author(s)
M Srinivas, R Sunitha Devi, N Rama Gopala Varma and R Jagadeeshwar

abstract
It is predicted that the current atmospheric CO₂ concentration will be doubled and global mean temperature will increase by 1.5-6 °C by the end of this century. Although a number of studies have addressed the separate effects of CO₂ and temperature on plant-insect interactions, few have concerned with their combined impacts. The present investigation was carried out to examine the interactive effect of temperature and CO₂on resistance of rice to brown planthopper, Nilaparvata lugens (Stal.) in different rice genotypesduring the period of 2015-2016 at Rice Research Centre, ARI, Rajendranagar and Agro Climatic Research Centre, ARI, Rajendranagar. The results revealed that, among the eight genotypes tested, six genotypes viz., MTU 1001, BPT 5204, MTU 1010, RNR 8860-5, GSR 221 and RNR 20933 showed no change in resistance reaction to BPH at different combination effects of two CO₂ levels i.e. 380±25ppm and 580±25ppm and four temperature regimes i.e. 25 ºC, 30 ºC, 35 ºC, 40 ºC. RNR 11718 showed moderate resistant reaction both at ambient and elevated CO₂ at 25 °C and 35 °C, respectively. However, it showed moderately susceptible at 30 °C both at ambient and elevated CO₂. While IET 23993, showed resistance reaction at combination of ambient CO₂ with 25, 30 and 35 °C and at elevated CO₂ with 35 °C but it showed moderately resistant reaction at elevated CO₂ and 30 °C.