBph4.3). All other genotypes carried at least one resistance gene or QTL. The highly resistant MO 22 (Sreyas) possessed the major resistance gene Bph32 and QTL qBph4.3. The identification of traditional cultivars with multiple resistance genes and QTLs offers valuable genetic resources for breeding BPH resistant rice varieties. The resistant accessions identified in this study can serve as donor parents in rice breeding programs aimed at improving BPH resistance.