Enhanced Resistance against the Rice Leaffolder (Cnaphalocrocis medinalis) in Transgenic Rice Plants containing the Potato Proteinase Inhibitor II Gene

Abstract

Third generation transgenic plants of ten independently raised single-copy lines of Japonica (TNG67) and aromatic indica rice varieties (HBC19 and Pusa Basmati 1) containing potato proteinase inhibitor II gene (pinII) were evaluated for resistance against the rice leaffolder, Cnaphalocrocis medinalis (Guenee 1854) with emphasis on insect growth and development. Five of these transgenic lines (T-TNG-64, T-TNG-61, T-TNG-46b, T-TB-95 and T-TB-82) exhibited high level resistance against rice leaffolder. The highest larval mortality was noticed on T-TNG-46b (95.0%) followed by T-TB-82 (92.5%), T-TNG-64 (87.5%) and T-TNG-61 (87.5%) in comparison to only 4.0% in the control plants. The lowest larval feeding was observed on T-TNG-46b and T-TNG-61 (4.12 mm 2 and 4.50 mm 2 ) as against 19.1(TNG67), 18.6 (Pusa Basmati 1) and 23.0 (HBC19) mm 2 in control plants. In whole plant bioassay, the transgenic rice lines had 3 and 5 damage grades compared to 9 damage grade in control plants. Larval/ pupal growth and development (larval survival, larval period, larval weight, percent pupation, pupal period, pupal weight and moth emergence) were adversely affected when fed on transgenic leaf tissues. These results demonstrate that PinII in rice can provide effective control against rice leaffolder.