Identification of new sources for brown planthopper resistance from rice germplasm and introgression lines derived from O. nivara

Brown planthopper (BPH) Nilaparvata lugens (Stål) causes considerable yield losses worldwide. As many of the donors, genes identified, and resistant varieties developed have become ineffective against the Indian biotype (biotype 4), identification of new resistant sources and genes is important. Nine hundred and twenty rice germplasm accessions along with five introgression lines derived from O.nivara in the background of Swarna and 18 gene donors were screened for reaction to brown planthopper using Standard Seedbox Screening Test and damage was scored by following SES (SES 2002). Some of the resistant introgression lines and gene donors along with checks were screened in field at maximum tillering stage to understand the reaction of BPH at adult plant growth stage. Twelve rice germplasm accessions and five introgression lines showed resistance reaction at seedling stage with damage score of 1-3.0 in 0-9 scale. While 23 accessions showed moderate resistance with damage score of 3.1-5.0. Among the donors with different genes/gene combinations, Bph3+Bph17, Bph6, Bph20+Bph21, Bph22, Bph23 and bph24 showed resistance reaction. RP Bio 4918 (230S), OM4498, RP2068-18-3-5 and PTB33 were resistant in adult stage and rest were susceptible. These lines can be used in breeding resistant varieties as well as in identification of genes for BPH resistance.