Studies on Non-preference Mechanism and Biochemical Aspects of Resistance to BPH Nilaparvata lugens (Stal.) on Resistant Rice Genotypes

Aims: To conduct studies on non-preference mechanism and biochemical aspects of resistance to BPH on resistant rice genotype.

Study Design: Completely Randomized Design.

Place and Duration of Study: Poly-house, Department of Entomology, Rice Research Centre, Agriculture Research Institute (ARI), Rajendranagar, Hyderabad, India, between June 2017 and May 2018.

Methodology: The selected rice entries were selected including PTB33 (resistant check) and TN1 (susceptible check), this was replicated thrice. After 30 days, about hundred first instar nymphs were released in the pots. The number of nymphs settled on each entry was counted from randomly selected 10 hills at 24, 48, 72, 96 and 120 hours after release. Number of probing marks made by a day old single female insect during 24 hours of its feeding was recorded on all the selected entries along with resistant and susceptible rice cultures. Estimation of total phenols, total sugars and proteins was done for selected rice genotypes.

Results: Among all the test cultures, KNM 2305, KNM 2307, JGL 24423 and Sabita recorded lowest number of nymphal settlement. Biochemical aspects of resistance like total phenols, total sugars and protein content in selected rice genotypes was done. The amount of total phenol was observed to be maximum in the leaf sheath of moderately resistant JGL 24423 (2.70 mg/g). The amount of total sugars was lowest in RNR 26111 (0.33 mg/ g), RNR 21571(0.86 mg/g) followed by JGL 24423 (1.40 mg/g) and highest in susceptible check TN-1 (2.97 mg/g). Least amount of protein was observed in JGL 24423 (0.76 mg/g) followed by IET 23993 (1.43 mg/g).