Among the abiotic stresses, drought is the major factor for heavy yield losses in rice production. The present study was undertaken with an aim of understanding the effect of mega QTLs of Apo controlling yield under drought. The BILs viz., CB 229 and CB 193-3 were evaluated for their drought responses under green house conditions along with the parents Apo, IR64 and check Norungan during Summer 2015, Kharif 2015, Rabi 2015-16. The results from this study reported that, Apo and BILs had higher photosynthetic rate when compared to IR64 under drought. | Comparative study on backcross inbred lines of IR64 rice (Oryza sativa L.) introgressed with drought QTLs under varied moisture regimes over different seasons