Combining Ability and Heterosis for Seed Yield and Its Components in Indian Mustard ( Brassica juncea L.)

Abstract

Brassica juncea L. is an important oilseed crop which occupies prem ier position in Indian agriculture. Developing high yielding genoty pes has been a major breeding objective in Indian mustard. Present study was cond ucted at Directorate of Rapeseed- Mustard Research, India, during 2010-2013 to determ ine General combining ability (GCA) and Specific combining ability (SCA) of paren tal lines and better parent heterosis of 36 crosses of Indian mustard. Parents and F 1 hybrids were evaluated in RCBD with 3 replications. Line×tester analysis involving nine b reeding lines and four testers revealed the operation of both additive and non-additive gen e actions with predominance of non- additive gene action in controlling yield and contr ibuting traits. Four lines, namely, DRMR 2243, DRMR 2341, DRMR 2486, DRMR 2613, and one tester, NRCHB 101, were adjudged the best general combiner possessing highl y significant positive GCA effects for seed yield and yield contributing traits. Significa nt SCA effects for seed yield, 1000-seed weight, oil content, and other attributing traits i n desirable direction were recorded in a series of hybrids and a close association between S CA effects and heterosis was observed amongst the best hybrids identified on the basis of SCA effects. Hybrids DRMR 2243/NRCHB 101, DRMR 2269/NRCHB 101, DRMR 2326/NRCH B 101, DRMR 2341/NRCDR 2, DRMR 2398/NRCHB 101, DRMR 2486/Ashirw ad and DRMR 2613/NRCDR 2 exhibited highest magnitude of better parent heterosis with highly significant SCA effects and higher per se performan ce for seed yield. The high yielding crosses may be exploited for developing superior ge notypes and the parents involved may be converted to well adapted cytoplasmic male steri le or restorer lines. Keywords: Additive gene actions, High yielding genotypes, Re storer lines, Specific combining ability.