Genetic analysis of heterosis and inbreeding depression in Indian mustard [Brassica juncea (L.) Czern and Coss]

Abstract

The present study was initiated to gather information about the phenomenon of heterosis and inbreeding depression in relation to seed yield and its component traits in five hybrids of Indian mustard [Brassica juncea (L.) Czern & Coss]. The results revealed significant instances of relative heterosis and/or heterobeltosis, indicating favorable outcomes, in terms of seed yield per plant and yield attributing traits. Notably, crosses GM 2 × Rayad 9602, GM 3 × NRCM 120, and GM 3 × NRCM 353 demonstrated substantial relative heterosis and heterobeltosis in the desired direction. Among these, the cross GM 2 × Rayad 9602 exhibited the highest level of relative heterosis and heterobeltosis for seed yield per plant. Additionally, this cross exhibited significant and positive effects of relative heterosis and heterobeltosis for secondary branches per plant, siliqua per plant, 1000 seed weight, biological yield per plant and harvest index (%). Therefore, these particular crosses hold promise for further advancement in order to produce transgressive segregants. On the other hand, the extent of heterotic effects on seed yield and its contributing traits in the remaining crosses was relatively low, rendering them unsuitable for commercial cultivation and exploitation.