Resistance of Oryza nivara and Oryza eichingeri derived lines to Brown planthopper, Nilaparvata lugens (Stal) in Sri Lanka

Abstract

Abstract: This study evaluates the basis of Brown planthopper (BPH) resistance in O. nivara (9864, WRAC 04), O. eichingeri (TC 01, TC 02), IR 54751-2-34-10-6-2 (an introgression line of Oryza officinalis), Ptb 33, Bg 380 and Bg 379/2 accessions by screening for resistance, and characterizes the genes by molecular techniques. Four BPH populations reared on Ptb33, Bg 380, Bg 379/2, IR 54751-2-34-10-6-2 and a virulent BPH population collected from rice fields in Kegalle area were used for screening tests. Screening for resistance was conducted following the standard honeydew test and molecular screening was carried out using specific molecular markers for bph2, Bph10 and Bph13 genes. Results of the screening tests for resistance showed that the level of resistance of the tested wild rice accessions (O. nivara and O. eichingeri) was not significantly different from that of Ptb 33. These accessions also showed high level of resistance to all the BPH populations used in this study. Molecular screening revealed positive results with O. nivara (WRAC 04) accession for bph 2 and Bph 13 markers and O. eichinigeri derived lines (TC 01 & TC 02) for Bph 13 marker. Results showed that the emergence of virulent biotype in field rice cultivations have the potential to overcome the BPH resistance in Bg 379/2.