Assessment of Genetic Variability and Resistance Screening of Rice Genotypes against Brown Planthopper (Nilaparvata lugens) Using Modified Seedbox Technique

Abstract

Background: The brown planthopper (Nilaparvata lugens Stal) remains one of the most destructive insect pests of rice (Oryza sativa L.), causing direct feeding damage and transmitting viral diseases that significantly reduce yield. Aim: This present investigation aims to evaluate BPH resistance and the genetic variability, heritability and genetic advance for yield and its attributing traits in order to identify promising rice types suitable for specific regional conditions like Karnataka, ultimately contributing to the development of high-yielding, pest-and disease-resistant rice cultivars. Method: The present study was conducted during the kharif 2019 season at the Agricultural Research Station (ARS), Gangavati, affiliated with the University of Agricultural Sciences, Raichur, Karnataka, India. In this study, 28 rice genotypes were evaluated for resistance to brown planthopper (BPH) under controlled conditions using the Modified Seedbox Screening Technique (MSST). The data were subjected to analysis using the Web Agri Stat Package (WASP 2.0) and Microsoft Excel 2019.  Results: MSST evaluation confirmed three genotypes with highly resistance scores and minimal damage symptoms, suggesting the presence of constitutive defence mechanisms. Agronomic trait analysis revealed high phenotypic and genotypic variability among genotypes, particularly in grain yield and related traits. High heritability and genetic advance estimates indicated the potential for effective selection in breeding programs. Conclusion: The presence of substantial genetic variability, along with high heritability and GAM across several traits, provides a valuable foundation for future breeding strategies aimed at durable BPH resistance, contributing to sustainable rice production under biotic stress.