Heterosis and Inbreeding Depression for Yield and its Components in Indian Mustard

Heterosis and inbreeding depression were studied in 45 hybrids developed through 10×10 diallel set of Indian mustard [Brassica juncea (L.) Czern & Coss.]. Heterobilities varied from-21.4 to 19.6 per cent and standard heterosis from - 23.6 to 29.6 per cent for seed yield. Significant desirable heterosis over best parent (Rohini) was observed for all the characters studied. Maximum significant standard heterosis was observed for main shoot length (56.6%) followed by secondary branches (35.8%), seed yield (29.6%), siliquae on main shoot (28.6%), seeds per siliqua (23.4%) and primary branches (22.4%) while heterobeltosis for main shoot length (68.7%), secondary branches (49.8%), siliquae on main shoot (41.6%), seeds per siliqua (39.1%), primary branches (33.4%) and seed yield (19.6%). The inbreeding depression for seed yield ranged from-35.2 to 12.8 per cent. The highest significant positive heterobeltosis and standard heterosis and high inbreeding depression was recorded in hybrids Rohini X Varuna followed by RK 9870×Vardan and Rohini×Vardan for seed yield. These crosses may be utilized for developing hybrids.