In vitro assessment of different rice genotypes for resistance to brown plant hopper Nilaparvata lugens (Stal.)

Five hundred twenty rice genotypes were screened against BPH, (Nilaparvata lugens (Stal). Out of these, 5 genotypes were categorized as highly resistant, 128 as resistant, while 82 as moderately resistant and rest as moderately susceptible and susceptible to BPH. The average plant damage score of highly resistant genotypes was ranged from 0.50 to 0.91 whereas 1.00 to 2.98 in resistant and 3.01 to 5.00 in moderately resistant category. The average probing marks per seedling was ranged from 12.00 to 35.00. The genotype R1723-1413-357-1 had the highest (35.00) average probing marks followed by R1959-173-3-27-1 (31.80), R1600-1124-3-619-1 (31.20), BP10625-BB4-19-BB8 (30.80) and IR64 (30.60). The minimum average probing marks per seedling (11.30) was observed in susceptible check TN1. Significantly higher number of probing marks was found in all resistant genotypes as compared to susceptible check TN1. As regards to days required to wilt due to BPH feeding, the genotype IR78554-145-1-3-2 required the maximum days (35.80) followed by R1959-173-27-1 (35.60), IR64 (35.20) and Ganjeikalli (32.80). All the resistant genotypes had significantly higher number of days required to wilt in comparison to susceptible check TN1.