Choice of parents for developing two line hybrids in rice (Oryza sativa L.)

Abstract

An investigation was carried out to evaluate two line hybrids in rice for yield traits. Four TGMS lines and eleven testers were crossed in line x Tester design. Greater proportion of sca variance was observed for all the characters which revealed that preponderance of non- additive gene action governing traits concerned and selection procedures based on the accumulation of additive effects would be successful in improving these traits. The line TS09 24 and testers viz., T 2006, KDML 105, Improved white ponni and BPT 5204 were found to be good combiners for the yield and yield components. The best hybrids based on sca value, TNAU 27S x Improved white ponni was derived from low x low combiners for thousand grain weight and TS 29 X ADT 38 for the number of filled grains per panicle spikelet fertility. The best performing hybrid TS 29 x KDML 105 produced 54.25g of grain yield per plant in 128 days which was 92.89 and 85.47 per cent increase over the standard checks CORH 3 and Improved white ponni respectively. This hybrid also recorded 27.32 and 64.30 per cent increase CORH 3 and Improved white ponni for thousand grain weight. Hence, the two line hybrid breeding system, utilizing thermo sensitive genic male sterility is economically feasible as well as viable alternative to cytoplasmic male sterile (CMS) based three line breeding due to much simplified hybrid seed production.