Gene effects for earliness and seed yield in castor (Ricinus Communis L.)

Abstract

The present investigation was undertaken with a view to generate genetic information on gene effects for characters related to earliness and seed yield in castor. On simple additive-dominance model. three parameters viz., 'm', additive [d] and dominance [h] were significant for days to 50 % flowering in JP 96 ⨯ JI 368. The X² at nine degrees of freedom was found non-significant for days to 50% flowering in cross JP 96 ⨯ JI 368 proving adequacy of additive-dominance model. Under six-parameters model of Hill (1966), the components 'm', additive [d], dominance [h] and digenic ([i] and [j]) were found significant for days to 50% flowering in cross JP 96 x JI 372. The X² at six degrees of freedom was found non-significant for days to 50% flowering in cross JP 96 ⨯ JI 372 proving six-parameters model as the best fit model. For all traits in all crosses (except days to 50 % flowering in JP 96 x JI 368 and JP 96 x JI 372) were found significant for X² and were subjected to trigenic ten-parameter model. The trigenic ten-parameter model was found adequate for days to maturity in crosses JP 96 x JI 368 and JP 101 x SKI 215 along with non-significant X² with two degrees of freedom indicating major role of trigenic interaction for the inheritance of above said traits. On the other hand, X² with two degrees of freedom was found significant for remaining traits in all the three crosses showing the presence of higher order epistasis and/or linkage. Besides, all the ten-parameters were significant for seed yield per plant in all the three crosses.