ROOT QTL TRAITS AND WATER USE EFFICIENCY PYRAMIDING THROUGH MARKER ASSISTED SELECTION LEADS TOWARD SUPERIOR GENOTYPES FOR DROUGHT TOLERANCE IN RICE (Oryza sativa L.)

H.B. MAHESH¹, FARHAD KAHANI²*, SHAILAJA HITTALMANI^3
1Marker Assisted Selection Lab, Department of Genetics and Plant Breeding, College of Agriculture, UAS, GKVK, Bangalore, 560065, India
²Marker Assisted Selection Lab, Department of Genetics and Plant Breeding, College of Agriculture, UAS, GKVK, Bangalore, 560065, India
³Marker Assisted Selection Lab, Department of Genetics and Plant Breeding, College of Agriculture, UAS, GKVK, Bangalore, 560065, India
* Corresponding Author : fk7097@gmail.com

Received : 24-03-2016     Accepted : 19-06-2016     Published : 06-10-2016
Volume : 8     Issue : 44       Pages : 1888 - 1896
Int J Agr Sci 8.44 (2016):1888-1896

Keywords : Near isogenic lines (NILs) – root QTL– pyramiding– Drought–Carbon 13 isotope discrimination– Rice
Conflict of Interest : None declared
Acknowledgements/Funding : None declared
Author Contribution : None declared

Twenty two NILs and 94 pyramided lines were evaluated for shoot, root traits and water use efficiency (WUE) under two water regimes. Significant differences for different pyramid genotypes were observed under low moisture stress (LMS) condition. Higher yield was recorded in qRT 2+7-14-4 genotype containing root length QTL on chromosome 2 and 7, under well watered condition; under stress, yield was high in genotype qRT 2+9- 19-3 having QTL on chromosome 2 and 9. A set of 50 root pyramid genotypes were analyzed for carbon-13 isotope discrimination, a surrogate trait for WUE. Highest WUE among QTL introgressed lines was observed for qRT 1+7-16-4 genotype for root QTL on Chr. 1 and 7. Root phenology using polypropylene pipes revealed significant differences among genotypes for root length, root number, root volume, root fresh weight and root dry weight. Maximum root length and root number were for qRT 1+7-18-4 and qRT 1+7-19 genotypes containing QTL on chromosome 1 and 7 respectively. Root volume was highest in QTL introgressed genotype qRT 2+7-10-4. The best performed lines were forwarded for subsequent testing towards developing drought tolerant genotypes.