Harnessing Combining Ability and Multi-environment Evaluation to Identify Superior Parents and Heterotic Hybrids for Sustainable Rice Yield Improvement
K. Rajendra Prasad *
Department of Genetics and Plant Breeding, Professor Jayashankar Telangana Agricultural University, Telangana– 500 030, India.
P. Senguttuvel
ICAR–Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana– 500 030, India.
K. V. Radha Krishna
Department of Genetics and Plant Breeding, Professor Jayashankar Telangana Agricultural University, Telangana– 500 030, India.
S. Sudheer Kumar
Department of Genetics and Plant Breeding, Professor Jayashankar Telangana Agricultural University, Telangana– 500 030, India.
L. V. Subba Rao
ICAR–Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana– 500 030, India.
P. Nagaraju
ICAR–Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana– 500 030, India.
*Author to whom correspondence should be addressed.
Abstract
The present investigation was conducted to assess combining ability, gene action and promising hybrid combinations for grain yield and associated traits in rice across multiple environments. Four WA-CMS lines, namely APMS 6A, IR79156A, IR68897A and PUSA 5A, were crossed with twelve elite restorer lines to generate 48 F1 hybrids. The hybrids, parents and three standard checks were evaluated during Rabi 2016-17 at Rudrur, Warangal and Rajendranagar using a randomised complete block design with two replications. Observations were recorded for eleven agronomic traits, including days to 50% flowering, plant height, panicle length, panicle weight, total tillers per plant, productive tillers per plant, filled grains per panicle, spikelet fertility, 1000-grain weight, grain yield per plant and days to maturity. Combining ability analysis indicated substantial variability among lines, testers and hybrids. Specific combining ability variance was greater than general combining ability variance for most yield and yield-contributing traits, suggesting the predominance of non-additive gene action. In contrast, days to 50% flowering and days to maturity showed a greater influence of additive gene action. Among the CMS lines, APMS 6A and IR79156A were identified as useful general combiners for grain yield and related traits, while TCP-718, TCP-783, TCP-963 and PSV-49 were promising restorers. The hybrids APMS 6A × TCP-718, PUSA 5A × TCP-795, APMS 6A × PSV-49, IR79156A × TCP-964 and IR68897A × TCP-783 showed desirable specific combining ability and favourable performance for grain yield and associated traits. These parental lines and hybrid combinations may be useful in further hybrid rice breeding and evaluation programmes.
Keywords: Rice, combining ability, hybrid rice, general combining ability, specific combining ability, Heterosis, Line × Tester