LAUSR

Five rice accessions belonging to three wild species viz., IRGC99577 ( Oryza punctata Kotschy ex Steud.), IRGC105270, IRGC105275 ( O. australiensis Domin.), IRGC104646, CR100204 ( O. nivara Sharma et Shastry) along with TN1 (susceptible check) and Ptb33 (resistant check) were used to study antixenosis and the role of biophysical factors in imparting resistance to brown planthopper (BPH), Nilaparvata lugens (Stål). The settling of BPH nymphs and adults was significantly less on IRGC99577, IRGC104646, and Ptb33 than on TN1. Oviposition and egg viability was less, while probing/feeding marks was more on IRGC99577 and IRGC105270 accessions. IRGC104646 showed longest trichomes while trichome density was greater in Ptb33. Largest silica cells were observed in IRGC99577 and TN1. Antixenosis resistance parameters did not show any significant association with biophysical factors. The accession IRGC99577 displayed a high level of antixenosis resistance for nymph settling, adult settling, feeding/probing marks and oviposition to BPH. This accession has emerged as a new source of resistance, which can be used for resistance breeding and to find gene/QTLs for antixenosis parameters.