Biochemical basis of resistance in rice hybrids and conventional varieties against brown plant-hopper, Nilaparvata lugens (stal.)

The phloem sap samples of resistant and susceptible genotypes including 5 rice hybrids namely CORH2 (IR 58025A/C20R), IR 58025A (IR4843A/PUSA 167–120 - 3–28), C20R, C10, IET 15423, TN1, PTB33 and IR54742–22-19–3R were screened to UV light, absorbing compounds by means of high performance liquid chromatography. The gallic acid content was highest in IR 54742–22-19–3R (3713.85 mg/g) followed by C20 R (3514.36 mg/g) which was 84.3 and 83.6% higher than T(N)1. The total phenol was highest from the leaf sheath of the resistant genotype IR 54742–22-19–3R with 22.52 ppm. The total sugar content was highest in C20 R with 3511.2 μg/g which was 33.51% higher than T(N)1. Total chlorophyll was minimum in IR 54742–22-19–3R, that was 2.60 times lower than T(N)1. Chlorophyll ‘a’ and ‘ b’ content in T(N)1 was 2.40 and 2.50 times, respectively higher than in IET 16934.