Department of Genetics and Plant Breeding, Faculty of Agriculture, University of Kalyani. Kalyani, Nadia, West Bengal
Three intervarietal crosses of C. olitorius, CG × WO, JRO 632 2 WO Ond CG × WO, along their respective parents, backcrosses and F2 generations were utilized for studying gene effects and heterosis for height, base diameter, node number and flowering date. One of these crosses, CG × WO, was grown at two locations.
For height in the crosses GG × WO and JRO 632 × WO; for base diameter in the cross JRO 632 × WO and in CG × WO at one locatton; for node number in all the crosses and for flowering date in the CG × WO additive effects were significant. For most of the characters dominance components either exceeded or equalled the respective additive components indicating overdominance or complete dominance. Additive × additive components for height, base diameter and node number in the crosses JRO 632 × WO and CG × DRE were ssgnificant.
Additive × dominance component for node number and flowering date in the cross CG × WO were significant, while these components for other characters in the same cross were significant at either of the locations. Dominance × dominance components were considerable in magnitude in comparison to other components for all the characters in the crosses studied but were only significant for height and node number in the GG × DRE cross and for base diameter in the cross JRO 632 × WO. All the characters in the crosses JRO 632 × WO and GG × DRE and flowering date in the GG × WO cross showed duplicate epistasis. Height, base diameter and node number in the CG × WO cross showed complementary at one location and duplicate epistasis at the other. In almost all the crosses heterosis was negative and if positive, of negligible amount.
