Genetic Studies of Yield and Its Component in Castor Ricinus Communis : Generation Mean Analysis in castor [Ricinus communis (L.)

Estimates of gene effects based on analysis of generation mean were obtained for nine traits in three crosses in castor (Ricinus communis L.): SKP-84 x DCS-94, VP-1 x DCS-94 and GEETA x GC-3. The study material includes P1, P2, F1, F2, BC1 and BC2 generations of these crosses.The individual scaling test and joint scaling test indicated that an additive-dominance model was adequate in three traits viz., length of main raceme, number of effective branches per plant and seed index in the cross VP-1 x DCS-94. The analysis showed the presence of additive, dominance and epistasis gene effects for the traits.However, to exploit both additive and non-additive gene action reciprocal recurrent or biparental mating procedure may be adopted for improvement of traits. Duplicate epistasis played a greater role than complementary epistasis. Key words:- Castor, Gene action, Generation mean, Polygenic traits, Scaling test