ABSTRACT
Rice genotypes having high crop water productivity in dry direct-seeded rice (DDSR) need to be assessed while promoting labor- and water-saving technology. The objective of this study was to evaluate the ability of several selection indices to identify genotypes with high crop water productivity in DDSR. A set of 16 genotypes [13 recombinant inbred lines (RILs) and three genotypes as check for control] were evaluated under DDSR for two consecutive years (2013 and 2014) using two irrigation regimes [-10 kPa (non-stress) and -20 kPa (stress)]. Grain yield varied from 5.3 to 8.4 t ha-1 and 5.9 to 8.7 t ha-1 for irrigation regimes of -20 and -10 kPa, respectively. Yield reductions caused by water stress ranged from 2.9 to 25.1%; being lowest in RIL1649 and highest in hybrid SVH-127. The genotypes with high stress-tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP) and harmonic mean productivity (HAR) were identified as the most productive genotypes for high crop water productivity in DDSR. The results implied that selection based on stress tolerance indices likes STI, MP, GMP and HAR was useful in identifying genotypes with high crop water productivity under DDSR and RIL 1649 and SVH-127 were identified as superior genotypes in this regard.
Acknowledgments
We are grateful to Dr. Manjit S. Kang (Kansas State University, Manhattan) (Technical Editor, Crop Science) and four anonymous reviewers for critically reviewing this manuscript. We also acknowledge funding from the Department of Biotechnology, India.
Disclosure statement
No potential conflict of interest was reported by the authors.
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