Heterosis for seed yield and its components over environments in castor (Ricinus communis L.)

Abstract

A study was conducted in castor ( Ricinus communis L. ) to assess the extent of heterosis over environments for twelve quantitative traits including seed yield per plant. Four pistillate lines and 13 monoecious lines were crossed in a line x tester fashion to develop 52 F 1 hybrids. The pooled analysis of variance over environments showed significant differences among the environments (Sowing dates) for all the characters except number of capsules on primary raceme indicating wide variation in environmental conditions or differential expression of traits under different sowing dates. The mean square due to parents, hybrids and parents vs. hybrids were also found significant for all the characters, indicating the presence of sufficient amount of genetic diversity in the material for the twelve traits studied. Heterosis was worked-out over better parent and standard check, GCH-7. Significant desired heterobeltiosis ranged from -37.14 to 75.95% and standard heterosis ranged from -61.77 to 18.64% for seed yield per plant. However, magnitude of heterosis was found to vary substantially from cross to cross and character to character. The crosses JP-89 x PCS-124, JP-89 x RG-2826, SKP-84 x 48-1, SKP-106 x 48-1 and SKP-106 x PCS-124 were the best heterotic combinations for seed yield per plant, which recorded 75.95, 70.45, 61.11, 60.45 and 58.57 % heterobeltiosis, respectively. The heterosis for seed yield per plant was associated with the heterosis expressed by its component characters.