DRR DHAN 42 [IR 64 (Drt 1)] - First Drought Tolerant MAS derived Rice Variety
DRR Dhan 42 (IR 64 Drt1) is a first drought tolerant rice variety released in 2014, developed using Marker Assisted Selection. It produces high yield under drought stress conditions at reproductive and grain filling stages. DRR Dhan 42 is a near-isogenic line of IR 64 with two QTLs introgressed for yield under stress qDTY 2.2 and qDTY 4.1. The QTLs for yield under drought stress were introgressed from Aday Sel by repeated backcrossing followed by intermating under IRRI-India STRASA programme. DRR Dhan 42 is characterized by high yield than IR 64 under drought situations and on par yield with IR 64 under normal conditions.
It is estimated that by 2025, 15-20 million hectares of irrigated rice will suffer from some degree of water scarcity. In this context, it is important to develop and promote strategies to help the farmers to adapt for improving water management and productivity. Developing drought tolerant varieties, using the concept of introgressing yield QTLs under drought in high yielding back ground without reducing yield under normal condition is the ideal strategy to maximise rice yields in drought prone areas. This concept was used in the development of DRR Dhan 42. The QTLs for yield under drought stress identified at IRRI and elsewhere were used at IIRR and introgressed qDTY2.2+qDTY4.1 QTLs under drought in the back ground of mega variety IR 64 grown under rainfed mid land using two back cross followed by two selected intermating in association with IRRI, Philippines.
Practical Utility/ Scalability
- DRR Dhan 42 produces high yield under drought stress conditions at reproductive and grain filling stages.
- Improving yield of varieties along with drought tolerance is very difficult. Hence, instead of developing drought tolerant varieties, the concept of introgressing yield QTLs under drought in high yielding back ground without reducing yield under normal condition is the ideal strategy to maximise rice yields in drought prone areas.
- Mr Harikrishna Reddy of Shabad Mandal, Rangareddy District of Telangana State cultivated DRR Dhan 42 and IR 64 each in one acre of land during Kharif 2016. DRR Dhan 42 expressed yield advantage of 19.5% over IR 64.