Phenotypic and genotypic insights into rice germplasm resistance against a biotype of the brown planthopper Nilaparvata lugens (stal)

This study explores the resistance of rice landraces, genotypes and wild rice to the South Asian brown planthopper (BPH) population, a significant pest affecting rice crops. Phenotypic screening identified a few landraces, genotypes and wild rice varieties with resistance to the South Asian biotype, including, PTB-33, Oryza officinalis, O. nivara, Adukkan, Vellai Kombi Samba and Onamuttan which exhibited damage scores <= 3 Moderate resistance was observed in IR 36, ARC 10550, T12, Manvilayan, Rathu Heenati, CR 2711, Mysore Malli, Swarnalata, Pokkali, Babawee and ASD 7, while other varieties demonstrated varying levels of susceptibility. Molecular analysis using SSR markers revealed the presence of BPH resistance genes across these genotypes. Notably, Onamuttan and Vellai kombi samba exhibited a broad resistance gene profile, while Adukkan, Manvilayan possess two BPH-resistant genes. Conversely, ASD 7 and Rathu Heenati, despite possessing several resistance gene markers, displayed moderate resistance. This study underscores the potential of integrating resistant genotypes into breeding programs, employing SSR markers for precise gene mapping and marker-assisted selection. The combined phenotypic and genotypic data provide valuable insights for advancing rice breeding strategies for sustainable BPH management and improved pest resistance.