Antibiosis in wild rice accessions induced by Nilaparvata lugens (Stål) feeding

Abstract

Plant resistance to phytophagy is one of the pillars of integrated pest management. Five wild rice accessions viz. IRGC99577, IRGC104646, IRGC105270, IRGC105275, CR100204 along with susceptible (TN1) and resistant (Ptb33) controls were studied for levels of antibiosis resistance and their defense response to brown planthopper (BPH), Nilaparvata lugens (Stal) (Hemiptera: Delphacidae) feeding. Parameters involved in antibiosis resistance viz., honeydew excretion, nymph emergence, nymph survival and development duration and the potential role of antioxidant enzymes viz. superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11) and H2O2 content in imparting antibiosis against BPH was studied during wet (Kharif) crop seasons of 2017 and 2018. Increased level of antioxidant enzymes were recorded after BPH infestation both in leaf blade and sheath in IRGC99577. Higher induced level of peroxidase was observed in Ptb33 and IRGC99577. Maximum percent increase in H2O2 content after insect infestation was observed in IRGC104646 and CR100204 accessions. The correlation between nymph emergence and superoxide dismutase, peroxidase and H2O2 was significantly negative (r = −0.99, −0.89, −0.93, respectively), while, it was significantly positive with catalase and ascorbate peroxidase (r = 0.99 and 0.98, respectively). Enhanced activities of enzymes may impart resistance in selected accessions against BPH as indicated by correlation and regression analysis. IRGC99577 has come out a potential source of resistance against BPH, which could be used in breeding programmes to develop BPH resistant varieties.