According to the sources, it has been reported that iotic stresses made DRR17B has been developed by the Indian Institute of Rice Research, Hyderabad, an obvious choice for improvement through DBT’s Accelerated Crop Improvement Program (ACIP) which aimed at targeted improvement of several elite rice varieties and parents used in hybrid rice breeding for resistance against major rice pests and diseases. Under this project, two major resistance genes, Xa21 (conferring resistance against bacterial blight disease, sourced from an accession of wild species of rice, named Oryza longistaminata) and Pi54 (conferring resistance against blast disease, sourced from a landrace of rice, named Tetep) were introduced to DRR 17B (which is a high yielding female parent used in hybrid rice development, possessing the highly desirable medium-slender grain type with stable maintenance ability, but is highly susceptible to bacterial blight and blast diseases.
Further, it has been explained that after development of improved versions of DRR17B possessing bacterial blight and blast resistance through marker-assisted breeding, the next step involved conversion of the improved versions of DRR17B possessing multiple biotic stress resistance genes to its cytoplasmic male sterile counterpart (DRR17A) so that it can be immediately used for developing promising, high yielding, biotic stress resistant hybrids. In addition to improve DRR17B, the team at the Indian Institute of Rice Research has also developed pest such as gall midge and brown plant hopper as well as disease such as bacterial blight and blast resistant versions of a high yielding variety, Akshaydhan, which possesses good adaptability and an elite restorer line, named RPHR-1005.
Furthermore, in this matter it has been revealed that the improved versions of Akshayadhan, DRR17B and RPHR1005 possessing multiple biotic stress resistance is under evaluation in the All India Coordinated Rice Improvement Programme at multiple locations in the country. The improvement of RPHR1005 is very important as it is the male parent of the country’s first hybrid possessing high yield along with the highly desirable medium slender grain type, named DRRH3. Improved versions of RPHR1005 along with that of DRRH3 have already been developed and tested for their yield and biotic stress resistance and it has been found highly promising as compared to their original parents.