EVALUATION OF BROWN PLANTHOPPER Nilaparvata lugens (stal) RESISTANCE IN Oryza nivara WILD RICE ACCESSIONS FOUND IN SRI LANKA

Abstract

Brown planthopper (BPH), Nilaparvata lugens Stal is one of the most serious rice pests in Sri Lanka. The study evaluated the nature of BPH resistance in seventeen O. nivara (WRAC 01, 02, 04, 07, 11, 12, 14, 19, 21, 22, 24, 25, 35, 41, 46, 62, and 9864) accessions collected from different locations in Sri Lanka using standard seed box screening test. Ptb 33(resistant), Bg 379/2, Bg 300(moderately resistant) and Bg 380 (susceptible) were used as check varieties. BPH culture maintained at the Rice Research and Development Institute, Batalagoda on Bg 380 was used for the test. BPH damage was scored (0-to-9 scale) according to the standard evaluation system for rice, developed by International Rice Research Institute. According to the results WRAC 04, 41, 25 and Ptb 33 recorded as resistant (score 0-3), WRAC 46, 35, 24, 22, 21, 14, 7, 2,1, 9864 and Bg 379/2 as resistant to moderately resistant (score 3.1-4.0), WRAC 11, 12 and Bg 300 as moderately resistant (score 4.1-5.0), WRAC 19 and 62 as moderately resistant to moderately susceptible (score 5.1-6.0), while no checked accessions were recorded as susceptible to the BPH indicating potential of using  Oryza nivara as a source of BPH resistance.