HETEROSIS AND COMBINING ABILITY ANALYSIS IN INDIAN MUSTARD ( Brassicajuncia L.).

Abstract

An experiment on olei lerous lfrasswa juncia 1.. was conducted to evaluate the heterosis and combining ability of difThrcnt characters on seed yield. Out of 21 Es, the cross 3-8 x 3- 9 showed desirable heterosis for primary branch, secondary branch and seed yield per plant J-7 x J-9 for primary branches, seed yield per plant and thousand seed weight: J-7 x i-Il for days to maturity: i-LU x 3-I Ifor 50% flowering and maturity. The cross 3-I x 3-2. J-1 x J-7, i-I x i-tO. i-I x J-J 1 .3-2 x J-7 . 3-2 x J- 8, i-2 x i-I S and J-8 x 3-li were also good for seed yield per plant. the parent 3-7 and J-9 were good general combiner for days to flowering and maturity: J49 for plant height: 3-7 for number of primary branch and seed yield per plant and 3-8 For thousand seed weight. On the basis of average score and rank position. the hybrid i-S J-9 was superior specific combiner for number of primary branches per plant. number of secondary branch per plant. number of siliquae per plant and seed yield per plant: i-I x J-2 for maturity, primary branches per plant. number of siliqtmae per plant and siliqua length per plant; J-7 x J-9 for number of primary branches per plant and number of secondary branches per plant. 3-7 x .1-1 I and 3-10 x i-I S L'or maturity, .1-2 x .f-8.J-7 x i-S and i-S x i-ID for thousand seed weight: i-I x i-tO. J-2 x J-8. 3-2 xi- II and J-7 x J-S also good for seed yield per plant. The mean sum of square due to general combining ability (gca) was significant for plant height .days to 50% flowering, days to maturity and thousand seed weight indicating that the additive gene actions was predominant thr the expression of these character. The signilicant mean sum of square due to specific combining ability (sea) was also observed for plant height. days to maturity, number of primary branches/plant. number of secondary branches/plant , number of siliquae/ plant. thousands seed weight and seed yield/plant indicating that the non-additive gene actions were predominant for the expression of these characters. The higher magnitude of gca variance was observed than that of sea variance for plant height, days to 50% flowering. days to maturity, length of siliquae. number of seeds per siliqua and thousand seed weight.