Genetic analysis for some morphological and yield attributes of Indian mustard (Brassica juncea L.)

The present study was conducted for the estimation of genetic variability, heterosis, combining ability, and association among various traits in Brassica juncea L. Six lines (NR-5, R-4, ZN-M-1, ZM-R-7, UCD, RBJ-8003) and five testers (ZN-M-6, RBJ-8005, FZ, ZNM-5) were crossed in a line x tester fashion. Crosses along with parents were sown in a randomized complete block design with three replications. Data were recorded on seed yield related traits (plant height, number of primary branches, number secondary branches per plant, siliquae length, seeds per siliquae, siliquae per plant, 1000-seed weight, harvest index and seed yield per plant) and plant descriptive traits (leaf shape, beak shape of leaf dissection, seed colour). Analysis of variance showed significant differences among entries for all plant parameters indicating the presence of genetic variability in breeding material. The cross combinations NR-5 x FZ, ZN-M-1 x ZN-M-5 NR-5 x RBJ-27017 and ZM-R-7 x ZN-M-6 showed significant heterosis over mid and better parents. The line RBJ-8003 and tester ZN-M-5 were best general combiners for majority of traits. The cross combination R-4 x ZN-M-5 proved best specific combiner for plant height, number of primary branches, seeds per siliquae and harvest index. Number of primary branches per plant, number of secondary branches per plant, siliquae length, seeds per siliquae, harvest index and 1000-seed weight had significant and positive phenotypic and genotypic correlations with seed yield per plant. Path coefficient analysis showed that seeds per siliquae had maximum positive direct effect on seed yield followed by 1000-seed weight. The indirect effects of primary branches per plant and siliquae per plant were high and positive via number of secondary branches per plant.